Document:

EX-10.2

 Exhibit 10.2 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been
requested with respect to the omitted portions. 
 EXCLUSIVE LICENSE AGREEMENT 

This Exclusive License Agreement (“Agreement”; and as further defined herein) is made effective as of July 25,
2016 (the “Effective Date”) between: 
 UNIVERSITY HEALTH NETWORK, an Ontario corporation
incorporated by special statute under the University Health Network Act, 1997, having a principal office at 190 Elizabeth Street, R. Fraser Elliott Building – Room 1S-417, Toronto, Ontario M5G 2C4
(“UHN”) 
 -AND- 

PROTHENA BIOSCIENCES LIMITED, an Irish private limited company, having a principal office at Adelphi Plaza, Upper George’s
Street, Dun Laoghaire, Co. Dublin A96 T927, Ireland (“Prothena”) 
 (In this Agreement, UHN and Prothena may be referred to individually as
a “Party”, or collectively as the “Parties”.) 
 BACKGROUND: 

Whereas: 
  

	A.	 UHN under the guidance of UHN principal investigator Dr. Avi Chakrabartty is engaged in research relating
to misfolded Transthyretin (“TTR”) in disease (the “Technology”), and owns UHN Background IP (defined below), which relates to the Technology; 

 

	B.	 UHN and Prothena have been jointly conducting collaborative research activities relating to the Technology
pursuant to two separate sponsored research agreements dated April 1, 2013 and April 1, 2014 (the “SRAs”) pursuant to which the Parties generated the Foreground IP (as defined below), which is jointly owned.

  

	C.	 Prothena wishes to license the UHN Background IP and UHN’s interest in the Foreground IP in accordance
with the following terms and conditions stated in this Agreement; and 

 NOW, THEREFORE, THIS AGREEMENT WITNESSES that in consideration
for the mutual promises, representations, covenants and agreements of the Parties contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties agree as follows: 

ARTICLE 1 – INTERPRETATION 
  

	1.1	 Defined Terms. For the purposes of this Agreement, unless the context otherwise requires, the
following terms shall have the respective meanings set out below and grammatical variations of such terms shall have corresponding meanings: 

  

	 	(a)	 “Asset Transfer” shall have the meaning provided in Section 14.3.

  
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	 	(b)	 “Affiliate” means any corporation or other entity that controls, is controlled by, or
is under common control a Party. An entity shall be regarded as in control of another corporation or entity if it owns or directly or indirectly controls more than fifty percent (50%) of the voting securities or other ownership interest of the other
corporation or entity. 

  

	 	(c)	 “Agreement” means this Exclusive License Agreement, and all of its Schedules, and the
terms “herein”, “hereunder”, “hereto” and such similar expressions shall refer to this Agreement. 

  

	 	(d)	 “Claims” shall have the meaning provided in Section 10.1. 

 

	 	(e)	 “Confidential Information” of a Party means any and all information of and disclosed
by, a Party and/or any of its Affiliates (a “Disclosing Party”) which has or does come into the possession or knowledge of the other Party and/or any of its Affiliates (a “Receiving Party”) in
connection with or as a result of entering into this Agreement and which is (1) marked as confidential or identified as confidential at the time of disclosure, or (2) given the nature of the information or circumstances of disclosure,
would be recognized as confidential or proprietary by a reasonable person, in each case including information concerning the Disclosing Party’s past, present and future business, research and development, technology, customers and suppliers.
Information shall not be considered “Confidential Information” to the extent that the information: 

  

	 	(i)	 is part of the public domain at the time of disclosure, 

 

	 	(ii)	 subsequently becomes part of the public domain through no act or fault of the Receiving Party or its agents or
employees in violation of this Agreement, 

  

	 	(iii)	 can be demonstrated by the Receiving Party’s written records to have been known or otherwise available to
the Receiving Party prior to the disclosure by the Disclosing Party, 

  

	 	(iv)	 can be demonstrated by the Receiving Party’s written records to have been provided to the Receiving Party,
without restriction, by a Third Party who is not under a duty of confidentiality respecting the information disclosed and who has a legal right to disclose it, 

 

	 	(v)	 can be demonstrated by the Receiving Party’s written records to have been independently developed by or on
behalf of the Receiving Party without use of or reference to the Confidential Information disclosed hereunder, or 

  

	 	(vi)	 is identified in writing by the Disclosing Party as no longer constituting Confidential Information.

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

	 	(f)	 “Disclosing Party” shall have the meaning provided in Section 1.1(e).

  

	 	(g)	 “Diagnostics” means use for prognosis, or diagnosis of medical risk or conditions in
humans or animals, including companion diagnostics. 

  

	 	(h)	 “Field” means all fields of use including, without limitation, Diagnostics,
Therapeutics and any other uses. 

  

	 	(i)	 “Foreground IP” or “Foreground Intellectual Property” means
(a) the Patents and Patent Applications listed in Schedule B, (b) any Patents that issue from the Patent Applications listed in Schedule B, and (c) any Patents and/or Patent Applications that claim priority to a Patent or Patent
Application listed in Schedule B; and all foreign or international equivalents, including supplementary protection certificates, of any of the foregoing in any country. 

 

	 	(j)	 “Gross Sales” means the gross amount received by Prothena and its Affiliate(s) and any
permitted Sublicensee(s), where such gross amount is received in respect of the sale of a Licensed Product(s) or Licensed Services. Any Licensed Products and Licensed Services transferred by Prothena to an Affiliate and/or permitted Sublicensee for
(i) end use (but not resale) by the Affiliate or Sublicensee shall be treated as sales made by Prothena based on gross amounts received by Prothena, or (ii) resale by the Affiliate or Sublicensee shall be treated as sales made by the
Affiliate or Sublicensee based on gross amounts received by the Affiliate or Sublicensee. 

  

	 	(k)	 “Infringement Suit” shall have the meaning provided in Section 6.4.

  

	 	(l)	 “License” shall have the meaning provided in Section 2.1. 

 

	 	(m)	 “Licensed Product” means any product or composition, the manufacture, use, sale, offer
for sale, import, export of which would constitute, but for the license(s) granted herein, infringement of a Valid Claim. 

  

	 	(n)	 “Licensed Intellectual Property” means the UHN Background IP and the Foreground IP.

  

	 	(o)	 “Licensed Services” means a method or process utilizing a Licensed Product, or is
otherwise a service which would constitute, but for the license(s) granted herein, an infringement of a Valid Claim. 

  

	 	(p)	 “License Transfer Fee” shall have the meaning provided in Section 14.4.

  

	 	(q)	 “Litigating Party” shall have the meaning provided in Section 6.4(d).

  

	 	(r)	 “Net Sales” means, the Gross Sales net of any of the following charges or expenses that
are incurred with respect to the Licensed Products or Licensed Services: 

  

	 	(i)	 reasonable trade or cash allowance/discounts, credits or volume discounts; 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

	 	(ii)	 credits, rebates or allowances because of damaged goods or returns or retroactive price reductions (including
Medicaid, Medicare, government, commercial and similar types of rebates); 

  

	 	(iii)	 freight, postage, shipping and insurance charges incurred in transporting the Licensed Products to the end
customer; 

  

	 	(iv)	 taxes, duties or other governmental charges (other than income taxes) levied on, absorbed or otherwise imposed
on sales of products or services; 

  

	 	(v)	 reasonable allowances actually given or made for wastage replacement; and 

 

	 	(vi)	 taxes paid by Prothena, Affiliates and/or Sublicensees to the United States Government or an instrumentality
thereof under 42 U.S.C. 300 aa-1 et seq. or other similar legislation, or to a State of the United States or to a government of another country or portion thereof. 

with (i) – (vi) to be as determined from the books and records of Prothena, and/or its Affiliates, and/or Sublicensee(s), maintained in
accordance with generally accepted accounting principles. 
  

	 	(s)	 “Notice(s)” shall have the meaning provided in Section 13.1.

  

	 	(t)	 “Patent” means (a) letters patent (or other equivalent legal instrument),
including without limitation utility and design patents, extensions, substitutions, registrations, confirmations, reissues, re-examinations or renewals thereof listed in Schedule A or Schedule B, as the case
may be, (b) any patents that issue from the patent applications listed in Schedule A or Schedule B, as the case may be, (c) any patents that claim priority to any of the foregoing, and (d) all foreign or international equivalents,
including supplementary protection certificates, of any of the foregoing in any country. 

  

	 	(u)	 “Patent Application” means (a) an application, for letters patent listed in
Schedule A or Schedule B, as the case may be, including without limitation a provisional application, a non-provisional application, a reissue application, a
re-examination application, a continuation application, a continued prosecution application, a continuation-in-part application,
a divisional application or any equivalent thereof that is pending at any time during the Term before a government patent agency, (b) any patent applications that claim priority to any of the foregoing, and (c) all foreign or international
equivalents of any of the foregoing in any country. 

  

	 	(v)	 “Phase 1 Clinical Trial” means a human clinical trial of a Licensed Product that would
satisfy the requirements of 21 C.F.R. 312.21(a) or corresponding foreign regulations. 

  

	 	(w)	 “Phase 2 Clinical Trial” means a human clinical trial of a Licensed Product that would
satisfy the requirements of 21 C.F.R. 312.21(b) or corresponding foreign regulations. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

	 	(x)	 “Phase 3 Clinical Trial” means a human clinical trial of a Licensed Product that would
satisfy the requirements of 21 C.F.R. 312.21(c) or corresponding foreign regulations. 

  

	 	(y)	 “Phase 2/3 Clinical Trial” means a human clinical trial of a Licensed Product that is
not a Phase 2 Clinical Trial or a Phase 3 Clinical Trial, but some combination thereof. 

  

	 	(z)	 “Phase 1/2 Clinical Trial” means a human clinical trial of a Licensed Product that is
not a Phase 1 Clinical Trial or a Phase 2 Clinical Trial, but some combination thereof. 

  

	 	(aa)	 “Prothena Insurance” shall have the meaning provided in Section 11.1.

  

	 	(bb)	 “Publication” means any means of making available to the public of any information by
way of speech, talk, paper, drawing, photograph, printed work, tape, video recording or other electronic means, or any other disclosure given or distributed. 

  

	 	(cc)	 “Quarterly Period” means each successive three calendar month period during the Term
ending March 31, June 30, September 30 and December 31. The first and last Quarterly Periods may be less than three (3) calendar months and will commence on the Effective Date of this Agreement and terminate on the date this
Agreement expires or is earlier terminated, respectively. 

  

	 	(dd)	 “Receiving Party” shall have the meaning provided in Section 1.1(e).

  

	 	(ee)	 “Regulatory Approval” shall mean authorization(s) by the appropriate governmental
entity or entities in a country necessary for commercial sale of a Licensed Product or Licensed Services in said country in the Territory. 

  

	 	(ff)	 “Representatives” shall have the meaning provided in Section 7.1.

  

	 	(gg)	 “Royalty” shall have the meaning provided in Section 3.4(a).

  

	 	(hh)	 “Sponsored Research Agreements” or “SRAs” means the agreements
between UHN and Prothena dated April 1, 2013 and April 1, 2014, by which Prothena provided financial support to conduct specific and defined research at UHN. 

 

	 	(ii)	 “Sublicense(s)” shall have the meaning provided in Section 2.3.

  

	 	(jj)	 “Sublicensee(s)” shall have the meaning provided in Section 2.3.

  

	 	(kk)	 “Sublicensing Revenue” means all revenue(excluding taxes) received by Prothena and/or
its Affiliates from Sublicensees in consideration for sublicensing of the Licensed Intellectual Property including issue fees and milestone payments, but excluding earned royalties based on sales of Licensed Products, investments, loans and
reimbursement for research and development activities, and reimbursement of 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

	 	
patent costs. Notwithstanding the foregoing, exclusions are only to the extent such remuneration is a bona fide payment in respect of such matters, and not being made in order to reallocate what
is otherwise intended to be upfront payments, milestones and royalties). 

  

	 	(ll)	 “Sublicensing Fee” shall have the meaning provided in Section 3.5.

  

	 	(mm)	 “Term” shall have the meaning provided in Section 9.1. 

 

	 	(nn)	 “Territory” means the world. 

 

	 	(oo)	 “Therapeutics” means use as a therapeutic agent in humans or animals.

  

	 	(pp)	 “Third Party” means any person or entity who is not a Party or an Affiliate of a Party.

  

	 	(qq)	 “UHN Background IP” or “UHN Background Intellectual Property”
means (a) the Patents and Patent Applications listed in Schedule A, (b) any Patents that issue from the Patent Applications listed in Schedule A, and (c) any Patents and/or Patent Applications that claim priority to a Patent or
Patent Application listed in Schedule A, and all foreign or international equivalents, including supplementary protection certificates, of any of the foregoing in any country. 

 

	 	(rr)	 “UHN Indemnitees” shall have the meaning provided in Section 10.1.

  

	 	(ss)	 “Valid Claim” in respect of a Licensed Product or Licensed Service shall mean a claim
of (i) any issued, unexpired Patent within the Licensed Intellectual Property that has not been revoked or held unenforceable or invalid by a court or governmental agency or other body of competent jurisdiction, or (ii) any patent
application within the Licensed Intellectual Property that has not been cancelled, withdrawn or abandoned, or pending for more than [***] years, with the exception that if a claim that has been pending for more than [***] years becomes issued, that
claim shall thereafter be considered a Valid Claim. 

  

	 	(tt)	 “Yearly Period” means each calendar year period during the Term ending December 31st. The first and last Yearly Periods may be less than a full calendar year and will commence on the Effective Date of this Agreement and terminate on the date this Agreement terminates, respectively.

  

	1.2	 Other Defined Terms. All other defined terms in this Agreement shall have the meanings as otherwise
specifically set out within the body of this Agreement. 

  

	1.3	 Sections and Headings. The division of this Agreement into articles, sections and subsections and the
insertion of headings are for reference purposes only and shall not affect the interpretation of this Agreement. Unless otherwise indicated, any reference herein to a particular Article, Section, Subsection or Schedule refers to the specified
Article, Section or Subsection of, or Schedule to, this Agreement. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

	1.4	 Number, Gender and Language. Except where the context otherwise requires, words importing the singular
number shall include the plural and vice versa, words importing gender shall include all. The language of this Agreement shall be deemed to be the language mutually chosen by the Parties and no rule of strict construction shall be applied against
either Party hereto. 

  

	1.5	 Currency. All monetary amounts in this Agreement are in U.S. funds. 

 

	1.6	 Schedules. The following Schedules are annexed to and form part of this Agreement:

 Schedule “A” – UHN Background IP 

Schedule “B” – Foreground IP 
  

	1.7	 Accounting Principles. Any reference in this Agreement to “generally accepted accounting
principles” refers to accounting principles generally accepted in the United States (“GAAP”). 

  

	1.8	 Best of Knowledge. “To the best of the knowledge” or “to the knowledge”,
unless otherwise qualified hereunder means a statement of the declaring Party’s knowledge of the actual facts or circumstances to which such phrase relates without having made any inquiries or investigations outside of its own incorporated
organization in connection with such facts and/or circumstances. 

 ARTICLE 2 – GRANT OF RIGHTS 

 

	2.1	 License Grant. Subject to the terms and conditions of this Agreement, UHN grants to Prothena an
exclusive, royalty bearing license, with the further right to grant Sublicenses, in and to the Licensed Intellectual Property to research, develop, make, have made, use, have used, sell or have sold, offer for sale, import, have imported, export and
otherwise exploit Licensed Product(s) and Licensed Services in the Field in the Territory (the “License”). The License includes the ability for Prothena to engage Third Parties to assist in research, development
manufacturing, distribution, sales, importing, exporting and other exploitation of Licensed Product(s) and Licensed Services. 

  

	2.2	 UHN Retention of Right. UHN reserves its right to use (i) Licensed Intellectual Property for
non-commercial research, academic and/or teaching purposes, with the further retention of its rights to grant noncommercial licenses to Third Party non-profit academic
or research institutions for the same purposes, subject to Articles 7 and 8. UHN further retains the right to use the Licensed Intellectual Property for internal diagnostic purposes, excluding companion diagnostics. Nothing in this retention of
rights is intended to prevent the Agreement being regarded overall as an exclusive license for litigation purposes. For the avoidance of doubt, neither UHN nor any other non-profit academic or research
institution shall have any rights in any Licensed Intellectual Property for Therapeutics without written permission from Prothena. 

  

	2.3	 Sublicenses. Prothena shall have the right to grant sublicense(s) to the Licensed Intellectual Property
(the “Sublicense(s)”) to one or more sublicensees (the “Sublicensee(s)”); provided, however, that the Sublicense shall not have any terms which are inconsistent with this Agreement.

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Unless otherwise indemnified by Prothena directly, the Sublicense shall provide that the
Sublicensee will directly indemnify UHN on terms at least as favourable as those in Article 10 hereof unless approved otherwise in writing by UHN. 

Upon termination of this Agreement for any reason, provided that a Sublicensee is not in material breach of its Sublicense, UHN shall grant to
such Sublicensee license rights and terms equivalent to the sublicense rights and terms which Prothena previously granted to such Sublicensee. 

ARTICLE 3 – CONSIDERATION 
  

	3.1	 Payment of Funds. Payments to be made by Prothena to UHN hereunder shall be made by wire transfer,
account details for which shall be included on the applicable invoice, and shall reference the following address: 

University Health Network 

Technology Development & Commercialization 

College Street – Suite 150 

Heritage Building – MaRS Centre 

Toronto, Ontario, Canada, M5G 1L7 

Attention: [***] 
 Invoices
shall be sent to: 
 Accounting@Prothena.com 

with a copy to: 
 [***] 

 

	3.2	 Upfront License Fee. Upon execution of this Agreement by both Parties, and within [***] days after
receipt by Prothena of an invoice from UHN, Prothena shall pay UHN a non-refundable and non-creditable license fee payment of [***], net of all transfer and transaction
fees. 

  

	3.3	 License Maintenance Fee. 

 

	 	(a)	 Commencing on the first anniversary of the Effective Date, and on each anniversary thereafter, up to and
including the year in which the first dosing of a subject in a Phase 1 Clinical Trial with a Licensed Product is made, Prothena shall pay UHN a yearly license maintenance fee payment of [***] dollars. 

 

	 	(b)	 Commencing on the first anniversary of the Effective Date immediately following the first dosing of a subject
in a Phase 1 Clinical Trial with a Licensed Product, and up to and including the anniversary of the Effective Date in which the first dosing 

  
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of a subject in a study which prior to the first dosing has been deemed as a registrational study for purposes of Regulatory Approval (e.g., a Phase 2 Clinical Trial, a Phase 2/3 Clinical Trial
or a Phase 3 Clinical Trial) is made, Prothena shall pay UHN a yearly license maintenance fee payment of [***] dollars. 

  

	 	(c)	 Commencing on the first anniversary of the Effective Date immediately following the first dosing of a subject
in a study which has been deemed as a registrational study for purposes of Regulatory Approval, up to and terminating following the first sale of a Licensed Product in the Territory, Prothena shall pay UHN a yearly maintenance fee payment of [***]
dollars. 

 All license maintenance fee payments are due and payable within [***] days of receipt by Prothena of an invoice
from UHN issued after the applicable anniversary and are non-refundable and non-creditable as against future royalty payments. No payments are due under this
Section 3.3 for any anniversary of the Effective Date following the first commercial sale of a Licensed Product. 
  

	3.4	 Royalties. 

  

	 	(a)	 Prothena shall, on a
country-by-country basis, and on a Licensed Product by Licensed Product basis, or Licensed Service by Licensed Service basis (as the case may be) pay UHN a running
royalty in the amount of: 

  

	 	(i)	 [***] of Net Sales of Licensed Product(s) and Licensed Services sold by Prothena, its Affiliates or
Sublicensees in the United States in the Field of Diagnostics and Therapeutics; 

  

	 	(ii)	 [***] of Net Sales of Licensed Product(s) and Licensed Services sold by Prothena, its Affiliates or
Sublicensees outside of the United States in the Field of Diagnostics and Therapeutics; and 

  

	 	(iii)	 [***] of Net Sales of Licensed Product(s) and Licensed Services sold by Prothena, its Affiliates or
Sublicensees in the Territory in a Field which is not Diagnostics or Therapeutics, collectively (“Royalty”). 

  

	 	(b)	 Royalties will be payable from the date of first commercial sale of the applicable Licensed Product(s) or
Licensed Services in a country until the expiration of the last Valid Claim that covers the sale of of the applicable Licensed Product(s) or Licensed Services in that country. 

 

	 	(c)	 In the event that Prothena is required to pay royalties to one or more Third Party(ies) in order to
commercialize a Licensed Product or Licensed Service, the Royalty for such Licensed Product or Licensed Services will be reduced by the amount of royalties payble to said Third Party; provided, however, that the Royalty shall not be decreased in any
instance to less than than [***] of the Royalty stated above. 

  
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	3.5	 Sublicensing Fees. In further consideration of the license granted hereunder, Prothena shall pay to UHN
the following percentage of Sublicensing Revenue received in consideration for Sublicense(s) of the Licensed Intellectual Property: 

  

	 	(a)	 [***] of all Sublicensing Revenue received by Prothena and Affiliate(s) under any Sublicense [***];

  

	 	(b)	 [***] of all Sublicensing Revenue received by Prothena and Affiliate(s) under any Sublicense [***];

 collectively “Sublicensing Fee”. 

 

	3.6	 Payments. The Royalty and Sublicensing Fee described in Sections 3.4 and 3.5 respectively, shall accrue
as of the date of Prothena’s receipt of Gross Sales and Sublicensing Revenue, and shall be paid by Prothena within [***] after the end of the relevant reporting period (as determined in accordance with Section 3.12 and concurrently with
receipt by UHN of the Royalty Report. 

  

	3.7	 Past Patent Cost Reimbursement. Upon execution of this Agreement, and within [***] days of receiving an
itemized invoice regarding same from UHN, Prothena shall reimburse all patent costs paid by UHN in filing and maintaining the patents and patent applications in the UHN Background IP up to and including the Effective Date. Such costs through the
Effective Date are estimated to be [***]. 

  

	3.8	 Patent Milestone Payment. Within [***] days of receiving an invoice regarding same from UHN, Prothena
shall pay to UHN [***] upon issuance of a first United States patent [***]. 

  

	3.9	 Milestone Payments. As additional consideration under the Agreement, Prothena shall pay to UHN the
following one-time milestone payments for the first Licensed Product as a Therapeutic in the first indication to meet such milestone. Prothena shall promptly provide Notice to UHN of the fulfillment of a
milestone (whether such milestone is achieved by Prothena or its Affiliate or Sublicensee). Each noted milestone payment is payable within [***] days following receipt of an invoice for the applicable amount: 

 

	 	(a)	 [***] dollars for the dosing of a first human subject in a first Phase 1 Clinical Trial; 

 

	 	(b)	 [***] dollars for the dosing of a first human subject in a first Phase 2 Clinical Trial; 

 

	 	(c)	 [***] dollars for the dosing of a first human subject in a first Phase 3 Clinical Trial; 

 

	 	(d)	 [***] dollars upon receipt of a Regulatory Approval of a first Licensed Product in the United States;

  

	 	(e)	 [***] dollars upon receipt of a Regulatory Approval of a first Licensed Product in Europe;

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 In the event that a regulatory authority allows one or more clinical trial phases to be
combined (including e.g. a Phase1/2 Clinical Trial, a Phase 2/3 Clinical Trial etc.) milestone payments for each of the milestone events encompassed within the combined clinical trial will be due and payable upon the dosing of a first human subject
in the combined clinical trial. The above milestones payments shall be payable one time only, regardless of indication, for the first Licensed Product to reach such stage. 
  

	3.10	 Interest. All undisputed monies payable to UHN by Prothena hereunder and not paid when due bear interest
at the prime rate of interest quoted by the Bank of Canada, plus [***] per annum until the date paid to UHN. UHN will be entitled to that interest in addition to any other rights or remedies available to it in respect of Prothena’s payment
default. Prothena shall notify UHN of any dispute before the due date for the relevant payment, and thereafter the parties will use good faith efforts to promptly resolve the dispute, including discussions between the parties’ respective
executive leaders. 

  

	3.11	 Withholdings. In the event that Prothena is required by any law to withhold and/or make payments to tax
authorities in respect of any payments payable by Prothena to UHN under this Agreement, the liability of Prothena under this Agreement shall be to that extent satisfied, and such amounts shall be deemed to have been paid to UHN on their due dates,
provided that Prothena shall furnish to UHN acceptable evidence of such payments. 

  

	3.12	 Royalty Report. Prothena shall prepare a report (the “Royalty Report”), setting
out the Gross Sales, the Net Sales (including an itemized statement of any permitted discounts, refunds and taxes deducted) from Prothena, Affiliates and Sublicensees, along with Sublicensing Revenue and calculations of any Royalties and
Sublicensing Fees that are payable to UHN. Prothena shall prepare and provide Royalty Reports on an annual basis (“Yearly Period”) upon UHN’s written request, unless UHN requests in writing that a Royalty Reports be provided for a
Quarterly Period. Royalty Reports shall be due within [***] days after the end of the relevant reporting period. If no payments are due for any reporting period, then the Royalty Report shall so state. 

 

	3.13	 Complete Records. Prothena shall keep true and accurate records and books of account containing all data
reasonably required for the computing and verification of all payments owed by Prothena to UHN, including records for Gross Sales and Net Sales, all in accordance with generally accepted accounting principles. Prothena shall contractually require
all Prothena Affiliates and Sublicensees to keep same and provide a copy of same to Prothena for purposes of inspection pursuant to Section 3.14. Such records shall be maintained by Prothena for at least [***] years from the date of the payment
to which such records are relevant. 

  

	3.14	 Inspection of Records. The records specified in this Agreement shall be available for inspection by UHN
or their duly appointed auditor, but not more than once per Yearly Period, upon reasonable written notice and during normal business hours at the principal place of business of Prothena, for the sole purpose of verifying payments owed under this
Agreement. The costs of any such inspection shall be borne by UHN unless the report of an auditor shows that the Royalty Report was understated by more than [***] in respect of the period under review, in which case UHN’s reasonable out of
pocket costs of the 

  
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examination shall be fully paid by Prothena. Prothena may require such auditor to enter into a commercially reasonable confidentiality agreement with Prothena prior to being provided with any
such records. 

  

	3.15	 Discrepancy in Records. In the event that the records inspection conducted under Section 3.14
reveals any undisputed underpayment of royalties due to UHN, Prothena will promptly pay UHN the full amount of the undisputed underpayment together with interest thereon at the rate of interest referred to in Section 3.10 herein. In the event
that the records inspection conducted under Section 3.14 reveals any overpayment of royalties by Prothena, the overpaid amount will, in Prothena’s discretion, be credited against future amounts payable to UHN hereunder or promptly refunded
to Prothena. 

  

	3.16	 Commercialization Diligence. As part of Prothena’s ongoing obligation, Prothena agrees to utilize
commercially reasonable efforts to [***]. 

 ARTICLE 4 – REPRESENTATIONS, WARRANTIES AND LIABILITY 

 

	4.1	 UHN Reps & Warranties. UHN represents and warrants to Prothena that:

  

	 	(a)	 it is duly incorporated and organized and validly existing under the laws of Ontario, and has all requisite
corporate power and authority to enter into and perform its obligations under this Agreement; 

  

	 	(b)	 it has taken all necessary corporate action, steps and proceedings to approve or authorize, validly and
effectively, the execution and delivery of this Agreement and perform its obligations hereunder; 

  

	 	(c)	 the execution and delivery of this Agreement by UHN and the performance of its obligations hereunder shall not
result in either a breach or violation of any of the provisions of, or constitute a default under, or conflict with or cause the acceleration of, any obligation of UHN under: 

 

	 	(i)	 any agreement to which UHN is a party or is otherwise bound by; 

 

	 	(ii)	 any judgment, decree, order or award of any court, governmental body or arbitrator having jurisdiction over
UHN; 

  

	 	(iii)	 any license, permit, approval, consent or authorization held by UHN; or 

 

	 	(iv)	 any applicable law, statute, ordinance, regulation or rule. 

 

	 	(d)	 as of the Effective Date, UHN is the sole owner of all right, title and interest in and to the UHN Background
IP and to the best of its knowledge UHN and Prothena are jointly the sole owners of the Foreground IP. 

  
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	4.2	 Prothena Reps & Warranties. Prothena represents and warrants to UHN that:

  

	 	(a)	 it is duly organized and validly existing under the laws of Ireland and has all the requisite corporate power
and authority to enter into and perform its obligations under this Agreement; 

  

	 	(b)	 it has taken all necessary corporate action, steps and proceedings to approve or authorize, validly and
effectively, the execution and delivery of this Agreement and the performance of its obligations hereunder and to cause all necessary meetings of directors and shareholders of Prothena to be held for such purposes; and 

 

	 	(c)	 the execution and delivery of this Agreement by Prothena and the performance of its obligations hereunder shall
not result in either a breach or violation of any of the provisions of, or constitute a default under, or conflict with or cause the acceleration of, any obligation of Prothena under: 

 

	 	(i)	 any agreement to which Prothena is a party or is otherwise bound by; 

 

	 	(ii)	 any of the terms and provisions of the organizational documents or
by-laws, or resolutions of the board of directors (or any committee thereof), of Prothena; 

  

	 	(iii)	 any judgment, decree, order or award of any court, governmental body or arbitrator having jurisdiction over
Prothena; 

  

	 	(iv)	 any license, permit, approval, consent or authorization held by Prothena; or 

 

	 	(v)	 any applicable law, statute, ordinance, regulation or rule. 

 

	4.3	 Limitations of Liability. Except as otherwise expressly set out in this agreement:

  

	 	(a)	 each Party expressly disclaims any and all implied or express warranties and makes no express or implied
warranties of any kind, including warranties of merchantability, safety or fitness for any particular purpose of the Licensed Intellectual Property, or that the Licensed Intellectual Property can be exploited to generate revenues;

  

	 	(b)	 UHN does not warrant or represent that issued Patents are valid, or pending Patent Applications will issue, or
when issued will be valid, or that the practice or exploitation of any Licensed Intellectual Property provided to Prothena pursuant to this agreement, does not, or will not, constitute infringement of rights of persons not parties hereto.
Notwithstanding the foregoing, UHN warrants that it has not granted rights to Third Parties that would conflict with those granted to Prothena under this agreement; and 

 

	 	(c)	 neither Party shall be liable to the other Party for any indirect, special, consequential, exemplary or
punitive damage or loss of business or loss of profits suffered by such other Party resulting from the use or other exploitation of the Licensed Intellectual Property, including without limitation the sale of any Licensed Product(s) or Licensed
Services. Furthermore, UHN makes no representation that the Licensed Intellectual Property is free from defect. 

  
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treatment has been requested with respect to the omitted portions. 

 ARTICLE 5 – FURTHER COVENANTS AND OBLIGATIONS. 

 

	5.1	 Prothena Covenants. Prothena covenants and agrees for the benefit of UHN that it shall:

  

	 	(a)	 exercise the License granted herein or otherwise exploit the Licensed Intellectual Property in accordance this
Agreement, and with all applicable laws, statutes, ordinances, regulations, guidelines and rules, including, all applicable statutes and regulations and applicable guidelines set forth by the Canadian Institutes of Health Research (CIHR), National
Institutes of Health (NIH) or other governmental agencies where applicable; 

  

	 	(b)	 cause to be applied to Licensed Products where appropriate any markings required by applicable government
statutes and laws to maintain continued validity and enforcement of UHN Background IP and Foreground IP; and 

  

	 	(c)	 use commercially reasonable efforts to develop and commercialize Licensed Product(s). 

ARTICLE 6 – MANAGEMENT OF INTELLECTUAL PROPERTY RIGHTS 
  

	6.1	 IP Rights Ownership. As between the Parties, UHN shall retain ownership of the UHN Background IP and UHN
and Prothena shall retain joint ownership of the Foreground IP. If either UHN or Prothena desires to file a continuation-in-part patent application that includes claims
that are entitled to claim the benefit of a priority date of any patent or application in the UHN Background IP or the Foreground IP, the Parties will negotiate in good faith the strategy for filing and ownership of any such patent application(s)
with a view to maximizing the patent coverage for the subject inventions. The Parties agree to revisit an ownership decision made pursuant to the prior sentence if, during the course of patent prosecution, a Party reasonably believes that different
ownership of any such patent application would be beneficial for obtaining a granted patents (e.g., in order to overcome an obviousness rejection over another patent or patent application owned by a Party). The Parties will document their
agreement regarding any such continuation-in-part patent application by way of amendment to this Agreement. 

 

	6.2	 Patent Prosecution. Prothena and UHN will assume joint responsibility to control the preparing, filing,
prosecuting, obtaining and maintaining the UHN Background IP, at Prothena’s sole cost and expense and using patent counsel acceptable to UHN (acting reasonably) during the Term. With input from UHN, Prothena shall continue to have the
responsibility to control the preparing, filing, prosecuting, obtaining and maintaining the Foreground IP, at Prothena’s sole cost and expense and using patent counsel acceptable to UHN (acting reasonably) during the Term. For purposes of the
UHN Background IP, UHN will provide Prothena with (a) a copy of any proposed document pertaining to the prosecution for review and comment reasonably in advance of filing, and (b) will keep Prothena informed in a timely manner of the
status of such filing, prosecution and 

  
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maintenance, including (i) by providing Prothena in a timely manner with copies of all material communications received from or filed in patent office(s) with respect to such UHN Background
IP, and (ii) by providing to Prothena, a reasonable time prior to taking or failing to take any action that would materially affect the scope or validity of any such filing, prior written notice of such proposed action or inaction so that
Prothena has a reasonable opportunity to review and comment. For purposes of the Foreground IP, Prothena (a) will provide UHN with a copy of any proposed patent application constituting Foreground IP for review and comment reasonably in advance
of filing, and (b) will keep UHN informed in a timely manner of the status of such filing, prosecution and maintenance, including (i) by providing UHN in a timely manner with copies of all material communications received from or filed in
patent office(s) with respect to such filing, and (ii) by providing to UHN, a reasonable time prior to taking or failing to take any action that would materially affect the scope or validity of any such filing, prior written notice of such
proposed action or inaction so that UHN have a reasonable opportunity to review and comment. In the event that Prothena decides to (x) forego or cease prosecution, or (y) cease maintenance, of any Patent or Patent Application within the
UHN Background IP or Foreground IP in any jurisdiction, UHN may (in its sole discretion and expense, except to the extent such abandonment would reasonably benefit the prosecution or maintenance of the remaining Patents and Patent Applications
within the UHN Background IP or Foreground IP) continue such prosecution or maintenance and Prothena shall have no further obligations in respect of such Patent or Patent Application in such jurisdiction, and such Patent or Patent Application will
no longer be licensed to Prothena as part of the Licensed Intellectual Property. 

  

	6.3	 Cooperation and Notice. As provided for in this Article 6, a Party shall cooperate with the other Party
in the preparation, filing, prosecution and maintenance of any Patents or Patent Applications within the UHN Background IP and Foreground IP, including executing all papers and instruments required in order to enable the Party to apply for, to
prosecute and to maintain applications and registrations in any country. 

  

	6.4	 Infringement. Each Party will immediately notify the other Party upon becoming aware of any infringement
or threatened infringement of the Licensed Intellectual Property by a Third Party (“Infringement Notice”). The Parties shall co-operate fully in the abatement of such infringement without litigation.
If the infringing activity of potential commercial significance by the infringer has not been abated within [***] days following the date of the Infringement Notice, Prothena and/or its Sublicensee(s) shall have the first right to institute suit for
patent infringement against the infringer. UHN may voluntarily join such suit, but may not thereafter commence suit against the infringer for the acts of infringement that are the subject of Prothena’s or its Sublicensee(s)’ suit or any
judgment rendered in that suit. If deemed a necessary party by a court of competent jurisdiction, UHN shall join the suit at [***]. Prothena and/or its Sublicensee(s) shall be responsible for all reasonable costs, including (a) legal fees and
disbursements incurred by Prothena, (b) reasonable legal fees and disbursements incurred by UHN at the request of Prothena, and (c) awards by the Court against UHN or Prothena pertaining to the enforcement by Prothena of any Licensed
Intellectual Property. If UHN desires to enforce any Licensed Intellectual Property after Prothena has declined in writing to do so, then UHN may do so at its sole cost and expense and shall keep Prothena reasonably apprised of the progress of any
such enforcement 

  
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activities. Any monies, including compensatory and other non-compensatory damages or recovery, actually received by a Party from a Third Party as a result
of any action or settlement shall first go to reimburse Prothena, and/or its Sublicensee(s) and UHN for all costs incurred in the action. If after such reimbursement any funds shall remain from such damages or other sums recovered, such funds [***];
provided, however, that (a) if [***], (b) if [***], and (c) if [***]. 

 In the event that any Third Party brings or
asserts a claim against Prothena, Prothena Affiliate, Sublicensee or UHN that the manufacture, use, sale, distribution, marketing or importation of the Licensed Intellectual Property, Licensed Product or Licensed Services infringes rights in Patents
or Patent Applications owned or otherwise controlled by such Third Party (an “Infringement Suit”), the following shall apply: 
  

	 	(a)	 the Party receiving a claim, or learning of the threat of such a claim, shall give the other Party prompt
written notice detailing as many facts as possible concerning the claim; 

  

	 	(b)	 Prothena, in its sole discretion, shall have the first right, but not an obligation, to defend against the
Infringement Suit; 

  

	 	(c)	 if Prothena does not take steps to defend against the Infringement Suit within [***] days after the date that
notice thereof was received from or delivered to UHN, and the Infringement Suit relates to a Licensed Product or Licensed Services, UHN may take such legally permissible action as it deems necessary or appropriate to defend against the Infringement
Suit, but shall not be obligated to do so; 

  

	 	(d)	 the Party defending against the Infringement Suit (in this Subsection, the “Litigating
Party”) shall have the right to control such litigation and shall bear all legal expenses (including court costs and legal fees), but it shall have no right to settle any dispute in any manner which would abridge the rights of the
other Party under this Agreement. By way of example and not by way of limitation, neither Party may stipulate or admit to the invalidity or unenforceability of any Licensed Intellectual Property without the other Party’s prior written consent.
Before any action is taken by either Party which could abridge the rights of the other Party hereunder, the Parties agree, in good faith, to consult with each other with a goal of adopting a mutually satisfactory position; 

 

	 	(e)	 the Litigating Party shall keep the other Party fully informed of the actions and positions taken or proposed
to be taken by the Litigating Party and the actions and positions taken by all other parties to such litigation; and 

  

	 	(f)	 in the event that Prothena defends against the Infringement Suit, UHN may elect to participate formally in the
Infringement Suit to the extent that the court may permit, provided that any additional expenses generated by UHN’s formal participation shall be paid by UHN. 

  
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treatment has been requested with respect to the omitted portions. 

 Where either Prothena or UHN wishes to act alone pursuant to this Section 6.4, but
formalities require participation of the other Party, then the other Party shall join in the proceeding to the extent necessary for formalities. Each of Prothena and UHN will cooperate with the other Party in making available all necessary documents
and witnesses for any legal proceedings, without charging any fees to the other Party, but the other Party shall reimburse reasonable out of pocket costs and expenses. 
  

	6.5	 No Actions. The Parties agree to not knowingly take any action which would jeopardize the obtaining or
maintaining of the Licensed Intellectual Property, except in compliance with Sections 6.2, 6.3 and 6.4. Notwithstanding the foregoing, nothing in this Agreement shall prohibit Prothena from challenging the validity of UHN Background IP in a court of
law; provided, however, that upon the filing of a claim challenging the validity of a Patent within UHN Background IP, UHN shall have the right to terminate this Agreement immediately upon notice. 

ARTICLE 7 – CONFIDENTIAL INFORMATION 
  

	7.1	 Confidentiality. A Receiving Party shall take all reasonable measures, and at least the same measures as
it takes in respect of its own Confidential Information of a similar nature, to keep confidential the Confidential Information of the Disclosing Party. A Receiving Party may disclose such Confidential Information to those of its directors, officers,
employees, subcontractors, consultants and agents (collectively, “Representatives”) having a need to know such information in connection with exercising the Receiving Party’s rights and/or fulfilling the Receiving
Party’s obligations under this Agreement With respect to Prothena, Representatives also include proposed and actual Sublicensees. A Receiving Party will ensure that any of its Representatives having access to the Confidential Information of the
Disclosing Party are under a legal obligation to maintain such Confidential Information in confidence and are duly informed of this obligation. A Receiving Party will neither use nor disclose to any other party any of the Confidential Information of
the Disclosing Party except as expressly permitted hereunder. The terms of this Agreement are the Confidential Information of both Parties. 

  

	7.2	 Equitable Relief. The Parties acknowledge that a breach of this Article 7 by either Party or any of its
representatives may cause irreparable harm and that the non-breaching Party may be entitled to equitable relief, including injunction and specific performance, as a remedy for any such breach. Such remedies
shall not be deemed to be the exclusive remedies but shall be in addition to all other remedies available at law or equity. 

  

	7.3	 Disclosure to Advisors. Notwithstanding the confidentiality obligations of this Agreement, each Party
shall be permitted to disclose the terms of this Agreement without the prior written consent of the other Party to those of its directors, officers, employees, advisors, shareholders, investors, potential investors, underwriters, partners, potential
partners, potential acquirers under circumstances that reasonably ensure the confidentiality thereof. 

  

	7.4	 Other Permitted Disclosures. Notwithstanding the confidentiality obligations of this Agreement, a
Receiving Party shall be permitted to disclose the Confidential Information 

  
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of the Disclosing Party without the prior written consent of the Disclosing Party (a) to the extent required to be disclosed by law (including the securities laws, regulations and listing
requirements in Canada, United States and other jurisdictions) or an order of a court, tribunal, or government agency, provided that to the extent legally permissible the Receiving Party (i) gives to the Disclosing Party prompt written notice
of the required disclosure in order to allow the Disclosing Party reasonable opportunity to seek a confidentiality order or the like, and (ii) cooperates with efforts of the Disclosing Party (at the Disclosing Party’s expense) in
connection therewith; and (b) as required to be disclosed in connection with the filing with, or approval, certification or endorsement from, any governmental body or medical protocol, in each case for the Licensed Product or Licensed Services.

 ARTICLE 8 – PUBLICATION 
  

	8.1	 Publications. Subject to Section 6 and UHN’s prior written consent, Prothena shall acknowledge
the contribution of UHN investigator(s) in Prothena’s related academic Publications in accordance with scientific custom. No Publication by a Party shall disclose the Confidential Information of the other Party without the prior written consent
of such other Party. 

 ARTICLE 9 – TERM & TERMINATION 

 

	9.1	 Term. Unless earlier terminated pursuant to Sections 9.2, the term of this Agreement shall be for the
period of time beginning on the Effective Date and ending on the expiration date of the longest-lived Licensed Intellectual Property (the “Term”). 

 

	9.2	 Earlier Termination. This Agreement shall terminate prior to the expiration of the Term:

  

	 	(a)	 automatically without the obligation to provide notice upon the filing of a petition for relief under the
United States Bankruptcy Code by or against Prothena as a debtor or alleged debtor; 

  

	 	(b)	 at the discretion of UHN, effective upon sixty (60) days written notice to Prothena, if Prothena
materially breaches Sections 3.2 to 3.10, 4.2, 5.1, Article 11 or Section 14.4 and fails to remedy the breach within sixty (90) days after being given written notice thereof by UHN; 

 

	 	(c)	 as permitted under Section 6.5; 

 

	 	(d)	 at the discretion of Prothena upon ninety (90) days written notice to UHN; or 

 

	 	(e)	 by mutual written agreement of the Parties. 

  
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	9.3	 Effects of Early Termination. In the event of the earlier termination of this Agreement prior to
expiration of the Term pursuant to Section 9.2: 

  

	 	(a)	 the License will be terminated, all of UHN’s Interest in the Licensed Intellectual Property shall revert
to UHN, and within [***] days either destroy or return to UHN (at the request of UHN in its sole discretion) all UHN Confidential Information; 

  

	 	(b)	 Prothena shall within [***] days of the date of such earlier termination, pay UHN all current amounts then owed
to UHN pursuant to this Agreement; for purposes of certainty and clarity, no term or provision of this Agreement shall be construed to waive the payment of any monies to UHN accrued at the date of said earlier termination, or arising thereafter; and

  

	 	(c)	 No termination of this Agreement shall be construed as a termination of any valid Sublicense of any Sublicensee
hereunder, and thereafter each such Sublicensee shall be considered a direct licensee of UHN, provided that: (i) such Sublicensee is then in full compliance with all material terms and conditions of its Sublicense, and (ii) such
Sublicensee agrees in writing to assume all material and relevant obligations (including, without limitation, those of a financial nature) of Prothena under this Agreement. 

ARTICLE 10 – INDEMNIFICATION 
  

	10.1	 Indemnification. Prothena agrees to indemnify, save harmless, and defend UHN and its directors,
officers, research staff, employees, research trainees, students, and agents (collectively, “UHN Indemnitees”), against any and all Third Party claims, suits, losses, damages, costs, fees, and expenses (including reasonable
legal expenses) (collectively, “Claims”), arising out of (a) any product liability claims with respect to any Licensed Product or Licensed Services, (b) any Intellectual Property infringement or alleged infringement
claims, and (c) any damages, losses, or liabilities whatsoever with respect to death or injury to any person and damage to any property arising from this Agreement and the License granted herein, including, without limitation, the manufacture,
design, distribution, and offer for sale of Licensed Product(s) or Licensed Services or otherwise arising from any exploitation of the Licensed Intellectual Property, except in each case to the extent caused by the negligence or willful misconduct
of UHN or any of the other UHN Indemnitees or otherwise arising from UHN’s breach of its obligations under this Agreement (including any representations, warranties or covenants under this Agreement). 

 

	10.2	 Indemnification Procedure. Upon the assertion of any Claim, UHN shall promptly notify Prothena thereof
and Prothena shall appoint counsel to represent the applicable UHN Indemnitees with respect to such Claim for which indemnification is sought. The UHN Indemnitees shall cooperate with Prothena in defense and settlement of such Claim. Neither
Prothena nor the UHN Indemnitees shall enter into any settlement agreement with any Third Party without the consent of the other Party, which consent shall not be unreasonably withheld; provided that affected UHN Indemnitees shall be permitted in
their sole discretion to settle any such Claim if they have first irrevocably waived in writing their rights to indemnification hereunder with respect to such Claim. 

  
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 ARTICLE 11 – INSURANCE 

 

	11.1	 Prothena Insurance. No later than [***] days prior to the sooner of the first use of Licensed
Intellectual Property with humans or first sale of Licensed Product(s), Prothena, at Prothena’s expense, shall obtain and maintain general liability, product liability and/or clinical trial liability insurance (the “Prothena
Insurance”) applicable to clinical trials and/or sale of Licensed Products and/or Licensed Services, of a minimum of [***], naming UHN as an additional insured. Prothena shall provide to UHN a Certificate of Insurance evidencing
compliance with this provision within [***] days prior to such first use. Prothena shall, at its own expense, obtain and maintain the Prothena Insurance from the date required by this Section 11.1 until the end of the Term.

  

	11.2	 Sublicensee Insurance. Unless said activities are otherwise covered by Prothena Insurance, any
Sublicense shall require Sublicensee(s), at the Sublicensee(s) expense, to obtain and maintain liability insurance at a level commensurate with the Prothena Insurance, naming Prothena and UHN as additional insured; provided, however, that if the
Sublicensee is a substantial multi-national entity which has a policy of self-insuring, then at UHN and Prothena’s reasonable discretion Sublicensee may self-insure. Sublicense agreements shall require Sublicensee(s) to provide to Prothena and
to UHN a Certificate of Insurance evidencing compliance with this provision prior to the earlier of the first use of the Licensed Intellectual Property with humans or first sale of Licensed Product(s) under any Sublicense. In no event shall the
Sublicensee(s) use the Licensed Intellectual Property with humans or engage in the sale of Licensed Product(s) or Licensed Services under this or any sublicense agreement prior to the delivery to UHN of the Certificate of Insurance or an indication
of self-insurance, as applicable. The Sublicense shall provide that Sublicensee(s) (at no expense to UHN) shall obtain and maintain from the date required by this Section 11.2 until the end of the term of the Sublicense, a policy of appropriate
liability insurance (or self-insurance, if applicable) at a level commensurate with the Prothena Insurance. 

  

	11.3	 Qualified Insurance. All insurance policies required in accordance with this Article 11 shall be
obtained, prior to the initiation of any clinical trial involving Licensed Products, from an insurance company qualified to offer protection in the jurisdictions where Licensed Intellectual Property is to be exploited or Licensed Products or
Licensed Services are offered for sale. 

  

	11.4	 Notice. All insurance policies required in accordance with this Article 11 shall provide for [***] days
written notice by the insurer to Prothena by registered or certified mail in the event of any modification, cancellation or termination of such insurance policy. Prothena shall promptly inform UHN if the amount of Prothena Insurance should fail to
meet the levels required under Section 11.1. 

  

	11.5	 Copy of Policy. Prothena shall, on written request, provide UHN with a copy of the insurance policy in
force at the time of the request and this provision shall survive the early termination or expiration of this Agreement for a period of [***]. 

  
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	11.6	 Incomplete Insurance. In the event Prothena (or Sublicensee, as appropriate) is unable to obtain the
insurance coverage required by Section 11.1, or if any portion of the Prothena Insurance / Sublicensee insurance corresponding to that required by Section 11.1 is cancelled and not immediately replaced, Prothena shall promptly inform UHN
and UHN shall be free to terminate this Agreement upon [***] days written notice to Prothena. 

 ARTICLE 12 –
DISPUTE RESOLUTION 
  

	12.1	 Reasonable Efforts. Before filing any lawsuit or claim in court, the Parties agree to make reasonable
efforts to resolve amicably among themselves any dispute arising out of or relating to this Agreement (including the breach of this Agreement). 

  

	12.2	 Referral for Resolution. If the Parties are unable to resolve the dispute under Section 12.1 within
[***] days of written notice of one Party to the other Party of such dispute, then before filing any lawsuit or claim in court, the dispute shall be referred to the Vice President, Research of UHN (or designate) and an executive (or designate) of
Prothena for their discussion and resolution for an additional period of [***] days. The Parties may further agree to mediation of the dispute, but in no event is mediation mandatory. 

 

	12.3	 Interim Protection. This Article 12 shall not prevent a Party from applying to a court of competent
jurisdiction for interim protection such as, by way of example, an interim injunction. 

 ARTICLE 13 – NOTICE

  

	13.1	 Notice. All notices which are required or permitted to be given hereunder
(“Notices”) including judicial payment notices must be in writing. All such Notices must be sent as follows: 

to UHN: 

Attention:          [***] 

Director, Technology Development & Commercialization 

University Health Network 
 101
College Street – Suite 150 
 Heritage Building – MaRS Centre 

Toronto, Ontario, Canada M5G 1L7 

Telephone No.: [***] 
 Facsimile
No.: [***] 
 E-mail: [***] 

to Prothena: 

Attention:          Director 

              Prothena Biosciences Limited 

              Adelphi Plaza, Upper George’s Street 

              Dun Laoghaire, Co. 

              Dublin, Ireland A96 T927 

  
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treatment has been requested with respect to the omitted portions. 

 With a copy to: 

                Legal Department 

                Prothena Biosciences Inc 

                650 Gateway Boulevard South 

                San Francisco, CA 94080 

Telephone No.: (650) 837-8550 

Facsimile No.: (650) 837-8560 

or to such other address as a Party may designate by Notice given in accordance with this Article 13. Any such Notice may be delivered by hand,
by registered mail, or sent by facsimile or electronically, and will be deemed to have been delivered on the date of delivery if delivered by hand, five (5) days after mailing if sent by registered mail, or on the first business day following
the date of sending if sent by facsimile or electronically with confirmation of delivery. 
 ARTICLE 14 – GENERAL 

 

	14.1	 Entire Agreement. The Parties hereto acknowledge that this Agreement and its Schedules is the entire
agreement and understanding of the Parties as to the subject matter hereof, and supersedes all prior discussions, agreements and writings in respect hereto. 

  

	14.2	 General Assurances. The Parties agree to do all such things and to execute such instruments and
documents as may be reasonably necessary or desirable in order to carry out the provisions and intent of this Agreement. 

  

	14.3	 Assignment. This Agreement may not be assigned or otherwise transferred by Prothena without the express
written consent of UHN, such consent not to be unreasonably withheld, provided, however, that Prothena may, without prior consent, assign the License Agreement and/or the rights and obligations thereunder to (i) a Prothena Affiliate, or
(ii) a Third Party in connection with the transfer or sale of all or substantially all of Prothena’s assets relating to the subject matter of this Agreement, or that part encompassing or otherwise associated with the development and
commercialization of the Licensed Intellectual Property (an “Asset Transfer”), or (iii) in connection with a change in control, merger, acquisition, consolidation or similar transaction involving Prothena or its ultimate
parent entity. In the event of an Asset Transfer, a “License Transfer Fee”, payable to UHN in accordance with the following: 

  

	 	(a)	 [***] 

  

	 	(b)	 [***] 

Payment of the License Transfer fee shall be made by Prothena to UHN within [***] days after the closing of such sale and/or
transfer and/or assignment and/or disposition, or as otherwise agreed by the Parties. At UHN’s request, Prothena shall provide written evidence in support of the calculation of the License Transfer Fee. 

  
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 The License Agreement shall be binding upon and inure to the benefit of the Parties’
respective successors and permitted assigns. Any purported assignment or transfer in violation of this section shall be void. The Parties agree to notify the other Party of any such assignment. 

 

	14.4	 No Use of Names. Except as required for the purposes of complying with the provisions of this Agreement
or as required by applicable laws, rules and regulations, and except as set forth below, neither Party shall use the name, logo, trade-mark or trade-name of the other Party in connection with any Licensed Product(s), publicity, promotion news
release, advertising or similar public statements or otherwise without the prior written consent of the other Party, which consent shall not be unreasonably withheld. The Parties have agreed upon the text of a press release to be issued by Prothena
following execution of this Agreement by both Parties. 

  

	14.5	 No Joint Venture. Each Party is and will remain at all times independent of each other. The Parties are
not and shall not be considered to be joint venturers, partners or agents of each other and neither of them shall have the power to bind or obligate the other except as set forth in this Agreement. The Parties mutually covenant and agree that
neither shall they, in any way, incur any contractual or other obligation in the name of the other, nor shall they have liability for any debts incurred by the other. No representation will be made or acts taken by any of the Parties which could
establish any apparent relationship of agency, joint venture, partnership or employment. 

  

	14.6	 Waiver. No amendment, supplement or waiver of any provision of this Agreement shall be binding on any
Party unless consented to in writing by such Party. No waiver of any provision of this Agreement shall constitute a waiver of any other provision, nor shall any waiver constitute a continuing waiver unless otherwise expressly provided. Further, no
failure or delay by any Party in exercising any right or remedy shall operate as a waiver thereof, nor shall any single or partial exercise or waiver of any right or remedy preclude its further exercise or the exercise of any other right or remedy.

  

	14.7	 Joint Preparation. This Agreement shall be deemed to be jointly prepared by the Parties, and any
ambiguity herein shall not be construed for or against any single Party. 

  

	14.8	 Governing Law. This Agreement shall be governed by the laws of New York. Subject to Article 12, the
Parties irrevocably and unconditionally submit to the exclusive jurisdiction the courts of New York and all courts competent to hear appeals therefrom in connection with any matters arising under this Agreement. 

 

	14.9	 Severability of Provisions. In the event that any provisions of this Agreement are determined to be
invalid or unenforceable by a court of competent jurisdiction in any jurisdiction, the remainder of this Agreement shall remain in full force and effect without said provision in said jurisdiction and such determination shall not affect the validity
or enforceability of such provision or this Agreement in any other jurisdiction. The Parties shall in good faith negotiate a substitute clause for any provision declared invalid or unenforceable, which shall most nearly approximate the intent of the
Parties in entering this Agreement. 

  
 23 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

	14.10	 Force Majeure. In the event that any one of the Parties is prevented from fulfilling any of its
obligations herein by acts of God, war, terrorism, strikes, riots, storms, fires, governmental orders or restrictions or any other cause beyond its control, the payment of royalties, or the applicable pro rata portion thereof, shall be suspended
during the full period of any such prevention, but payment of royalties which have accrued for payment prior to or after such cause shall not be excused. UHN will have the right to terminate this Agreement in the event that Prothena is unable to
fulfill a material obligation for a period of at least [***] months. 

  

	14.11	 Survival. The termination or expiration of this Agreement shall not relieve the Parties of any
obligations accruing prior to such expiration or termination, and any such expiration or termination shall be without prejudice to the rights of either Party against the other Party. Articles 1, 6, 7, 8, 10, 12 and 13 in their entirety, Article 11
(for the period of time wherein Prothena/Sublicensees have an obligation to maintain insurance), and Sections 3.14 (for the period of time stated therein), 3.15 (for the period of time Prothena is required to maintain records under
Section 3.14), 3.16 (for the period of time Prothena is required to maintain records under Section 3.14), 4.3, 9.3, 14.1, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14.9, 14.10 and 14.11. 

 

	14.12	 Counterparts. This Agreement may be executed in counterparts each of which shall be deemed an original but all
of which together shall constitute one and the same instrument. Transmission by facsimile, email or other form of electronic transmission of an executed counterpart of this Agreement shall be deemed to constitute due and sufficient delivery of such
counterpart. 

 The Parties are executing this Agreement so as to be effective on the Effective Date. 

 

									
	UNIVERSITY HEALTH NETWORK	 		 	PROTHENA BIOSCIENCES LIMITED
					
	Per:	 	 /s/ Christopher J. Paige
	 		 	Per:	 	 /s/ Yvonne Tchrakian

	Name:	 	Dr. Christopher J. Paige	 		 	Name:	 	Yvonne Tchrakian
	Title:	 	Executive Vice President Research	 		 	Title:	 	Director

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 SCHEDULE “A” 

UHN BACKGROUND INTELLECTUAL PROPERTY 

[***] 

  
 25 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 SCHEDULE “B” 

FOREGROUND INTELLECTUAL PROPERTY 
 A.

 [***] 

  
 26 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions.EX-10.3

 Exhibit 10.3 

CONFIDENTIAL 
 EXECUTION
VERSION 
 [***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 
 MASTER COLLABORATION AGREEMENT 

by and among 
 PROTHENA
BIOSCIENCES LIMITED 
 And 

CELGENE SWITZERLAND LLC 

Dated as of March 20, 2018 

 TABLE OF CONTENTS 

 

							
	 	 	 	  	Page	 
	 ARTICLE 1
	 	 DEFINITIONS
	  	 	1	 
			
	 ARTICLE 2
	 	 COLLABORATION AND DEVELOPMENT
	  	 	16	 
			
	 2.1
	 	 Collaboration Overview
	  	 	16	 
			
	 2.2
	 	 Program Development
	  	 	16	 
			
	 2.3
	 	 Research Term Extension
	  	 	20	 
			
	 2.4
	 	 Disputes Regarding Antibodies and Lead Candidates
	  	 	20	 
			
	 2.5
	 	 Celgene Phase 1 Portion Participation Right
	  	 	21	 
			
	 2.6
	 	 Regulatory Responsibilities
	  	 	24	 
			
	 2.7
	 	 Subcontracting
	  	 	25	 
			
	 2.8
	 	 Audit
	  	 	26	 
			
	 2.9
	 	 Material Transfer
	  	 	26	 
			
	 2.10
	 	 Compliance Provisions
	  	 	27	 
			
	 2.11
	 	 Global License Agreement
	  	 	28	 
			
	 ARTICLE 3
	 	 OPTIONS
	  	 	28	 
			
	 3.1
	 	 Option Grant
	  	 	28	 
			
	 3.2
	 	 Government Approvals
	  	 	31	 
			
	 ARTICLE 4
	 	 GOVERNANCE
	  	 	33	 
			
	 4.1
	 	 Generally
	  	 	33	 
			
	 4.2
	 	 Joint Steering Committee
	  	 	34	 
			
	 4.3
	 	 Patent Committee
	  	 	38	 
			
	 4.4
	 	 Manufacturing Committee
	  	 	39	 
			
	 ARTICLE 5
	 	 EXCLUSIVITY
	  	 	40	 
			
	 5.1
	 	 Exclusivity
	  	 	40	 
			
	 5.2
	 	 Failure to Exercise Phase 1 Option
	  	 	41	 
			
	 5.3
	 	 Prothena Exception for Active Immunotherapeutic Approaches
	  	 	41	 
			
	 ARTICLE 6
	 	 FINANCIAL TERMS
	  	 	41	 
			
	 6.1
	 	 Upfront Payment
	  	 	41	 
			
	 6.2
	 	 Equity Investment
	  	 	42	 
			
	 6.3
	 	 Option Fees
	  	 	42	 
			
	 6.4
	 	 Additional Payment Terms
	  	 	42	 

  
 -i- 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 TABLE OF CONTENTS 

(continued) 
  

							
	 	 	 	  	Page	 
	 ARTICLE 7
	 	 LICENSES; INTELLECTUAL PROPERTY
	  	 	44	 
			
	 7.1
	 	 Licenses to Celgene
	  	 	44	 
			
	 7.2
	 	 Grant Back for Lapsed Targets
	  	 	44	 
			
	 7.3
	 	 Rights Retained by the Parties
	  	 	44	 
			
	 7.4
	 	 No Implied Licenses
	  	 	45	 
			
	 7.5
	 	 Insolvency
	  	 	45	 
			
	 7.6
	 	 Ownership
	  	 	45	 
			
	 7.7
	 	 Prosecution and Maintenance of Prothena Collaboration Patents and Program Patents
	  	 	47	 
			
	 7.8
	 	 Enforcement of Prothena Collaboration Patents and Program Patents
	  	 	49	 
			
	 7.9
	 	 Matters Involving Joint Program Patents
	  	 	50	 
			
	 7.10
	 	 Common Interest Agreement
	  	 	50	 
			
	 7.11
	 	 License Filing
	  	 	50	 
			
	 7.12
	 	 Defense of Claims Brought by Third Parties
	  	 	50	 
			
	 7.13
	 	 Celgene Activities
	  	 	51	 
			
	 ARTICLE 8
	 	 CONFIDENTIALITY
	  	 	51	 
			
	 8.1
	 	 Nondisclosure
	  	 	51	 
			
	 8.2
	 	 Collaboration Specific Confidential Information
	  	 	51	 
			
	 8.3
	 	 Exceptions
	  	 	52	 
			
	 8.4
	 	 Authorized Disclosure
	  	 	53	 
			
	 8.5
	 	 Terms of this Agreement
	  	 	54	 
			
	 8.6
	 	 Securities Filings
	  	 	54	 
			
	 8.7
	 	 Publicity
	  	 	54	 
			
	 8.8
	 	 Permitted Publications
	  	 	55	 
			
	 8.9
	 	 Re-Publication;
Re-Presentation
	  	 	56	 
			
	 8.10
	 	 Use of Names
	  	 	56	 
			
	 8.11
	 	 Relationship to Existing Confidentiality Agreement
	  	 	57	 
			
	 8.12
	 	 Clinical Trials Registry
	  	 	57	 
			
	 8.13
	 	 U.S. License Agreement; Global License Agreement
	  	 	57	 

  
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treatment has been requested with respect to the omitted portions. 

 TABLE OF CONTENTS 

(continued) 
  

							
	 	 	 	  	Page	 
	 ARTICLE 9
	 	 REPRESENTATIONS AND WARRANTIES; COVENANTS
	  	 	57	 
			
	 9.1
	 	 Representations and Warranties of Both Parties
	  	 	57	 
			
	 9.2
	 	 Representations and Warranties of Prothena
	  	 	58	 
			
	 9.3
	 	 Additional Representations, Warranties and Covenants of Prothena
	  	 	61	 
			
	 9.4
	 	 Representations and Warranties of Celgene
	  	 	61	 
			
	 9.5
	 	 Prothena Covenants
	  	 	62	 
			
	 9.6
	 	 Disclaimer
	  	 	62	 
			
	 ARTICLE 10
	 	 INDEMNIFICATION; INSURANCE
	  	 	62	 
			
	 10.1
	 	 Indemnification by Celgene
	  	 	62	 
			
	 10.2
	 	 Indemnification by Prothena
	  	 	63	 
			
	 10.3
	 	 Procedure
	  	 	63	 
			
	 10.4
	 	 Insurance
	  	 	64	 
			
	 10.5
	 	 LIMITATION OF LIABILITY
	  	 	64	 
			
	 ARTICLE 11
	 	 TERM AND TERMINATION
	  	 	64	 
			
	 11.1
	 	 Term; Expiration
	  	 	64	 
			
	 11.2
	 	 Termination for Breach
	  	 	64	 
			
	 11.3
	 	 Voluntary Termination
	  	 	65	 
			
	 11.4
	 	 Termination for Bankruptcy
	  	 	66	 
			
	 11.5
	 	 Termination for Patent Challenge
	  	 	66	 
			
	 11.6
	 	 Effects of Expiration or Termination
	  	 	66	 
			
	 11.7
	 	 Certain Additional Remedies of Celgene in Lieu of Termination
	  	 	67	 
			
	 11.8
	 	 Surviving Provisions
	  	 	68	 
			
	 ARTICLE 12
	 	 MISCELLANEOUS
	  	 	68	 
			
	 12.1
	 	 Severability
	  	 	68	 
			
	 12.2
	 	 Notices
	  	 	69	 
			
	 12.3
	 	 Force Majeure
	  	 	70	 
			
	 12.4
	 	 Assignment
	  	 	70	 
			
	 12.5
	 	 Waivers and Modifications
	  	 	71	 
			
	 12.6
	 	 WAIVER OF JURY TRIAL
	  	 	71	 
			
	 12.7
	 	 Choice of Law; Dispute Resolution
	  	 	71	 
			
	 12.8
	 	 Relationship of the Parties
	  	 	72	 

  
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 TABLE OF CONTENTS 

(continued) 
  

							
	 	 	 	  	Page	 
	 12.9
	 	 No Third Party Beneficiaries
	  	 	73	 
			
	 12.10
	 	 Entire Agreement
	  	 	73	 
			
	 12.11
	 	 Counterparts
	  	 	73	 
			
	 12.12
	 	 Equitable Relief
	  	 	73	 
			
	 12.13
	 	 Interpretation
	  	 	74	 
			
	 12.14
	 	 Further Assurances
	  	 	75	 
			
	 12.15
	 	 Extension to Affiliates
	  	 	75	 

  
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treatment has been requested with respect to the omitted portions. 

			
	LIST OF SCHEDULES
		
	 SCHEDULE 1.14
	 	CERTAIN EXISTING COLLABORATION CANDIDATES
	 SCHEDULE 1.42
	 	IN-LICENSE AGREEMENTS AND OTHER THIRD PARTY AGREEMENTS
	 SCHEDULE 1.66
	 	CERTAIN PROTHENA COLLABORATION PATENTS
	 SCHEDULE 1.69
	 	PROTHENA PLATFORM TECHNOLOGY

			
	
	LIST OF EXHIBITS
		
	 EXHIBIT A
	 	FORM OF GLOBAL LICENSE AGREEMENT
	 EXHIBIT B
	 	FORM OF U.S. LICENSE AGREEMENT

  
 [***] Certain information
in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 MASTER COLLABORATION AGREEMENT 

This MASTER COLLABORATION AGREEMENT (this “Agreement”) is entered into and made effective as of March 20, 2018
(the “Effective Date”) by and among Prothena Biosciences Limited, an Irish limited company (“Prothena”) and Celgene Switzerland LLC, a Delaware limited liability company (“Celgene”). Celgene
and Prothena are each referred to herein by name or as a “Party”, or, collectively, as the “Parties”. 

RECITALS 
 WHEREAS,
Prothena is a drug discovery company; 
 WHEREAS, Celgene possesses expertise in the development and commercialization of
pharmaceutical products; 
 WHEREAS, Prothena may carry out research and development activities with respect to Antibodies that
Target a Collaboration Target (with a focus on the treatment of neurodegenerative conditions including Alzheimer’s disease, amyotrophic lateral sclerosis, progressive supranuclear palsy, frontotemporal dementia, Parkinson’s disease,
corticobasal degeneration, chronic traumatic encephalopathy and other proteinopathies of a Collaboration Target), with the goal of discovering, identifying, generating and developing lead candidates with respect to each Collaboration Target and
Filing an IND with the FDA for a Phase 1 Clinical Trial for each Collaboration Target; 
 WHEREAS, if Prothena identifies any lead
candidates with respect to a particular Collaboration Target and Files an IND with the FDA for such lead candidate for such Collaboration Target, then Celgene shall have the exclusive option to enter into a U.S. License Agreement with Prothena with
respect to Antibodies that Target such Collaboration Target, on the terms and subject to the conditions set forth herein; 
 WHEREAS,
if Celgene exercises its option to enter into a U.S. License Agreement with respect to a given Collaboration Target, then Prothena may thereafter carry out a Phase 1 Clinical Trial for such Collaboration Target, and Celgene shall have the exclusive
option to enter into a Global License Agreement (as defined below) with Prothena with respect to Antibodies that Target such Collaboration Target, on the terms and subject to the conditions set forth herein. 

NOW, THEREFORE, in consideration of the foregoing and the mutual agreements set forth below, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties hereby agree as follows: 
 ARTICLE 1 

DEFINITIONS 
 Unless
specifically set forth to the contrary herein, the following terms shall have the respective meanings set forth below: 

1.1    “Affiliate” means any Person which, directly or indirectly through one or more intermediaries,
controls, is controlled by or is under common control with a Party. For purposes of this definition, the term “control” (including, with correlative meanings, the terms “controlled 

  
 1 

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treatment has been requested with respect to the omitted portions. 

 
by” and “under common control with”) as used with respect to a Person means (a) direct or indirect ownership of fifty percent (50%) or more of the voting securities or other
voting interest of any Person (including attribution from related parties), or (b) the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of such Person, whether through ownership of
voting securities, by contract, as a general partner, as a manager, or otherwise. 
 1.2    “Antibody”
means any [***] antibody (including [***]), [***] whether human, humanized, chimeric, murine, synthetic or from any other source. 

1.3    “Antitrust Law” means the Hart-Scott-Rodino Antitrust Improvements Act of 1976 and the rules and
regulations promulgated thereunder (the “HSR Act”), the Sherman Act, as amended, the Clayton Act, as amended, the Federal Trade Commission Act, as amended, and any other Applicable Laws of the United States, a state or territory
thereof, or any foreign government or supranational body (including the European Commission) that are designed to prohibit, restrict or regulate actions having the purpose or effect of monopolization or restraint of trade. 

1.4    “Applicable Law” or “Applicable Laws” means all applicable laws, statutes, rules,
regulations, orders, judgments or ordinances having the effect of law of any national, multinational, federal, state, provincial, county, city or other political subdivision, including, to the extent applicable, GCP, GLP and GMP, as well as all
applicable data protection and privacy laws, rules and regulations, including, to the extent applicable, the United States Department of Health and Human Services privacy rules under the Health Insurance Portability and Accountability Act
(“HIPAA”) and the Health Information Technology for Economic and Clinical Health Act and the EU Data Protection Directive (Council Directive 95/46/EC) and applicable laws implementing the EU Data Protection Directive and, when in
force, the General Data Protection Regulation (2016/679). 
 1.5    “Biomarker” means a parameter or
characteristic in a patient or Patient Sample, the measurement of which is useful (a) for purposes of selecting appropriate therapies or patient populations or monitoring disease susceptibility, severity or state, or monitoring therapies for
such patient and/or (b) for predicting the outcome of a particular treatment of such patient. 

1.6    “Biosimilar Application” means an application or submission filed with a Regulatory Authority for
marketing authorization of a Biosimilar Product. 
 1.7    “Biosimilar Product” means,
with respect to a given Collaboration Product, a biological product (a) that contains (i) an identical active ingredient(s) as the Collaboration Candidate in such Collaboration Product, or (ii) a “highly similar” active
ingredient(s) to the Collaboration Candidate in such Collaboration Product, as the phrase “highly similar” is used in 42 U.S.C. § 262(i)(2), and subject to the factors set forth in FDA’s Guidance for Industry, “Quality
Considerations in Demonstrating Biosimilarity to a Reference Protein Product,” (February 2012), at Section VI, or any successor FDA guidance thereto, (b) for which Regulatory Approval is obtained by referencing Regulatory Materials of such
Collaboration Product, (c) is approved for use in such country (or region) pursuant to a Regulatory Approval process governing approval of interchangeable or biosimilar biologics as described in 42 U.S.C. §§ 262, or a similar process
for Regulatory Approval in any country (or region) outside the United States, or any other similar 

  
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provision that comes into force, or is the subject of a notice with respect to such Collaboration Product under 42 U.S.C. § 262(l)(2) or any other similar provision that comes into force in
such country (or region), and (d) is sold in the same country as such Collaboration Product by any Third Party that is not a sublicensee of Celgene or its Affiliates with respect to the Prothena IP and did not purchase such product in a chain
of distribution that included any of Celgene or any of its Affiliates or its sublicensees. 

1.8    “BPCIA” means Biologics Price Competition and Innovation Act of 2009, as amended. 

1.9    “Business Day” means a day on which banking institutions in New York City, New York are open for
business, excluding any Saturday or Sunday. 
 1.10    “Calendar Quarter” means the period beginning on
the Effective Date and ending on the last day of the calendar quarter in which the Effective Date falls, and thereafter each successive period of three (3) consecutive calendar months ending on the last day of March, June, September, or
December, respectively; provided that the final Calendar Quarter shall end on the last day of the Term. 

1.11    “Calendar Year” means the period beginning on the Effective Date and ending on December 31
of the calendar year in which the Effective Date falls, and thereafter each successive period of twelve (12) consecutive calendar months beginning on January 1 and ending on December 31; provided that the final Calendar Year shall end on
the last day of the Term. 
 1.12    “Celgene IP” means Patents and Know-How Controlled (other than through the grant of a license from Prothena to Celgene pursuant to this Agreement) by Celgene or any of its Affiliates (including any Know-How
that is created, conceived, discovered, first generated, invented, first made or first reduced to practice by or on behalf of Celgene or any of its Affiliates pursuant to the conduct of activities under this Agreement, including Celgene Phase 1 Know-How). For the avoidance of doubt, Celgene IP excludes (i) Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to
practice by or on behalf of Prothena, solely or jointly with a Third Party, (ii) [***], and (iii) Joint Program IP. 

1.13    “Clinical Trial” means a human clinical trial, including any Phase 1 Clinical Trial, Phase 2
Clinical Trial or Registration Enabling Clinical Trial, any study incorporating more than one of these phases, or any human clinical trial commenced after Regulatory Approval. 

1.14    “Collaboration Candidate” means, on a Program-by-Program basis, (i) the Antibodies that Target the Collaboration Target under such Program that are Developed under such Program and (ii) Related Antibodies with respect to any Antibodies
described in the foregoing clause (i); it being understood and agreed that a “Lead Candidate” and a “Development Candidate” shall remain included in the definition of “Collaboration Candidate”. Notwithstanding the
foregoing, a “Collaboration Candidate” shall exclude any proprietary Antibody owned or otherwise controlled (through license or otherwise, other than as a result of a license from Prothena hereunder) by Celgene or any of its Affiliates and
that is Developed or acquired outside the scope of a Program. The Antibodies listed on Schedule 1.14 (broken down on a Program-by-Program basis) shall be
included as Collaboration Candidates with respect to the applicable Program. 

  
 3 

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treatment has been requested with respect to the omitted portions. 

 1.15    “Collaboration Product” means, on a Program-by-Program basis, any product that constitutes, incorporates, comprises or contains a Collaboration Candidate from such Program, whether or not as the sole active
ingredient, and in all forms, presentations, and formulations (including manner of delivery and dosage). For clarity, different forms, formulations, presentations or dosage strengths of a given Collaboration Product that constitute, incorporate,
comprise or contain the same Collaboration Candidate shall be considered the same Collaboration Product for purposes of this Agreement. 

1.16    “Collaboration Target” means each of (i) Tau, including Derivatives thereof, (ii) [***],
including Derivatives thereof (this clause (ii), the “[***] Target”), (iii) TDP-43, including Derivatives thereof and (iv) in the event that the JSC agrees in writing to substitute any of
the foregoing targets in (i), (ii) or (iii) with a replacement target as set forth in Section 4.2.5(a), such replacement target (including Derivatives thereof). Collaboration Targets shall exclude all Lapsed Targets and Derivatives
thereof. 
 1.17    “Commercialization” means any and all activities directed to the commercialization
of a product (which may include related diagnostic products, if applicable), including commercial manufacturing (including Manufacturing) and commercial supply of a product, marketing, detailing, promotion, market research, distributing, order
processing, handling returns and recalls, booking sales, customer service, administering and commercially selling such product, importing, exporting and transporting such product for commercial sale, and seeking of pricing and reimbursement of a
product (if applicable), whether before or after Regulatory Approval has been obtained (including making, having made, using, importing, selling and offering for sale such product (or related diagnostic product, if applicable)), as well all
regulatory compliance with respect to the foregoing. For clarity, “Commercialization” does not include any Clinical Trial commenced after Regulatory Approval. When used as a verb, “Commercialize” means to engage in
Commercialization. 
 1.18    “Commercially Reasonable Efforts” means, with respect to Celgene in
relation to an obligation under this Agreement with respect to a Collaboration Candidate or Collaboration Product, such efforts that are consistent with the efforts and resources normally used by Celgene in the exercise of its commercially
reasonable business practices relating to performance of an obligation for a similar pharmaceutical compound or product (including the research, development, manufacture and commercialization of a pharmaceutical compound or product), as applicable,
at a similar stage in its research, development or commercial life as the relevant Collaboration Candidate or Collaboration Product, and that has commercial and market potential similar to the relevant Collaboration Candidate or Collaboration
Product, taking into account issues of intellectual property coverage, safety and efficacy, stage of development, product profile, competitiveness of the marketplace, proprietary position, regulatory exclusivity, anticipated or approved
labeling, present and future market and commercial potential, the likelihood of receipt of Regulatory Approval, profitability (including pricing and reimbursement status achieved or likely to be achieved), amounts payable to licensors of patents or
other intellectual property rights, [***] and legal issues. 
 1.19    “Confidential Information”
means, with respect to a Party, all confidential and proprietary information and materials, including Know-How, marketing plans, strategies, and customer lists, in each case, that are disclosed by or on behalf
of such Party to the other Party 

  
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pursuant to this Agreement, regardless of whether any of the foregoing are marked “confidential” or “proprietary” or communicated to the other Party by or on behalf of the
disclosing Party in oral, written, visual, graphic or electronic form. 
 1.20    “Control”,
“Controls” or “Controlled” means, with respect to any intellectual property (including Know-How) or Confidential Information, the ability of a Party or its Affiliates, as
applicable, (whether through ownership or license (other than a license granted in this Agreement)) to grant to the other Party the licenses or sublicenses as provided herein, or to otherwise disclose such intellectual property or Confidential
Information to the other Party, without violating the terms of any then-existing agreement with any Third Party at the time such Party or its Affiliates, as applicable, would be required hereunder to grant the other Party such license or sublicenses
as provided herein or to otherwise disclose such intellectual property or Confidential Information to the other Party. 

1.21    “Data Lock” means, with respect to a Clinical Trial being conducted by or on behalf of Prothena
(or by or on behalf of Celgene with respect to a Phase 1 Clinical Trial if it exercises the Celgene Phase 1 Portion Participation Right) for a Development Candidate under the Collaboration, the locking by or on behalf of Prothena (or by or on behalf
of Celgene with respect to a Phase 1 Clinical Trial if it exercises the Celgene Phase 1 Portion Participation Right) of the database that contains the data for such Clinical Trial following completion of such Clinical Trial in order to prevent or
control any further changes to such data after review, query resolution and reasonable determination by Prothena (or Celgene, if applicable) (in accordance with industry standards) that such database is ready for analysis. 

1.22    “Derivative” means, with respect to a Collaboration Target, all [***] thereof. 

1.23    “Development” means (i) research activities (including drug discovery, identification and/or
synthesis) with respect to a product (which may include related diagnostic products, if applicable), and/or (ii) preclinical and clinical drug development activities, and other development activities, with respect to a product (which may
include related diagnostic products, if applicable), including test method development and stability testing, toxicology, formulation, process development, qualification and validation, manufacture scale-up,
development-stage manufacturing (including Manufacturing), quality assurance/quality control, Clinical Trials (including Clinical Trials and other studies commenced after Regulatory Approval), statistical analysis and report writing, the preparation
and submission of INDs and MAAs, regulatory affairs with respect to the foregoing and all other activities necessary or useful or otherwise requested or required by a Regulatory Authority or as a condition or in support of obtaining or maintaining a
Regulatory Approval. When used as a verb, “Develop” means to engage in Development. 

1.24    “Development Candidate” means a Lead Candidate that is the subject of an IND Filed with the FDA
for a Program for which Celgene has exercised its IND Option in accordance with Section 3.1.1. 

1.25    “Dollars” or “$” means the legal tender of the United States. 

1.26    “EEA” means all countries that are officially recognized as member states of the European
Economic Area at any particular time. 

  
 5 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 1.27    “End of Discovery Portion Date” means, with
respect to a given Program, the date on which Prothena delivers to Celgene the first complete IND Data Package, if any, for such Program, in accordance with Section 2.2.2(d). 

1.28    “End of Phase 1 Date” means, with respect to a given Program, the earlier of (a) (i) the
date on which Prothena delivers to Celgene the first complete Phase 1 Data Package, if any, for such Program, in accordance with Section 2.2.3(b) or (ii) the date deemed the “End of Phase 1 Date” pursuant to Section 2.5.2
(as applicable), or (b) such other date as approved by the JSC with respect to such Program (this clause (b), an “Alternative End of Phase 1 Date” for a given Program). 

1.29    “EU” means all countries that are officially recognized as member states of the European Union at
any particular time. 
 1.30    “Executive Officers” means Prothena’s Chief Executive Officer and
Celgene’s Executive Vice President, Research and Early Development (or such Executive Vice President’s designee). 

1.31    “File” or “Filing” means, with respect to an IND, the filing of an IND with, and
acceptance of such IND by, the FDA. 
 1.32    “Global License Agreement” means a Global License
Agreement in the form attached hereto as Exhibit A. 
 1.33    “Good Clinical Practices” or
“GCP” means the applicable then-current ethical and scientific quality standards for designing, conducting, recording, and reporting trials that involve the participation of human subjects as are required by applicable Regulatory
Authorities or Applicable Law in the relevant jurisdiction, including in the United States, Good Clinical Practices established through FDA guidances, and, outside the United States, Guidelines for Good Clinical Practice – ICH Harmonized
Tripartite Guideline (ICH E6). 
 1.34    “Good Laboratory Practices” or “GLP” means
the applicable then-current good laboratory practice standards as are required by applicable Regulatory Authorities or Applicable Law in the relevant jurisdiction, including in the United States, those promulgated or endorsed by the FDA in U.S. 21
C.F.R. Part 58, or the equivalent thereof as promulgated or endorsed by the applicable Regulatory Authorities outside of the United States. 

1.35    “Good Manufacturing Practices” or “GMP” means all applicable standards relating
to manufacturing practices for fine chemicals, intermediates, bulk products and/or finished pharmaceutical products, as are required by applicable Regulatory Authorities or Applicable Law in the relevant jurisdiction, including, as applicable,
(a) all applicable requirements detailed in the FDA’s current Good Manufacturing Practices regulations, U.S. 21 C.F.R. Parts 210 and 211, (b) all applicable requirements detailed in the EMA’s “The Rules Governing Medicinal
Products in the European Community, Volume IV, Good Manufacturing Practice for Medicinal Products”, and (c) all Applicable Laws promulgated by any Governmental Authority having jurisdiction over the manufacture of the applicable compound
or pharmaceutical product, as applicable. 

  
 6 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 1.36    “Governmental Authority” means any
(a) federal, state, local, municipal, foreign or other government, (b) governmental or quasi-governmental authority of any nature (including any governmental division, subdivision, department, agency, bureau, branch, office, commission,
council, board, instrumentality, officer, official, representative, organization, unit, body or entity and any court or other tribunal), (c) multinational governmental organization or body or (d) entity or body exercising, or entitled to
exercise, any executive, legislative, judicial, administrative, regulatory, police, military or taxing authority or power of any nature. 

1.37    “IND” means an investigational new drug application (including any amendment or supplement
thereto) submitted to the FDA pursuant to U.S. 21 C.F.R. Part 312, including any amendments thereto. References herein to IND shall include, to the extent applicable, any comparable filing(s) outside the U.S. for the investigation of any product in
any other country or group of countries (such as a Clinical Trial Application in the EU). 
 1.38    “IND Data
Package” means, with respect a given Program for which an IND has been Filed with the FDA, the following: (i) a reasonably detailed analysis of the key data related to the Lead Candidate(s) from such Program, (ii) [***], (iii) [***],
(iv) [***], (v) a list of [***], as well as a [***], and (vi) [***]. 
 1.39    “IND Option Term”
means, with respect to a given Program, the period beginning on the Effective Date and ending [***] ([***]) days after the End of Discovery Portion Date with respect to such Program ([***]); provided that, in the event that Celgene exercises its IND
Option for a given Program in accordance with this Agreement, then the IND Option Term for such Program shall automatically be extended until the Parties execute the U.S. License Agreement for such Program, and upon execution thereof, the IND Option
Term for such Program shall automatically be deemed to expire. 
 1.40    “Indication” means an
entirely separate and distinct disease or medical condition in humans (i) [***], and/or (ii) [***]. For clarity, (a) [***], (b) [***] and (c) [***]. 

1.41    “Initial Research Term” means the period beginning on the Effective Date and ending on the six
(6) year anniversary thereof. 
 1.42    “In-License
Agreements” means any agreement between Prothena (or its Affiliates, as applicable) and any Third Party pursuant to which such Third Party licenses to Prothena (or its Affiliates, as applicable) any Patents or
Know-How included in the Prothena IP, including those set forth on Schedule 1.42. 

1.43    “Know-How” means all proprietary (a) information,
techniques, technology, practices, trade secrets, inventions, methods (including methods of use or administration or dosing), knowledge, data, results and software and algorithms, including pharmacological, toxicological and clinical test data and
results, compositions of matter, chemical structures, protein sequences, and formulations, sequences, processes, formulae, techniques, research data, reports, standard operating procedures, batch records, manufacturing data, analytical and quality
control data, analytical methods (including applicable reference standards), assays and research tools, in each case, whether patentable or not; and (b) tangible manifestations thereof, including any and all of the foregoing relating to Program
Biological and Chemical Materials. 

  
 7 

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treatment has been requested with respect to the omitted portions. 

 1.44    “Lapsed Target” means (i) any
Collaboration Target that is deemed to be a “Lapsed Target” pursuant to Section 3.1.3(a) or Section 4.2.5, or (ii) any other Collaboration Target that the Parties mutually agree in writing should be a “Lapsed
Target”. It is understood and agreed that a “Lapsed Target” shall not be included in the definition of a “Collaboration Target”. 

1.45    “Lead Candidate” means, with respect to a given Program, any Collaboration Candidate that Targets
the Collaboration Target under such Program that (i) satisfies the Lead Candidate Criteria, or (ii) if no Collaboration Candidate has satisfied the Lead Candidate Criteria at the time when Celgene exercises its IND Option for a given
Program, the Collaboration Candidate under such Program that is at the most advanced stage of Development under such Program. It is understood and agreed that a “Development Candidate” shall remain included in the definition of “Lead
Candidate”. 
 1.46    “Lead Candidate Criteria” means the criteria approved by the JSC after the
Effective Date in order to determine if a given Collaboration Candidate could be a Lead Candidate, as such criteria may be amended from time to time by the JSC. 

1.47    “Manufacture” means all activities related to the manufacturing of a product or diagnostic
product or, in either case, any component or ingredient thereof, including test method development and stability testing, formulation, process development, manufacturing scale-up whether before or after
Regulatory Approval, manufacturing any product or diagnostic product in bulk or finished form for Development or Commercialization (as applicable), including filling and finishing, packaging, labeling, shipping and holding, in-process and finished product testing, release of a product or diagnostic product or, in either case, any component or ingredient thereof, quality assurance and quality control activities related to manufacturing
and release of a product or diagnostic product, and regulatory activities related to any of the foregoing. 

1.48    “Marketing Authorization Application” or “MAA” means a Marketing Authorization
Application, Biologics License Application or similar application, as applicable, and all amendments and supplements thereto, submitted to the FDA, or any equivalent filing in a country or regulatory jurisdiction other than the U.S. with the
applicable Regulatory Authority, to obtain marketing approval for a pharmaceutical or diagnostic product, in a country or in a group of countries. 

1.49    “Option Term” means, with respect to a given Program, the IND Option Term for such Program and
the Phase 1 Option Term for such Program. 
 1.50    “Patents” means (a) all patents and patent
applications in any country or supranational jurisdiction worldwide, (b) any substitutions, divisionals, continuations, continuations-in-part, reissues, renewals,
registrations, confirmations, re-examinations, extensions, supplementary protection certificates and the like of any such patents or patent applications, and (c) foreign counterparts of any of the
foregoing. 
 1.51    “Patient Sample” means tissue, fluid, or cells collected from a patient, or
components of the foregoing. 

  
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treatment has been requested with respect to the omitted portions. 

 1.52    “Person” means any individual, partnership,
joint venture, limited liability company, corporation, firm, trust, association, unincorporated organization, governmental authority or agency, or any other entity not specifically listed herein. 

1.53    “Personal Data” means any information relating to an identified or identifiable individual or
otherwise as defined under Applicable Laws. 
 1.54    “Phase 1 Clinical Trial” means a human clinical
trial of a product that would satisfy the requirements of U.S. 21 C.F.R. Part 312.21(a) (as amended), or a similar clinical study prescribed by the Regulatory Authorities in a foreign country, and is intended to (a) determine the safety,
pharmacokinetics and pharmacodynamic parameters in healthy individuals or patients, and (b) following the foregoing clause (a), further evaluate safety and pharmacokinetics (including exploration of trends of a biomarker-based or clinical
endpoint-based efficacy relationship to dose which need not be designed to be statistically significant) of the product, whether or not in combination with concomitant treatment, and which provides sufficient evidence of safety to be included in
filings for a Phase 2 Clinical Trial or a Registration Enabling Clinical Trial with Regulatory Authorities. 

1.55    “Phase 1 Data Package” means, with respect to a given Program for which a Phase 1 Clinical Trial
is conducted, the following: (i) a reasonably detailed analysis of the data and applicable endpoints of the Phase 1 Clinical Trial after Data Lock (“Phase 1 Data”), including [***]; (ii) [***]; (iii) [***]; (iv) [***]; (v)
[***]; (vi) [***]; (vii) [***]; (viii) [***]; (ix) [***]; (x) [***]; (xi) [***]; (xii) a list of [***], as well as a [***]; and (xiii) [***]. 

1.56    “Phase 1 Option Term” means, with respect to a given Program, the period commencing upon exercise
of the IND Option with respect to such Program and ending [***] ([***]) days after the End of Phase 1 Date with respect to such Program ([***]); provided that, in the event that Celgene exercises its Phase 1 Option for a given Program in accordance
with this Agreement, then the Phase 1 Option Term for such Program shall automatically be extended until the Parties execute the Global License Agreement for such Program, and upon execution thereof, the Phase 1 Option Term for such Program shall
automatically be deemed to expire. 
 1.57    “Phase 1 Term” means, with respect to a given Program,
the period commencing upon exercise of the IND Option with respect to such Program and ending upon the earlier of (i) the End of Phase 1 Date with respect to such Program and (ii) the exercise by Celgene of its Phase 1 Option with respect
to such Program. 
 1.58    “Phase 2 Clinical Trial” means a human clinical trial of a product that
would satisfy the requirements of U.S. 21 C.F.R. Part 312.21(b), as amended, and is intended to explore a variety of doses, dose response, and duration of effect, and to generate evidence of clinical safety and effectiveness for a particular
Indication or Indications in a target patient population, or a similar clinical study prescribed by the relevant Regulatory Authorities in a country other than the United States. 

1.59    “Primary Patent Countries” means [***]. 

  
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treatment has been requested with respect to the omitted portions. 

 1.60    “Program” means a Development program hereunder
with respect to a given Collaboration Target undertaken by or on behalf of Prothena or its Affiliates with respect to such Collaboration Target, including all Collaboration Candidates that Target such Collaboration Target and all Program Biological
and Chemical Materials with respect thereto; it being understood and agreed that if, at any time during the Research Term, two (2) or more Collaboration Candidates each Target the same applicable Collaboration Target, then each such
Collaboration Candidate shall be deemed part of the same applicable Program for purposes of this Agreement (and any applicable U.S. License Agreement and Global License Agreement, as applicable). For the avoidance of doubt, each Collaboration Target
shall be the subject of a separate Program. For clarity, (i) if a Collaboration Candidate binds to more than one Collaboration Target it shall be deemed part of the Program in which such Collaboration Candidate was primarily Developed and
(ii) any activities undertaken pursuant to a U.S. License Agreement or Global License Agreement shall not be part of the Program, except as expressly set forth in Section 2.3.1 of a U.S. License Agreement and Section 2.1.3(a) of a
Global License Agreement. 
 1.61    “Program Biological and Chemical Materials” means, on a Program-by-Program basis, any and all compositions of matter, cells, cell lines, assays, animal models, imaging agents, Patient Samples, Biomarkers and any other physical,
biological or chemical material, that are Controlled by Prothena or its Affiliates and [***] the Collaboration Target or Collaboration Candidates under such Program (or the Development, Manufacture or Commercialization thereof), including physical
embodiments of such Program’s Collaboration Candidates and any diagnostics intended for use with such Collaboration Candidates, in each case, (i) created, conceived, discovered, first generated, invented, first made or first reduced to
practice by or on behalf of Prothena or its Affiliates, whether solely or jointly with any Third Party, in such Program or (ii) otherwise utilized by or on behalf of Prothena or its Affiliates in such Program. To the extent the Program
Biological and Chemical Materials are created, conceived, discovered, first generated, invented, first made or first reduced to practice under a given Program, such Program Biological and Chemical Materials shall be “Program Know-How” hereunder, and to the extent the Program Biological and Chemical Materials are not created, conceived, discovered, first generated, invented, first made or first reduced to practice under a given
Program, but are otherwise utilized in such Program, such Program Biological and Chemical Materials shall be “Prothena Collaboration Know-How” hereunder. 

1.62    “Program IP” means, collectively: 

(a)    “Program Know-How” which means any and all Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to practice, in each case (i) by or on behalf of [***], (ii) by or on behalf of [***] or (iii) by or
on behalf of [***], but expressly excluding any Joint Program Know-How. 

(b)    “Program Patents” which means any Patents Controlled by Prothena or its Affiliates that claim or
cover any Program Know-How, but expressly excluding any Joint Program Patents. 

1.63    “Prosecution and Maintenance” or “Prosecute and Maintain” means, with regard to
a Patent, the preparation, filing, prosecution and maintenance of such Patent, as well as re-examinations, reissues, appeals, and requests for patent term adjustments and patent term

  
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treatment has been requested with respect to the omitted portions. 

 
extensions with respect to such Patent, together with the initiation or defense of interferences, oppositions, inter partes review, re-examinations,
derivations, post-grant proceedings and other similar proceedings (or other defense proceedings with respect to such Patent, but excluding the defense of challenges to such Patent as a counterclaim in an infringement proceeding) with respect to the
particular Patent, and any appeals therefrom. For clarification, “Prosecution and Maintenance” or “Prosecute and Maintain” shall not include any other enforcement actions taken with respect to a Patent. 

1.64    “Prothena Collaboration IP” means all Prothena Collaboration
Know-How and Prothena Collaboration Patents. 
 1.65    “Prothena
Collaboration Know-How” means any and all Know-How that is Controlled by Prothena or its Affiliates on or after the Effective Date that is
(a) necessary or [***] to research, develop, make, have made, import, use, offer to sell, sell or otherwise exploit any Collaboration Target, Collaboration Candidate or Collaboration Product or (b) [***], including any Know-How related to diagnostics intended for use with any such Collaboration Candidate or Collaboration Product, but expressly excluding Joint Program Know-How and Program Know-How. 
 1.66    “Prothena Collaboration Patents” means any and
all Patents that are Controlled by Prothena or its Affiliates on or after the Effective Date that claim or cover (a) any Collaboration Target, Collaboration Candidate or Collaboration Product, or the research, development, making, having made,
import, use, offering to sell, selling or other exploitation of any of the foregoing, or (b) any Prothena Collaboration Know-How; but expressly excluding Joint Program Patents and Program Patents.
Prothena Collaboration Patents shall include the Patents set forth on Schedule 1.66. 
 1.67    “Prothena
IP” means the Prothena Collaboration Patents, the Prothena Collaboration Know-How, the Program Patents and the Program Know-How, as well as
Prothena’s (and its Affiliates’) right, title and interest in and to the Joint Program IP. 

1.68    “Prothena Platform Patent” means a Patent within the Prothena Collaboration Patents that [***]
claims the Prothena Platform Technology. 
 1.69    “Prothena Platform Technology” means [***], which
shall [***]; but in any case excluding [***]. 
 1.70    “Registration Enabling Clinical Trial” means
(a) a human clinical trial of a product that would satisfy the requirements of U.S. 21 C.F.R. Part 312.21(c), as amended, and is intended to (i) establish that the product is safe and efficacious for its intended use, (ii) define
contraindications, warnings, precautions and adverse reactions that are associated with the product in the dosage range to be prescribed, and (iii) support Regulatory Approval for such product, or (b) a similar clinical study prescribed by
the relevant Regulatory Authorities in a country other than in the United States. 
 1.71    “Regulatory
Approval” means all approvals, licenses and authorizations of the applicable Regulatory Authority necessary for the marketing and sale of a pharmaceutical or 

  
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treatment has been requested with respect to the omitted portions. 

 
diagnostic product for a particular Indication in a country or region (including separate pricing or reimbursement approvals, as necessary), and including the approvals by the applicable
Regulatory Authority of any expansion or modification of the label for such Indication. 
 1.72    “Regulatory
Authority” means any national or supranational Governmental Authority, including the U.S. Food and Drug Administration (and any successor entity thereto) (the “FDA”) in the U.S., the European Medicines Agency (and any
successor entity thereto) (the “EMA”) in the EU and the Ministry of Health, Labour and Welfare of Japan, or the Pharmaceuticals and Medical Devices Agency of Japan (or any successor to either of them) as the case may be (the
“MHLW”) in Japan, or any health regulatory authority in any country or region that is a counterpart to the foregoing agencies, in each case, that holds responsibility for development and commercialization of, and the granting of
Regulatory Approval for, a pharmaceutical or diagnostic product, as applicable, in such country or region. 

1.73    “Regulatory Materials” means the regulatory registrations, applications, authorizations and
approvals (including approvals of MAAs, supplements and amendments, pre- and post-approvals, pricing and reimbursement approvals, and labeling approvals), Regulatory Approvals and other submissions made to or
with any Regulatory Authority for research, development (including the conduct of Clinical Trials), manufacture, or commercialization of a pharmaceutical or diagnostic product in a regulatory jurisdiction, together with all related correspondence to
or from any Regulatory Authority and all documents referenced in the complete regulatory chronology for each MAA, including all Drug Master Files (if any), INDs and supplemental biologics license applications (sBLAs) and foreign equivalents of any
of the foregoing. 
 1.74    “Related Antibody” means, with respect to a given Antibody, any (a) [***]
or (b) [***], and in each case of (a) and (b), that [***]. 
 1.75    “Research Extension
Period” means the period commencing at the end of the Initial Research Term and ending on (i) the twelve (12) month anniversary of the end of the Initial Research Term, if the Initial Research Term is extended pursuant to
Section 2.3.1, (ii) the twenty-four (24) month anniversary of the end of the Initial Research Term if the Initial Research Term is extended pursuant to Section 2.3.2, or (iii) the end of the extension period agreed to by the
Parties, if the Initial Research Term is extended pursuant to Section 2.3.3. 
 1.76    “Research
Plan” means, with respect to a given Program, a research and development plan (which may be developed and adopted by the JSC after the Effective Date, and may be amended from time to time by the JSC pursuant to Section 4.2.3) for the
activities of the Collaboration that may be conducted by or on behalf of Prothena for such Program, (i) during the Research Term, with the goal of discovering, identifying, generating and developing Collaboration Candidates and Lead Candidates
for the Collaboration Target under such Program, and Filing an IND with the FDA for a Phase 1 Clinical Trial for a Lead Candidate for such Collaboration Target, with a focus on the treatment of neurodegenerative conditions including Alzheimer’s
disease, amyotrophic lateral sclerosis, progressive supranuclear palsy, frontotemporal dementia, Parkinson’s disease, corticobasal degeneration, chronic traumatic encephalopathy and other proteinopathies of such Collaboration Target, and
(ii) during the Phase 1 Term for such Program, with the goal of advancing Development Candidates from such Program to completion of Phase 1 Clinical Trial. 

  
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treatment has been requested with respect to the omitted portions. 

 1.77    “Research Term” means the Initial Research Term
plus, if applicable, the Research Extension Period. 
 1.78    “Target” means, with respect to a given
Antibody and a given Collaboration Target, that such Antibody [***]; provided that, [***]. For the purposes of the “Target” definition, “[***]” means [***]. 

1.79    “Territory” means worldwide. 

1.80    “Third Party” means any Person other than Prothena or Celgene that is not an Affiliate of
Prothena or of Celgene. 
 1.81    “Third Party Claim” means any and all suits, claims, actions,
proceedings or demands brought by a Third Party. 
 1.82    “Third Party Damages” means all losses,
costs, claims, damages, judgments, liabilities and expenses payable to a Third Party by a Party (or the Prothena Indemnitees or Celgene Indemnitees, as applicable) under a Third Party Claim (including reasonable attorneys’ fees and other
reasonable out-of-pocket costs of litigation in connection therewith). 

1.83    “United States” or “U.S.” means the United States of America and all of its
territories and possessions. 
 1.84    “[***]” means [***]. 

1.85    “U.S. License Agreement” means a U.S. License Agreement in the form attached hereto as Exhibit
B. 
 1.86    “Violation” means that Prothena or any of its officers or directors or any other
Prothena personnel (or other permitted agents of Prothena performing activities hereunder including any of Prothena’s Affiliates, Third Party contractors and their respective officers and directors) has been: (1) convicted of any of the
felonies identified among the exclusion authorities listed on the U.S. Department of Health and Human Services, Office of Inspector General (OIG) website, including 42 U.S.C. 1320a-7(a)
(http://oig.hhs.gov/exclusions/authorities.asp); (2) identified in the OIG List of Excluded Individuals/Entities (LEIE) database (http://exclusions.oig.hhs.gov/) or otherwise excluded from contracting with the federal government (see the System for
Award Management (formerly known as the Excluded Parties Listing System) at http://sam.gov/portal/public/SAM/); or (3) listed by any U.S. federal agency as being suspended, debarred, excluded or otherwise ineligible to participate in federal
procurement or non-procurement programs, including under 21 U.S.C. 335a (http://www.fda.gov/ora/compliance_ref/debar/) (each of (1), (2) and (3) collectively the “Exclusions Lists”). 

  
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treatment has been requested with respect to the omitted portions. 

 1.87    Additional Definitions. Each of the following terms has
the meaning described in the corresponding section of this Agreement indicated below: 
  

			
	 Definition:
	  	Section:
	 Active Immunotherapeutic Approaches
	  	5.3.1
	 Agreement
	  	Preamble
	 Alliance Manager
	  	4.1.3
	 Alternative End of Phase 1 Date
	  	1.28
	 Celgene
	  	Preamble
	 Celgene Indemnitees
	  	10.2
	 Celgene Phase 1 Know-How
	  	2.5.3
	 Celgene Phase 1 Portion Participation Right
	  	2.5.1(b)
	 Celgene Product
	  	4.2.7
	 Celgene Proposed Terms
	  	5.3.2
	 Clearance Date
	  	3.2.2
	 Collaboration
	  	2.1
	 Collaboration Non-Specific IP
	  	8.2
	 Collaboration Material Transfer Agreement
	  	2.9.1
	 Collaboration Specific IP
	  	8.2
	 Competing Compound
	  	5.1
	 Confirmation Notice
	  	2.4.1
	 Cure Period
	  	11.2.1
	 Disclosing Party
	  	8.1
	 Discovery Portion
	  	2.1
	 Dispute
	  	12.7.2
	 DOJ
	  	3.2.2
	 Effective Date
	  	Preamble
	 Electronic Delivery
	  	12.11
	 EMA
	  	1.72
	 Excluded Claim
	  	12.7.3(d)
	 Exclusion Lists
	  	1.86
	 Existing Confidentiality Agreement
	  	8.11
	 First Extended Research Term
	  	2.3.1
	 Force Majeure
	  	12.3
	 FTC
	  	3.2.2
	 FDA
	  	1.72
	 Grant
	  	5.3.2
	 Grant Notice
	  	5.3.2
	 HIPAA
	  	1.4
	 HSR Act
	  	1.3
	 HSR Filing
	  	3.2.2
	 Implementation Date
	  	3.2.2
	 IND Option
	  	3.1.1
	 IND Option Exercise Fee
	  	6.3.1
	 IND Option Exercise Notice
	  	3.1.3(a)
	 Indemnitee
	  	10.3
	 Indemnitor
	  	10.3

  
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treatment has been requested with respect to the omitted portions. 

			
	 Definition:
	  	Section:
	 Indirect Taxes
	  	6.4.2(b)
	 Insolvency Event
	  	11.4
	 Investment Agreements
	  	6.2
	 Joint Program IP
	  	7.6.4
	 Joint Program Know-How
	  	7.6.4
	 Joint Program Patent
	  	7.6.4
	 JSC
	  	4.2.1
	 Manufacturing Committee
	  	4.4.1
	 Material Receiving Party
	  	2.9.1
	 MHLW
	  	1.72
	 Negotiation Period
	  	5.3.2
	 [***]
	  	[***]
	 Notice Period
	  	5.3.2
	 Officials
	  	2.10.2
	 Option
	  	3.1
	 Participation Term Extension
	  	2.5.4
	 Party or Parties
	  	Preamble
	 Patent Committee
	  	4.3.1
	 Patent Liaison
	  	4.1.4
	 Patent Strategy
	  	4.3.4
	 Payee Party
	  	6.4.2(b)
	 Paying Party
	  	6.4.2(b)
	 Payment
	  	2.10.2
	 Permitted Celgene Purpose
	  	2.9.1
	 Phase 1 Data
	  	1.55
	 Phase 1 Development Portion
	  	2.1
	 Phase 1 Option
	  	3.1.2
	 Phase 1 Option Exercise Fee
	  	6.3.2
	 Phase 1 Option Exercise Notice
	  	3.1.3(b)
	 Program Assets
	  	3.1.5(a)
	 Program Know-How
	  	1.62(a)
	 Program Patents
	  	1.62(b)
	 Program Regulatory Materials
	  	2.6.1(a)
	 [***]
	  	[***]
	 Prothena
	  	Preamble
	 Prothena Indemnitees
	  	10.1
	 Publishing Party
	  	8.8.1
	 Qualified Scientist
	  	2.4.3
	 Receiving Party
	  	8.1
	 Regulatory Transfer Date
	  	2.6.1(b)
	 Right of First Negotiation
	  	5.3.2
	 Scientific Panel
	  	2.4.3
	 SEC
	  	8.4.1(a)
	 Securities Regulators
	  	8.6
	 Subcommittee
	  	4.1.1(b)

  
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treatment has been requested with respect to the omitted portions. 

			
	 Definition:
	  	Section:
	 Subcontracting Essential Provisions
	  	2.7
	 Tax Benefit
	  	6.4.2(c)
	 Term
	  	11.1
	 Transferred Prothena Materials
	  	2.9.1
	 Transferring Party
	  	2.9.1
	 Upfront Payment
	  	6.1

 ARTICLE 2 

COLLABORATION AND DEVELOPMENT 

2.1    Collaboration Overview. Pursuant to this Agreement and as further provided in this Article 2, with respect
to each Collaboration Target, (a) Prothena may conduct discovery activities with the goal of discovering, identifying and generating Collaboration Candidates that Target such Collaboration Target, and (b) Prothena may conduct pre-clinical Development activities (including comparator reference research and proprietary antibodies as required for the characterization of the Program antibodies) with respect to Collaboration Candidates with
the goal of (i) identifying and further Developing Lead Candidates that Target such Collaboration Target and (ii) Filing an IND with the FDA for a Phase 1 Clinical Trial for a Lead Candidate for such Collaboration Target, and with a focus
on the treatment of neurodegenerative conditions including Alzheimer’s disease, amyotrophic lateral sclerosis, progressive supranuclear palsy, frontotemporal dementia, Parkinson’s disease, corticobasal degeneration, chronic traumatic
encephalopathy and other proteinopathies of a Collaboration Target (clauses (a) and (b), the “Discovery Portion”), (c) if Celgene exercises its IND Option with respect to a given Program as more specifically provided in Article
3, then Prothena may conduct further Development activities with the goal of advancing Development Candidates that Target the applicable Collaboration Target to completion of Phase 1 Clinical Trial, and with a focus on the treatment of
neurodegenerative conditions including Alzheimer’s disease, amyotrophic lateral sclerosis, progressive supranuclear palsy, frontotemporal dementia, Parkinson’s disease, corticobasal degeneration, chronic traumatic encephalopathy and other
proteinopathies of a Collaboration Target (clause (c), the “Phase 1 Development Portion”) ((a), (b) and (c), the “Collaboration”). In addition, (x) in the event that Celgene exercises its IND Option with
respect to one or more Programs as more specifically provided in Article 3, then the Parties shall enter into U.S. License Agreement for such Program(s) and (y) in the event that Celgene exercises its Phase 1 Option for one or more Programs as
more specifically provided in Article 3, the Parties shall enter into a Global License Agreement for such Program(s). 

2.2    Program Development. 

2.2.1    Generally. 

(a)    During the Research Term, for each Collaboration Target, Prothena may conduct discovery activities to characterize,
identify and generate Antibodies to become Collaboration Candidates that Target such Collaboration Target, and thereafter may pre-clinically Develop Collaboration Candidates to identify Lead Candidates that
Target such Collaboration Target and File an IND with the FDA for a Phase 1 Clinical Trial for such Lead Candidates. In connection therewith, Prothena shall provide regular updates to Celgene at JSC meetings in

  
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accordance with Section 4.2, including providing reasonable data and information related to the Collaboration Targets and Collaboration Candidates for purposes of informing Celgene of the
progress of the Programs and enabling robust discussions regarding the Programs. 
 (b)    In the event that Celgene
exercises its IND Option with respect to a given Program, then during the Phase 1 Term for such Program, Prothena may conduct further Development activities with respect to the Development Candidates from such Program through completion of the Phase
1 Clinical Trial. In connection therewith, Prothena shall provide regular updates to Celgene at JSC meetings in accordance with Section 4.2, together with all material data and information in Prothena’s and its Affiliates’ possession
relating to such Development Candidates for such Program and the applicable Collaboration Target. 
 (c)    To the
extent that Prothena, at its discretion, conducts a Program, Prothena shall be responsible for the Manufacture of Collaboration Candidates and Collaboration Products for use in such Program, and the associated costs, in connection therewith. 

(d)    If Prothena conducts Development activities under the Collaboration, Prothena may provide to Celgene a Research
Plan, if any, and any updates thereto promptly after any modifications to a Research Plan are made; provided that activities conducted with respect to each separate Collaboration Target shall be considered as separate Program under a Research Plan.
For the avoidance of doubt, if any Development activities are undertaken by or on behalf of Prothena or its Affiliates for a given Collaboration Target, or for Antibodies that Target a given Collaboration Target, then such activities shall be deemed
to be undertaken under the Program for such Collaboration Target pursuant to this Agreement (and such Antibodies shall be deemed to be “Collaboration Candidates” for such Program), even if such activities are not included in a Research
Plan. Prothena shall be responsible for research strategy and the conduct of activities under any Research Plan during the Research Term. 

(e)    For the avoidance of doubt, (i) each Collaboration Target shall only be the subject of a single Program and
(ii) each Program shall only include activities conducted with respect to one Collaboration Target. 

2.2.2    Discovery Portion. 

(a)    Collaboration Candidate Research. During the Research Term, Prothena shall notify Celgene, on a regular
basis at JSC meetings, of Collaboration Candidates identified by or on behalf of Prothena or its Affiliates in the course of its ongoing research activities pursuant to a Program, as well as any material developments or new material data or
information relating to previously identified Collaboration Candidates. The identity of such Collaboration Candidates shall be included in the minutes of the JSC meeting. 

(b)    Lead Candidate Designation. During the Research Term, Prothena shall notify Celgene, on a regular basis at
JSC meetings, of Collaboration Candidates identified by or on behalf of Prothena or its Affiliates in the course of its ongoing research activities pursuant to a Program that satisfies the Lead Candidate Criteria, as well as notify Celgene with
respect to material developments or new data or information in Prothena’s (or its Affiliates’) possession relating to such Lead Candidates. The identity of such Lead Candidates shall be included in the

  
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minutes of the JSC meeting. The Lead Candidate Criteria for the Collaboration Target described in Section 1.16(i) (i.e., Tau) shall be determined by the JSC within [***] ([***]) days after
the Effective Date, and for each other Collaboration Target, at such time as the JSC agrees, but in no event later than [***] of the Effective Date. The Lead Candidate Criteria for each Collaboration Target may be amended from time to time by the
JSC. For clarity, there may be more than one Lead Candidate for a given Program. 
 (c)    IND Filing. Subject
to Section 2.6, Prothena shall provide to Celgene (i) at least [***] ([***]) days prior to the expected filing of an IND for a particular Lead Candidate, [***], and a copy of the proposed draft IND, and Prothena shall consider in good
faith any comments of Celgene with respect thereto, (ii) a final copy of the IND within [***] ([***]) days after filing the IND, and (iii) any communications to and from any Regulatory Authority with respect to such IND promptly following
receipt or submission of such communications, as applicable. Prothena shall not (and Prothena shall ensure that its Affiliates do not) file any INDs with respect to any Collaboration Candidates under any Program other than Lead Candidates. 

(d)    IND Data Package. Within [***] ([***]) days after Filing of the first IND with the FDA for a Lead Candidate
from a given Program ([***]), Prothena shall provide to Celgene (or a Third Party advisor designated by Celgene) the IND Data Package for such Program (which, for clarity, shall specify all then-existing Lead Candidates from such Program). If
Celgene designates a Third Party advisor to receive the IND Data Package, such Third Party advisor shall, prior to receiving such IND Data Package, be bound by confidentiality obligations and restrictions on use consistent with those set forth in
Article 8. Upon receipt of the complete IND Data Package, Celgene (or its designee) shall review such IND Data Package, and Celgene (or its designee) shall notify Prothena, no later than [***] ([***]) days after receiving such IND Data
Package, of [***]. If [***], the IND Option Term with respect to such Program shall [***]. 
 2.2.3    Phase 1
Development Portion. 
 (a)    Conduct of Phase 1 Clinical Studies. In the event that Celgene exercises its
IND Option for a given Program, then (i) the Phase 1 Development Portion of the Collaboration may commence with respect to the Development Candidates from such Program, (ii) Prothena may commence one or more Phase 1 Clinical Trials for
such Program, and (iii) Prothena may update a Research Plan for such activities. Subject to Section 2.5, Prothena shall be responsible for the clinical strategy and conduct of such Phase 1 Clinical Trials. For the avoidance of doubt, if
Celgene has exercised its IND Option for a given Program, the Phase 1 Development Portion of the Collaboration with respect to such Program may continue beyond the end of the Research Term until delivery of the Phase 1 Data Package for such Program.

 (b)    Phase 1 Data Package. If a Phase 1 Clinical Trial is conducted for a Development Candidate in a given
Program, within [***] ([***]) days after Data Lock for the applicable Clinical Trial ([***]), Prothena shall provide to Celgene (or a Third Party advisor designated by Celgene) the Phase 1 Data Package for such Program. If Celgene designates a Third
Party advisor to receive the Phase 1 Data Package, such Third Party advisor shall, prior to receiving such Phase 1 Data Package, be bound by confidentiality obligations and restrictions on use consistent with those set forth in Article 8. Upon
receipt of the complete Phase 1 Data Package, Celgene (or its designee) shall review such Phase 1 Data Package, and Celgene (or its designee) 

  
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shall, no later than [***] ([***]) days after receiving such Phase 1 Data Package, notify Prothena of [***]. If [***], the Phase 1 Option Term with respect to such Program shall [***]. For the
avoidance of doubt, with respect to a given Program, during the period from the end of the End of Phase 1 Date until the end of the Phase 1 Option Period for such Program, no further activities shall be conducted by or on behalf of Prothena with
respect to such Program (including the Collaboration Target, Collaboration Candidates or Collaboration Product thereunder), unless agreed to by Celgene in writing (such agreement not to be unreasonably withheld). 

(c)    Final Study Report. As soon as possible, but in all cases within [***] ([***]) months after Data Lock for
the applicable Clinical Trial, Prothena shall provide to Celgene (or a Third Party advisor designated by Celgene) the final study report for the Phase 1 Clinical Trial for such Program (which shall be prepared in accordance with customary practice
that meets the standards of ICH Topic E3 of ICH Guidelines for Structure and Content of Clinical Study Reports dated July 1996). 

2.2.4    Costs. Prothena shall be solely responsible for any and all costs and expenses in connection with the
performance, in its discretion, of any Program, except for any activities undertaken by Celgene pursuant to Section 2.5 for such Program. 

2.2.5    Records; Results. 

(a)    Prothena (with respect to all Development and Manufacturing activities conducted by or on behalf of it hereunder)
and, if Celgene conducts a Phase 1 Clinical Trial pursuant to Section 2.5 under a Program, Celgene (with respect to such Phase 1 Clinical Trial conducted pursuant to Section 2.5) shall maintain (and shall cause their Affiliates to
maintain) complete, current and accurate records of all such activities, and all data and other information resulting from such activities, and such Party shall retain the same for a period of no less than [***] ([***]) years from their creation (or
such longer period of time as may be required by Applicable Law). Such records shall fully and properly reflect all work done and results achieved in the performance of such activities in good scientific manner appropriate for regulatory and patent
purposes, and shall be prepared and maintained in accordance with Applicable Law, including, as applicable, ICH GCP, GLP and GMP record keeping requirements where applicable. Prothena (with respect to all studies, including Clinical Trials and all IND-enabling studies, conducted by or on behalf of it hereunder) and, if Celgene conducts a Phase 1 Clinical Trial pursuant to Section 2.5 under a Program, Celgene (with respect to such Phase 1 Clinical Trial
conducted pursuant to Section 2.5) shall document such studies in formal written study records according to Applicable Laws, including national and international guidelines such as, to the extent applicable, ICH, GCP, GLP and GMP. Each Party
shall have the right to review and copy such records as reasonably requested by such Party. 
 (b)    At least [***]
([***]) Business Days in advance of each JSC meeting, (i) Prothena shall provide the JSC written progress reports on the status of any activities undertaken by or on behalf of Prothena under each Program including (a) the identification of
any Collaboration Candidates and potential Lead Candidates and Development Candidates, and (b) reasonably detailed summaries of data associated with the activities with respect to each Program and (ii) if Celgene conducts a Phase 1
Clinical Trial pursuant to Section 2.5 under a Program, Celgene shall provide the JSC written progress report on the status of any activities undertaken 

  
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with respect to such Phase 1 Clinical Trial conducted pursuant to Section 2.5, including reasonably detailed summaries of data associated with the activities with respect to such Phase 1
Clinical Trial. In addition, in furtherance of the Collaboration, Prothena shall provide Celgene such other data and information regarding the Programs, the Collaboration Targets and Collaboration Candidates as Celgene may reasonably request. 

2.2.6    Activities Under Collaboration. Prothena may (in its discretion) conduct (or have conducted) Development
activities during the Research Term for Antibodies that Target a Collaboration Target only pursuant to a Program under this Agreement, and subject to Celgene’s Options hereunder. 

2.3    Research Term Extension. 

2.3.1    Extension by Celgene. Celgene shall have the right, in its sole discretion, to extend the Research Term for
an additional twelve (12) months from the end of the Initial Research Term (the Initial Research Term as extended by such additional twelve (12) month period, the “First Extended Research Term”) by providing Prothena with
written notice of such election no later than [***] ([***]) days prior to the end of the Initial Research Term and by paying Prothena an extension fee of Ten Million Dollars ($10,000,000) within [***] ([***]) days after delivery of such notice. 

2.3.2    Additional Extension by Celgene. In the event that Celgene exercises its extension right pursuant to
Section 2.3.1, then Celgene shall have the additional right, in its sole discretion, to extend the Research Term for an additional twelve (12) months from the end of the First Extended Research Term (for a total of twenty-four
(24) months beyond the Initial Research Term) by providing Prothena with written notice of such election no later than [***] ([***]) days prior to the end of the First Extended Research Term and by paying Prothena an extension fee of Ten
Million Dollars ($10,000,000) within [***] ([***]) days after delivery of such notice. 
 2.3.3    Extension by
Mutual Agreement. Without limiting Celgene’s rights under Section 2.3.1 and 2.3.2, the Parties may mutually agree in writing (in each Party’s discretion) to extend the Research Term. In such case, the Parties shall agree to the
specific period of time that the Research Term will be extended. 
 2.4    Disputes Regarding Antibodies and Lead
Candidates. 
 2.4.1    Antibodies. If [***] during the Research Term either Party has a
reasonable belief that an Antibody that is being researched or Developed by or on behalf of Prothena (or its Affiliates) Targets a given Collaboration Target, and wishes to confirm whether or not such Antibody Targets such Collaboration Target, then
either Party may issue a notice to the other Party with respect thereto (a “Confirmation Notice”). The Parties shall discuss in good faith for a period of [***] ([***]) days whether or not such Antibody Targets the applicable
Collaboration Target. In the event that the Parties do not agree in writing within such [***] ([***]) day period whether or not such Antibody Targets the applicable Collaboration Target, either Party may issue a written notice to the other Party
requesting the independent evaluation described in Section 2.4.3. [***] 

  
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 2.4.2    Lead Candidates. If during the Research Term either
Party wishes to determine whether or not a given Collaboration Candidate satisfies the Lead Candidate Criteria, then either Party may issue a notice to the other Party with respect thereto. The Parties shall discuss in good faith for a period of
[***] ([***]) days whether or not such Collaboration Candidate satisfies the Lead Candidate Criteria. In the event that the Parties do not agree in writing within such [***] ([***]) day period whether or not such Collaboration Candidate satisfies
the Lead Candidate Criteria, either Party may issue a written notice to the other Party requesting the independent evaluation described in Section 2.4.3. [***] 

2.4.3    Scientific Panel. In the event that either of the Parties wishes to have a panel of three Qualified
Scientists appointed as provided in this Section 2.4 (each such panel of three Qualified Scientists, a “Scientific Panel”) to determine whether or not (i) a given Antibody that is being Developed by or on behalf of
Prothena (or its Affiliates) Targets a given Collaboration Target or (ii) a given Collaboration Candidate satisfies the Lead Candidate Criteria, then in each such case the Parties agree to the procedure as provided in this Section 2.4.3.
Within [***] ([***]) days following any such request for a Scientific Panel, [***] shall [***] and, if [***]. Each Scientific Panel shall act as follows: (1) [***]; (2) [***]; and (3) [***]. The Scientific Panel shall [***]. The [***] shall be
[***]. For purposes of this Agreement, “Qualified Scientist” shall mean any scientist (A) [***], and (B) [***]. Notwithstanding the foregoing, in no event shall a Party be entitled to request that a Scientific Panel review any
specific matter for which a Scientific Panel has previously rendered a decision. 
 2.5    Celgene Phase 1 Portion
Participation Right. 
 2.5.1    Phase 1 Portion Participation Right. 

(a)    At the final meeting of the JSC prior to expiration of the Term (but in any case at least [***] ([***]) days prior
to expiration of the Term) or at any time prior thereto at the written request of Celgene from time to time, with respect to any Programs for which Celgene has exercised its IND Option but for which the Phase 1 Option Term has not yet
expired, Prothena shall (a) prepare and provide to Celgene a written list setting forth the Collaboration Target under any such Program and all Lead Candidates and Development Candidates that Target the Collaboration Target under the applicable
Program, (b) prepare and provide to Celgene a summary of the status of the Development activities under any such Program and (c) provide to Celgene all available data and information then in Prothena’s (or its Affiliates’)
Control related to the Collaboration Target, Lead Candidates and/or Development Candidates under any such Program, including a summary of [***] as well as the status of and information related to any Phase 1 Clinical Trial. Upon request by Celgene
the Parties shall promptly meet to discuss each such Collaboration Target (including the Lead Candidates and Development Candidates under the applicable Program) and data and information relating thereto as provided to Celgene pursuant to this
Section 2.5.1(a). 
 (b)    Following exercise of its IND Option for a given Program, Celgene shall have the
right, at its discretion upon written notice to Prothena, to take over such Program (as and to the extent determined by Celgene, on a Program-by-Program basis) to
continue the Development of Collaboration Candidates and Collaboration Products under such Program to completion of the Phase 1 Clinical Trial (the “Celgene Phase 1 Portion Participation Right”).

  
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If Celgene decides to take over such Program, then in the event that any Phase 1 Clinical Trial has been commenced by or on behalf of Prothena as of the time Celgene exercises its Celgene Phase 1
Portion Participation Right, the Parties will coordinate in good faith the conduct of such Phase 1 Clinical Trial, which may include, at Celgene’s written request, the transition of the conduct of such Phase 1 Clinical Trial to Celgene or
wind-down of such Phase 1 Clinical Trial (in accordance with Applicable Law and ethical standards applicable to such Phase 1 Clinical Trial). In the event that Celgene exercises its Celgene Phase 1 Portion Participation Right with respect to one or
more Programs, then the following shall apply: 
 (i)    Prothena shall transition such Program to Celgene (or its
designee) as and to the extent reasonably requested by Celgene, including by providing to Celgene (or its designee) all Program Biological and Chemical Materials necessary [***] for Celgene to continue activities under such Program to completion of
the Phase 1 Clinical Trial for such Program, as well as providing access to the physical embodiments of all Prothena IP, that is necessary [***] for Celgene to continue such activities under such Program; 

(ii)    except as otherwise directed by Celgene, and subject to completion of the transfer to Celgene of the Program
Regulatory Materials pursuant to Section 2.6.1(b) and the safety database and other safety information pursuant to Section 2.6.3, Prothena shall reasonably promptly wind-down and cease activities under such Program; 

(iii)    Subject to the terms and conditions of this Agreement, Prothena shall grant, and hereby does grant to Celgene, a
non-exclusive, worldwide, fully paid-up, royalty-free right and license, with the right to grant sublicenses (through multiple tiers), under the Prothena IP solely to
Develop Collaboration Candidates and Collaboration Products under such Program to completion of a Phase 1 Clinical Trial for such Collaboration Candidates and Collaboration Products. 

(iv)    Prothena shall use reasonable efforts to supply to Celgene ([***]), or if Prothena is not manufacturing ([***])
Collaboration Product to cooperate with Celgene [***] supply of, Collaboration Product for Celgene’s conduct of the Phase 1 Clinical Trial for such Program; 

(v)    all matters related to such Program shall continue to be within the purview of the JSC or any Subcommittee until
such time as Celgene exercises its Phase 1 Option for such Program provided that [***]; 
 (vi)    Celgene shall be
solely responsible for any costs incurred by it (or its Affiliates) in its conduct of any Phase 1 Clinical Trial pursuant to the Celgene Phase 1 Portion Participation Right; and 

(vii)    Celgene shall use Commercially Reasonable Efforts to commence and conduct such Phase 1 Clinical Trial; 

(viii)    the provisions of Section 3.2 shall apply, mutatis mutandis, as applicable. 

  
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 (c)    In the event that Celgene exercises its Celgene Phase 1 Portion
Participation Right for a given Program, at the request of either Party, the Parties shall negotiate in good faith and enter into an appropriate agreement to document the rights granted to Celgene pursuant to this Section 2.5.1. 

(d)    In the event that Prothena determines to abandon or cease a given Program during the Phase 1 Development Portion,
then Prothena shall notify Celgene thereof in writing (and Prothena shall not abandon or cease such Program for a period of [***] ([***]) days thereafter), and if Celgene thereafter notifies Prothena in writing within [***] ([***]) days of receipt
by it of Prothena’s notice that Celgene intends to exercise its Celgene Phase 1 Portion Participation Right for such Program, then the provisions of this Section 2.5.1 shall apply with respect to such Program, mutatis mutandis. 

2.5.2    Phase 1 Option. In the event that (i) Celgene exercises its Celgene Phase 1 Portion Participation
Right for a given Program, and (ii) Celgene completes a Phase 1 Clinical Trial with respect to a Lead Candidate from such Program, then Celgene shall notify Prothena of Data Lock for such Phase 1 Clinical Trial and Prothena shall provide a
Phase 1 Data Package to Celgene for such Program within [***] ([***]) days after the Data Lock for such Phase 1 Clinical Trial in accordance with this Agreement (provided that, for clarity, Prothena shall not be required to include in the Phase 1
Data Package any Phase 1 Data generated by Celgene in the performance of such Phase 1 Clinical Trial). Celgene shall have the right to exercise its Phase 1 Option with respect to such Program as set forth in Article 3 (including entering into a
Global License Agreement for such Program with Prothena), with the date that Prothena so delivers the complete Phase 1 Data Package for such Program being deemed be the End of Phase 1 Date for such Program, and the provisions of Article 3 shall
apply in connection therewith, mutatis mutandis. For the avoidance of doubt, no additional amounts shall be payable by Celgene upon exercise by Celgene of the Celgene Phase 1 Portion Participation Right, and the Phase 1 Option Exercise Fee
shall only be payable if, and when, Celgene determines to exercise its Phase 1 Option for such Program as set forth in Article 3. 

2.5.3    Data and other Know-How. For clarity, the data and other Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to practice, in each case, [***], and all intellectual property rights therein, shall, as between the Parties,
be owned by Celgene (“Celgene Phase 1 Know-How”), and [***]. 

2.5.4    Continuation of Agreement. In the event that Celgene exercises its Celgene Phase 1 Portion Participation
Right under this Section 2.5 with respect to one or more Programs, then, unless this Agreement is otherwise terminated in accordance with Article 11, the Term shall continue with respect to the applicable Programs until the end of the Phase 1
Option Term for such Program (“Participation Term Extension”) and the provisions of this Agreement shall continue with respect to the applicable Programs during the Participation Term Extension to allow Celgene to exercise
its rights as set forth in this Section 2.5 (including the terms related to Celgene’s Options in connection with such Program). Notwithstanding the foregoing, if the Parties enter into a Global License Agreement for a given Program, then
the Participation Term Extension for such Program shall automatically end and this Agreement shall no longer apply with respect to such Program (except as otherwise expressly set forth herein). If the Participation Term Extension extends beyond the
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Section 5.1 shall continue to apply for the duration of the Participation Extension Term, but solely with respect to the Collaboration Target that is the subject of the Program(s) for which
Celgene exercised its rights under this Section 2.5. 
 2.6    Regulatory Responsibilities. 

2.6.1    Regulatory Materials. 

(a)    On a Program-by-Program basis,
commencing on the Effective Date until the Regulatory Transfer Date, Prothena shall have the right, in consultation with Celgene, to prepare, file and maintain all Regulatory Materials (including any Regulatory Approvals) necessary for the
Development and Manufacture of any Collaboration Candidates and Collaboration Products for such Program (collectively, the “Program Regulatory Materials”), and to interact with Regulatory Authorities in connection with the
Development and Manufacture of any Collaboration Candidates and Collaboration Products for such Program. Prothena will provide Celgene with a reasonable opportunity to comment substantively on all material Regulatory Materials prior to filing or
taking material action, and will reasonably and in good faith consider any comments and actions recommended by Celgene, including with respect to filing strategy. In addition, Prothena will allow Celgene or its representative to attend any and all
meetings with Regulatory Authorities to the extent such attendance is not prohibited or limited by such Regulatory Authority. 

(b)    If Celgene exercises its Phase 1 Portion Participation Right for a given Program, then immediately after such
exercise, Prothena shall initiate the transfer of all Program Regulatory Materials, including for clarity any IND for the relevant Collaboration Candidates and/or Collaboration Products that are the subject of such Program to Celgene. The
date on which such Program Regulatory Materials are transferred to Celgene shall be the “Regulatory Transfer Date” for such Program. Thereafter, Celgene shall have the right, in consultation with Prothena, to prepare, file, and
maintain such Program Regulatory Materials, and to interact with Regulatory Authorities in connection with the Development and, as applicable, Manufacture of such Collaboration Candidates and Collaboration Products for such Program in accordance
with the terms and conditions of Section 2.5. Additionally, with respect to any Phase 1 Clinical Trial conducted by Celgene pursuant to Section 2.5, Celgene will provide Prothena with a reasonable opportunity to comment substantively on
all material Program Regulatory Materials prior to filing or taking material action, and will reasonably and in good faith consider any comments and actions recommended by Prothena, including with respect to filing strategy. In addition, with
respect to any Phase 1 Clinical Trial conducted by Celgene pursuant to Section 2.5, Celgene will allow Prothena or its representative to attend any and all meetings with Regulatory Authorities to the extent such attendance is not prohibited or
limited by such Regulatory Authority. For clarity, if the Regulatory Transfer Date does not occur prior to the expiration of the Option Term for such Program, Section 2.6.1(a) (and not this Section 2.6.1(b)) shall apply. 

2.6.2    Right of Reference. On a
Program-by-Program basis, Celgene (and its designees) shall have, and Prothena (on behalf of itself and its Affiliates) hereby grants to Celgene (and its designees),
access and a right of reference (without any further action required on the part of Prothena or its Affiliates, whose authorization to file this consent with any Regulatory Authority is hereby granted) to all Regulatory Materials (including any
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to Collaboration Candidates or Collaboration Products, and all data contained or referenced in any such Regulatory Materials (including any Regulatory Approvals), for Celgene (and its designees)
solely to the extent necessary for Celgene to exercise its rights and perform hereunder. 
 2.6.3    Safety
Information. On a Program-by-Program basis, commencing on the Effective Date until the expiration of the Option Term for such Program, Prothena shall be responsible
for reporting, in accordance with Applicable Law, all safety information to Regulatory Authorities with respect to the Programs (unless Celgene exercises its Celgene Phase 1 Portion Participation Right pursuant to Section 2.5.1, in which case
Celgene shall be so responsible with respect to any Phase 1 Clinical Trial conducted pursuant to Section 2.5). Prothena (or Celgene, if it exercises its Phase 1 Portion Participation Right, with respect to any conduct of the Phase 1 Clinical
Trial pursuant to Section 2.5) shall, to the extent permitted by Applicable Law, (a) promptly provide the other Party with all safety information related to serious adverse events (as defined and within the time periods required under the
relevant Clinical Trial protocol, if applicable) [***] and (b) provide the other Party with all other information concerning the pharmaceutical safety of each Lead Candidate at least once per [***]. 

2.6.4    License Agreement. In the event that a U.S. License Agreement (but no Global License Agreement) is entered
into with respect to a given Program, then the provisions of such U.S. License Agreement shall control with respect to regulatory responsibilities with respect to such Program in the United States. In the event that a Global License Agreement is
entered into with respect to a given Program, then the provisions of such Global License Agreement shall control with respect to regulatory responsibilities with respect to such Program worldwide. 

2.7    Subcontracting. Subject to the terms of this Agreement, each Party shall have the right to engage Affiliates
or Third Party subcontractors to perform its obligations under this Agreement. Such Party shall ensure that any such Affiliate or subcontractor shall [***] and shall perform such work consistent with the terms of this Agreement; provided, however,
that any Party engaging an Affiliate or a Third Party subcontractor hereunder shall remain fully responsible and obligated for such activities. In addition, to the extent a Party engages an Affiliate or a Third Party subcontractor to perform any
activities under a Program, such Party shall in all cases (i) [***]; provided that if (a) [***] and (b) [***], then [***]; and (ii) with respect to [***], obtain Control of any and all other Know-How and
Patent Rights which are otherwise used in the performance of such activities, as more particularly described in Section 7.6. The Party engaging an Affiliate or Third Party subcontractor shall ensure that such Affiliate or Third Party
subcontractor, as applicable, complies with all applicable provisions of this Agreement, including Sections 2.2.5, 2.8, 2.10, 7.6 and Article 8 (the “Subcontracting Essential Provisions”). Without limiting the foregoing, prior to
subcontracting to any subcontractor for the performance of any portion of a Program, each Party shall (i) notify the other Party in writing thereof, and (ii) have entered into a written agreement with such subcontractor that complies with
the terms and conditions of this Agreement, including the Subcontracting Essential Provisions (and such Party shall, upon the other Party’s request, provide a true, correct and complete copy of each agreement promptly after such agreement is
entered into; provided that such agreement may be redacted to the extent not related to the Program). Each Party hereby expressly waives any requirement that the other Party exhaust any right, power or remedy, or proceed against any subcontractor
for any obligation or performance hereunder, prior to proceeding directly against such Party with respect to any failure of such Party to perform its obligations under this Agreement through such subcontractor. 

  
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treatment has been requested with respect to the omitted portions. 

 2.8    Audit. Celgene shall have the right, at its own cost, to
audit and inspect the activities conducted by or on behalf of Prothena under the applicable Programs and, if Celgene exercises its Celgene Phase 1 Portion Participation Right with respect to a given Program, Prothena shall have the right, at its own
cost, to audit and inspect the activities conducted by or on behalf of Celgene with respect to the Phase 1 Clinical Trial conducted pursuant to Section 2.5 for such Program, which, in each case, shall include the right to access records and
facilities as reasonably requested by the auditing Party (and in any event on not less than [***] ([***]) days’ notice) to confirm compliance with the requirements of, and performance under, this Agreement. Such audit and inspection shall not
be performed more than [***] and shall be reasonably coordinated in advance between the Parties. 
 2.9    Material
Transfer. 
 2.9.1    Transfer. On a
Program-by-Program basis, commencing on the Effective Date until the expiration of the Research Term (or expiration of the Option Term for such Program, if later),
Prothena shall transfer to Celgene certain biological or chemical materials (including Patient Samples) created or utilized hereunder, including reasonably sufficient quantities of any Collaboration Candidates and Collaboration Products (the
“Transferred Prothena Materials”), in each case, that are reasonably requested by Celgene to the extent necessary or reasonably useful for the following purposes (the “Permitted Celgene Purposes”): (i) to
determine whether a given Collaboration Candidate may be a Lead Candidate pursuant to Section 2.2.2(b), (ii) to evaluate whether to exercise its Options with respect to such Program, (iii) [***] and (iv) for such other purposes as may be
agreed to by the Parties in writing. Celgene shall be the “Material Receiving Party” and Prothena shall be the “Transferring Party” for the Transferred Prothena Materials. For the avoidance of doubt, this
Section 2.9.1 shall not apply to any transfers of materials or data as part of Celgene’s exercise of its Celgene Phase 1 Portion Participation Right (or otherwise under any U.S. License Agreement or Global License Agreement). All transfers
of such Transferred Prothena Materials by the Transferring Party to the Material Receiving Party shall be documented in a material transfer agreement in a form to be agreed upon in good faith by the Parties, which agreement shall contain customary
material transfer agreement provisions contained in agreements for the transfer of similar materials in the pharmaceutical industry or otherwise as necessary to comply with obligations to Third Parties (if applicable), and shall set forth the type
and name of the Transferred Prothena Material transferred, the amount of the Transferred Prothena Material transferred and the date of the transfer of such Transferred Prothena Material (each, a “Collaboration Material Transfer
Agreement”). The Material Receiving Party shall only use the Transferred Prothena Materials provided pursuant to this Section 2.9.1 for the Permitted Celgene Purposes and the Material Receiving Party agrees that such Transferred
Prothena Materials shall be used in compliance with Applicable Law and the terms and conditions of the material transfer agreement and this Agreement. The data that is generated by the Material Receiving Party pursuant to the Permitted Celgene
Purposes under this Section 2.9.1 shall be deemed to be Program Know How; provided that Prothena shall grant, and hereby does grant, to Celgene a fully-paid up, royalty-free, worldwide, nonexclusive license (with the right to grant sublicenses
through multiple tiers) to use such Program Know-How for [***]. 

2.9.2    License; Ownership. At the time the Transferring Party provides the Transferred Prothena Materials to the
Material Receiving Party as provided herein and to the extent not separately licensed under this Agreement, subject to the terms and conditions of this 

  
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Agreement, the Transferring Party shall grant, and hereby grants, to the Material Receiving Party a non-exclusive license under the Patents and Know-How Controlled by the Transferring Party necessary to use such Transferred Prothena Materials solely for the Purposes. Except as otherwise provided under this Agreement (or a U.S. License Agreement or Global
License Agreement, as applicable), all such Transferred Prothena Materials delivered by the Transferring Party to the Material Receiving Party shall remain the sole property of the Transferring Party, shall only be used by the Material Receiving
Party in furtherance of the Purposes, and, subject to Article 11, shall be returned to the Transferring Party or destroyed, in the Transferring Party’s sole discretion, upon the earliest of (i) termination of this Agreement,
(ii) completion of the Purposes, or (iii) discontinuation of the use of such Transferred Prothena Materials by the Material Receiving Party. With respect to Transferred Prothena Materials transferred pursuant to Section 2.9.1, the
Material Receiving Party shall cause the Transferred Prothena Materials not to be delivered to any Third Party without the prior written consent of the Transferring Party unless such Third Party is a Third Party subcontractor as set forth in
Section 2.7. 
 2.10    Compliance Provisions. With respect to any activities conducted by or on behalf of a
Party under this Agreement, the following shall apply: 
 2.10.1    General. To the extent that activities are
conducted by or on behalf of a Party or its Affiliates pursuant to this Agreement, including all Development and Manufacturing of Collaboration Candidates and Collaboration Products, such Party shall [***] that such activities are conducted in
compliance with all Applicable Laws (including, to the extent applicable, GCP, GLP and GMP), and good business ethics, and such Party will promptly notify the other Party in writing after it becomes aware of any deviations from any of the foregoing.
In addition, each Party hereby certifies that it has not employed or otherwise used in any capacity, and will not employ or otherwise use in any capacity, the services of any Person (i) debarred under United States law (including
Section 21 USC 335a) or any foreign equivalent thereof or (ii) that is the subject of an FDA debarment investigation or proceeding (or similar proceeding by any Regulatory Authority outside the United States), in each case, in performing
any portion of the activities hereunder, including any Development and Manufacturing of Collaboration Candidates and Collaboration Products. Each Party will notify the other Party in writing immediately if any such debarment occurs or comes to its
attention, and will, with respect to any person or entity so debarred promptly remove such person or entity from performing any such activities, function or capacity related to any such activities. 

2.10.2    Governments and International Public Organizations. Neither Party will make any payment (and each Party
shall ensure that its Affiliates and subcontractors do not make any payment), either directly or indirectly, of money or other assets, including any compensation such Party derives from this Agreement (hereinafter collectively referred to as a
“Payment”), to government or political party officials, officials of international public organizations, candidates for public office, or representatives of other businesses or persons acting on behalf of any of the foregoing
(hereinafter collectively referred to as “Officials”) where such Payment would constitute a violation of any Applicable Law. In addition, regardless of legality, neither Party will make any Payment (and will ensure that its
Affiliates and subcontractors make no payment), either directly or indirectly to Officials if such Payment is for the purpose of influencing decisions or actions with respect to the subject matter of this Agreement or any other aspect of a
Party’s business. 

  
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treatment has been requested with respect to the omitted portions. 

 2.10.3    No Authority. Each Party acknowledges that no employee
of the other Party or its Affiliates will have authority to give any direction, either written or oral, relating to the making of any commitment by such Party or its agents to any Third Party in violation of terms of this or any other provisions of
this Agreement. 
 2.10.4    Exclusions Lists. Prothena, and Celgene if it conducts any Development under this
Agreement pursuant to Section 2.5, will not use (and will cause its Affiliates and subcontractors not to use) in the performance of the Program any Person (including any employee, officer, director or Third Party contractor) who is (or has
been) on the Exclusions List, or who is (or has been) in Violation, in the performance of any activities hereunder. [***] After the execution of this Agreement, Prothena, and Celgene if it conducts any Development under this Agreement pursuant to
Section 2.5, will notify the other Party in writing immediately if any such Violation occurs or comes to its attention. 

2.10.5    Personal Data. Prothena, and Celgene if it conducts any Development under this Agreement pursuant to
Section 2.5, shall ensure that all Personal Data is processed in accordance with Applicable Laws, including the fair and lawful collection and processing of such Personal Data, the disclosure of such Personal Data to Celgene in accordance with
this Agreement and the transfer of such Personal Data (including any transfer from inside the EEA to outside the EEA). Prothena, and Celgene if it conducts any Development under this Agreement pursuant to Section 2.5, shall promptly notify the
other Party if it becomes aware that any data provided to the other Party is inaccurate or has been unlawfully obtained or processed or, where consent to process Personal Data has been provided, consent is withdrawn or such Party becomes aware that
consent may not be reliable. 
 2.11    Global License Agreement. Notwithstanding the foregoing provisions of
this Article 2, if a Global License Agreement is entered into with respect to a given Program, then, except as otherwise expressly set forth in such Global License Agreement, Prothena’s conduct of the Program hereunder shall cease, and the
provisions of such Global License Agreement shall control with respect to such Program. 
 ARTICLE 3 

OPTIONS 

3.1    Option Grant. Subject to the terms and conditions of this Agreement, on a Program-by-Program basis, Prothena hereby grants to Celgene the following exclusive options (each, an “Option”): 

3.1.1    IND Option. Prothena hereby grants to Celgene an exclusive Option, exercisable at any time during the
applicable IND Option Term, in Celgene’s sole discretion, to enter into a U.S. License Agreement with respect to such Program (including all applicable Collaboration Candidates and Collaboration Products thereunder) on the terms and conditions
set forth in the U.S. License Agreement (the Option pursuant to this Section 3.1.1 for a given Program, the “IND Option”). For the avoidance of doubt, (i) Celgene shall not be required to exercise any IND Option, even if
an IND is Filed for such Program and (ii) if Celgene determines to exercise its IND Option for a given Program, Celgene shall only be required to exercise its IND Option for a given Program one (1) time (and shall only be required to pay
the IND Option Exercise Fee for 

  
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such Program one (1) time) regardless of the number of Collaboration Candidates, Lead Candidates and Development Candidates under such Program. Prothena acknowledges and agrees that all IND
Options granted by Prothena to Celgene as set forth herein will be granted by Prothena exclusively to Celgene until the end of the applicable IND Option Term, and Prothena shall not (and shall procure that its Affiliates do not) grant any options
(or other rights) to any other Person that would conflict with or are inconsistent with the IND Options granted to Celgene hereunder. 

3.1.2    Phase 1 Option. In the event that Celgene exercises its IND Option for a given Program, Prothena hereby
grants to Celgene an exclusive Option, exercisable at any time during the applicable Phase 1 Option Term, in Celgene’s sole discretion, to enter into a Global License Agreement with respect to such Program (including all applicable
Collaboration Candidates and Collaboration Products thereunder) on the terms and conditions set forth in the Global License Agreement (the Option pursuant to this Section 3.1.2 for a given Program, the “Phase 1 Option”). For
the avoidance of doubt, (i) Celgene shall not be required to exercise any Phase 1 Option, even if a Phase 1 Clinical Trial is completed for such Program and (ii) if Celgene determines to exercise its Phase 1 Option for a given Program,
Celgene shall only be required to exercise its Phase 1 Option for a given Program one (1) time (and shall only be required to pay the Phase 1 Option Exercise Fee for such Program one (1) time) regardless of the number of Collaboration
Candidates, Lead Candidates and Development Candidates under such Program. Prothena acknowledges and agrees that all Phase 1 Options granted by Prothena to Celgene as set forth herein will be granted by Prothena exclusively to Celgene until the end
of the applicable Phase 1 Option Term, and Prothena shall not (and shall procure that its Affiliates do not) grant any options (or other rights) to any other Person that would conflict with or are inconsistent with the Phase 1 Options granted to
Celgene hereunder. 
 3.1.3    Option Exercise. 

(a)    IND Option. On a
Program-by-Program basis, during the applicable IND Option Term, Celgene shall have the right, but not the obligation, to exercise the IND Option for such Program in its
sole discretion by delivering written notice of such exercise to Prothena prior to the end of the IND Option Term (the “IND Option Exercise Notice”). Within [***] ([***]) days following each IND Option Exercise Notice delivery, and
subject to Section 3.2, Celgene [***] and Prothena shall enter into a U.S. License Agreement with respect to such Program (including completing the exhibits and schedules thereto). On a Program-by-Program basis, if Celgene fails to provide its IND Option Exercise Notice before the expiration of the applicable IND Option Term, then (i) Celgene’s IND Option shall expire with respect
to such Program, and (ii) the Collaboration Target under such Program shall be deemed a “Lapsed Target” and shall thereafter be excluded from the definition of Collaboration Target. For the avoidance of doubt, if a
Collaboration Target becomes a “Lapsed Target” pursuant to this Section 3.1.3(a), then the licenses granted by Prothena pursuant to Section 7.1.1 with respect to such Lapsed Target and Collaboration Candidates and Collaboration
Products [***] Targeting such Lapsed Target [***] shall terminate, and subject to the rights and licenses granted to Celgene hereunder (and under any U.S. License Agreement and Global License Agreement), Prothena shall have the right to pursue,
outside of this Agreement, Development and Commercialization of Antibodies or other compounds that Target such Lapsed Target (but excluding, in all cases, the Development or Commercialization of any Antibodies that Target any remaining Collaboration
Target); provided that for clarity, the foregoing is not intended to be a grant to Prothena of any rights or licenses to any intellectual property of Celgene (or its Affiliates) or otherwise. 

  
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 (b)    Phase 1 Option. On a Program-by-Program basis, during the applicable Phase 1 Option Term, Celgene shall have the right, but not the obligation, to exercise the Phase 1 Option for such Program in its sole discretion by delivering
written notice of such exercise to Prothena prior to the end of the Phase 1 Option Term (the “Phase 1 Option Exercise Notice”). Within [***] ([***]) days following each Phase 1 Option Exercise Notice delivery, and subject to
Section 3.2, Celgene [***] and Prothena shall enter into a Global License Agreement with respect to such Program (including completing the exhibits and schedules thereto). On a
Program-by-Program basis, if Celgene fails to provide its Phase 1 Option Exercise Notice before the expiration of the applicable Phase 1 Option Term, then Celgene’s
Phase 1 Option shall expire with respect to such Program. For the avoidance of doubt, subject to the rights and licenses granted to Celgene hereunder (and under any U.S. License Agreement and Global License Agreement), Prothena shall have the right
to pursue, outside of this Agreement, Development and Commercialization of Antibodies or other compounds that Target the Collaboration Target in respect of which Celgene has not exercised its Phase 1 Option prior to the expiry of the
applicable Phase 1 Option Term (but excluding, in all cases, the Development or Commercialization of any Antibodies that Target any remaining Collaboration Target); provided that if a U.S. License Agreement relating to such Collaboration Target is
in force, all clinical Development and Commercialization activities must occur outside of the United States; and for clarity, the foregoing is not intended to be a grant to Prothena of any rights or licenses to any intellectual property of Celgene
(or its Affiliates) or otherwise. 
 (c)    Certain Remedies. Each Party agrees and acknowledges that if Celgene
exercises the applicable Option, then any failure of a Party to thereafter enter into the applicable U.S. License Agreement or Global License Agreement, as applicable, in accordance with this Section 3.1.3 would cause severe and irreparable
damage to the other Party, for which money damages may represent an insufficient remedy, and in such event, notwithstanding the provisions of Section 12.7, each Party shall be authorized and entitled to seek from any court of competent
jurisdiction specific performance with respect to such violation as well as any other relief permitted by Applicable Law, and may obtain that relief without making a showing of insufficiency of money damages or irreparable harm. Each Party agrees to
waive any requirement that the other Party post bond as a condition for obtaining any such relief. The remedies described in this Section 3.1.3(c) shall be in addition to any other remedies available to a Party hereunder or at law or in equity.

 3.1.4    Option Payments. The amounts payable by Celgene, if any, in connection with the exercise of an Option
for a given Program shall be as set forth in Section 6.3. 
 3.1.5    Covenant. 

(a)    No Conflicts. On a
Program-by-Program basis, commencing on the Effective Date until expiration of the Option Term for such Program, Prothena shall not, and shall cause its Affiliates not
to (a) assign, transfer, convey, encumber (through any liens, charges, security interests, mortgages, or similar actions) or dispose of, or enter into any agreement with any Third Party to assign, transfer, convey, encumber (through lien,
charge, security interest, 

  
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treatment has been requested with respect to the omitted portions. 

 
mortgage, or similar action) or dispose of, any [***] (collectively, the “Program Assets”), except to the extent such assignment, transfer, conveyance, encumbrance or disposition
would not conflict or be inconsistent with any of the rights or licenses granted to Celgene hereunder, including the Options, (b) license or grant to any Third Party, or agree to license or grant to any Third Party, any rights to any Program
Assets if such license or grant would conflict or be inconsistent with any of the rights or licenses granted to Celgene hereunder, including the Options, or (c) disclose any Confidential Information relating to the Program Assets to any Third
Party if such disclosure could reasonably be deemed to impair or conflict in any respect with any of the rights or licenses granted to Celgene hereunder, including the Options. During the Option Term for a given Program, Prothena shall maintain
Control of all [***] such that the foregoing are unencumbered and available to license to Celgene in accordance with this Agreement and, if applicable, any U.S. License Agreement and Global License Agreement. 

(b)    Ordinary Course of Business. Without limiting the provisions of Section 3.1.5(a), subject to the other
applicable terms and conditions of this Agreement, during the Option Term for a given Program, Prothena shall operate and maintain the Program Assets in the ordinary course of business, and in compliance with Applicable Law, including not
terminating, amending or otherwise modifying or permitting to be terminated, amended or modified, any agreements that license any Prothena Collaboration IP to Prothena (or its Affiliates) in any manner that would impair or conflict in any respect
with any of the rights or license granted to Celgene hereunder, including the Options. 
 3.1.6    Tax Matters.
Notwithstanding anything to the contrary in the Agreement, any U.S. License Agreement or Global License Agreement, including the use of the term “option” (or any derivation thereof), the Parties hereby agree and acknowledge that none of
the Options will be treated as options for US federal (or applicable state or local) income tax purposes, and the Parties agree not to take any position inconsistent with the foregoing. 

3.2    Government Approvals. 

3.2.1    Efforts. Each of Prothena and Celgene will use its commercially reasonable good faith efforts to eliminate
any concern on the part of any Governmental Authority regarding the legality of any proposed U.S. License Agreement or Global License Agreement under any Antitrust Law, including, if required by federal or state antitrust authorities, promptly
taking all steps to secure government antitrust clearance, including cooperating in good faith with any government investigation including the prompt production of documents and information demanded by a second request for documents and of witnesses
if requested. Notwithstanding the foregoing, this Section 3.2.1 and the term “commercially reasonable good faith efforts” do not require that either Party [***]. 

3.2.2    Filings. [***], each of Prothena and Celgene will, within [***] ([***]) [***] after the execution of a
U.S. License Agreement (or such later time as may be agreed to in writing by the Parties) or the execution of a Global License Agreement (or such later time as may be agreed to in writing by the Parties), as applicable, file with the U.S. Federal
Trade Commission (“FTC”) and the Antitrust Division of the U.S. Department of Justice (“DOJ”) any HSR Filing required of it under the HSR Act in the reasonable opinion of [***] with respect to the transactions
contemplated by such U.S. License Agreement or such Global License Agreement, as applicable, 

  
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as well as any other similar filing with any other Governmental Authority as reasonably determined by [***]. The Parties shall cooperate with one another to the extent necessary in the
preparation of any such HSR Filing (as well as any other similar filing with any other Governmental Authority as reasonably determined by [***]). Each Party shall be responsible for its own costs and expenses associated with any HSR Filing as well
as any other similar filing with any other Governmental Authority as reasonably determined by [***]. In the event that the Parties make an HSR Filing (or any other similar filing with any other Governmental Authority as reasonably determined by
[***]) under this Section 3.2.2, the relevant U.S. License Agreement or Global License Agreement, as applicable, shall terminate (i) at the election of [***], in the event that the FTC or DOJ (or other applicable Governmental Authority)
obtains a preliminary injunction under the HSR Act (or other applicable Antitrust Law) against the Parties to enjoin the transactions contemplated by such U.S. License Agreement or Global License Agreement, as applicable, or (ii) at the
election of [***], in the event that the Clearance Date shall not have occurred on or prior to [***] ([***]) [***] after the effective date of the HSR Filing (or other similar filing with any other Governmental Authority as reasonably determined by
[***]). Notwithstanding anything to the contrary contained herein, except for the terms and conditions of this Section 3.2.2, none of the terms and conditions (i) contained in the applicable U.S. License Agreement (including the obligation
of Celgene to make any payments thereunder), as well as the obligation of Celgene to pay the IND Option Exercise Fee hereunder or (ii) contained in the applicable Global License Agreement (including the obligation for Celgene to make any
payments thereunder), as well as the obligation of Celgene to pay the Phase 1 Option Exercise Fee hereunder), as applicable, shall be effective until the “Implementation Date,” which is agreed and understood to mean the later of
(A) the date of execution of the U.S. License Agreement or the date of execution date of the Global License Agreement, as applicable, or (B) if a determination is made by [***] pursuant to this Section 3.2.2 that a notification of the
U.S. License Agreement or the Global License Agreement, as applicable, is required to be made under the HSR Act (or any other similar filing with any other Governmental Authority as reasonably determined by [***]), the Clearance Date. As used
herein: (x) “Clearance Date” means the earliest date on which the Parties have actual knowledge that all applicable waiting periods under the HSR Act (and other applicable Antitrust Law, as reasonably determined by [***], as
applicable) with respect to the transactions contemplated by a U.S. License Agreement or Global License Agreement, as applicable, have expired or have been terminated; and (y) “HSR Filing” means a filing by Prothena and Celgene with
the FTC and the DOJ of a Notification and Report Form for Certain Mergers and Acquisitions (as that term is defined in the HSR Act) with respect to the matters set forth in the U.S. License Agreement or Global License Agreement, as applicable,
together with all required documentary attachments thereto. 
 3.2.3    Information Exchange. Each of Prothena
and Celgene will, in connection with any HSR Filing (as well as any other similar filing with any other Governmental Authority as reasonably determined by [***]), (i) reasonably cooperate with each other in connection with any communication, filing
or submission and in connection with any investigation or other inquiry (including any proceeding initiated by a private party); (ii) keep the other Party and/or its counsel informed of any communication received by such Party from, or given by such
Party to, the FTC, the DOJ or any other Governmental Authority (including any communication received or given in connection with any proceeding by a private party), in each case regarding the transactions contemplated by any proposed U.S. License
Agreement or Global License Agreement, as applicable; (iii) consult with each other in advance of any meeting or conference with the FTC, the DOJ or any other Governmental Authority (or, in connection with any proceeding by a private

  
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party, with such private party), and to the extent permitted by the FTC, the DOJ or such other Governmental Authority (or such private party), give the other Party and/or their counsel the
opportunity to attend and participate in such meetings and conferences; and (iv) permit the other Party and/or its counsel to review in advance any submission, filing or communication (and documents submitted therewith) intended to be given by
it to the FTC, the DOJ or any other Governmental Authority (or, in connection with any proceeding by a private party, to such private party); provided that materials may be redacted to remove references concerning [***]. Prothena and Celgene, as
each deems advisable and necessary, may reasonably designate any competitively sensitive material to be provided to the other under this Section 3.2.3 as “Antitrust Counsel Only Material.” Such materials and the information contained
therein shall be given only to the outside antitrust counsel of the recipient and will not be disclosed by such outside counsel to employees, officers or directors of the recipient unless express permission is obtained in advance from the source of
the materials (Prothena or Celgene, as the case may be) or the applicable Party’s legal counsel. 

3.2.4    Assistance. Subject to this Section 3.2, at the reasonable request of Celgene, Prothena and Celgene
shall cooperate and use respectively all reasonable efforts to make all other registrations, filings and applications, to obtain as soon as practicable all governmental or other consents, transfers, approvals, orders, qualifications, authorizations,
permits and waivers, if any, and to do all other things necessary for the consummation of the transactions as contemplated by any U.S. License Agreement or Global License Agreement, as applicable, in accordance with applicable Antitrust Laws. 

3.2.5    No Further Obligations. If a U.S. License Agreement or Global License Agreement, as applicable, is
terminated pursuant to this Section 3.2, then, notwithstanding any provision in this Agreement to the contrary, neither Party shall have any obligation to the other Party with respect to the subject matter of such U.S. License Agreement or
Global License Agreement, as applicable, including any payment obligations on the part of Celgene, including under Section 6.3 (and to the extent any payments have been made under Section 6.3, such amounts shall be [***] refunded from
Prothena to Celgene); provided that Celgene shall be permitted to [***], to comply with any Antitrust Law (in which event no such payments under Section 6.3 shall be refunded by Prothena). 

ARTICLE 4 
 GOVERNANCE

 4.1    Generally. 

4.1.1    Committees. 

(a)    Establishment. Pursuant to this Article 4, the Parties will establish a JSC within the timeframes set forth
in Section 4.2.1. The JSC shall have decision-making authority with respect to the matters within its purview to the extent expressly and as more specifically provided herein. 

(b)    Subcommittees. From time to time, the JSC may establish subcommittees to oversee particular projects or
activities, as the JSC deems necessary or advisable 

  
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(each, a “Subcommittee”); provided that the JSC may not grant any responsibilities to a Subcommittee that are beyond the scope of the responsibilities of the JSC as set forth
herein. Each Subcommittee shall consist of such number of members as the JSC determines is appropriate from time to time. Such members shall be individuals with expertise and responsibilities in the relevant areas. Such Subcommittees shall operate
under the same principles as are set forth in this Article 4 for the committee forming such Subcommittee. As of the Effective Date, the JSC hereby establishes the Patent Committee as a Subcommittee and the Manufacturing Committee as a Subcommittee.

 4.1.2    Execution of Global License Agreement, U.S. License Agreement or Exercise of Rights under
Section 2.5. On a Program-by-Program basis, upon execution of the applicable Global License Agreement for such Program (or following the exercise
of Celgene’s rights under Section 2.5 with respect to such Program, if earlier), such Program (including the Collaboration Target, Collaboration Candidates and Collaboration Products) and matters related thereto (including the Prothena IP
licensed to Celgene in connection therewith that specifically relates to such Program, the Collaboration Target, Collaboration Candidate or Collaboration Product (including the composition of matter or method of use thereof)) shall no longer
continue to be within the purview of the JSC or any Subcommittee (except as expressly set forth in any U.S. License Agreement). In addition, on a Program-by-Program
basis, upon execution of the applicable U.S. License Agreement for such Program, the activities under such U.S. License Agreement shall not be within the purview of the JSC or any Subcommittee (except as expressly set forth in such U.S. License
Agreement). 
 4.1.3    Alliance Managers. Promptly after the Effective Date, each Party shall appoint an
individual to act as alliance manager for such Party, which may be one of the representatives of such Party on the JSC (each, an “Alliance Manager”). The Alliance Managers shall be the primary point of contact for the Parties
regarding the activities contemplated by this Agreement and shall facilitate all such activities hereunder. The Alliance Managers shall attend all meetings of the JSC and shall be responsible for assisting the JSC in performing its oversight
responsibilities. The name and contact information for each Party’s Alliance Manager, as well as any replacement(s) chosen by such Party, in its sole discretion, from time to time, shall be promptly provided to the other Party in accordance
with Section 12.2. 
 4.1.4    Patent Liaisons. Promptly after the Effective Date, each Party shall appoint
an individual to act as a patent liaison for such Party (each, a “Patent Liaison”). The Patent Liaisons shall be the primary point of contact for the Parties regarding intellectual property-related activities and matters
contemplated by this Agreement and shall facilitate all such activities and matters hereunder. The name and contact information for each Party’s Patent Liaison, as well as any replacement(s) chosen by such Party, in its sole discretion, from
time to time, shall be promptly provided to the other Party in accordance with Section 12.2. 
 4.2    Joint
Steering Committee. 
 4.2.1    Establishment; Meetings. Within [***] ([***]) days after the Effective Date,
the Parties shall establish a joint steering committee (the “JSC”) as more fully described in this Section 4.2. Subject to Section 4.1.2, the JSC shall have review, oversight and decision-making responsibilities for those
activities performed under the Programs to the extent expressly 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
and as more specifically provided in Section 4.2.3. Each Party agrees to keep the JSC informed of its progress and activities hereunder with respect to the Collaboration. The first scheduled
meeting of the JSC shall be held no later than [***] ([***]) days after establishment of the JSC unless otherwise agreed by the Parties. After the first scheduled meeting of the JSC until the JSC is disbanded, the JSC shall meet in person or
telephonically [***], or more or less frequently as the Parties mutually deem appropriate, on such dates and at such places and times as provided herein or as the Parties shall agree, provided the JSC shall meet [***]. In any case where a matter
within the JSC’s authority arises, the JSC shall convene a meeting and consider such matter as soon as reasonably practicable, but in no event later than [***] ([***]) days after the matter is first brought to the JSC’s attention (or, if
earlier, at the next regularly scheduled JSC meeting). The JSC shall disband upon the expiration or termination of this Agreement in its entirety. Meetings that are held in person shall be at such location as the Parties may agree. The members of
the JSC may also convene or be polled or consulted from time to time by means of telecommunications, video conferences, electronic mail or correspondence, as deemed necessary or appropriate. Each Party will bear all expenses it incurs in regard to
participating in all meetings of the JSC, including all travel and living expenses. 
 4.2.2    Membership. The
JSC shall be comprised of three (3) representatives (or such other number of representatives as the Parties may mutually agree) from each of Celgene and Prothena. Each representative of a Party shall have sufficient seniority and expertise to
participate on the JSC as determined in such Party’s reasonable judgment. [***] shall have the right to designate the chairperson of the JSC. Each Party may replace any or all of its representatives on the JSC at any time upon written notice to
the other Party in accordance with Section 12.2. Each Party may, subject to the other Party’s prior approval, invite non-member representatives of such Party and any Third Party to attend meetings of
the JSC as non-voting participants; provided that (i) any such representative or Third Party is bound by obligations of confidentiality, non-disclosure and non-use consistent with those set forth in Article 8 and is obligated to assign inventions to the relevant Party as necessary to effect the intent of Section 7.6 prior to attending such meeting, (ii) such non-member representative or Third Party shall not have any voting or decision-making authority on the JSC and (iii) with respect to any Third Party, such Third Party shall be approved by the other Party in
writing (such approval not to be unreasonably withheld) prior to attendance at such meeting. 

4.2.3    Responsibilities. Except as otherwise set forth in this Section 4.2, the JSC may perform the
following functions, subject to the final decision-making authority as set forth in Section 4.2.4: (a) oversee, review and monitor progress of the Programs, including serving as a forum for exchanging information and facilitating discussions
regarding the conduct of the Programs; (b) on a Program-by-Program basis, review and amend a Research Plan; (c) review and discuss the Collaboration Targets,
and discuss and approve any replacement Collaboration Targets (in accordance with Section 4.2.5(a)); (d) review and comment on Collaboration Candidates, Lead Candidates and Development Candidates; (e) [***]; (f) manage the strategic direction
of the Programs; (g) oversee implementation of the Collaboration in accordance with this Agreement; (h) subject to Article 8, discuss a communications strategy for the results of any Program (including publications in journals, posters,
presentations at conferences and abstracts submitted in advance of conferences) for communications prior to the exercise of the Phase 1 Option for such Program, (i) discuss and attempt to resolve any disputes in any Subcommittees;
(j) discuss material issues regarding the enforcement and defense of Prothena IP; (k) determine the Alternative End of 

  
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treatment has been requested with respect to the omitted portions. 

 
Phase 1 Date for a given Program, if any, (l) determine the Lead Candidate Criteria, and any amendments thereto, (m) approve the [***] and (n) perform such other responsibilities
as may be mutually agreed by the Parties from time to time. For purposes of clarity, the JSC shall not have any authority beyond the specific matters set forth in this Section 4.2.3 (or otherwise expressly set forth in this Agreement), and in
particular shall not have any power to amend, modify, interpret or waive the terms of this Agreement, any U.S. License Agreement or any Global License Agreement, or to alter, diminish, expand or waive compliance by a Party with a Party’s
obligations under this Agreement, or any U.S. License Agreement or any Global License Agreement. 

4.2.4    Decisions. Except as otherwise set forth in this Agreement, all decisions of the JSC shall be made by
consensus, with each Party having one (1) vote. If the JSC cannot agree on a matter for which the JSC has decision-making authority within [***] ([***]) [***] after it has met and attempted to reach such decision, then either Party may, by
written notice to the other, have such issue referred to the Executive Officers for resolution. The Parties’ respective Executive Officers shall meet within [***] ([***]) [***] after such matter is referred to them, and shall negotiate in good
faith to resolve the matter. If the Executive Officers are unable to resolve the matter within [***] ([***]) [***], or such other longer time frame the Executive Officers may otherwise agree upon, after the matter is referred to them in accordance
with this Section 4.2.4, then, except as otherwise set forth in this Agreement, [***] shall have the final decision making authority; provided that [***] shall [***] in making such final decision. Notwithstanding the foregoing, in
exercising [***]’s final decision making authority, [***] shall not have the right to exercise its final decision-making authority to: (i) determine that [***], or that [***]; (ii) determine that milestone events or other events have or
have not occurred; (iii) make a decision that is stated to require the mutual agreement or mutual consent of the Parties (or that is subject to the determination of [***] as set forth herein); (iv) determine any matter which is the subject of
the dispute resolution provided for in Section 2.4; (v) modify a Party’s rights or reduce a Party’s obligations under this Agreement, any U.S. License Agreement or any Global License Agreement, or otherwise amend, modify, interpret or
waive the terms of this Agreement, any U.S. License Agreement or any Global License Agreement; (vi) determine any Alternative End of Phase 1 Date for a given Program, (vii) determine the Lead Candidate Criteria, or any amendments thereto,
(viii) approve any replacement Collaboration Targets in accordance with Section 4.2.5(a) (including the identity of the new target, the existing Collaboration Target that is being replaced [***]); (ix) determine to [***] that Target the
Collaboration Target for such Program or (x) approve the [***]; and any of the foregoing decisions or determinations shall require mutual agreement of the Parties. Any final decision made by [***] in the course of exercising its final
decision-making authority must be consistent with the terms of this Agreement and within the scope of authority delegated to the JSC under this Agreement. 

4.2.5    Replacement Targets; Lapsed Targets. 

(a)    From time to time during the Research Term, the JSC may discuss alternative targets to bring into the Collaboration
as potential Collaboration Targets to replace a then-existing Collaboration Target. Subject to Section 4.2.4, if the JSC unanimously consents in writing, then the Parties may replace an existing Collaboration Target with an alternative target;
provided that for selection of a replacement for a Collaboration Target, as part of such written consent, the JSC shall specifically identify the new target as well as the existing Collaboration Target that is being replaced [***]. In the event that
the JSC so agrees to replace a given existing 

  
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treatment has been requested with respect to the omitted portions. 

 
Collaboration Target with a new Collaboration Target, then (i) the existing Collaboration Target that is being replaced shall be deemed to be a “Lapsed Target” for purposes of this
Agreement, and the Program for such replaced Collaboration Target shall promptly cease, (ii) the new target [***] shall be deemed to be a “Collaboration Target” for purposes of this Agreement, such Collaboration Target shall be the
subject of a separate Program under the Collaboration, and the JSC may update the Research Plan for such new Program, and (iii) if agreed to by the JSC as part of the mutual written consent, [***]. 

(b)    During the Research Term, Celgene shall also have the right, in its discretion, to notify Prothena in writing that
it is no longer interested in considering whether to exercise its IND Option for a given Collaboration Target, in which case, (i) such Collaboration Target shall be deemed to be a “Lapsed Target” for purposes of this Agreement and
(ii) the Program for such Collaboration Target shall promptly cease. 
 (c)    Subject to the rights and licenses
granted to Celgene hereunder (and under any U.S. License Agreement and Global License Agreement), Prothena shall have the right to pursue, outside of this Agreement, Development and Commercialization of Antibodies that Target any Lapsed Target
([***]); provided that for clarity, the foregoing is not intended to be a grant to Prothena of any rights or licenses to any intellectual property of Celgene (or its Affiliates) or otherwise. 

4.2.6    [***]. The JSC shall also review and determine if [***]. If the JSC determines unanimously (for clarity,
without [***] having a final decision making right) that [***], then the Parties shall negotiate in good faith [***]. 

4.2.7    Exceptions for Celgene Products and Celgene IP. Notwithstanding the provisions of Section 4.2.4 or
anything to the contrary contained herein, no activities performed by or on behalf of Prothena hereunder, including any activities under any Programs, may involve any product that is being researched, developed, marketed or sold by or on behalf of
Celgene (or any of its Affiliates) (a “Celgene Product”) (provided that such Celgene Product is publicly known or Celgene has otherwise notified Prothena of such Celgene Product) or otherwise involve any Celgene IP, in each case,
without Celgene’s prior written consent (in its sole discretion), and such decisions and determinations shall not be under the purview of the JSC (or Prothena). In the event that Celgene approves any such activities with respect to any such
Celgene Product or Celgene IP, then at the request of Celgene, the Parties shall negotiate in good faith and enter into a separate agreement with respect to the terms and conditions under which such activities may be undertaken under this Agreement
with respect to any Celgene Product or Celgene IP. 
 4.2.8    Minutes. Prothena shall be responsible for
preparing and circulating minutes of each meeting of the JSC, setting forth, inter alia, an overview of the discussions at the meeting and a list of any actions, decisions or determinations approved by the JSC. A draft of such minutes shall
be circulated by Prothena to all members of the JSC within [***] ([***]) days after the applicable meeting. Such minutes shall be effective only after such minutes have been approved by both Parties in writing. Definitive minutes of all JSC meetings
shall be finalized no later than [***] ([***]) days after the meeting to which the minutes pertain. 

  
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treatment has been requested with respect to the omitted portions. 

 4.3    Patent Committee. 

4.3.1    Establishment. Within [***] ([***]) days after the Effective Date, the Parties shall establish a patent
Subcommittee (the “Patent Committee”) as more fully described in this Section 4.3. The Patent Committee shall facilitate the discussion and coordination of Patent Prosecution and Maintenance matters with respect to Prothena
Collaboration Patents and Program Patents, in accordance with and subject to the terms of Article 7. 

4.3.2    Meetings. The Patent Committee shall convene at such times, places and frequencies as the Patent Committee
determines is necessary. In any case where a matter within the Patent Committee’s authority arises, the Patent Committee shall convene a meeting and consider such matter as soon as reasonably practicable, but in no event later than [***]
([***]) days after the matter is first brought to the Patent Committee’s attention (or, if earlier, at the next regularly scheduled Patent Committee meeting). The Patent Committee shall disband upon the expiration or termination of this
Agreement. Meetings of the Patent Committee that are held in person shall be at such location as the Parties may agree but it is expected by the Parties that meetings of the Patent Committee will generally be held by means of telecommunications or
video conferences and only in the event that the Parties agree to do so will meetings be held in person. The members of the Patent Committee also may convene or be polled or consulted from time to time by means of telecommunications, video
conferences, electronic mail or correspondence, as deemed necessary or appropriate. Each Party will bear all expenses it incurs in regard to participating in all meetings of the Patent Committee, including all travel and living expenses. 

4.3.3    Membership. The Patent Committee shall be comprised of one (1) representative (or such other number
of representatives as the Parties may mutually agree) from each of Celgene and Prothena (who shall be employees of such Party or its Affiliates), which shall include the Patent Liaison for each such Party. Each Party may replace any or all of its
representatives on the Patent Committee at any time upon written notice to the other Party in accordance with Section 12.2. Each representative of a Party shall have sufficient seniority and expertise in the Prosecution and Maintenance of
Patents to participate on the Patent Committee as determined in such Party’s reasonable judgment. Each Party may, subject to the other Party’s prior approval, invite Third Parties or non-member
representatives of such Party to attend meetings of the Patent Committee as non-voting participants; provided that (i) any such representative or Third Party is bound by obligations of confidentiality, non-disclosure and non-use consistent with those set forth in Article 8 and is obligated to assign inventions to the relevant Party as necessary to effect the intent of
Section 7.6 prior to attending such meeting, (ii) such non-member representative or Third Party shall not have any voting or decision-making authority on the Patent Committee and (iii) with
respect to any Third Party, such Third Party shall be approved by the other Party in writing (such approval not to be unreasonably withheld) prior to attendance at such meeting. [***] shall have the right to designate the chairperson of the Patent
Committee. 
 4.3.4    Responsibilities. The Patent Committee shall perform the following functions:
(a) discuss material issues and provide input to each other regarding the Prosecution and Maintenance of Prothena Collaboration Patents, Joint Program Patents and Program Patents, (b) coordinate the implementation of Prothena’s
strategies for the protection of the Prothena Collaboration Patents and Program Patents, including (i) the filing and prosecution of continuing or divisional Patent applications with respect to Prothena Collaboration Patents and Program
Patents, as appropriate to [***] (the foregoing referred to herein as the “Patent Strategy”); (b) serve as a forum for exchanging information and facilitating discussions regarding patentability

  
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treatment has been requested with respect to the omitted portions. 

 
and freedom to operate assessments with respect to the Programs; and (c) perform such other responsibilities as may be mutually agreed by the Parties from time to time. The Patent Committee
shall also be responsible for coordinating the implementation of Prothena’s strategies for Prothena Collaboration Patents and Program Patents but shall not have authority to decide such matters, which decisions are reserved to the Parties by
Sections 7.7 and 7.8. For clarity, the Patent Committee shall be a forum for discussion only and shall not have any decision-making authority and shall not have any power to amend, modify, interpret or waive the terms of this Agreement, any U.S.
License Agreement or any Global License Agreement, or to alter or waive compliance by a Party with a Party’s obligations under this Agreement, any U.S. License Agreement or any Global License Agreement. 

4.3.5    Minutes. A representative of Prothena shall be responsible for preparing and circulating minutes of each
meeting of the Patent Committee, setting forth, inter alia, an overview of the discussions at the meeting and a list of any actions, decisions or determinations approved by the Patent Committee. A draft of such minutes shall be circulated by
Prothena to all members of the Patent Committee within [***] ([***]) days after the applicable meeting. Such minutes shall be effective only after such minutes have been approved by both Parties in writing. Definitive minutes of all Patent Committee
meetings shall be finalized no later than [***] ([***]) days after the meeting to which the minutes pertain. 

4.4    Manufacturing Committee. 

4.4.1    Establishment. Within [***] ([***]) days after the Effective Date, the Parties shall establish a
manufacturing Subcommittee (the “Manufacturing Committee”) as more fully described in this Section 4.4. The Manufacturing Committee shall facilitate the discussion and coordination of Manufacturing matters with respect to
Collaboration Candidates and Collaboration Products under a given Program. The Manufacturing Committee shall be a forum for discussion and coordination, but shall have no decision making authority. For the avoidance of doubt, Manufacturing matters
with respect to activities under a U.S. License Agreement or Global License Agreement shall be outside the purview of the Manufacturing Committee. 

4.4.2    Meetings. The Manufacturing Committee shall convene at such times, places and frequencies as the
Manufacturing Committee determines is necessary, but in all cases no less than [***] (unless otherwise agreed to by the Parties). In any case where a matter within the Manufacturing Committee’s purview arises, the Manufacturing Committee shall
convene a meeting and consider such matter as soon as reasonably practicable, but in no event later than [***] ([***]) days after the matter is first brought to the Manufacturing Committee’s attention (or, if earlier, at the next regularly
scheduled Manufacturing Committee meeting). The Manufacturing Committee shall disband upon the expiration or termination of this Agreement. Meetings of the Manufacturing Committee that are held in person shall be at such location as the Parties may
agree but it is expected by the Parties that meetings of the Manufacturing Committee will generally be held by means of telecommunications or video conferences and only in the event that the Parties agree to do so will meetings be held in person.
The members of the Manufacturing Committee also may convene or be polled or consulted from time to time by means of telecommunications, video conferences, electronic mail or correspondence, as deemed necessary or appropriate. Each Party will bear
all expenses it incurs in regard to participating in all meetings of the Manufacturing Committee, including all travel and living expenses. 

  
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treatment has been requested with respect to the omitted portions. 

 4.4.3    Membership. The Manufacturing Committee shall be
comprised of two (2) representatives (or such other number of representatives as the Parties may mutually agree) from each of Celgene and Prothena (who shall be employees of such Party or its Affiliates). Each Party may replace any or all of
its representatives on the Manufacturing Committee at any time upon written notice to the other Party in accordance with Section 12.2. Each representative of a Party shall have sufficient seniority and expertise in Manufacturing matters to
participate on the Manufacturing Committee as determined in such Party’s reasonable judgment. Each Party may, subject to the other Party’s prior approval, invite Third Parties or non-member
representatives of such Party to attend meetings of the Manufacturing Committee as non-voting participants; provided that (i) any such representative or Third Party is bound by obligations of
confidentiality, non-disclosure and non-use consistent with those set forth in Article 8 and is obligated to assign inventions to the relevant Party as necessary to
effect the intent of Section 7.6 prior to attending such meeting, and (ii) with respect to any Third Party, such Third Party shall be approved by the other Party in writing (such approval not to be unreasonably withheld) prior to
attendance at such meeting. [***] shall have the right to designate the chairperson of the Manufacturing Committee. 

4.4.4    Responsibilities. The Manufacturing Committee shall perform the following functions: (a) discuss
material issues and provide input to each other regarding the Manufacture of Collaboration Candidates and Collaboration Products, including pre-formulation, formulation, manufacturability and supply sources
with respect to Collaboration Candidates and Collaboration Products, as well as the selection of any Third Party manufacturers (including any agreements to be entered into with such Third Party manufacturers); (b) serve as a forum for exchanging
information and facilitating discussions regarding Manufacturing matters with respect to the Programs; and (c) perform such other responsibilities as may be mutually agreed by the Parties from time to time. 

4.4.5    Minutes. A representative of Prothena shall be responsible for preparing and circulating minutes of each
meeting of the Manufacturing Committee, setting forth, inter alia, an overview of the discussions at the meeting. A draft of such minutes shall be circulated by Prothena to all members of the Manufacturing Committee within [***] ([***]) days
after the applicable meeting. Such minutes shall be effective only after such minutes have been approved by both Parties in writing. Definitive minutes of all Manufacturing Committee meetings shall be finalized no later than [***] ([***]) days after
the meeting to which the minutes pertain. 
 ARTICLE 5 

EXCLUSIVITY 

5.1    Exclusivity. During the Term, and subject to Sections 5.2 and 5.3, Prothena shall not and shall ensure its
Affiliates shall not, anywhere in the world: (i) alone or with or through any Third Party, research [***], Develop, Manufacture or Commercialize (a) any Collaboration Target or any Competing Compound, or (b) any diagnostic product
intended for use, or Developed or approved for use with, with any Collaboration Target (including any diagnostic product intended for use, or Developed or approved for use with any Competing Compound), in each case, other than in performance of a
Program pursuant to this Agreement (including engaging Third Party subcontractors to perform the Program activities in accordance with this Agreement); (ii) grant a license, sublicense or other rights to any Third Party to conduct any of the
activities in the foregoing clause (i), other than in performance of Collaboration activities (including engaging 

  
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Third Party subcontractors to perform the Collaboration activities in accordance with this Agreement) pursuant to a Program under this Agreement; or (iii) transfer, assign, convey or
otherwise sell (a) any Competing Compound or (b) any diagnostic product intended for use, or Developed or approved for use with any Collaboration Target, including any diagnostic product intended for use, or Developed or approved for use
with any Competing Compound. As used herein, the term “Competing Compound” means [***]. For clarity, the restrictions described in this Section 5.1 shall not apply to any Lapsed Targets. 

5.2    Failure to Exercise Phase 1 Option. In the event that Celgene exercises its IND Option with respect to a
given Program, but does not exercise its Phase 1 Option with respect to such Program by the end of the Phase 1 Option Term for such Program, then, notwithstanding the provisions of Section 5.1, from and after the end of such Phase 1 Option Term
the provisions of Section 5.1 shall no longer apply with respect to the Collaboration Target that was the subject of such Program, solely with respect to activities conducted by Prothena or its Affiliates or sublicensees outside of the United
States (and, for the avoidance of doubt, the provisions of Section 5.1 shall continue to apply to such Collaboration Target with respect to activities conducted in the United States). 

5.3    Prothena Exception for Active Immunotherapeutic Approaches. 

5.3.1    Exception for Active Immunotherapeutic Approaches. Notwithstanding the provisions of Section 5.1, but
subject to the provisions of Section 5.3.2, Prothena and its Affiliates (themselves, but not with or through any Third Parties) may conduct research, development, manufacture and commercialization of Active Immunotherapeutic Approaches outside
of this Agreement; provided that no Collaboration Candidates or Collaboration Products are utilized in the conduct of any such activities (including no use of a Collaboration Candidate or Collaboration Product for an Active Immunotherapeutic
Approach). As used herein, “Active Immunotherapeutic Approaches” means [***]. 
 5.3.2    Celgene
Right of First Negotiation. During the Research Term [***], in the event that Prothena or its Affiliates intends to, directly or indirectly, sublicense, assign, transfer, convey or grant other rights, however structured, to a Third Party with
respect to any Active Immunotherapeutic Approaches (including any rights with respect to the Development or Commercialization of any Active Immunotherapeutic Approaches (each, a “Grant”), [***] will [***]. [***] will [***] (a
“[***]”). If [***], [***] will [***] which [***] will [***]. If [***], the Parties will [***]. Until [***] or the [***], as applicable, [***]. If [***] that it [***], then [***]. For the avoidance of doubt, this Section 5.3.2 [***].
For clarity, [***]. 
 ARTICLE 6 

FINANCIAL TERMS 

6.1    Upfront Payment. In consideration for the rights granted to Celgene under this Agreement, Celgene shall pay
to Prothena within [***] ([***]) [***] after the Effective Date a one-time upfront payment of one hundred million Dollars ($100,000,000) (the “Upfront Payment”). 

  
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treatment has been requested with respect to the omitted portions. 

 6.2    Equity Investment. The Parties acknowledge and agree that
simultaneously with the execution of this Agreement, the Parties are entering into that certain Share Subscription Agreement and certain additional agreements related thereto (collectively, the “Investment Agreements”)
with respect to an equity investment by Celgene (or its Affiliate) in Prothena Corporation plc. Prothena further agrees and acknowledges that Prothena’s entering into, and performance of, this Agreement is an essential factor for Celgene
entering into the Investment Agreements, without which Celgene would not have entered into the Investment Agreements. 

6.3    Option Fees. 

6.3.1    IND Option Exercise Fee. Subject to Section 3.2, in the event that Celgene exercises (in its
discretion) its IND Option for a given Program, the Parties shall enter into the U.S. License Agreement for such Program in accordance with Section 3.1.3(a). In such case, Celgene shall, within [***] ([***]) days after the effective date
of the U.S. License Agreement for such Program, pay to Prothena a non-refundable payment (except as otherwise set forth in Section 3.2.5) in the amount of the IND Option Exercise Fee for such Program. For
the avoidance of doubt, in the event that Celgene exercises (in its discretion) its IND Option for a given Program, Celgene shall only be obligated to pay the IND Option Exercise Fee one (1) time for such Program regardless of the number of
Collaboration Candidates, Lead Candidates or Development Candidates under such Program. As used herein, the term “IND Option Exercise Fee” shall mean, for a given Program, an amount equal to (i) Eighty Million Dollars
($80,000,000) [***]. 
 6.3.2    Phase 1 Option Exercise Fee. Subject to Section 3.2, in the event that
Celgene exercises (in its discretion) its Phase 1 Option for a given Program, the Parties shall enter into the Global License Agreement for such Program in accordance with Section 3.1.3(b). In such case, Celgene shall, within [***]
([***]) days after the effective date of the Global License Agreement for such Program, pay to Prothena a non-refundable payment (except as otherwise set forth in Section 3.2.5) in the amount of the Phase
1 Option Exercise Fee for such Program. For the avoidance of doubt, in the event that Celgene exercises (in its discretion) its Phase 1 Option for a given Program, Celgene shall only be obligated to pay the Phase 1 Option Exercise Fee one
(1) time for such Program regardless of the number of Collaboration Candidates, Lead Candidates or Development Candidates under such Program. As used herein, the term “Phase 1 Option Exercise Fee” shall mean, for a given
Program, an amount equal to Fifty-Five Million Dollars ($55,000,000). 
 6.4    Additional Payment Terms. 

6.4.1    Currency. All payments hereunder shall be made in Dollars by wire transfer to a bank designated in writing
by Prothena (if the payment is to be made to Prothena) or by Celgene (if the payment is to be made by Celgene). 

6.4.2    Taxes; Withholding. 

(a)    Generally. Each Party will pay any and all income taxes levied on account of all payments it receives under
this Agreement except as otherwise provided in this Section 6.4.2. 

  
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treatment has been requested with respect to the omitted portions. 

 (b)    Tax Withholding. Each Party shall be entitled to deduct
and withhold from any amounts payable under this Agreement, any U.S. License Agreement or any Global License Agreement such taxes as are required to be deducted or withheld therefrom under any provision of Applicable Law. The Party that is required
to make such withholding (the “Paying Party”) will: (i) deduct those taxes from such payment, (ii) timely remit the taxes to the proper taxing authority, and (iii) send evidence of the obligation together with
proof of tax payment to the other Party (the “Payee Party”) on a timely basis following that tax payment; provided, however, that before making any such deduction or withholding, the Paying Party shall give the Payee Party notice of
the intention to make such deduction or withholding (such notice shall include an explanation of the reason for and the calculation of the proposed deduction or withholding and shall be given before such deduction or withholding is required in order
for such Payee Party to obtain reduction of or relief from such deduction or withholding). Each Party agrees to reasonably cooperate with the other Party in claiming refunds or exemptions from such deductions or withholdings under any relevant
agreement or treaty which is in effect to ensure that any amounts required to be withheld pursuant to this Section 6.4.2(b) are reduced in amount to the fullest extent permitted by Applicable Law. In addition, the Parties shall cooperate in
accordance with Applicable Laws to minimize indirect taxes (such as value added tax, sales tax, consumption tax and other similar taxes (“Indirect Taxes”)) in connection with this Agreement or any U.S. License Agreement or Global
License Agreement, as applicable. Notwithstanding anything to the contrary in this Section 6.4.2(b), the Parties acknowledge and agree that Celgene will not, absent a change in Applicable Law or relevant circumstance between the Effective Date
and the date of the payment pursuant to Section 6.1, deduct or withhold from the amounts payable pursuant to Section 6.1 any amount in respect of any taxes provided that Prothena provides Celgene with [***]. 

(c)    Tax Gross-up. Notwithstanding the foregoing, if (a) any Party
redomiciles, assigns its rights or obligations or extends its rights under this Agreement or any U.S. License Agreement or Global License Agreement, (b) as a result of such redomiciliation, assignment or extension, such Party (or its assignee)
is required by Applicable Law to [***], or such redomiciliation, assignment or extension results in [***], and (c) such [***] exceed the amount of [***] that would have been applicable but for such redomiciliation, assignment or extension, then
any such amount payable shall [***] so that, after making all required [***], as the case may be, the Payee Party (or its assignee) [***]. The [***] (A) [***] to the extent such [***] but for [***], and (B) [***]. For purposes of the preceding
sentence, “Tax Benefit” shall mean any cash refund or credit for Taxes resulting in a reduction in the amount of Taxes otherwise owed by the Payee Party as a result of [***] relating to payments by the Paying Party, as reasonably
determined by Payee Party. Solely for purposes of this Section 6.4.2(c), a Party’s “domicile” shall include its jurisdiction of incorporation or tax residence and a “redomiciliation” shall include a reincorporation or
other action resulting in a change in tax residence of the applicable Party or its assignee, or resulting in the attribution of any amounts payable to a branch or permanent establishment located outside the country of tax residence of the applicable
Party or its assignee. 
 (d)    Tax Documentation. Prothena has provided a properly completed and duly executed
IRS Form W-8BEN-E to Celgene. Prior to the receipt of any payment under this Agreement, each recipient Party (and any other recipient of payments under this Agreement)
shall, to the extent it is legally permitted to, provide to the other Party, at the time or times reasonably requested by such other Party or as required by Applicable Law, such properly completed and duly executed documentation (for example, IRS
Forms W-8 or W-9 or foreign equivalents) as will permit payments made under this Agreement to be made without, or at a reduced rate of, withholding for taxes. 

  
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treatment has been requested with respect to the omitted portions. 

 6.4.3    Prothena Third Party Agreements. Notwithstanding
anything to the contrary, Prothena shall be solely responsible for all costs and payments of any kind (including all upfront fees, annual payments, milestone payments and royalty payments) arising under any agreements between Prothena (or any of its
Affiliates) and any Third Party, which costs or payments arise in connection with, or as a result of, the activities hereunder, including the Development, Manufacture or Commercialization of Collaboration Candidates or Collaboration Products. 

ARTICLE 7 
 LICENSES;
INTELLECTUAL PROPERTY 
 7.1    Licenses to Celgene. 

7.1.1    Performance under Agreement. Subject to the terms and conditions of this Agreement, Prothena hereby grants
to Celgene a non-exclusive, worldwide, fully paid-up, royalty-free right and license, with the right to grant sublicenses (through multiple tiers), under the Prothena IP
for Celgene to conduct its activities and perform its obligations under this Agreement, including as set forth in Section 2.4 and 2.9. 

7.1.2    Research and Development License. Prothena hereby grants to Celgene a
non-exclusive, worldwide, fully paid-up, royalty-free, perpetual and irrevocable right and license, with the right to grant sublicenses (through multiple tiers), under
its rights in [***] for [***]. 
 7.2    Grant Back for Lapsed Targets. If a Collaboration Target under a Program
becomes a Lapsed Target pursuant to Sections 3.1.3(a) or 4.2.5, then effective upon the date that a Collaboration Target becomes a Lapsed Target pursuant to Sections 3.1.3(a) or 4.2.5, and subject to the terms and conditions of this Agreement,
Celgene shall, and hereby does, grant to Prothena an non-exclusive, fully paid-up, worldwide royalty-free, perpetual and irrevocable right and license, with the right to
grant sublicenses (through multiple tiers), under its rights in any and all (i) Celgene Phase 1 Know-How (from such Program) Controlled by Celgene and [***] to Develop and Commercialize Antibodies
Targeting such Lapsed Target or products containing such Antibodies, and (ii) all Patents Controlled (as of the date that the applicable Collaboration Target becomes a Lapsed Target) by Celgene claiming such Celgene Phase 1 Know-How, in each case, to research, develop, manufacture, use, sell, offer for sale and import Antibodies Targeting such Lapsed Target and products containing such Antibodies, for all purposes. Additionally,
Celgene shall transfer to Prothena within a reasonable time after a Collaboration Target becomes a Lapsed Target, at Prothena’s request [***], any and all Program Regulatory Materials pertaining to Collaboration Candidates Targeting such Lapsed
Target that were transferred to Celgene pursuant to Section 2.6.1(b). 
 7.3    Rights Retained by the
Parties. For purposes of clarity, each Party retains all rights under Know-How and Patents Controlled by such Party not expressly granted to the other Party pursuant to this Agreement. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.4    No Implied Licenses. Except as explicitly set forth in
this Agreement, neither Party shall be deemed by estoppel or implication to have granted the other Party any license or other right to any intellectual property of such Party. 

7.5    Insolvency. In the event that this Agreement is terminated due to the rejection of this Agreement by or on
behalf of a Party due to an Insolvency Event, all licenses and rights to licenses granted under or pursuant to this Agreement by a Party to the other Party are and shall otherwise be deemed to be licenses of rights to “intellectual
property”. The Parties agree that each Party, as a licensee of such rights under this Agreement, shall retain and may fully exercise all of its rights and elections under any applicable insolvency statute, and that upon commencement of an
Insolvency Event by or against the other Party, such Party shall be entitled to a complete duplicate of or complete access to (as such Party deems appropriate), any such intellectual property and all embodiments of such intellectual property. Such
intellectual property and all embodiments thereof shall be promptly delivered to such Party (i) upon any such commencement of a bankruptcy proceeding (or other Insolvency Event) upon written request therefor by such Party, unless the other
Party elects to continue to perform all of its obligations under this Agreement or (ii) if not delivered under (i) above, upon the rejection of this Agreement by or on behalf of the other Party, then upon written request therefor by such
Party. The provisions of this Section 7.5 shall be (1) without prejudice to any rights a Party may have arising under any applicable insolvency statute or other Applicable Law and (2) effective only to the extent permitted by
Applicable Law. 
 7.6    Ownership. 

7.6.1    Inventions. Notwithstanding the provisions of Section 12.7.1, inventorship of Know-How shall be determined by application of U.S. patent law pertaining to inventorship, and, except as provided for in Sections 7.6.2, 7.6.3 and 7.6.4, ownership of
Know-How shall be determined by inventorship. 
 7.6.2    Ownership of
Prothena Collaboration IP and Celgene IP. 
 (a)    Prothena. As between the Parties (including their
respective Affiliates), Prothena will retain all right, title and interest in and to all Prothena Collaboration IP, except to the extent that any such rights are licensed or granted to Celgene under this Agreement, any U.S. License Agreement or any
Global License Agreement. Prothena shall [***] that all Patents, Know-How and other intellectual property (other than Program IP and Celgene IP, if any) utilized in the performance of a Program falls within
the Prothena Collaboration IP and is and remains during the Term and the term of any applicable U.S. License and Global License Agreement Controlled by Prothena such that Prothena has the full rights to grant the rights and licenses to the Prothena
Collaboration IP to Celgene hereunder (and under any U.S. License Agreement and any Global License Agreement), including the Options (including that such Patents, Know-How and other intellectual property
remains unencumbered such that Prothena is able to grant such rights and licenses to Celgene). 

(b)    Celgene. As between the Parties (including their respective Affiliates), Celgene (or its Affiliate) will
retain all right, title and interest in and to all Celgene IP, except as otherwise expressly set forth herein, including all rights to Prosecute and Maintain, and enforce any such Celgene IP, and no rights or licenses are granted to Prothena
hereunder with 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
respect to any Celgene IP except as expressly provided in Section 7.2. In the event that Prothena desires to utilize any Celgene IP not subject to Section 7.2 for the performance of a
Program, then Prothena may request such right in writing from Celgene (which writing shall identify the particular Celgene IP that Prothena would like to use), and if Celgene agrees, in its sole discretion, the Parties shall negotiate and enter into
a separate agreement setting for the terms and conditions under which Prothena may utilize such Celgene IP. 

7.6.3    Ownership of Program IP. 

(a)    As between the Parties (including their respective Affiliates), Prothena will solely own and Control all Program
IP. Celgene shall, and hereby does, assign to Prothena all of Celgene’s interest in any and all Program Know-How that falls within Section 1.62(a)(iii) and all Program Patents claiming such Program Know-How. Celgene shall, and shall require its Affiliates to, take all reasonable actions and execute all documents necessary to effect the intent of the preceding sentence. As between the Parties (and their
respective Affiliates) and any Third Party, Prothena will solely own and Control all Program IP; provided that if (a) [***] and (b) [***]. 

(b)    If any Program IP is created, conceived, discovered, first generated, invented, first made or first reduced to
practice pursuant to this Agreement by any Third Party that is in contractual privity with or otherwise engaged by Prothena or its Affiliates, [***], Prothena [***] include in such agreement with such Third Party an obligation to [***] to Prothena
[***] such Program IP to enable Prothena to grant to Celgene the rights provided for in this Agreement and any U.S. License Agreement and Global License Agreement for the duration of this Agreement, and if applicable any U.S. License Agreement and
Global License Agreement. 
 7.6.4    Joint Program IP. The Parties shall each own an equal, undivided interest
in any and all Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to practice, in each case, jointly by or on behalf of Prothena or its Affiliates, on the
one hand, and Celgene or its Affiliates, on the other hand, pursuant to the conduct of activities under this Agreement at any time during the Term, (the “Joint Program Know-How”), and
(b) any Patents that claim any Joint Program Know-How (the “Joint Program Patents”, together with Joint Program Know-How the “Joint Program
IP”). Each Party shall assign, and hereby assigns, to the other Party, a joint equal and undivided interest in and to such Joint Program IP (provided, however, that for clarity, the foregoing joint ownership rights with respect to Joint
Program IP shall not be construed as granting, conveying or creating any license or other rights to any of the other Party’s other intellectual property, unless otherwise expressly set forth in this Agreement), and at the request of a Party,
the other Party will execute such documents (including any necessary assignments) to effect such joint ownership of such Joint Program IP. Each Party shall have the right to disclose (except as otherwise set forth in Section 8.2) and exploit
the Joint Program IP without a duty of seeking consent or accounting to the other Party, except as expressly provided in the U.S. License Agreement or the Global License Agreement; provided that, such rights shall be subject to the rights and
licenses (including the Options) granted to Celgene and Prothena hereunder (and under any U.S. License Agreement or Global License Agreement), including the obligations of Prothena as set forth in Article 5. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.6.5    Ownership of Collaboration Candidates. Prothena shall
[***] that it owns and Controls all Collaboration Candidates such that it is able to grant the rights and licenses to Celgene hereunder (and under a U.S. License Agreement and Global License Agreement) with respect to such Collaboration Candidates.

 7.6.6    Further Actions. Each Party shall cause its and its Affiliates’ employees, consultants,
sublicensees, agents and contractors to, as applicable, (i) assign or (ii) grant a license (as set forth in Section 7.6.3(a)), to such Party, in and under such Person’s right, title and interest in and to any and all Program IP
or Joint Program IP, and intellectual property rights therein, as is necessary to effect the intent of this Section 7.6. 

7.7    Prosecution and Maintenance of Prothena Collaboration Patents and Program Patents. 

7.7.1    Pre-Phase 1 Option Exercise. Subject to Section 7.7.2, on a Program-by-Program basis, the provisions of this Section 7.7.1 shall apply with respect to Prothena Collaboration Patents and Program Patents for such Program prior to
the execution of a Global License Agreement (or the expiration of the Phase 1 Option Term if Celgene does not timely exercise its Phase 1 Option) with respect to such Program. 

(a)    Prothena First Right. Subject to Section 7.7.1(b), Prothena shall have the first right (but not the
obligation) to Prosecute and Maintain the Prothena Collaboration Patents and Program Patents; provided that Prothena shall [***] Prosecute and Maintain the Prothena Collaboration Patents and Program Patents in the Primary Patent Countries ([***]).
All such Prosecution and Maintenance by Prothena shall be through patent counsel [***]. Prothena shall keep Celgene informed as to material developments with respect to the Prosecution and Maintenance of such Patents including by providing copies of
all substantive office actions, examination reports, communications or any other substantive documents to or from any patent office, including notice of all interferences, reissues, re-examinations, inter
partes reviews, derivations, post grant proceedings, oppositions or requests for patent term extensions. Prothena shall also provide Celgene with a reasonable opportunity to comment substantively on the Prosecution and Maintenance of such Patents
prior to taking material actions (including the filing of initial applications), and will in good faith consider any comments made by and actions recommended by Celgene, provided however that Celgene provides its comments reasonably in advance of
any applicable filing deadlines. 
 (b)    Back-Up Right. If Prothena in
any country decides not to file, or decides not to participate in any interferences, reissues, re-examinations, inter partes reviews, post grant proceedings or oppositions with respect to, a Prothena
Collaboration Patent or a Program Patent, in each case other than a Prothena Platform Patent, or intends to allow such Patent to lapse or become abandoned without having first filed a substitute, it shall notify and consult with Celgene of such
decision or intention at least [***] ([***]) days prior to the date upon which the subject matter of such Patent shall become unpatentable or such Patent shall lapse or become abandoned, Celgene shall thereupon have the right (but not the
obligation) upon written notice to Prothena to assume the Prosecution and Maintenance thereof, at Celgene’s expense with counsel of its choice ([***]). For clarity, the provisions of this Section 7.7.1(b) shall not (i) limit
Prothena’s obligations to Prosecute and Maintain the Prothena Collaboration Patents and Program Patents in 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
the Primary Patent Countries as set forth in Section 7.7.1(a), or (ii) apply to a Prothena Collaboration Patent or Program Patent solely claiming or covering a Lapsed Target or an
Antibody that Targets a Lapsed Target (and no other Collaboration Target). 
 (c)    Cooperation in Prosecution and
Maintenance. 
 (i)    Further Assurances. If Celgene determines to undertake the Prosecution and Maintenance
of a Prothena Collaboration Patent or Program Patent in accordance with this Section 7.7, Prothena agrees to make its employees, agents and consultants reasonably available to Celgene (and to Celgene’s authorized attorneys, agents or
representatives), to enable Celgene to undertake such Prosecution and Maintenance. In addition, Prothena shall (and shall cause its Affiliates and its and their employees, agents and consultants to) provide reasonable assistance to Celgene (and to
Celgene’s authorized attorneys, agents or representatives), to enable Celgene to undertake such Prosecution and Maintenance, including by executing powers of attorney and other documents for Celgene to undertake such Prosecution and
Maintenance. 
 (ii)    Assistance. The Parties shall reasonably cooperate with one another, through the Patent
Committee (including their respective Patent Liaisons), with respect to the Prosecution and Maintenance of the Prothena Collaboration Patents and Program Patents for which either Party is responsible for Prosecution and Maintenance pursuant to this
Section 7.7, including in the furtherance of the Patent Strategy. [***], the Parties shall cooperate with one another to [***], in each case that are applicable to a Collaboration Target or Collaboration Candidate, as applicable, if practicable
to [***]. 
 (d)    Costs of Prosecution and Maintenance. Except as otherwise expressly set forth in this
Section 7.7.1, each Party shall be responsible for all costs and expenses associated with its Prosecution and Maintenance activities under this Section 7.7.1 with respect to Prothena Collaboration Patents and Program Patents for which it
is responsible pursuant to Sections 7.7.1(a) or 7.7.1(b), as applicable. 

7.7.2    Post-IND Option Exercise. On a Program-by-Program basis, after Celgene’s execution of a U.S. License Agreement with respect to such Program, Prosecution and Maintenance of the Prothena Collaboration Patents and Program Patents for
such Program in the United States shall be in accordance with the applicable U.S. License Agreement for such Program. In the event that a given Prothena Collaboration Patent or Program Patent relates to multiple Programs, then the provisions of this
Section 7.7.2 shall control over the provisions of Section 7.7.1. 
 7.7.3    Post-Phase 1 Option
Exercise. On a Program-by-Program basis, after execution of a Global License Agreement with respect to such Program, Prosecution and Maintenance of the Prothena
Collaboration Patents and Program Patents for such Program shall be in accordance with the applicable Global License Agreement for such Program. In the event that a given Prothena Collaboration Patent or Program Patent relates to multiple Programs,
then the provisions of this Section 7.7.3 shall control over the provisions of Section 7.7.1, Section 7.7.2 and the provisions of the applicable U.S. License Agreement for such Program. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.8    Enforcement of Prothena Collaboration Patents and Program
Patents. 
 7.8.1    Prior to Exercise of Phase 1 Option. Subject to Section 7.8.2, on a Program-by-Program basis, the provisions of this Section 7.8.1 shall apply with respect to Prothena Collaboration Patents and Program Patents for such Program prior to
the exercise of Celgene’s IND Option with respect to such Program. 
 (a)    Notice. If any Party learns of
an infringement or threatened infringement by a Third Party of any Prothena Collaboration Patent or Program Patent in each case other a Prothena Platform Patent (including in connection with any Biosimilar Application referencing a Collaboration
Product (regardless of whether such notice or copy is provided under any Applicable Laws) including under the BPCIA or the United States Patient Protection and Affordable Care Act or its successor provisions, or any similar provisions in a country
outside the United States, as applicable), such Party shall promptly notify the other Party and shall provide such other Party with available evidence of such infringement, and following such notification, the Parties shall confer. 

(b)    Enforcement. As between the Parties, subject to the remaining provisions of this Section 7.8.1,
Prothena shall have the sole right, but not the obligation, to institute, prosecute, and control any action or proceeding (which may include settlement or otherwise seeking to secure the abatement of such infringement) with respect to any
infringement of any Prothena Collaboration Patent or Program Patent in each case other than a Prothena Platform Patent (including in connection with any Biosimilar Application referencing a Collaboration Product (regardless of whether such notice or
copy is provided under any Applicable Laws) including under the BPCIA or the United States Patient Protection and Affordable Care Act or its successor provisions, or any similar provisions in a country outside the United States, as applicable), by
counsel of its own choice, in Prothena’s own name and under Prothena’s direction and control, including the right to control the defense of any challenges to such Patents as a counterclaim in such infringement proceeding as well as the
defense of declaratory judgment actions. 
 (c)    Consultation. Prothena will keep Celgene regularly informed
of the status and progress of such enforcement efforts. Prothena shall consult with Celgene and will take comments of Celgene into good faith consideration with respect to the infringement or claim construction of any claim in any Prothena
Collaboration Patent or Program Patent in each case other a Prothena Platform Patent. 
 (d)    Settlement. A
settlement or consent judgment or other voluntary final disposition of a suit with respect to Prothena Collaboration Patents or Program Patents in each case other than a Prothena Platform Patent, under this Section 7.8.1 may be entered into
without the consent of Celgene; provided, however, that any such settlement, consent judgment or other disposition of any action or proceeding by Prothena under this Section 7.8.1 shall not, without the prior written consent of Celgene,
(i) impose [***] liability or obligation on Celgene or any of its Affiliates, (ii) conflict with [***] the subject matter claimed in the applicable Prothena Collaboration Patent or Program Patent, (iii) include the grant of any
license, covenant or other rights to any Third Party that would conflict with [***] the rights or licenses (including Options) granted to Celgene under this Agreement, any U.S. License Agreement or any Global License Agreement, or (iv) [***]. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (e)    Costs and Recoveries. Prothena shall bear all costs
incurred in connection with its activities under this Section 7.8.1. Any damages or other monetary awards recovered in any action, suit or proceeding brought under this Section 7.8.1 to the extent related to any Prothena Collaboration
Patents or Program Patents shall be shared as follows: 
 (i)    the amount of such recovery actually received shall
first be applied to reimburse costs and expenses incurred by each Party in connection with such action (including, for this purpose, [***] counsel); and 

(ii)    [***] any additional sums recovered by it under such proceeding. 

7.8.2    Post-IND Option Exercise. On a Program-by-Program basis and after Celgene’s exercise of its IND Option with respect to such Program, enforcement of the Prothena Collaboration Patents and Program Patents for such Program in the United
States shall be in accordance with the applicable U.S. License Agreement for such Program. In the event that a given Prothena Collaboration Patent or Program Patent relates to multiple Programs, then the provisions of this Section 7.8.2 shall
control over the provisions of Section 7.8.1. 
 7.8.3    Post-Phase 1 Option Exercise. On a Program-by-Program basis and after Celgene’s exercise of its Phase 1 Option with respect to such Program, enforcement of the Prothena Collaboration Patents and Program
Patents for such Program shall be in accordance with the applicable Global License Agreement for such Program. In the event that a given Prothena Collaboration Patent or Program Patent relates to multiple Programs, then the provisions of this
Section 7.8.3 shall control over the provisions of Section 7.8.1, Section 7.8.2 and the provisions of the applicable U.S. License Agreement for such Program. 

7.9    Matters Involving Joint Program Patents. The Prosecution and Maintenance, and the enforcement and defense,
of any Joint Program Patents shall be jointly managed by the Parties through independent patent counsel (mutually agreed to by the Parties) jointly representing the Parties, including any costs and recoveries regarding same. Prior to either Party
publishing any Joint Program Know-How, the Parties will discuss if a Joint Program Patent claiming such Joint Program Know-How should be filed. 

7.10    Common Interest Agreement. At the request of either party, the Parties shall negotiate in good faith to
enter into a common interest agreement to govern their discussion of Patent matters. 
 7.11    License Filing.
At the request of Celgene, Prothena shall, and shall cause its Affiliates to assist in any license registration processes with applicable Governmental Authorities that may be available for the protection of Celgene’s interests in this
Agreement. 
 7.12    Defense of Claims Brought by Third Parties. If a Party becomes aware of any actual or
potential claim that the Development or Manufacture of any Collaboration Target, Collaboration Candidate or Collaboration Product by or on behalf of Prothena pursuant to the conduct of a Program under this Agreement infringes the intellectual
property rights of any Third Party, such Party shall promptly notify the other Party. In any such instance, the Parties shall as soon as practicable thereafter meet (which may be through the JSC) to discuss in good faith regarding the best response
to such notice. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.13    Celgene Activities. Notwithstanding anything to the
contrary in this Agreement, any U.S. License Agreement or any Global License Agreement, in no event may Prothena or its Affiliates Prosecute and Maintain, or enforce, by virtue of this Agreement, any U.S. License Agreement and/or any Global License
Agreement, any Patent that claims or covers any Antibody Targeting a Collaboration Target, or any product constituting, incorporating, comprising or containing any such Antibody, that Celgene or any of its Affiliates Develops, Manufactures or
Commercializes under this Agreement, any U.S. License Agreement or any Global License Agreement, unless such Patent is included in the Prothena Collaboration Patents and Program Patents as expressly set forth in Article 7 of this Agreement or in the
applicable provisions of any U.S. License Agreement or any Global License Agreement, as applicable. 
 ARTICLE 8 

CONFIDENTIALITY 

8.1    Nondisclosure. Each Party agrees that a Party (the “Receiving Party”) receiving
Confidential Information of the other Party (the “Disclosing Party”) pursuant to this Agreement shall (a) maintain in confidence such Confidential Information using not less than the efforts such Receiving Party uses to
maintain in confidence its own proprietary information of similar kind and value, but in no event less than a reasonable degree of efforts, (b) not disclose such Confidential Information to any Third Party without the prior written consent of
the Disclosing Party, except for disclosures expressly permitted pursuant to this Article 8, and (c) not use such Confidential Information for any purpose except those permitted by this Agreement, any U.S. License Agreement or any Global
License Agreement, including, in the case of Celgene, the exercise of the rights and licenses (including Options) granted to Celgene hereunder and thereunder (it being understood that this clause (c) shall not create or imply any rights or
licenses not expressly granted under this Agreement). The obligations of confidentiality, non-disclosure and non-use under this Section 8.1 shall be in full force
and effect during the Term and for a period of [***] ([***]) years thereafter. The Receiving Party will return all copies of or destroy (and certify such destruction in writing) the Confidential Information of the Disclosing Party disclosed or
transferred to it by the other Party pursuant to this Agreement, within [***] ([***]) days after the termination or expiration of this Agreement; provided, however, that a Party may retain (i) Confidential Information of the other Party to
exercise rights and licenses which expressly survive such termination or expiration pursuant to this Agreement (including, in the case of Celgene as the receiving Party, exercising its rights and licenses under a U.S. License Agreement or Global
License Agreement, as applicable, and in such case, Celgene shall not be required to return or destroy any Confidential Information of Prothena), and (ii) one (1) copy of all other Confidential Information in archives solely for the purpose of
establishing the contents thereof. Without limiting the foregoing, [***] will keep confidential, and will cause its Affiliates and its and their employees, consultants, licensees, sublicensees and professional advisors to keep confidential, [***] on
confidentiality terms at least as protective as the confidentiality provisions of this Agreement (without regard to Section 8.3). 

8.2    Collaboration Specific Confidential Information. Notwithstanding anything to the contrary contained herein,
the Parties agree and acknowledge that any Collaboration Specific IP 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
shall be deemed to be Confidential Information of each Party (without regard to Section 8.3), and each Party shall be deemed to be the Disclosing Party with respect to the Collaboration
Specific IP. As used herein, (a) the term “Collaboration Specific IP” means, with respect to a given Program, (i) [***], (ii) [***], and (iii) [***]; and (b) the term “Collaboration
Non-Specific IP” means all Prothena Platform Technology within the Prothena Collaboration Know-How, and other Collaboration
Know-How and Program Know-How other than Collaboration Specific IP; provided that, in the event that Celgene does not exercise its IND Option for a given Program, then
the Collaboration Specific IP with respect to such Program shall thereafter no longer be deemed to be Collaboration Specific IP pursuant to this Section 8.2, solely to the extent that such Collaboration Specific IP does not include
Collaboration Specific IP relating to a different Program. For clarity, Collaboration Non-Specific IP shall be deemed to be the Confidential Information of Prothena. 

8.3    Exceptions. 

8.3.1    General. The obligations in Section 8.1 shall not apply with respect to any portion of the
Confidential Information of the Disclosing Party that the Receiving Party can show by competent written proof: 

(a)    was known to the Receiving Party or any of its Affiliates, without any obligation to keep it confidential or any
restriction on its use, prior to disclosure by the Disclosing Party; 
 (b)    is subsequently disclosed to the
Receiving Party or any of its Affiliates by a Third Party lawfully in possession thereof and without any obligation to keep it confidential or any restriction on its use; 

(c)    is published by a Third Party or otherwise becomes publicly available or enters the public domain, either before
or after it is disclosed to the Receiving Party, without any breach by the Receiving Party of its obligations hereunder; 

(d)    is published by a Party in accordance with Section 8.7 without any breach by such Party of its obligations
hereunder; or 
 (e)    is independently developed by or for the Receiving Party or its Affiliates without reference to
or reliance upon the Disclosing Party’s Confidential Information. 
 Any combination of features or disclosures shall not be deemed to
fall within the foregoing exclusions merely because individual features are published or available to the general public or in the rightful possession of the Receiving Party unless the combination itself and principle of operation are published or
available to the general public or in the rightful possession of the Receiving Party. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 8.4    Authorized Disclosure. 

8.4.1    Disclosure. Notwithstanding Section 8.1, the Receiving Party may disclose Confidential Information
belonging to the Disclosing Party in the following instances: 
 (a)    subject to Section 8.6, to comply with
Applicable Law (including the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) or any national securities exchange) or with judicial process (including prosecution or defense of litigation), if, in the
reasonable opinion of the Receiving Party’s counsel, such disclosure is necessary for such compliance or for such judicial process (including prosecution or defense of litigation); 

(b)    is disclosed to governmental or other regulatory agencies in order to obtain Patents or to gain or maintain
approval to conduct Clinical Trials under this Agreement, in each case, in accordance with this Agreement, but such disclosure shall only be to the extent reasonably necessary to obtain such Patents or authorizations, and provided that reasonable
steps are taken to ensure confidential treatment of such Confidential Information (if available); 
 (c)    to any of
its officers, employees, consultants, agents or Affiliates (including, (i) [***] (ii) in the case of either Party to such Party’s subcontractors for purpose of such subcontractor performing obligations of such Party under this Agreement) as it
deems necessary or advisable in the course of conducting activities in accordance with this Agreement in order to carry out its responsibilities or exercise its rights under this Agreement (including the exercise of the rights and licenses
(including, the evaluation of its Options) granted to the relevant Party hereunder, and (iii) in the case of either Party, to such Party’s actual or potential acquirers; provided that each such disclosee is bound by written confidentiality
obligations and non-use obligations no less restrictive than those set forth in this Article 8 to maintain the confidentiality thereof and not to use such Confidential Information except as expressly permitted
by this Agreement; provided, however, that, in each of the above situations in this Section 8.4.1(c), the Receiving Party shall remain responsible for any failure by any Person who receives Confidential Information from such Receiving Party
pursuant to this Section 8.4.1(c) to treat such Confidential Information as required under this Article 8; and 

(d)    disclosure, solely on a “need to know basis” to its advisors (including attorneys and accountants) in
connection with activities hereunder; provided that, prior to any such disclosure, each disclosee must be bound by written obligations of confidentiality, non-disclosure and
non-use no less restrictive than the obligations set forth in this Article 8 (provided, however, that in the case of legal advisors, no written agreement shall be required), which for the avoidance of doubt,
will not permit use of such Confidential Information for any purpose except those expressly permitted by this Agreement; provided, however, that, in each of the above situations in this Section 8.4.1(d), the Receiving Party shall remain
responsible for any failure by any Person who receives Confidential Information from such Receiving Party pursuant to this Section 8.4.1(d) to treat such Confidential Information as required under this Article 8. 

8.4.2    Terms of Disclosure. If and whenever any Confidential Information is disclosed in accordance with this
Section 8.4, such disclosure shall not cause any such information to cease to be Confidential Information except to the extent that such disclosure results in a public disclosure of such information (other than by breach of this Agreement).
Where reasonably possible and subject to Section 8.6, the Receiving Party shall notify the Disclosing Party of the Receiving Party’s intent to make any disclosures pursuant to Section 8.4.1(a) sufficiently prior to making such
disclosure so as to allow the Disclosing Party adequate time to take whatever action it may deem appropriate to protect the confidentiality of the information, and the Receiving Party will provide reasonable assistance to the Disclosing Party with
respect thereto; provided that, in 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
such event, the Receiving Party will use reasonable measures to ensure confidential treatment of such information and shall only disclose such Confidential Information of the Disclosing Party as
is necessary for the purposes of Section 8.4.1(a), as applicable. 
 8.4.3    Collaboration Specific IP.
Neither Party shall disclose the Collaboration Specific IP without the prior written consent of the other Party, other than pursuant to Section 8.4.1. 

8.5    Terms of this Agreement. The Parties agree that this Agreement and the terms hereof shall be deemed to be
Confidential Information of both Prothena and Celgene, and each Party agrees not to disclose any of them without the prior written consent of the other Party, except that each Party may disclose any of them in accordance with the provisions of
Sections 8.4 and/or 8.6, as applicable. 
 8.6    Securities Filings; Disclosure under Applicable Law.
Each Party acknowledges and agrees that the other Party may submit this Agreement to (or file this Agreement with) the SEC or any national securities exchange in any jurisdiction (collectively, the “Securities Regulators”), or to
other Persons as may be required by Applicable Law, and if a Party does submit this Agreement to (or file this Agreement with) any Securities Regulators, or other Persons as may be required by Applicable Law, such Party agrees to consult with the
other Party with respect to the preparation and submission of a confidential treatment request for this Agreement. Notwithstanding the foregoing, if a Party is required by Applicable Law or any Securities Regulator to make a disclosure of the terms
of this Agreement in a filing or other submission as required by Applicable Law or Securities Regulator, and (a) such Party has provided copies of the disclosure to the other Party reasonably in advance of such filing or other disclosure under
the circumstances, (b) such Party has promptly notified the other Party in writing of such requirement and any respective timing constraints, and (c) such Party has given the other Party a reasonable time under the circumstances from the
date of notice by such Party of the required disclosure to comment upon and request confidential treatment for such disclosure, then such Party will have the right to make such disclosure at the time and in the manner reasonably determined by its
counsel to be required by Applicable Law or Securities Regulator. Notwithstanding the foregoing, it is hereby understood and agreed that if a Party seeks to make a disclosure as required by Applicable Law or Securities Regulator as set forth in this
Section 8.6, and the other Party provides comments within the respective time periods or constraints specified herein or within the respective notice, the Party seeking to make such disclosure or its counsel, as the case may be, will in good
faith consider incorporating such comments. 
 8.7    Publicity. 

8.7.1    Press Release. Subject to Sections 8.4 and 8.6 and this Section 8.7, each Party agrees not to, and
agrees to cause their Affiliates not to, issue any press release or other public statement disclosing this Agreement, the activities hereunder, or the transactions contemplated hereby unless such press release or other public statement is approved
by the other Party in writing; provided that either Party shall be authorized to make any disclosure, without the approval of the other Party, that is required by Applicable Law (including the U.S. Securities Act of 1933, as amended, and the U.S.
Securities Exchange Act of 1934, as amended) or the rules of any Securities Regulator, or by judicial process, subject to and in accordance with Sections 8.4 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
and 8.6, as applicable. Without limiting the foregoing, and subject to the foregoing proviso, in the event that Prothena desires to issue an initial press release regarding the execution of this
Agreement, Prothena shall have the right to do so provided that (i) [***] and (ii) [***]. 
 8.7.2    Additional
Restrictions on Disclosure. Without limiting any other restrictions on disclosure as set forth in this Article 8, on a Program-by-Program basis, with respect to any
press release or other public statement proposed to be made by Prothena prior to Celgene’s exercise of the Phase 1 Option for such Program, if such press release or public statement discloses any information with respect to [***], such press
release or other public statement may not be issued without Celgene’s prior written consent, except for such disclosures by Prothena as required by Applicable Law or Securities Regulators (solely and to the extent Prothena’s counsel
determines such disclosure is required by Applicable Law or Securities Regulators); provided that (i) in such case Prothena shall use reasonable efforts to afford Celgene a reasonable period of time to review any such disclosure and any
comments made by Celgene will be considered in good faith, and (ii) any information that has been previously publicly disclosed in accordance with this Agreement may be disclosed again as long as such disclosure does not exceed the scope of
such prior public disclosure. Subject to the foregoing, in the event Celgene proposes that Prothena use specific wording or language with respect thereto, Prothena shall in good faith consider incorporating such wording or language. This
Section 8.7.2 shall not apply, on a Program-by-Program basis following the expiration of the Phase 1 Option Term for the applicable Program if the Phase 1 Option
has not been exercised. 
 8.7.3    Previously Issued Public Statements. The contents of any press release or
other public statement that has been reviewed and approved by a reviewing Party may be re-released by the publishing Party or by such reviewing Party without a requirement for
re-approval. 
 8.8    Permitted Publications. 

8.8.1    Publication. In the event either Party (or its Affiliates) (the “Publishing Party”)
desires to publish or present any information (including publications in journals, posters, presentations at conferences and abstracts submitted in advance of conferences) with respect to [***], subject to Sections 8.4, 8.6 and 8.7, the Publishing
Party shall provide the other Party with a copy of such proposed publication or presentation no less than [***] ([***]) days prior(provided that the other Party shall use Commercially Reasonable Efforts to accommodate a shorter time period if
required due to circumstances outside of the Publishing Party’s control) prior to its intended submission for publication or public disclosure. For the avoidance of doubt, the foregoing shall apply with respect to each proposed publication or
presentation regardless of whether a prior publication or presentation was provided (e.g., if an abstract is provided in accordance with this Section 8.8.1 and a Publishing Party wishes to publish the corresponding full manuscript, the full
manuscript must be provided to the other Party pursuant to this Section 8.8.1). The other Party shall respond in writing promptly and in no event later than [***] ([***]) days after receipt of the proposed material (provided that the other
Party shall use Commercially Reasonable Efforts to accommodate a shorter time period if notified by the Publishing Party and required due to circumstances outside of the Publishing Party’s control), with one or more of the following: 

(a)    comments on the proposed material, which the Publishing Party shall consider in good faith; and/or 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (b)    a specific statement of concern, based upon the need to seek
patent protection or to block publication or public disclosure (including publications in journals, posters, presentations at conferences and abstracts submitted in advance of conferences) if such other Party reasonably determines that the proposed
disclosure is intellectual property that should be maintained as a trade secret to protect any Collaboration Target, Collaboration Candidate or Collaboration Product that is the subject of such Program, in which event the Publishing Party agrees not
to submit such publication or make such presentation that contains such information until: 
 (i)    with
respect to publication or presentation of Collaboration Non-Specific IP, the other Party is given [***] to seek patent protection for any such Collaboration Non-Specific
IP in such publication or presentation which it believes is patentable or to resolve any other issues, or 

(ii)    with respect to publication or presentation of Collaboration Specific IP, [***] for the other Party to
(x) enable further development and optimization of such Collaboration Specific IP (including related Collaboration Candidates and Collaboration Products), (y) seek patent protection for any such Collaboration Specific IP in such publication or
presentation which it believes is patentable or (z) resolve any other issues; and/or 
 (c)    an identification
of the other Party’s Confidential Information that is contained in the material reviewed, which the Publishing Party shall remove, if requested by the other Party. 

Notwithstanding the foregoing, if Celgene fails to exercise the IND Option during the IND Option Term for a Program, then
Section 8.8.1(b) shall no longer apply with respect to publications or presentations relating solely to such Program (and to no other Programs). 

8.8.2    Prothena Subcontractors. Except with respect to any subcontractors of Prothena who are [***] engaged by
Prothena to perform research under a Program and who are [***], Prothena shall [***] that no publication or presentation is made by any subcontractors or Affiliates of Prothena, with respect to the [***], except in accordance with
Section 8.8.1. 
 8.9    Re-Publication;
Re-Presentation. The contents of any publication or presentation that has been reviewed and approved by a reviewing Party may be re-released by the Publishing Party
or the reviewing Party without a requirement for re-approval. 
 8.10    Use
of Names. Except as otherwise expressly set forth herein, no Party (or its respective Affiliates) shall use the name, trademark, trade name or logo of the other Party or its Affiliates, or its or their respective employee(s), in any publicity,
promotion, news release or other public disclosure relating to this Agreement or its subject matter, without the prior written permission of the other Party; provided that such permission shall not be required to the extent use thereof may be
required by Applicable Law or Securities Regulators, including the rules of any securities exchange or market on which a Party’s (or its Affiliate’s) securities are listed or traded. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 8.11    Relationship to Existing Confidentiality Agreement. This
Agreement supersedes that certain Mutual Confidentiality Agreement entered into between Prothena and Celgene, effective as of March 6, 2017 (the “Existing Confidentiality Agreement”); provided that all “Confidential
Information” disclosed by the “Disclosing Party” thereunder shall be deemed Confidential Information of the Disclosing Party hereunder (subject to Section 8.2) and shall be subject to the terms and conditions of this Agreement
(or U.S. License Agreement or Global License Agreement, as applicable, pursuant to Section 8.13) and the “Receiving Party” thereunder shall be bound by and obligated to comply with such terms and conditions as if they were the
Receiving Party hereunder. The foregoing shall not be interpreted as a waiver of any remedies available to the “Disclosing Party” under the Existing Confidentiality Agreement as a result of any breach, prior to the Effective Date, by the
“Receiving Party”, of its obligations pursuant to the Existing Confidentiality Agreement. 

8.12    Clinical Trials Registry. Either Party shall have the right to publish registry information and customary
summaries of data and results from any Phase 1 Clinical Trials conducted by or on behalf of such Party under this Agreement, on its clinical trials registry or on a government-sponsored database such as www.clinicaltrials.gov, without requiring the
consent of the other Party. The Parties shall reasonably cooperate if required or reasonably requested by the Party seeking such publication in order to facilitate any such publication by such Party. 

8.13    U.S. License Agreement; Global License Agreement. Notwithstanding the foregoing provisions of this Article
8, (a) if a U.S. License Agreement is entered into with respect to a given Program, then to the extent there is a conflict between the provisions of this Article 8 and the provisions of Article 7 of such U.S. License Agreement, the provisions of
Article 7 of such U.S. License Agreement shall control with respect to Confidential Information related to such Program and (b) if a Global License Agreement is entered into with respect to a given Program, then the provisions of such Global
License Agreement shall control with respect to Confidential Information related to such Program in lieu of this Article 8. 
 ARTICLE 9

 REPRESENTATIONS AND WARRANTIES; COVENANTS 

9.1    Representations and Warranties of Both Parties. Each Party hereby represents and warrants to the other
Party, as of the Effective Date, that: 
 (a)    such Party is duly organized, validly existing and in good standing
under the Applicable Law of the jurisdiction of its formation and has full corporate power and authority to enter into this Agreement, and to carry out the provisions hereof; 

(b)    such Party has taken all necessary corporate action on its part to authorize the execution and delivery of this
Agreement and the performance of its obligations hereunder; 
 (c)    this Agreement has been duly executed and
delivered on behalf of such Party, and constitutes a legal, valid, binding obligation, enforceable against it in accordance with its terms, except to the extent that enforcement of the rights and remedies created hereby is subject to
(i) bankruptcy, insolvency, reorganization, moratorium and other similar laws of general application affecting the rights and remedies of creditors, or (ii) laws governing specific performance, injunctive relief and other equitable
remedies; 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (d)    the execution, delivery and performance of this Agreement by
such Party does not breach or conflict with any agreement or any provision thereof, or any instrument or understanding, oral or written, to which such Party (or any of its Affiliates) is a party or by which such Party (or any of its Affiliates) is
bound, nor violate any Applicable Law of any Governmental Authority having jurisdiction over such Party (or any of its Affiliates); 

(e)    no government authorization, consent, approval, license, exemption of or filing or registration with any court or
governmental department, commission, board, bureau, agency or instrumentality, domestic or foreign, under any Applicable Law currently in effect, is or will be necessary for, or in connection with, the transaction contemplated by this Agreement, or
for the performance by it of its obligations under this Agreement (including, in the case of Prothena, the grant of the rights to Celgene hereunder, including the Options), except (i) as may be required to conduct Clinical Trials or to seek or
obtain Regulatory Approvals or applicable Regulatory Materials or (ii) as set forth in Section 3.2; and 

(f)    it has obtained all necessary authorizations, consents and approvals of any Third Party that is required to be
obtained by it as of the Effective Date for, or in connection with, the transaction contemplated by this Agreement, or for the performance by it of its obligations under this Agreement (including, in the case of Prothena, the grant of the rights to
Celgene hereunder, including the Options), except (i) as may be required to conduct Clinical Trials or to seek or obtain Regulatory Approvals or applicable Regulatory Materials or (ii) as set forth in Section 3.2. 

9.2    Representations and Warranties of Prothena. Prothena hereby represents and warrants to Celgene, as of the
Effective Date, that: 
 (a)    Schedule 1.66 contains a complete and accurate list of all Patents included in
the Prothena IP that claim or cover any Collaboration Target or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target, including the composition or use of any of
the foregoing, and Prothena Controls all such Patents. Except for the Prothena IP, Prothena and its Affiliates do not own or control (by license or otherwise), as of the Effective Date, any Patent or Know-How
that is necessary or useful to Develop, Manufacture or Commercialize any Collaboration Targets or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target. To
Prothena’s and its Affiliates’ actual knowledge all issued Patents within the Prothena IP are in full force and effect, and are not invalid or unenforceable, in whole or in part; 

(b)    no claim has been issued or served, or written threat of a claim or litigation made by any Person, against
Prothena or its Affiliates that alleges that any Prothena IP is invalid or unenforceable; 
 (c)    neither Prothena
nor its Affiliates own or otherwise control (through license or otherwise) any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target a Collaboration Target other than as set forth on
Schedule 1.14; 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (d)    [***]; 

(e)    Except with respect to payment obligations under vendor agreements existing as of the Effective Date and entered
into by Prothena or its Affiliates in the ordinary course of business and not specifically for the purposes of this Agreement (which payment obligations are Prothena’s (or its Affiliates’, as applicable) sole responsibility), neither
Prothena nor its Affiliates are subject to any payment obligations to Third Parties as a result of the execution or performance of this Agreement, or the research, development, manufacture or commercialization of any Collaboration Target or any
Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target; 

(f)    Prothena has the full right and authority to grant all of the rights and licenses granted to Celgene (or purported
to be granted to Celgene) hereunder; and neither Prothena nor its Affiliates have granted any right or license to any Third Party relating to any of the Prothena IP or any other Program Assets, Collaboration Targets or Antibodies (or any products
constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target, that would conflict with [***] any of the rights or licenses (including the Options) granted to Celgene hereunder; 

(g)    Prothena is the sole and exclusive owner of the Prothena IP, except for the Prothena Collaboration IP that is
licensed to Prothena (or its Affiliates) pursuant to the In-License Agreements set forth on Schedule 1.42 on a nonexclusive or exclusive basis (as set forth on Schedule 1.42). All
Affiliates of Prothena have exclusively licensed or assigned all of their right, title and interest in and to the Prothena IP to Prothena. Neither Prothena nor its Affiliates have granted any mortgage, pledge, claim, security interest, lien or other
charge of any kind on the Prothena IP or other Program Assets, and the Prothena IP and the other Program Assets are free and clear of any mortgage, pledge, claim, security interest, lien or charge of any kind; 

(h)    neither Prothena nor its Affiliates have received any written notice of any claim that any Patent or Know-How (including any trade secret right) owned or controlled by a Third Party would be infringed or misappropriated by the Development, Manufacture, or Commercialization of any Collaboration Target or any
Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target; 

(i)    to Prothena’s and its Affiliates’ actual knowledge, (i) the Development and Manufacture of any
Collaboration Target or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target, as conducted by or on behalf of Prothena or its Affiliates prior to the Effective
Date, has not violated, infringed or misappropriated any intellectual property or proprietary right of any Third Party and (ii) [***]; 

(j)    there are no claims, judgments, settlements, litigations, suits, actions, disputes, arbitration, judicial or legal
administrative or other proceedings or governmental investigations pending or, to Prothena’s or its Affiliates’ actual knowledge, threatened against 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
Prothena or its Affiliates which would reasonably be expected to adversely affect or restrict the ability of Prothena to consummate or perform the transactions contemplated under this Agreement
(or pursuant to a U.S. License Agreement or Global License Agreement), or which would affect the Prothena IP or other Program Assets, or Prothena’s Control thereof, or any Collaboration Target or any Antibodies (or any products constituting,
incorporating, comprising or containing any such Antibody) that Target any Collaboration Target; 
 (k)    neither
Prothena nor its Affiliates have issued a claim against a Third Party alleging that a Third Party is infringing or has infringed or misappropriated any Prothena IP, and, to Prothena’s and its Affiliates’ actual knowledge, no issued Patents
within the Prothena IP are being infringed and no trade secrets within the Prothena IP are being misappropriated by any Third Party; 

(l)    neither Prothena nor its Affiliates have employed or otherwise used in any capacity, the services of any Person
suspended, proposed for debarment or debarred under United States law, including under 21 U.S.C. § 335a, or any foreign equivalent thereof, with respect to any Collaboration Target, or any Antibodies (or any products constituting,
incorporating, comprising or containing any such Antibody) that Target any Collaboration Target. All Manufacture and Development (including non-clinical studies and Clinical Studies) related to any
Collaboration Target, or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target, conducted by on behalf of Prothena or its Affiliates prior to the Effective Date
has been conducted in accordance with all Applicable Laws (including, to the extent applicable, GCP, GLP and GMP); 

(m)    neither Prothena nor its Affiliates have entered into any agreement under which Prothena or its Affiliates
(i) has obtained a license or sublicense of rights from a Third Party to any Collaboration Target, or to any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration
Target, or to any Prothena IP, except for the In-License Agreements set forth on Schedule 1.42, or (ii) has granted a license, sublicense, option or right to a Third Party that remains in
effect as of the Effective Date to research, develop, manufacture or commercialize any Collaboration Target or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration
Target, except (1) with respect to licenses or rights granted pursuant to the agreements set forth on Schedule 1.42 that were entered into in the ordinary course of business [***] performing activities on behalf of Prothena and (2)
[***]. The agreements set forth on Schedule 1.42 do not conflict with [***] the rights or licenses (including the Options) granted to Celgene hereunder; 

(n)    with respect to each In-License Agreement, (i) it is in full force
and effect; (ii) neither Prothena nor its Affiliates is in breach thereof; and (iii) neither Prothena nor its Affiliates has received any notice from the counterparty to such In-License Agreement of
Prothena’s breach or notice of threatened breach by Prothena or its Affiliates thereof; 
 (o)    Prothena has
disclosed to Celgene all material information and data, and all material correspondences to/from any Regulatory Authority, existing as at the Effective Date in the possession or control of Prothena or its Affiliates, in each case related to any
Collaboration Target or Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target; and 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (p)    Prothena has not obtained or filed, any INDs, MAAs or Regulatory
Approvals or any other form of regulatory application for approval of Clinical Trials, marketing or other purpose, for any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any
Collaboration Target and, to Prothena’s and its Affiliates actual knowledge, no other Person has obtained, or filed for, any such INDs, MAAs or Regulatory Approvals. 

9.3    Additional Representations, Warranties and Covenants of Prothena. Prothena hereby further represents,
warrants and covenants to Celgene that: 
 9.3.1    With respect to the
In-License Agreements, (a) Prothena (or its Affiliates, as applicable) shall not breach, or commit any acts or permit the occurrence of any omissions that would cause the material breach or termination,
of any In-License Agreement and (b) Prothena shall (or shall cause its Affiliates to, as applicable) satisfy all of its obligations under each In-License Agreement in all material respects and shall, or
shall cause its Affiliates to, as applicable, maintain each In-License Agreement in full force and effect. Prothena shall, or shall cause its Affiliates to, as applicable, enforce it rights under each In-License Agreement to the extent necessary to preserve Celgene’s rights under this Agreement or any U.S. License Agreement or Global License Agreement. Prothena shall not, and shall cause its Affiliates not
to, [***] unless Prothena otherwise obtains Celgene’s prior written consent (such consent not to be unreasonably withheld) if doing so [***] under this Agreement or any U.S. License Agreement or Global License Agreement. Prothena will provide
Celgene with prompt written notice of any claim of a breach of which it is aware under any of the In-License Agreements or notice of termination of any In-License
Agreement. 
 9.3.2    Prothena shall promptly notify Celgene in writing if any additional Prothena Collaboration
Patents that claim or cover any Collaboration Target or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target any Collaboration Target, including the composition or use of any of the
foregoing, becomes known to Prothena that are not listed on Schedule 1.66. 
 9.4    Representations and
Warranties of Celgene. Celgene hereby represents and warrants to Prothena, as of the Effective Date, that: 

9.4.1    there are no claims, judgments, settlements, litigations, suits, actions, disputes, arbitration, judicial or
legal administrative or other proceedings or governmental investigations pending or, to Celgene’s actual knowledge, threatened against Celgene which would reasonably be expected to adversely affect or restrict the ability of Celgene to
consummate or perform the transactions contemplated under this Agreement (or pursuant to a U.S. License Agreement or Global License Agreement); and 

9.4.2    Celgene is a limited liability company organized under the laws of Delaware and wholly owned by Celgene
Switzerland SA, which is incorporated in, and a tax resident of, Switzerland. Celgene is disregarded as separate from its owner, Celgene Switzerland SA, for U.S. federal income tax purposes. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 9.5    Prothena Covenants. Prothena hereby covenants to Celgene
that: 
 9.5.1    Prothena shall not (and shall ensure that its Affiliates do not) grant any right or license to any
Third Party relating to any of the Program Assets (including Prothena IP) or with respect to any Collaboration Target, Collaboration Candidates or Collaboration Products, which conflict with, [***] any of the rights or licenses (including the
Options) granted to Celgene hereunder. 
 9.6    Disclaimer. EXCEPT AS OTHERWISE EXPRESSLY PROVIDED IN THIS
AGREEMENT, NEITHER PARTY MAKES ANY REPRESENTATIONS OR EXTENDS ANY WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED (AND EACH PARTY HEREBY EXPRESSLY DISCLAIMS ANY AND ALL REPRESENTATIONS AND WARRANTIES NOT EXPRESSLY PROVIDED IN THIS AGREEMENT),
INCLUDING WITH RESPECT TO ANY PATENTS OR KNOW-HOW, OR MATERIALS, INCLUDING WARRANTIES OF VALIDITY OR ENFORCEABILITY, MERCHANTABILITY, FITNESS FOR A PARTICULAR USE OR PURPOSE, PERFORMANCE, AND NONINFRINGEMENT
OF ANY THIRD PARTY PATENTS OR OTHER INTELLECTUAL PROPERTY RIGHTS. WITHOUT LIMITING THE FOREGOING, NEITHER PARTY MAKES ANY REPRESENTATION, WARRANTY OR GUARANTEE THAT THE PROGRAMS WILL BE SUCCESSFUL, OR THAT ANY OTHER PARTICULAR RESULTS WILL BE
ACHIEVED WITH RESPECT TO THE PROGRAMS, ANY COLLABORATION TARGET, ANY COLLABORATION CANDIDATE OR ANY COLLABORATION PRODUCT HEREUNDER. 

ARTICLE 10 

INDEMNIFICATION; INSURANCE 

10.1    Indemnification by Celgene. Celgene shall indemnify, defend and hold harmless Prothena and its Affiliates,
and its and their respective directors, officers, employees, agents, successors and assigns (collectively, the “Prothena Indemnitees”), from and against any and all Third Party Damages to the extent arising out of or relating to,
directly or indirectly, any Third Party Claim based upon: 
 (a)    the gross negligence or willful misconduct of
Celgene or its Affiliates or its or their respective directors, officers, employees or agents, in connection with Celgene’s performance of its obligations under this Agreement; 

(b)    any breach by Celgene of any of its representations, warranties, covenants, agreements or obligations under this
Agreement; or 
 (c)    in the event that any Phase 1 Clinical Trial for a Collaboration Candidate or Collaboration
Product is performed by Celgene pursuant to Section 2.5.1(b), any claim by or on behalf of clinical trial subjects for personal injury or death arising out of such Phase 1 Clinical Trial; 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 in each case (a)-(c), provided, however, that such indemnity shall not apply to the extent Prothena has an
indemnification obligation pursuant to Section 10.2(a) or (b) for such Third Party Damages. 

10.2    Indemnification by Prothena. Prothena shall indemnify, defend and hold harmless Celgene, its Affiliates and
its and their respective directors, officers, employees, agents, successors and assigns (collectively, the “Celgene Indemnitees”), from and against any and all Third Party Damages to the extent arising out of or relating to,
directly or indirectly, any Third Party Claim based upon: 
 (a)    the gross negligence or willful misconduct of
Prothena or its Affiliates or its or their respective directors, officers, employees or agents, in connection with Prothena’s performance of its obligations under this Agreement; or 

(b)    any breach by Prothena of any of its representations, warranties, covenants, agreements or obligations under this
Agreement; or 
 (c)    any claim for personal injury or death arising out of the Development, Manufacture or
Commercialization of any Collaboration Candidate or Collaboration Product by or on behalf of Prothena or its Affiliates; 
 in each case (a)-(c), provided,
however, that such indemnity shall not apply to the extent Celgene has an indemnification obligation pursuant to Section 10.1(a) or (b) for such Third Party Damages. 

10.3    Procedure. If a Party is seeking indemnification under Section 10.1 or 10.2, as applicable (the
“Indemnitee”), it shall inform the other Party (the “Indemnitor”) of the claim giving rise to the obligation to indemnify pursuant to Section 10.1 or 10.2, as applicable, as soon as reasonably practicable after
receiving notice of the claim (provided, however, any delay or failure to provide such notice shall not constitute a waiver or release of, or otherwise limit, the Indemnitee’s rights to indemnification under Section 10.1 or 10.2, as
applicable, except to the extent that such delay or failure materially prejudices the Indemnitor’s ability to defend against the relevant claims). The Indemnitor shall have the right to assume the defense of any such claim for which the
Indemnitee is seeking indemnification pursuant to Section 10.1 or 10.2, as applicable. The Indemnitee shall cooperate with the Indemnitor and the Indemnitor’s insurer as the Indemnitor may reasonably request, and at the Indemnitor’s
cost and expense. The Indemnitee shall have the right to participate, at its own expense and with counsel of its choice, in the defense of any claim or suit that has been assumed by the Indemnitor. The Indemnitor shall not settle any claim without
the prior written consent of the Indemnitee, not to be unreasonably withheld; provided, however, that the Indemnitor shall not be required to obtain such consent if the settlement (i) involves only the payment of money and will not result in
the Indemnitee (or other Prothena Indemnitees or Celgene Indemnitees, as applicable) becoming subject to injunctive or other similar type of relief, (ii) does not require an admission by the Indemnitee (or other Prothena Indemnitees or Celgene
Indemnitees, as applicable) and (iii) does not adversely affect the rights or licenses granted to the Indemnitee (or its Affiliate) under this Agreement (or under a U.S. Commercial License Agreement or a Global License Agreement). The
Indemnitee shall not settle or compromise any such claim without the prior written consent of the Indemnitor, which it may provide in its sole discretion. If the Parties cannot agree as to the application of Section 10.1 or 10.2, as applicable,
to any claim, pending resolution of the dispute pursuant to Section 12.7, the 

  
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treatment has been requested with respect to the omitted portions. 

 
Parties may conduct separate defenses of such claims, with each Party retaining the right to claim indemnification from the other Party in accordance with Section 10.1 or 10.2, as
applicable, upon resolution of the underlying claim. In each case, the Indemnitee shall reasonably cooperate with the Indemnitor, and shall make available to the Indemnitor all pertinent information under the control of the Indemnitee, which
information shall be subject to Article 8. 
 10.4    Insurance. During the Term and for a period of [***]
([***]) years thereafter, each Party shall maintain, at its cost, a program of insurance and/or self-insurance against liability and other risks associated with its activities and obligations under this Agreement (including, with respect to its
Clinical Trials), and its indemnification obligations hereunder, in such amounts, subject to such deductibles and on such terms as are customary for such Party for the activities to be conducted by it under this Agreement. It is understood that such
insurance shall not be construed to create a limit on either Party’s liability with respect to its indemnification obligations under this Article 10, or otherwise. 

10.5    LIMITATION OF LIABILITY. NEITHER PROTHENA NOR CELGENE, NOR ANY OF THEIR RESPECTIVE AFFILIATES, WILL BE
LIABLE TO THE OTHER PARTY OR ITS AFFILIATES UNDER OR IN CONNECTION WITH THIS AGREEMENT FOR ANY INDIRECT, INCIDENTAL, CONSEQUENTIAL, SPECIAL OR PUNITIVE OR EXEMPLARY DAMAGES (INCLUDING LOST PROFITS OR LOST REVENUES), WHETHER LIABILITY IS ASSERTED IN
CONTRACT, TORT (INCLUDING NEGLIGENCE AND STRICT PRODUCT LIABILITY), INDEMNITY, CONTRIBUTION OR OTHERWISE, AND IRRESPECTIVE OF WHETHER THAT PARTY OR ANY REPRESENTATIVE OF THAT PARTY HAS BEEN ADVISED OF, OR OTHERWISE MIGHT HAVE ANTICIPATED THE
POSSIBILITY OF, ANY SUCH LOSS OR DAMAGE. NOTWITHSTANDING THE FOREGOING, NOTHING IN THIS SECTION 10.5 IS INTENDED TO OR SHALL LIMIT OR RESTRICT THE INDEMNIFICATION RIGHTS OR OBLIGATIONS OF ANY PARTY UNDER SECTIONS 10.1 OR 10.2 IN CONNECTION WITH ANY
THIRD PARTY CLAIMS [***]. 
 ARTICLE 11 

TERM AND TERMINATION 

11.1    Term; Expiration. This Agreement shall become effective on the Effective Date and, unless earlier
terminated in accordance with this Article 11, shall remain in effect until the last to occur of the following: (i) expiration of all IND Option Terms; (ii) expiration of all Phase 1 Option Terms, (iii) expiration of the Research Term
and (iv) the end of any Participation Term Extension (the “Term”). 
 11.2    Termination for
Breach. 
 11.2.1    Material Breach. This Agreement may be terminated by a Party (a) on a Program-by-Program basis prior to Celgene’s exercise of its IND Option for such Program, for the material breach by the other Party of this Agreement with respect to such
Program, or (b) on a Program-by-Program basis after Celgene’s exercise of its IND Option for such Program, if a U.S. License Agreement or a Global License
Agreement for such Program is terminated for material breach by the other Party; provided in each of (a) or (b) that the breaching Party has not cured such 

  
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breach within ninety (90) days after the date of written notice to the breaching Party of such breach (or thirty (30) days in the case of a breach as a result of non-payment of any amounts due under this Agreement) (the “Cure Period”), which notice shall describe such breach in reasonable detail and shall state the
non-breaching Party’s intention to terminate this Agreement with respect to a given Program, pursuant to this Section 11.2.1 with respect to such Program. For clarity, the Cure Period for any
allegation made as to a material breach under this Agreement with respect to a given Program, for events described in Sections 11.2.1(a) or (b) will run from the date that written notice was first provided to the breaching Party by the non-breaching Party. Any such termination of this Agreement with respect to a given Program, under this Section 11.2.1 shall become effective at the end of the Cure Period, unless the breaching Party has cured
such breach prior to the expiration of such Cure Period, or, if such breach is not susceptible to cure within the Cure Period, then such Cure Period shall be extended for an additional [***] ([***]) days so long as the breaching Party continues to
use commercially reasonable efforts to cure such material breach during such extension period. For the avoidance of doubt, termination of any particular Program(s) pursuant to this Section 11.2.1 shall not terminate (i) this Agreement with
respect to any other Program(s), or (ii) any U.S. License Agreement or Global License Agreement. The Parties understand and agree that the totality of this Agreement with respect to a given Program, and the totality of the circumstances with
respect to this Agreement with respect to a given Program, will be taken into account and assessed as a whole for purposes of determining whether a breach is material under this Agreement with respect to a given Program. 

11.2.2    Disagreement as to Material Breach. Notwithstanding Section 11.2.1, if the Parties in good faith
disagree as to whether there has been a material breach of this Agreement pursuant to Section 11.2.1, then: (a) the Party that disputes that there has been a material breach may contest the allegation by referring such matter, within
[***], for resolution to the Executive Officers, who shall meet promptly to discuss the matter and determine, within [***], whether or not a material breach has occurred pursuant to Section 11.2.1; provided that if the Executive Officers are
unable to resolve such dispute within such [***] ([***]) [***] period after it is referred to them, the matter will be resolved as provided in Section 12.7; (b) the relevant Cure Period with respect thereto will be tolled from the date the
breaching Party notifies the non-breaching Party of such dispute and through the resolution of such dispute in accordance with the applicable provisions of this Agreement; (c) during the pendency of such
dispute, all of the terms and conditions of this Agreement shall remain in effect and the Parties shall continue to perform all of their respective obligations hereunder; and (d) if it is ultimately determined that the breaching Party committed
such material breach, then the breaching Party shall have the right to cure such material breach, after such determination, within the Cure Period (as may be extended in accordance with Section 11.2.1) which shall commence as of the date of
such determination. 
 11.3     Voluntary Termination. Celgene may terminate this Agreement at will, in its sole
discretion, in its entirety or with respect to one or more Programs upon sixty (60) days’ prior written notice to Prothena at any time. For the avoidance of doubt, any such termination of any particular Program(s) pursuant to this Section 11.3
shall not terminate any other Program(s), and further provided that any such termination of this Agreement with respect to a Program shall only occur if any U.S. License Agreement or Global License Agreement in effect for such Program is also being
terminated. 

  
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treatment has been requested with respect to the omitted portions. 

 11.4    Termination for Bankruptcy. If either Party makes a
general assignment for the benefit of, or an arrangement or composition generally with, its creditors, appoints or suffers appointment of an examiner or of a receiver or trustee over all or substantially all of its property, passes a resolution for
its winding up or files a petition under any bankruptcy or insolvency act or law or has any such petition filed against it which is not dismissed, discharged, bonded or stayed within ninety (90) days after the filing thereof (each, an
“Insolvency Event”), the other Party may terminate this Agreement in its entirety effective immediately upon written notice to such Party, provided that, in connection therewith, the provisions of Section 7.5 shall apply.
Notwithstanding the foregoing, this Agreement may only be terminated in its entirety pursuant to this Section 11.4 in connection with the termination of all U.S. License Agreements and Global License Agreements. 

11.5     Termination for Patent Challenge. Prothena shall have the right to terminate this Agreement upon written
notice if Celgene or any Affiliate of Celgene challenges the validity, scope or enforceability of or otherwise opposes any Patent included in the Prothena IP that is licensed to Celgene under this Agreement, in each case through a formal proceeding
(other than as may be necessary or reasonably required to assert a cross-claim or a counter-claim or to respond to a court request or order or administrative law, request or order). If a sublicensee of Celgene with respect to any Prothena IP
challenges the validity, scope or enforceability of or otherwise opposes any Patent included in such Prothena IP under which such sublicensee is sublicensed, in each case through a formal proceeding (other than as may be necessary or reasonably
required to assert a cross-claim or a counter-claim or to respond to a court request or order or administrative law, request or order), then Celgene shall, upon written notice from Prothena, terminate such sublicense. 

11.6    Effects of Expiration or Termination. 

11.6.1    Termination by Prothena Pursuant to Section 11.2, 11.4 or 11.5, or by Celgene Pursuant to
Section 11.3. In the event of termination of this Agreement in its entirety or in part with respect to any one or more Programs (i) by Celgene pursuant to Section 11.3 or (ii) by Prothena pursuant to Sections
11.2 or 11.4, upon the effective date of such termination: 
 (a)    except as set forth in Section 11.8, all
rights (including all unexercised Options granted to Celgene hereunder) and licenses granted herein with respect to all terminated Programs shall terminate; provided, however, the licenses granted to Prothena in Section 7.2 for such Program
shall continue; 
 (b)    any and all Collaboration Specific IP solely related to the terminated Programs shall
thereafter no longer be deemed to be Collaboration Specific IP; and 
 (c)    each Party shall return or destroy all
Confidential Information of the other Party with respect to the terminated Programs as required by Article 8. 

  
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treatment has been requested with respect to the omitted portions. 

 11.6.2    Termination by Celgene Pursuant to
Section 11.2 or 11.4. In the event of termination of this Agreement in its entirety or in part with respect to any one or more Programs by Celgene pursuant to Section 11.2 or 11.4, upon the effective date of such
termination: 
 (a)    except as set forth in Section 11.8, all rights (including all unexercised Options granted
to Celgene hereunder) and licenses granted herein with respect to all terminated Programs shall terminate; 

(b)    any and all Collaboration Specific IP solely related to the terminated Programs shall thereafter no longer be
deemed to be Collaboration Specific IP; and 
 (c)    each Party shall return or destroy all Confidential Information
of the other Party with respect to the terminated Programs, as required by Article 8, except for any Celgene Phase 1 Program Know-How from such terminated Program that is licensed to Prothena under
Section 7.2. 
 11.7    Certain Additional Remedies of Celgene in Lieu of Termination. In the event that
(i) Celgene notifies Prothena in writing of a material breach of this Agreement by Prothena, either in its entirety or with respect to a given Program(s), and (ii) Celgene would have the right to terminate this Agreement in its entirety or
with respect to a given Program(s), as applicable pursuant to Section 11.2, then in lieu of Celgene terminating pursuant to Section 11.2, and without limiting any other rights or remedies of Celgene, Celgene may elect to have this
Agreement continue in full force and effect (in its entirety or with respect to the affected Program(s), as applicable) by providing written notice to Prothena, and, with respect to any Program(s) for which the applicable IND Option Term or Phase 1
Option Term, as applicable, has not yet expired, Celgene shall be entitled to (but shall not be required to), by written notice to Prothena (which election may be made by Celgene on a
Program-by-Program basis): 

(a)    exercise its IND Option and/or its Phase 1 Option (without the need to exercise its IND Option) on a Program-by-Program basis as set forth in Section 3.1 and enter into a U.S. License Agreement or a Global License Agreement for such Program as applicable; provided that
in such case, Celgene shall not be required to pay [***] IND Option Exercise Fee and/or the Phase 1 Option Exercise Fee, as applicable, in connection with the exercise of such IND Option and/or Phase 1 Option; and/or 

(b)    exercise its rights as set forth in Section 2.5 (without the need to pay [***] IND Option Exercise Fee or
Phase 1 Option Exercise Fee, to the extent any such amounts at any time become payable); 
 provided that, in either such case or (a) and/or (b),
without limiting any other rights or remedies of Celgene, any and all amounts thereafter payable by Celgene hereunder or under any U.S. License Agreement and any Global License Agreement (including milestones and royalties) with respect to any
Programs for which Celgene made such election in (a) and/or (b) above, as applicable, shall be reduced by [***] if the material breach triggering the rights of Celgene pursuant to this Section 11.7 with respect to the applicable
Program occurred prior to the End of Discovery Portion Date for such Program or [***] if the material breach triggering the rights of Celgene pursuant to this Section 11.7 with respect to the applicable Program occurred on or after the End of
Discovery Portion Date for such Program. 

  
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treatment has been requested with respect to the omitted portions. 

 11.8    Surviving Provisions. 

11.8.1    Accrued Rights; Remedies. Termination or expiration of this Agreement for any reason shall be without
prejudice to any rights that shall have accrued to the benefit of any Party prior to such termination or expiration, and any and all damages or remedies (whether in law or in equity) arising from any breach hereunder, each of which shall survive
termination or expiration of this Agreement. Such termination or expiration shall not relieve any Party from obligations which are expressly indicated to survive termination or expiration of this Agreement. Except as otherwise expressly set forth in
this Agreement, the termination provisions of this Article 11 are in addition to any other relief and remedies available to either Party under this Agreement and at Applicable Law. 

11.8.2    Survival. Without limiting the provisions of Section 11.8.1, the rights and obligations of the
Parties set forth in the following Sections and Articles of this Agreement shall survive the expiration or termination of this Agreement, in addition to those other terms and conditions that are expressly stated to survive termination or expiration
of this Agreement: Article 1 (to the extent the definitions are used in other surviving provisions), Section 2.2.5(a), Section 2.4.1 (solely as to the second to last sentence therein), Section 2.4.2 (solely as to the last sentence
therein), Section 2.5.3, Section 2.6.2-2.6.4, Section 2.8 (but only until the fifth (5th) anniversary after the termination or expiration of
this Agreement), Section 2.9.1 (solely as to the last sentence therein), Section 2.9.2, Section 3.1.6, Section 3.2, Section 4.1.2, Section 4.3 (solely for the purposes of effectuating Section 6.7 of
any U.S. License Agreement effective as of the termination or expiration of this Agreement), Section [***], Article 6 (as to payment obligations accrued prior to the effectiveness of termination or expiration of this Agreement), Section 7.1.2,
Sections 7.2-7.6, Section 7.9 (solely if there is no U.S. License Agreement or Global License Agreement for the Program covering the applicable Joint Program Patents), Section 7.13, Article 8,
Section 9.6, Article 10, Section 11.6, Section 11.7, Section 11.8, and Article 12. 

11.8.3    Relationship to U.S. License Agreements and Global License Agreements. Termination of this Agreement in
its entirety or with respect to a given Program shall not affect in any way the terms or provisions of any then-existing executed U.S. License Agreement (including any U.S. License Agreement for a terminated Program) or Global License Agreement
(including any Global License Agreement for a terminated Program), and such U.S. License Agreement and Global License Agreement shall continue in full force and effect in accordance with its terms and conditions. 

ARTICLE 12 

MISCELLANEOUS 
 12.1
    Severability. If any one or more of the terms or provisions of this Agreement is held by a court of competent jurisdiction to be void, invalid or unenforceable in any situation in any jurisdiction, such holding shall
not affect the validity or enforceability of the remaining terms and provisions hereof or the validity or enforceability of the invalid, void or unenforceable term or provision in any other situation or in any other jurisdiction, and the term or
provision shall be considered severed from this Agreement solely for such situation and solely in such jurisdiction, unless the invalid, void or unenforceable term or provision is of such essential importance to this Agreement that it is to be
reasonably assumed that the Parties would not have entered into this Agreement without the invalid, void or unenforceable term or provision. If the final judgment of such court declares that any term or provision hereof is invalid, void or
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agree to (a) reduce the scope, duration, area or applicability of the term or provision or to delete specific words or phrases to the minimum extent necessary to cause such term or provision
as so reduced or amended to be enforceable, and (b) make a good faith effort to replace any invalid, void or unenforceable term or provision with a valid and enforceable one such that the objectives contemplated by the Parties when entering
this Agreement may be realized. 
 12.2    Notices. Any notice required or permitted to be given by this
Agreement shall be in writing and in English and shall be (a) delivered by hand or by overnight courier with tracking capabilities, (b) mailed postage prepaid by first class, registered, or certified mail, or (c) delivered by
facsimile followed by delivery via either of the methods set forth in Sections 12.2(a) and (b), in each case, addressed as set forth below unless changed by notice so given: 

If to Celgene: 
 Celgene
Switzerland LLC 
 AON House 

30 Woodbourne Ave. 
 Pembroke HM
08, Bermuda 
 Attention:        [***] 

With copies to: 
 Celgene
Corporation 
 86 Morris Avenue 

Summit, New Jersey 07901 
 U.S.A.

 Attention:       General Counsel 

Facsimile:       (908) 673-2771 

If to Prothena: 
 Prothena
Biosciences Limited 
 Adelphi Plaza 

Upper George’s Street 
 Dun
Laoghaire, Co. Dublin, A96 T927 
 Ireland 

Attention:         Company Secretary 

Facsimile:
       +353-1-686-5675 

With copies to: 
 Prothena
Biosciences Inc 
 331 Oyster Point Boulevard 

South San Francisco, CA 94080 

U.S.A. 
 Attention:
       Vice President, Business Development 
 Facsimile:        +1 650-837-8560 

  
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treatment has been requested with respect to the omitted portions. 

 Any such notice shall be deemed given on the date received, except any notice received after 5:30 p.m. (in
the time zone of the receiving party) on a Business Day or received on a non-Business Day shall be deemed to have been received on the next Business Day. A Party may add, delete, or change the person or
address to which notices should be sent at any time upon written notice delivered to the other Parties in accordance with this Section 12.2. 

12.3    Force Majeure. A Party shall not be liable for delay or failure in the performance of any of its
obligations hereunder if such delay or failure is due to a cause beyond the reasonable control of such Party, including acts of God, fires, earthquakes, acts of war, terrorism, or civil unrest, or hurricane or other inclement weather (“Force
Majeure”); provided, however, that the affected Party promptly notifies the other Party and further provided that the affected Party shall use its commercially reasonable efforts to avoid or remove such causes of non-performance and to mitigate the effect of such occurrence, and shall continue performance in accordance with the terms of this Agreement whenever such causes are removed. When such circumstances arise, the
Parties shall negotiate in good faith any modifications of the terms of this Agreement that may be necessary or appropriate in order to arrive at an equitable solution. 

12.4    Assignment. 

12.4.1    Generally. Except as expressly permitted herein, this Agreement may not be assigned or transferred by any
Party, nor may any Party assign or transfer any rights or obligations created by this Agreement, except as expressly permitted hereunder without the prior written consent of the other Party, which consent will not be unreasonably withheld. 

12.4.2    Celgene. Notwithstanding the limitations in Section 12.4.1, but subject to Section 6.4.2,
Celgene may assign or transfer this Agreement, or any rights or obligations hereunder in whole or in part, to (a) one or more Affiliates (provided, however, that Celgene shall remain fully and unconditionally liable and responsible to the non-assigning Party hereto for the performance and observance of all such duties and obligations by such Affiliate); or (b) its successor in interest in connection with its merger, consolidation, or sale of all
or substantially all of its assets or that portion of its business pertaining to the subject matter of this Agreement. 

12.4.3    Prothena. Notwithstanding the limitations in Section 12.4.1, but subject to Section 6.4.2 and
the remaining provisions of this Section 12.4.3, Prothena may assign or transfer this Agreement, or any rights or obligations hereunder in whole or in part, to (a) one or more Affiliates (provided, however, that a Party assigning to an
Affiliate shall remain fully and unconditionally liable and responsible to the non-assigning Party hereto for the performance and observance of all such duties and obligations by such Affiliate); or
(b) its successor in interest in connection with its merger, consolidation, or sale of all or substantially all of its assets. 

12.4.4    Intellectual Property of Acquirer. Notwithstanding anything to the contrary in this Agreement, if a Party
is acquired by a Third Party after the Effective Date, then with respect to any intellectual property rights controlled by the Third Party acquiring party or its affiliates (other than one of the Parties to this Agreement or its Affiliates
immediately prior to such acquisition) involved in any assignment of this Agreement by such Party to such Third Party acquirer, such intellectual property rights shall not be included in the technology and intellectual property rights licensed to
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transaction by such acquirer or its affiliate (other than the relevant Party to this Agreement or its Affiliates immediately prior to such acquisition) and developed outside the scope of
activities conducted with respect to the Collaboration, any Program, any U.S. License Agreement or any Global License Agreement. The Prothena IP shall also exclude any intellectual property developed by such Third Party acquirer after such
acquisition; provided that (i) such intellectual property is developed independently of the activities under the Collaboration, any Program, any U.S. License Agreement or any Global License Agreement [***], (ii) Prothena and its Affiliates put
in place firewalls and other protections to [***] and (iii) [***]. 
 12.4.5    All Other Assignments Null and
Void. The terms of this Agreement will be binding upon and will inure to the benefit of the successors, heirs, administrators and permitted assigns of the applicable Party. Any purported assignment in violation of this Section 12.4 will be
null and void ab initio. 
 12.5    Waivers and Modifications. The failure of any Party to insist on the
performance of any obligation hereunder shall not be deemed to be a waiver of such obligation. Waiver of any breach of any provision hereof shall not be deemed to be a waiver of any other breach of such provision or any other provision on such
occasion or any succeeding occasion. No waiver, modification, release, or amendment of any obligation under or provision of this Agreement shall be valid or effective unless in writing and signed by the Parties. 

12.6    WAIVER OF JURY TRIAL. EXCEPT AS LIMITED BY APPLICABLE LAW, EACH PARTY HERETO HEREBY IRREVOCABLY WAIVES ALL
RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM (WHETHER BASED IN CONTRACT, TORT OR OTHERWISE) ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE ACTIONS OF ANY PARTY HERETO IN THE NEGOTIATION, ADMINISTRATION, PERFORMANCE AND
ENFORCEMENT HEREOF. 
 12.7    Choice of Law; Dispute Resolution. 

12.7.1    Choice of Law. This Agreement shall be governed by, enforced and construed in accordance with the laws of
the State of New York and the patent laws of the United States without reference to any rules of conflict of laws or renvoi and excluding the United Nations Convention on Contracts for the International Sales of Goods; provided, however, that with
respect to matters involving the validity or infringement of intellectual property rights in a given country, such matter may be brought in the applicable country (in accordance with Section 12.7.3) and the Applicable Laws of the applicable
country shall apply (subject to Section 7.6.1). 
 12.7.2    Exclusive Dispute Resolution Mechanism. The
Parties agree that the procedures set forth in Section 12.7.3 will be the exclusive mechanism for resolving any dispute (whether in contract, tort or otherwise), controversy or claim between the Parties arising out of or in connection with this
Agreement, any Party’s rights or obligations under this Agreement, breach of this Agreement or the transactions contemplated by this Agreement (each, a “Dispute”); provided that decisions that are subject to the decision making
authority of the JSC or a given Party, as expressly set forth in this Agreement, will not be subject to the provisions of Section 12.7.3 so long as such decisions are made in accordance with this Agreement. 

  
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treatment has been requested with respect to the omitted portions. 

 12.7.3    Jurisdiction. 

(a)    Except as otherwise set forth in this Section 12.7.3, the sole jurisdiction and venue for all actions, suits
and proceedings arising out of any Dispute (except in respect of an Excluded Claim, where jurisdiction is non-exclusive) will be the state and federal courts located in the Borough of Manhattan in New York,
New York, USA. Each Party hereby irrevocably and unconditionally (a) consents to submit to the exclusive jurisdiction of the state and federal courts located in the Borough of Manhattan in New York, New York, USA for any action, suit or
proceeding arising out of such Dispute, and (b) waives any objection to the laying of venue of any action, suit or proceeding arising out of such Dispute in the state and federal courts of the Borough of Manhattan in New York, New York, USA and
agrees not to plead or claim in any such court that any such action, suit or proceeding brought in any such court has been brought in an inconvenient forum. Each of the Parties agrees that process may be served upon it in the manner specified in
Section 12.2 and irrevocably waives and covenants not to assert or plead any objection which it might otherwise have to such jurisdiction, or to such manner of service of process. It shall be a condition precedent to the commencement of any
action in court or other tribunal (save an action for an interim injunction or provisional relief) in respect of any Dispute relating to this Agreement that the Parties have sought to resolve the Dispute by either Party notifying the other Party in
writing for resolution to the Executive Officers who shall meet (whether in person or via teleconference) within [***] ([***]) [***] of such notice to seek resolution in good faith. If the Executive Officers are unable to resolve the Dispute at such
meeting, either Party may pursue any remedy available to such Party at law or in equity, subject to the terms and conditions of this Agreement, including this Section 12.7.3. 

(b)    Notwithstanding the provisions of Section 12.7.3(a), either Party may, without waiving any remedy under this
Agreement, seek from any court having jurisdiction equitable relief, including any injunctive or provisional relief and specific performance to protect the rights or property of that Party. Such remedies will not be deemed to be the exclusive
remedies for a breach of this Agreement but will be in addition to all other remedies available at law or equity. In addition, notwithstanding the provisions of Section 12.7.3(a) either Party may bring an action in any court having jurisdiction
to enforce an award rendered pursuant to Section 12.7.3(a). 
 (c)    Until final resolution of the dispute
through judicial determination, (i) this Agreement will remain in full force and effect and (ii) the time periods for cure as to any termination will be tolled. The Parties further agree that any payments made pursuant to this Agreement
pending resolution of the dispute shall be refunded if a court determines that such payments are not due. 
 (d)    As
used in this Section 12.7, the term “Excluded Claim” means a dispute, controversy or claim that concerns (i) the validity or infringement of a Patent, trademark or copyright, or (ii) any antitrust, anti-monopoly or
competition law or regulation, whether or not statutory. 
 12.8    Relationship of the Parties. Prothena and
Celgene are independent contractors under this Agreement. Nothing contained herein is intended or is to be construed so as to constitute (a) Prothena as a partner, agent, or joint venturer of Celgene or (b) Celgene as a partner, agent or joint
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implied right or authority to assume or create any obligations on behalf of or in the name of Celgene or Prothena, respectively, or to bind Celgene or Prothena, respectively, to any contract,
agreement, or undertaking with any Third Party. 
 12.9    No Third Party Beneficiaries. There are no express or
implied Third Party beneficiaries hereunder. The provisions of this Agreement are for the exclusive benefit of the Parties, and no other person or entity shall have any right or claim against any Party by reason of these provisions or be entitled to
enforce any of these provisions against any Party. 
 12.10    Entire Agreement. This Agreement, together with
the attached Exhibits (including the form of U.S. License Agreement and the form of Global License Agreement) and Schedules, as well as any and all executed U.S. License Agreements and Global License Agreements, contains the entire agreement by the
Parties with respect to the subject matter hereof and supersedes any prior express or implied agreements, understandings and representations, either oral or written, which may have related to the subject matter hereof in any way, including the
Existing Confidentiality Agreement (as set forth in Section 8.11) and any and all term sheets relating to the transactions contemplated by this Agreement and exchanged between the Parties prior to the Effective Date. If a U.S. License
Agreement is entered into with respect to a given Program, then to the extent there is a conflict between the provisions of this Agreement and the provisions of such U.S. License Agreement, the provisions of such U.S. License Agreement shall control
with respect to such Program. If a Global License Agreement is entered into with respect to a given Program, then to the extent there is a conflict between the provisions of this Agreement (or the provisions of any prior U.S. License Agreement for
such Program), the provisions of such Global License Agreement shall control with respect to such Program. 

12.11    Counterparts. This Agreement may be executed in counterparts with the same effect as if both Parties had
signed the same document. All such counterparts shall be deemed an original, shall be construed together, and shall constitute one and the same instrument. Any such counterpart, to the extent delivered by means of a fax machine or by .pdf, .tif,
..gif, .jpeg or similar attachment to electronic mail (any such delivery, an “Electronic Delivery”) shall be treated in all manner and respects as an original executed counterpart and shall be considered to have the same binding
legal effect as if it were the original signed version thereof delivered in person. No Party hereto shall raise the use of Electronic Delivery to deliver a signature or the fact that any signature or agreement or instrument was transmitted or
communicated through the use of Electronic Delivery as a defense to the formation of a contract, and each Party forever waives any such defense, except to the extent that such defense relates to lack of authenticity. 

12.12    Equitable Relief; Cumulative Remedies. Notwithstanding anything to the contrary herein, the Parties shall
be entitled to seek equitable relief, including injunction and specific performance, as a remedy for any breach of this Agreement. Such remedies shall not be deemed to be the exclusive remedies for a breach of this Agreement but shall be in addition
to all other remedies available at law or equity. The Parties further agree not to raise as a defense or objection to the request or granting of such relief that any breach of this Agreement is or would be compensable by an award of money damages.
No remedy referred to in this Agreement is intended to be exclusive, but each shall be cumulative and in addition to any other remedy referred to in this Agreement or otherwise available under Applicable Law. 

  
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treatment has been requested with respect to the omitted portions. 

 12.13    Interpretation. 

12.13.1    Generally. This Agreement has been diligently reviewed by and negotiated by and among the Parties, and in
such negotiations each of the Parties has been represented by competent (in house or external) counsel, and the final agreement contained herein, including the language whereby it has been expressed, represents the joint efforts of the Parties and
their counsel. Accordingly, in interpreting this Agreement or any provision hereof, no presumption shall apply against any Party as being responsible for the wording or drafting of this Agreement or any such provision, and ambiguities, if any, in
this Agreement shall not be construed against any Party, irrespective of which Party may be deemed to have authored the ambiguous provision. 

12.13.2    Definitions; Interpretation. The definitions of the terms herein shall apply equally to the singular and
plural forms of the terms defined and where a word or phrase is defined herein, each of its other grammatical forms shall have a corresponding meaning. Whenever the context may require, any pronoun shall include the corresponding masculine,
feminine, and neuter forms. The word “will” shall be construed to have the same meaning and effect as the word “shall.” The word “any” shall mean “any and all” unless otherwise clearly indicated by context.
The words “including,” “includes,” “include,” “for example,” and “e.g.” and words of similar import will be deemed to be followed by the words “without limitation.” The word “or”
is disjunctive but not necessarily exclusive. The words “hereof,” “herein” and “herewith” and words of similar import shall, unless otherwise stated, be construed to refer to this Agreement as a whole and not to any
particular provision of this Agreement. Unless the context requires otherwise or otherwise specifically provided, (i) all references herein to Articles, Sections, Schedules or Exhibits shall be construed to refer to Articles, Sections,
Schedules and Exhibits of this Agreement and (ii) reference in any Section to any subclauses are references to such subclauses of such Section. 

12.13.3    Subsequent Events. Unless the context requires otherwise, (i) any definition of or reference to any
agreement, instrument, or other document herein shall be construed as referring to such agreement, instrument, or other document as from time to time amended, supplemented, or otherwise modified (subject to any restrictions on such amendments,
supplements, or modifications set forth herein), (ii) any reference to any Applicable Law herein shall be construed as referring to such Applicable Law as from time to time enacted, repealed, or amended, and (iii) any reference herein to any
Person shall be construed to include the Person’s successors and assigns (subject to Section 12.4). 

12.13.4    Headings. Headings, captions and the table of contents are for convenience only and are not to be used
in the interpretation of this Agreement. 
 12.13.5    Prior Drafts. No prior draft of this Agreement nor any
course of performance or course of dealing shall be used in the interpretation or construction of this Agreement. 

12.13.6    Independent Significance. Although the same or similar subject matters may be addressed in different
provisions of this Agreement, the Parties intend that, except as reasonably apparent on the face of the Agreement or as expressly provided in this Agreement, each such provision shall be read separately, be given independent significance and not be
construed as limiting any other provision of this Agreement (whether or not more general or more specific in scope, substance or content). 

  
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treatment has been requested with respect to the omitted portions. 

 12.14    Further Assurances. Each Party shall execute,
acknowledge and deliver such further instruments, and do all such other ministerial, administrative or similar acts, as may be reasonably necessary or appropriate in order to carry out the expressly stated purposes and the clear intent of this
Agreement. 
 12.15    Extension to Affiliates. Subject to Sections 6.4.2 and 12.4, Celgene shall have the right
to extend the rights, licenses, immunities and obligations granted in this Agreement to one or more of its Affiliates. All applicable terms and provisions of this Agreement shall apply to any such Affiliate to which this Agreement has been extended
to the same extent as such terms and provisions apply to Celgene. Celgene shall remain fully liable for any acts or omissions of such Affiliates. 

[Signature Page Follows] 

  
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treatment has been requested with respect to the omitted portions. 

 IN WITNESS WHEREOF, and intending to be legally bound hereby, the Parties have caused this
MASTER COLLABORATION AGREEMENT to be executed by their respective duly authorized officers as of the Effective Date. 
  

									
	PROTHENA BIOSCIENCES LIMITED	 		 	CELGENE SWITZERLAND LLC
					
	By:	 	 /s/ Yvonne
Tchrakian                                        

	 		 	By:	 	 /s/ Kevin
Mello                                        

	Name:	 	Yvonne Tchrakian	 		 	Name:	 	Kevin Mello
	Title:	 	Director	 		 	Title:	 	Manager

 [Signature Page to Master Collaboration Agreement] 

  
 [***] Certain information
in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 Schedule 1.14 

Certain Existing Collaboration Candidates 

1. Tau: 
 [***] 

 [***] 

2. [***] 
 3.
TDP-43: 
 [***] 

  
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treatment has been requested with respect to the omitted portions. 

 Schedule 1.42 

In-License Agreements and Other Third Party Agreements 

[***] 

  
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treatment has been requested with respect to the omitted portions. 

 [***] 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.66 

Certain Prothena Collaboration Patents 

[***] 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 [***] 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.69 

Prothena Platform Technology 

[***] 

  
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treatment has been requested with respect to the omitted portions. 

 Exhibit A 

Form of Global License Agreement 

(See Attached) 

  
 [***] Certain information
in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 FINAL FORM 

GLOBAL LICENSE AGREEMENT 

by and among 
 PROTHENA
BIOSCIENCES LIMITED 
 and 

CELGENE SWITZERLAND LLC 

Dated as of              , 20     

  
 [***] Certain information
in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 TABLE OF CONTENTS1 

LIST OF SCHEDULES2 
  

			
	 SCHEDULE 1.27
	  	 EXISTING IND

	 SCHEDULE 1.28
	  	 EXISTING PROGRAM AGREEMENTS

	 SCHEDULE 1.39
	  	 IN-LICENSE AGREEMENTS AND OTHER THIRD PARTY
AGREEMENTS

	 SCHEDULE 1.44
	  	 LICENSED PROGRAM ANTIBODIES

	 SCHEDULE 1.46(b)
	  	 LICENSED PROGRAM PATENTS

	 SCHEDULE 1.48
	  	 LICENSED TARGET

	 SCHEDULE 1.63
	  	 PROTHENA LICENSED COLLABORATION PATENTS

	 SCHEDULE 1.65
	  	 PROTHENA PLATFORM TECHNOLOGY

	 SCHEDULE 8.2
	  	 EXCEPTIONS TO PROTHENA REPRESENTATIONS AND WARRANTIES

	 SCHEDULE 8.4
	  	 EXCEPTIONS TO CELGENE REPRESENTATIONS AND WARRANTIES

  
  

	1 	 To be inserted in final version. 

	2 	 All Schedules to be completed prior to execution of the Agreement. 

  
 [***] Certain information
in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 GLOBAL LICENSE AGREEMENT 

This GLOBAL LICENSE AGREEMENT (this “Agreement”) is entered into and made effective as of
        , 20     (the “Effective Date”) by and between Prothena Biosciences Limited, an Irish limited company ( “Prothena”) and Celgene
Switzerland LLC, a Delaware limited liability company (“Celgene”) 3 . Celgene and Prothena are each referred to herein by name or as a “Party” or,
collectively, as the “Parties”. 
 RECITALS 

WHEREAS, Prothena and Celgene entered into that certain Master Collaboration Agreement, dated as of March 20, 2018 (the
“Master Collaboration Agreement”), pursuant to which, among other things, Prothena has conducted research and development programs with respect to certain targets (each, a “Program”) and Celgene has an exclusive
option to obtain an exclusive license to research, develop, manufacture and commercialize Antibodies that Target such targets; 

WHEREAS, pursuant to the terms of the Master Collaboration Agreement, upon exercise by Celgene of its Phase 1 Option (as defined in the
Master Collaboration Agreement) with respect to a given Program, the Parties are obligated to enter into a Global License Agreement with respect to such Program; 

WHEREAS, Celgene has exercised its Phase 1 Option (as defined in the Master Collaboration Agreement) with respect to the Licensed
Program, and, as such, the Parties are entering into this Agreement pursuant to which, among other things, Prothena grants to Celgene exclusive rights and licenses with respect to the research, development, manufacture and commercialization of
Licensed Antibodies and Licensed Products in the Territory, on the terms and subject to the conditions set forth herein; and 

WHEREAS, Celgene and Prothena have previously entered into that certain U.S. License Agreement with respect to the Licensed Program
(the “Licensed Program U.S. License Agreement”), and, pursuant to the terms of the Licensed Program U.S. License Agreement, such Licensed Program U.S. License Agreement automatically terminates upon entering into this Agreement, and
the Parties intend for this Agreement to supersede the Licensed Program U.S. License Agreement. 
  

 

	3	 [***] 

  
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treatment has been requested with respect to the omitted portions. 

 NOW, THEREFORE, in consideration of the foregoing and the mutual agreements set forth
below, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties hereby agree as follows: 

ARTICLE 1. 
 DEFINITIONS

 Unless specifically set forth to the contrary herein, the following terms shall have the respective meanings set forth below. Capitalized terms used,
but not defined, herein will have the meanings ascribed to them in the Master Collaboration Agreement. 

1.1    “Accounting Standards” means U.S. generally accepted accounting principles
(“GAAP”) or, to the extent that Celgene adopts International Financial Reporting Standards (“IFRS”), then “Accounting Standards” shall mean IFRS, in either case consistently applied. 

1.2    “Affiliate” means any Person which, directly or indirectly through one or more intermediaries,
controls, is controlled by or is under common control with a Party. For purposes of this definition, the term “control” (including, with correlative meanings, the terms “controlled by” and “under common control with”)
as used with respect to a Person means (a) direct or indirect ownership of fifty percent (50%) or more of the voting securities or other voting interest of any Person (including attribution from related parties), or (b) the possession,
directly or indirectly, of the power to direct or cause the direction of the management and policies of such Person, whether through ownership of voting securities, by contract, as a general partner, as a manager, or otherwise. 

1.3    “Annual Net Sales” means, on a Licensed Product-by-Licensed Product basis, total Net Sales by Celgene, its Affiliates and Sublicensees in the Territory of such Licensed Product in a particular Calendar Year, calculated in accordance with Accounting
Standards consistently applied. 
 1.4    “Antibody” means any [***] antibody (including [***]), [***]
whether human, humanized, chimeric, murine, synthetic or from any other source. 
 1.5    “Applicable
Law” or “Applicable Laws” means all applicable laws, statutes, rules, regulations, orders, judgments or ordinances having the effect of law of any national, multinational, federal, state, provincial, county, city or
other political subdivision, including, to the extent applicable, GCP, GLP and GMP, as well as all applicable data protection and privacy laws, rules and regulations, including, to the extent applicable, the United States Department of Health and
Human Services privacy rules under the Health Insurance Portability and Accountability Act (“HIPAA”) and the Health Information Technology for Economic and Clinical Health Act and the EU Data Protection Directive (Council Directive
95/46/EC) and applicable laws implementing the EU Data Protection Directive and, when in force, the General Data Protection Regulation (2016/679). 

1.6    “Biomarker” means a parameter or characteristic in a patient or Patient Sample, the measurement of
which is useful (a) for purposes of selecting appropriate therapies or patient populations or monitoring disease susceptibility, severity or state, or monitoring therapies for such patient and/or (b) for predicting the outcome of a
particular treatment of such patient. 

  
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treatment has been requested with respect to the omitted portions. 

 1.7    “Biosimilar Application” means an application or
submission filed with a Regulatory Authority for marketing authorization of a Biosimilar Product. 

1.8    “Biosimilar Product” means, with respect to a given Licensed Product, a biological product
(a) that contains (i) an identical active ingredient(s) as the Licensed Antibody in such Licensed Product, or (ii) a “highly similar” active ingredient(s) to the Licensed Antibody in such Licensed Product, as the phrase
“highly similar” is used in 42 U.S.C. § 262(i)(2), and subject to the factors set forth in FDA’s Guidance for Industry, “Quality Considerations in Demonstrating Biosimilarity to a Reference Protein Product,” (February
2012), at Section VI, or any successor FDA guidance thereto, (b) for which Regulatory Approval is obtained by referencing Regulatory Materials of such Licensed Product, (c) is approved for use in such country (or region) pursuant to a
Regulatory Approval process governing approval of interchangeable or biosimilar biologics as described in 42 U.S.C. §§ 262, or a similar process for Regulatory Approval in any country (or region) outside the United States, or any other
similar provision that comes into force, or is the subject of a notice with respect to such Licensed Product under 42 U.S.C. § 262(l)(2) or any other similar provision that comes into force in such country (or region), and (d) is sold in
the same country as such Licensed Product by any Third Party that is not a Sublicensee of Celgene or its Affiliates with respect to the Prothena IP and did not purchase such product in a chain of distribution that included any of Celgene or any of
its Affiliates or its Sublicensees. 
 1.9    “BPCIA” means Biologics Price Competition and Innovation
Act of 2009, as amended. 
 1.10    “Business Day” means a day on which banking institutions in New
York City, New York, are open for business, excluding any Saturday or Sunday. 
 1.11    “Calendar
Quarter” means the period beginning on the Effective Date and ending on the last day of the calendar quarter in which the Effective Date falls, and thereafter each successive period of three (3) consecutive calendar months ending on
the last day of March, June, September, or December, respectively; provided that the final Calendar Quarter shall end on the last day of the Term. 

1.12    “Calendar Year” means the period beginning on the Effective Date and ending on December 31
of the calendar year in which the Effective Date falls, and thereafter each successive period of twelve (12) consecutive calendar months beginning on January 1 and ending on December 31; provided that the final Calendar Year shall end on
the last day of the Term. 
 1.13    “Celgene IP” means Patents and Know-How owned or otherwise controlled (through license or otherwise, but excluding through grant of a license from Prothena to Celgene pursuant to this Agreement) by Celgene or any of its Affiliates (including any Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to practice by or on behalf of Celgene or any of its Affiliates pursuant to the conduct of activities under
this Agreement). For the avoidance of doubt, Celgene IP excludes (i) Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to practice by or on behalf of
Prothena, solely or jointly with a Third Party; (ii) Joint Program IP (as defined under the Master Collaboration Agreement); (iii) [***], and (iv) Joint IP. 

  
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treatment has been requested with respect to the omitted portions. 

 1.14    “Change of Control” in respect of a Person (an
“Acquired Person”) shall be deemed to have occurred upon any of the following occurring after the Effective Date: (i) any Person or group of Persons that is not an Affiliate of such Acquired Person becomes the beneficial owner
(directly or indirectly) of more than fifty percent (50%) of the voting shares; (ii) such Acquired Person consolidates with or merges into or with another Person that is not an Affiliate of such Acquired Person pursuant to a transaction in
which more than fifty percent (50%) of the voting shares of the acquiring or resulting entity outstanding immediately after such consolidation or merger is not held by the holders of the outstanding voting shares of such Acquired Person immediately
preceding such consolidation or merger; and/or (iii) that Acquired Person sells or transfers to another Person that is not an Affiliate of such Acquired Person all or substantially all of its assets. 

1.15    “Clinical Trial” means a human clinical trial, including any Phase 1 Clinical Trial, Phase 2
Clinical Trial or Registration Enabling Clinical Trial, any study incorporating more than one of these phases, or any human clinical trial commenced after Regulatory Approval. 

1.16    “Commercialization” means any and all activities directed to the commercialization of a product
(which may include related diagnostic products, if applicable), including commercial manufacturing (including Manufacturing) and commercial supply of a product, marketing, detailing, promotion, market research, distributing, order processing,
handling returns and recalls, booking sales, customer service, administering and commercially selling such product, importing, exporting and transporting such product for commercial sale, and seeking of pricing and reimbursement of a product (if
applicable), whether before or after Regulatory Approval has been obtained (including making, having made, using, importing, selling and offering for sale such product (or related diagnostic product, if applicable)), as well all regulatory
compliance with respect to the foregoing. For clarity, “Commercialization” does not include any Clinical Trial commenced after Regulatory Approval. When used as a verb, “Commercialize” means to engage in Commercialization.

 1.17    “Commercially Reasonable Efforts” means, with respect to Celgene in relation to an
obligation under this Agreement with respect to a Licensed Antibody or Licensed Product, such efforts that are consistent with the efforts and resources normally used by Celgene in the exercise of its commercially reasonable business practices
relating to performance of an obligation for a similar pharmaceutical compound or product (including the research, development, manufacture and commercialization of a pharmaceutical compound or product), as applicable, at a similar stage in its
research, development or commercial life as the relevant Licensed Antibody or Licensed Product, and that has commercial and market potential similar to the relevant Licensed Antibody or Licensed Product, taking into account issues of intellectual
property coverage, safety and efficacy, stage of development, product profile, competitiveness of the marketplace, proprietary position, regulatory exclusivity, anticipated or approved labeling, present and future market and commercial potential,
the likelihood of receipt of Regulatory Approval, profitability (including pricing and reimbursement status achieved or likely to be achieved), amounts payable to licensors of patents or other intellectual property rights, [***], and legal issues.

  
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treatment has been requested with respect to the omitted portions. 

 1.18    “Confidential Information” means, with respect
to a Party, all confidential and proprietary information and materials, including Know-How, marketing plans, strategies, and customer lists, in each case, that are disclosed by or on behalf of such Party to
the other Party pursuant to this Agreement, regardless of whether any of the foregoing are marked “confidential” or “proprietary” or communicated to the other Party by or on behalf of the disclosing Party in oral, written,
visual, graphic or electronic form. 
 1.19    “Control”, “Controls” or
“Controlled” means, with respect to any intellectual property (including Know-How) or Confidential Information, the ability of a Party or its Affiliates, as applicable, (whether through
ownership or license (other than a license granted in this Agreement)) to grant to the other Party the licenses or sublicenses as provided herein, or to otherwise disclose such intellectual property or Confidential Information to the other Party,
without violating the terms of any then-existing agreement with any Third Party at the time such Party or its Affiliates, as applicable, would be required hereunder to grant the other Party such license or sublicenses as provided herein or to
otherwise disclose such intellectual property or Confidential Information to the other Party. 

1.20    “Cover”, “Covering” or “Covered” means, with reference to a
Patent claim, that such Patent has a Valid Claim that claims the [***], and that the sale of a Licensed Antibody (or product incorporating such Licensed Antibody) would infringe such Valid Claim in the country in which such activity occurs without a
license thereto (or ownership thereof); provided, that with respect to method of use, such method of use is for an Indication for which Regulatory Approval has been received (as set forth on the approved labeling for the applicable Licensed Product
incorporating such Licensed Antibody) for such Licensed Antibody in such country.  

1.21    “Derivative” means, with respect to a Licensed Target, all [***] thereof. 

1.22    “Development” means (i) research activities (including drug discovery, identification and/or
synthesis) with respect to a product (which may include related diagnostic products, if applicable), and/or (ii) preclinical and clinical drug development activities, and other development activities, with respect to a product (which may
include related diagnostic products, if applicable), including test method development and stability testing, toxicology, formulation, process development, qualification and validation, manufacture scale-up,
development-stage manufacturing (including Manufacturing), quality assurance/quality control, Clinical Trials (including Clinical Trials and other studies commenced after Regulatory Approval), statistical analysis and report writing, the preparation
and submission of INDs and MAAs, regulatory affairs with respect to the foregoing and all other activities necessary or useful or otherwise requested or required by a Regulatory Authority or as a condition or in support of obtaining or maintaining a
Regulatory Approval. When used as a verb, “Develop” means to engage in Development. 

  
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treatment has been requested with respect to the omitted portions. 

 1.23    “Diagnostic Product” means, on a Licensed Product-by-Licensed Product basis, any diagnostic product (which may include a Licensed Antibody or Licensed Product being used as a diagnostic product) which is necessary or
reasonably useful (a) for the [***] in a patient or Patient Sample, and/or (b) to [***] in a patient or Patient Sample, and/or (c) to [***] to achieve improved safety or effectiveness, in each case of (a), (b) and (c), which is
intended for use or is Developed or approved for use in connection with a therapeutic Licensed Antibody or Licensed Product (which may include [***]).  

1.24    “Dollars” or “$” means the legal tender of the United States. 

1.25    “EU” means all countries that are officially recognized as member states of the European Union at
any particular time. 
 1.26    “Executive Officers” means Prothena’s Chief Executive Officer and
Celgene’s Executive Vice President, Research and Early Development (or such Executive Vice President’s designee). 

1.27    “Existing IND” means the IND for the conduct of Phase 1 Clinical Trials under the Licensed
Program as more particularly identified on Schedule 1.27. 
 1.28    “Existing Program
Agreements” means any agreement between Prothena (or its Affiliates, as applicable) and any Third Party solely related to the Development or Manufacture of any Licensed Antibodies or Licensed Products, in effect as of the Effective Date, as
set forth on Schedule 1.28. 
 1.29    “Field” means any and all uses or purposes, including the
treatment, prophylaxis, palliation, diagnosis or prevention of any human or animal disease, disorder or condition. 

1.30    “First Commercial Sale” means, on a Licensed Product-by-Licensed Product and country-by-country basis, the first sale of such Licensed Product in such country for use or
consumption by the general public (following receipt of all Regulatory Approvals that are required in order to sell such Licensed Product in such country) and for which any of Celgene or its Affiliates or Sublicensees has invoiced sales of Licensed
Products in the Territory; provided, however, that the following shall not constitute a First Commercial Sale: (a) any sale to an Affiliate or Sublicensee, unless the Affiliate or Sublicensee is the last Person in the distribution chain of the
Licensed Product; or (b) any use of such Licensed Product in Clinical Trials or non-clinical development activities with respect to such Licensed Product by or on behalf of a Party, or disposal or
transfer of such Licensed Product for a bona fide charitable purpose, compassionate use or samples. 

1.31    “Global License Agreement” means each Global License Agreement entered into between the Parties
(or their respective Affiliates, as applicable) pursuant to the Master Collaboration Agreement. When used in this Agreement, references to Global License Agreements are references to Global License Agreements other than this Agreement. 

  
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treatment has been requested with respect to the omitted portions. 

 1.32    “Good Clinical Practices” or
“GCP” means the applicable then-current ethical and scientific quality standards for designing, conducting, recording, and reporting trials that involve the participation of human subjects as are required by applicable Regulatory
Authorities or Applicable Law in the relevant jurisdiction, including in the United States, Good Clinical Practices established through FDA guidances, and, outside the United States, Guidelines for Good Clinical Practice – ICH Harmonized
Tripartite Guideline (ICH E6). 
 1.33    “Good Laboratory Practices” or “GLP” means
the applicable then-current good laboratory practice standards as are required by applicable Regulatory Authorities or Applicable Law in the relevant jurisdiction, including in the United States, those promulgated or endorsed by the FDA in U.S. 21
C.F.R. Part 58, or the equivalent thereof as promulgated or endorsed by the applicable Regulatory Authorities outside of the United States. 

1.34    “Good Manufacturing Practices” or “GMP” means all applicable standards relating
to manufacturing practices for fine chemicals, intermediates, bulk products and/or finished pharmaceutical products, as are required by applicable Regulatory Authorities or Applicable Law in the relevant jurisdiction, including, as applicable,
(a) all applicable requirements detailed in the FDA’s current Good Manufacturing Practices regulations, U.S. 21 C.F.R. Parts 210 and 211, (b) all applicable requirements detailed in the EMA’s “The Rules Governing Medicinal
Products in the European Community, Volume IV, Good Manufacturing Practice for Medicinal Products”, and (c) all Applicable Laws promulgated by any Governmental Authority having jurisdiction over the manufacture of the applicable compound
or pharmaceutical product, as applicable. 
 1.35    “Governmental Authority” means any
(a) federal, state, local, municipal, foreign or other government, (b) governmental or quasi-governmental authority of any nature (including any governmental division, subdivision, department, agency, bureau, branch, office,
commission, council, board, instrumentality, officer, official, representative, organization, unit, body or entity and any court or other tribunal), (c) multinational governmental organization or body or (d) entity or body exercising, or
entitled to exercise, any executive, legislative, judicial, administrative, regulatory, police, military or taxing authority or power of any nature. 

1.36    “IND” means an investigational new drug application (including any amendment or supplement
thereto) submitted to the FDA pursuant to U.S. 21 C.F.R. Part 312, including any amendments thereto. References herein to IND shall include, to the extent applicable, any comparable filing(s) outside the U.S. for the investigation of any product in
any other country or group of countries (such as a Clinical Trial Application in the EU). 

1.37    “Indication” means an entirely separate and distinct disease or medical condition in humans (i)
[***], and/or (ii) [***]. For clarity, (a) [***], (b) [***] and (c) [***] 

  
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treatment has been requested with respect to the omitted portions. 

 [***]. 

1.38     “Initiation” means, with respect to a given Clinical Trial, the administration of the first dose
of Licensed Product to the first properly enrolled subject in such Clinical Trial in accordance with the protocol for such Clinical Trial. 

1.39    “In-License Agreements” means any agreement between
Prothena (or its Affiliates, as applicable) and any Third Party pursuant to which such Third Party licenses to Prothena (or its Affiliates, as applicable) any Patents or Know-How included in the Prothena IP,
including those set forth on Schedule 1.39. 

1.40    “Know-How” means all proprietary (a) information,
techniques, technology, practices, trade secrets, inventions, methods (including methods of use or administration or dosing), knowledge, data, results and software and algorithms, including pharmacological, toxicological and clinical test data and
results, compositions of matter, chemical structures and formulations, sequences, processes, formulae, techniques, research data, reports, standard operating procedures, batch records, manufacturing data, analytical and quality control data,
analytical methods (including applicable reference standards), assays and research tools, in each case, whether patentable or not; and (b) tangible manifestations thereof, including any and all of the foregoing relating to Licensed Program
Biological and Chemical Materials. 
 1.41    “Licensed Antibody” means (a) any Licensed Program
Antibody and (b) any other Antibody that is a variant, fragment, derivative or other modification of a Licensed Program Antibody, that (i) Targets the Licensed Target, (ii) is made by or on behalf of Celgene or its Affiliates or
Sublicensees during the Term in the course of its activities performed under this Agreement (or during the term of the Licensed Program U.S. License Agreement in the course of its activities performed thereunder) and (iii) is claimed (or was
claimed in an issued Patent that has subsequently expired) as a composition of matter in a Licensed Program Patent set forth on Schedule 1.46(b), a Prothena Licensed Collaboration Patent set forth on Schedule 1.63,
or Joint Program Patent (as defined in the Master Collaboration Agreement) as applicable, or any substitutions, divisionals, continuations, continuations-in-part,
reissues, renewals, registrations, confirmations, re-examinations, extensions, supplementary protection certificates and the like of any such Licensed Program Patents, Prothena Licensed Collaboration Patents
or Joint Program Patents (as defined in the Master Collaboration Agreement). 
 1.42    “Licensed
Product” means any product that constitutes, incorporates, comprises or contains a Licensed Antibody, whether or not as the sole active ingredient, and in all forms, presentations, and formulations (including manner of delivery and dosage).
For clarity, different forms, formulations, presentations or dosage strengths of a given Licensed Product that constitute, incorporate, comprise or contain the same Licensed Antibody shall be considered the same Licensed Product for purposes of this
Agreement. Licensed Products shall include, in all cases, any Licensed Program Product. 
 1.43    “Licensed
Program” means the Development program undertaken by or on behalf of Prothena pursuant to the Master Collaboration Agreement with respect to the Licensed Target. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 1.44    “Licensed Program Antibody” means, with respect
to the Licensed Program, (i) the Collaboration Candidates (as defined in the Master Collaboration Agreement) that Target the Licensed Target and that were Developed under such Licensed Program pursuant to the Master Collaboration Agreement,
including those as set forth on Schedule 1.44 and (ii) all Related Antibodies with respect to any Antibody described in the foregoing clause (i) provided that such Related Antibodies are claimed (or were claimed in an issued
Patent that has subsequently expired) as a composition of matter in a Licensed Program Patent set forth on Schedule 1.46(b), a Prothena Licensed Collaboration Patent set forth on Schedule 1.63, or a Joint Program Patent (as defined in
the Master Collaboration Agreement) as applicable, or any substitutions, divisionals, continuations, continuations-in-part, reissues, renewals, registrations,
confirmations, re-examinations, extensions, supplementary protection certificates and the like of any such Licensed Program Patents or Prothena Licensed Collaboration Patents. For the avoidance of doubt,
Licensed Program Antibodies are included within the definition of Licensed Antibody. 
 1.45    “Licensed
Program Biological and Chemical Materials” means, with respect to the Licensed Program, any and all compositions of matter, cells, cell lines, assays, animal models, imaging agents, Patient Samples, Biomarkers and any other physical,
biological or chemical material, that are Controlled by Prothena or its Affiliates and [***], the Licensed Target or Licensed Program Antibodies (or the Development, Manufacture or Commercialization thereof), including physical embodiments of the
Licensed Program Antibodies and any diagnostics related to such Licensed Program Antibodies, in each case, (i) created, conceived, discovered, first generated, invented, first made or first reduced to practice by or on behalf of Prothena or its
Affiliates, whether solely or jointly with any Third Party, in such Licensed Program under the Master Collaboration Agreement or (ii) otherwise utilized by or on behalf of Prothena or its Affiliates in the Licensed Program under the Master
Collaboration Agreement. To the extent the Licensed Program Biological and Chemical Materials were created, conceived, discovered, first generated, invented, first made or first reduced to practice under the Licensed Program under the Master
Collaboration Agreement, such Licensed Program Biological and Chemical Materials shall be “Licensed Program Know-How” hereunder, and to the extent the Licensed Program Biological and Chemical
Materials were not created, conceived, discovered, first generated, invented, first made or first reduced to practice under the Licensed Program under the Master Collaboration Agreement, but were otherwise utilized in the development of the Licensed
Program under the Master Collaboration Agreement, such Licensed Program Biological and Chemical Materials shall be “Prothena Licensed Collaboration Know-How” hereunder. 

1.46    “Licensed Program IP” means, collectively: 

(a)    “Licensed Program Know-How” which means any and all Know-How that was created, conceived, discovered, first generated, invented, first made or first reduced to practice, in each case (i) by or on behalf of [***], (ii) by or on behalf of [***], or (iii) by
or on behalf of [***] 

  
 9 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
[***]. For the avoidance of doubt, Licensed Program Know-How (i) includes ‘Program Know-How’ (as
defined in the Master Collaboration Agreement) related to the Licensed Program but (ii) expressly excludes any Know-How created, conceived, discovered, first generated, invented, first made or first
reduced to practice in the course of activities performed under this Agreement or the Licensed Program U.S. License Agreement, and any Joint Program Know-How (as defined in the Master Collaboration Agreement);
and 
 (b)    “Licensed Program Patents” which means any Patents in the Territory Controlled by
Prothena or its Affiliates that claim or cover any Licensed Program Know-How, including the Patents set forth on Schedule 1.46(b). For the avoidance of doubt, Licensed Program Patents, include
‘Program Patents’ (as defined in the Master Collaboration Agreement) related to the Licensed Program, but expressly exclude Joint Program Patents (as defined in the Master Collaboration Agreement). 

1.47    “Licensed Program Product” means, with respect to the Licensed Program, any product that
constitutes, incorporates, comprises or contains a Licensed Program Antibody, whether or not as the sole active ingredient, and in all forms, presentations, and formulations (including manner of delivery and dosage). For clarity, different forms,
formulations, presentations or dosage strengths of a given Licensed Program Product that constitutes, incorporates, comprises or contains the same Licensed Program Antibody shall be considered the same Licensed Program Product for purposes of this
Agreement. For the avoidance of doubt, Licensed Program Products are included within the definition of Licensed Products. 

1.48    “Licensed Target” means the target set forth on Schedule 1.48, including Derivatives
thereof. 
 1.49    “Major Markets” means the United Kingdom, France, Germany, Italy and Spain. 

1.50    “Manufacture” means all activities related to the manufacturing of a product or diagnostic
product or, in either case, any component or ingredient thereof, including test method development and stability testing, formulation, process development, manufacturing scale-up whether before or after
Regulatory Approval, manufacturing any product or diagnostic product in bulk or finished form for Development or Commercialization (as applicable), including filling and finishing, packaging, labeling, shipping and holding, in-process and finished product testing, release of a product or diagnostic product or, in either case, any component or ingredient thereof, quality assurance and quality control activities related to manufacturing
and release of a product or diagnostic product, and regulatory activities related to any of the foregoing. 

1.51    “Marketing Authorization Application” or “MAA” means a Marketing Authorization
Application, Biologics License Application or similar application, as applicable, and all amendments and supplements thereto, submitted to the FDA, or any equivalent filing in a country or regulatory jurisdiction other than the U.S. with the
applicable Regulatory Authority, to obtain marketing approval for a pharmaceutical or diagnostic product, in a country or in a group of countries. 

  
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treatment has been requested with respect to the omitted portions. 

 1.52    “Net Sales” means, in respect of a given
Licensed Product, the total [***] amounts [***] for all sales of such Licensed Product in the Territory for use in the Field by Celgene, its Affiliates or Sublicensees to Third Party customers (including to distributors), less the following
deductions [***] so as to arrive at “net sales” under Accounting Standards as reported by Celgene, its Affiliates or Sublicensees, as applicable, in such Person’s financial statements: 

(a)    [***]; 

(b)    [***]; 

(c)    [***]; 

(d)    [***]; and 

(e)    [***]. 
 There shall
be no double counting in determining the foregoing deductions from gross amounts invoiced to calculate Net Sales. The calculations set forth in this definition of “Net Sales” shall be determined in accordance with Accounting Standards.

 Sales or other transfers between Celgene and its Affiliates or Sublicensees, as well as any transfers or dispositions of any Licensed Products for (i)
[***], (ii) [***], (iii) [***] or (iv) [***], in each case, shall be excluded from the computation of Net Sales. 
 The calculations set forth in this
section shall be determined in accordance with Accounting Standards. If any Licensed Product is, or is sold as part of, a Combination Product, Net Sales shall be calculated assuming that the gross sale price of each unit is equal to the product of
(i) Net Sales of the Combination Product calculated as above (i.e., calculated as for a non-Combination Product), and (ii) the fraction [***], where: 

[***] 

  
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treatment has been requested with respect to the omitted portions. 

 For purposes of this definition, “Combination Product” means any pharmaceutical product
that (a) contains two or more active ingredients, including both (1) a Licensed Antibody and (2) one or more other compounds (which may be Antibodies) but that are not a Licensed Antibody, either as a fixed dose product, co-formulated product or co-packaged product, and sold for a single price, and (b) is Developed or Commercialized, alone or together with a Third Party, by Celgene or any
of its Affiliates or Sublicensees. Any vehicles, adjuvants and excipients used in conjunction with any Licensed Antibody shall not be treated as active ingredients for the purposes of this definition. 

1.53    “Patents” means (a) all patents and patent applications in any country or supranational
jurisdiction worldwide, (b) any substitutions, divisionals, continuations, continuations-in-part, reissues, renewals, registrations, confirmations, re-examinations, extensions, supplementary protection certificates and the like of any such patents or patent applications, and (c) foreign counterparts of any of the foregoing. 

1.54    “Patient Sample” means tissue, fluid, or cells collected from a patient, or components of the
foregoing. 
 1.55    “Person” means any individual, partnership, joint venture, limited liability
company, corporation, firm, trust, association, unincorporated organization, governmental authority or agency, or any other entity not specifically listed herein. 

1.56    “Phase 1 Clinical Trial” means a human clinical trial of a product that would satisfy the
requirements of U.S. 21 C.F.R. Part 312.21(a) (as amended), or a similar clinical study prescribed by the Regulatory Authorities in a foreign country, and is intended to (a) determine the safety, pharmacokinetics and pharmacodynamic parameters
in healthy individuals or patients, and (b) following the foregoing clause (a), further evaluate safety and pharmacokinetics (including exploration of trends of a biomarker-based or clinical endpoint-based efficacy relationship to dose which
need not be designed to be statistically significant) of the product, whether or not in combination with concomitant treatment and which provides sufficient evidence of safety to be included in filings for a Phase 2 Clinical Trial or a Registration
Enabling Clinical Trial with Regulatory Authorities. 

  
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treatment has been requested with respect to the omitted portions. 

 1.57    “Phase 1 Option Exercise Fee” shall mean the
Phase 1 Option Exercise Fee (as defined in the Master Collaboration Agreement) for the Licensed Program. 

1.58    “Phase 2 Clinical Trial” means a human clinical trial of a product that would satisfy the
requirements of U.S. 21 C.F.R. Part 312.21(b), as amended, and is intended to explore a variety of doses, dose response, and duration of effect, and to generate evidence of clinical safety and effectiveness for a particular Indication or Indications
in a target patient population, or a similar clinical study prescribed by the relevant Regulatory Authorities in a country other than the United States. 

1.59    “Prosecution and Maintenance” or “Prosecute and Maintain” means, with regard to
a Patent, the preparation, filing, prosecution and maintenance of such Patent, as well as re-examinations, reissues, appeals, and requests for patent term adjustments and patent term extensions with respect to
such Patent, together with the initiation or defense of interferences, oppositions, inter partes review, derivations, re-examinations, post-grant proceedings and other similar proceedings (or other defense
proceedings with respect to such Patent, but excluding the defense of challenges to such Patent as a counterclaim in an infringement proceeding) with respect to the particular Patent, and any appeals therefrom. For clarification, “Prosecution
and Maintenance” or “Prosecute and Maintain” shall not include any other enforcement actions taken with respect to a Patent. 

1.60    “Prothena IP” means the Prothena Licensed Collaboration Patents, the Prothena Licensed
Collaboration Know-How, the Licensed Program Patents and the Licensed Program Know-How, as well as Prothena’s (and its Affiliates’) right, title and interest
in and to the Joint IP and any Joint Program IP (as defined under the Master Collaboration Agreement). 

1.61    “Prothena Licensed Collaboration IP” means all Prothena Licensed Collaboration Know-How and Prothena Licensed Collaboration Patents 
 1.62    “Prothena
Licensed Collaboration Know-How” means any and all Know-How that is Controlled by Prothena or its Affiliates on or after the Effective Date that (a) is
necessary or [***] to research, develop, make, have made, import, use, offer to sell, sell or otherwise exploit any Licensed Target, Licensed Program Antibody or Licensed Program Product or (b) is or was [***], including (i) any
diagnostics related to any such Licensed Program Antibody or Licensed Program Product and (ii) Know-How conceived, created, discovered, first generated, invented, first made or first reduced to practice
by or on behalf of a Prothena or its Affiliates, whether solely or jointly with any Third Party, in the course of activities performed under this Agreement; but expressly excluding Joint Know-How, Joint
Program Know-How (as defined in the Master Collaboration Agreement) and Licensed Program Know-How. 

1.63    “Prothena Licensed Collaboration Patents” means any and all Patents in the Territory that are
Controlled by Prothena or its Affiliates on or after the Effective Date that claim or cover (a) any Licensed Target, any Licensed Program Antibody or any Licensed Program Product, or the research, development, making, having made, import, use,
offering to sell, selling or other exploitation of any of the foregoing, or (b) any Prothena Licensed Collaboration Know-How; but expressly excluding Joint Patents, Joint Program Patents (as defined in the Master Collaboration Agreement) and
Licensed Program Patents. Prothena Licensed Collaboration Patents shall include the Patents set forth on Schedule 1.63. 

  
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treatment has been requested with respect to the omitted portions. 

 1.64    “Prothena Platform Patent” means a Patent
within the Prothena Licensed Collaboration Patents that [***] claims the Prothena Platform Technology. 

1.65    “Prothena Platform Technology” means [***], which shall [***]; but in any case excluding [***].

 1.66    “Registration Enabling Clinical Trial” means (a) a human clinical trial of a
product that would satisfy the requirements of U.S. 21 C.F.R. Part 312.21(c), as amended, and is intended to (i) establish that the product is safe and efficacious for its intended use, (ii) define contraindications, warnings, precautions
and adverse reactions that are associated with the product in the dosage range to be prescribed, and (iii) support Regulatory Approval for such product, or (b) a similar clinical study prescribed by the relevant Regulatory Authorities in a
country other than the United States. 
 1.67    “Regulatory Approval” means all approvals, licenses
and authorizations of the applicable Regulatory Authority necessary for the marketing and sale of a pharmaceutical or diagnostic product for a particular Indication in a country or region (including separate pricing or reimbursement approvals, as
necessary), and including the approvals by the applicable Regulatory Authority of any expansion or modification of the label for such Indication. 

1.68    “Regulatory Authority” means any national or supranational Governmental Authority, including the
U.S. Food and Drug Administration (and any successor entity thereto) (the “FDA”) in the U.S., the European Medicines Agency (and any successor entity thereto) (the “EMA”) in the EU and the Ministry of Health, Labour
and Welfare of Japan, or the Pharmaceuticals and Medical Devices Agency of Japan (or any successor to either of them) as the case may be (the “MHLW”) in Japan, or any health regulatory authority in any country or region that is a
counterpart to the foregoing agencies, in each case, that holds responsibility for development and commercialization of, and the granting of Regulatory Approval for, a pharmaceutical or diagnostic product, as applicable, in such country or region.

 1.69    “Regulatory-Based Exclusivity” means, on a Licensed Product-by-Licensed Product and country-by-country basis, that Celgene or any of its Affiliates or Sublicensees has been granted
the exclusive legal right by a Regulatory Authority in such country to market and sell the Licensed Product in such country, in each case, such that market exclusivity is maintained for Celgene (or its Affiliate or Sublicensee, as applicable) in
such country with respect to such Licensed Product as a result of such grant by such Regulatory Authority. 

1.70    “Regulatory Materials” means the regulatory registrations, applications, authorizations and
approvals (including approvals of MAAs, supplements and amendments, pre- and post-approvals, pricing and reimbursement approvals, and labeling approvals), Regulatory Approvals and other submissions made to or
with any Regulatory Authority for research, 

  
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treatment has been requested with respect to the omitted portions. 

 development (including the conduct of Clinical Trials), manufacture, or commercialization of a
pharmaceutical or diagnostic product in a regulatory jurisdiction, together with all related correspondence to or from any Regulatory Authority and all documents referenced in the complete regulatory chronology for each MAA, including all Drug
Master Files (if any), INDs and supplemental biologics license applications (sBLAs) and foreign equivalents of any of the foregoing. The Regulatory Materials shall include the Existing IND. 

1.71    “Related Antibody” means, with respect to a given Antibody, any (a) [***] or (b) [***], and in
each case of (a) and (b), that [***]. 
 1.72    “Royalty Term” means, on a Licensed Product-by-Licensed Product and country-by-country basis, the period of time commencing on the
First Commercial Sale of such Licensed Product in such country of sale and expiring upon the latest of (a) the first date on which there is no Valid Claim of a Patent within the Licensed Program Patents, Prothena Licensed Collaboration Patents
or Joint Program Patents (as defined in the Master Collaboration Agreement), in each case, that Covers such Licensed Product in such country of sale, (b) the expiration of Regulatory-Based Exclusivity for such Licensed Product in such country
of sale and (c) the [***] ([***]) year anniversary of the date of First Commercial Sale of such Licensed Product in such country of sale. 

1.73    “Select Indication” means each of the following separate and distinct Indications: [***] such
other Indications as the Parties may mutually agree in writing to be expressly included as a “Select Indication” for purposes of this Agreement; provided that such indication is identified as an approved use for the applicable Licensed
Product in the approved label for such Licensed Product in the applicable country. 

1.74    “Sublicensee” means, with respect to Celgene, a Third Party to whom Celgene has granted a
sublicense, either directly or indirectly, under the Prothena IP licensed to Celgene by Prothena pursuant to this Agreement, to Develop, Manufacture and/or Commercialize Licensed Antibodies and Licensed Products in the Field in the Territory, but
excluding any Third Party acting as a distributor and excluding Prothena and its Affiliates. 

1.75    “Target” means, with respect to a given Antibody and the Licensed Target, that such
Antibody [***]. For the purposes of the “Target” definition, “[***]” means [***].4 
  

 

	4 	 [***] For the purposes of the “Target” definition, “[***]” means [***]

  
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treatment has been requested with respect to the omitted portions. 

 1.76    “Territory” means worldwide. 

1.77    “Third Party” means any Person other than Prothena or Celgene that is not an Affiliate of
Prothena or of Celgene. 
 1.78    “Third Party Claim” means any and all suits, claims, actions,
proceedings or demands brought by a Third Party. 
 1.79    “Third Party Damages” means all losses,
costs, claims, damages, judgments, liabilities and expenses payable to a Third Party by a Party (or the Prothena Indemnitees or Celgene Indemnitees, as applicable) under a Third Party Claim (including reasonable attorneys’ fees and other
reasonable out-of-pocket costs of litigation in connection therewith). 

1.80    “United States” or “U.S.” means the United States of America and all of its
territories and possessions. 
 1.81    “U.S. License Agreement” shall mean each U.S. License Agreement
entered into between the Parties (or their respective Affiliates, as applicable) pursuant to the Master Collaboration Agreement. 

1.82    “Valid Claim” means a claim of a Patent within the Licensed Program Patents, Prothena Licensed
Collaboration Patents, or Joint Program Patents (as defined in the Master Collaboration Agreement) in the Territory that has issued and has not expired, lapsed, been cancelled or abandoned, or been dedicated to the public, disclaimed, or held
unenforceable, invalid, revoked or cancelled by a court or administrative agency of competent jurisdiction in an order or decision from which no appeal has been or can be taken, including through opposition, reexamination, reissue, disclaimer, inter
partes review, post grant procedures or similar proceedings [***]. 
 1.83    Additional Definitions. Each of the
following terms has the meaning described in the corresponding section of this Agreement indicated below: 
  

			
	 Definition:
	  	 Section:

	 Acquired Person
	  	1.14
	 Active Immunotherapeutic Approaches
	  	4.2.1
	 Agreement
	  	Preamble
	 Celgene
	  	Preamble
	 Celgene Acquired Competing Antibody
	  	4.5.2
	 Celgene Exclusivity Term
	  	4.5.1
	 Celgene Indemnitees
	  	9.2
	 Celgene Proposed Terms
	  	4.2.2
	 Celgene Share
	  	6.8.4
	 Celgene Third Party Payments
	  	5.3.4
	 Combination Product
	  	1.52
	 Competing Antibody
	  	4.5.1

  
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treatment has been requested with respect to the omitted portions. 

			
	 Definition:
	  	 Section:

	 Competing Compound
	  	4.1
	 Cure Period
	  	10.2.1
	 Disclosing Party
	  	7.1
	 Dispute
	  	11.7.2
	 Electronic Delivery
	  	11.11
	 Effective Date
	  	Preamble
	 EMA
	  	1.68
	 Excluded Claim
	  	11.7.3(d)
	 Existing Regulatory Materials
	  	2.2.1
	 FDA
	  	1.68
	 [***]
	  	[***]
	 Force Majeure
	  	11.3
	 GAAP
	  	1.1
	 Grant
	  	4.2.2
	 Grant Notice
	  	4.2.2
	 HIPAA
	  	1.5
	 IFRS
	  	1.1
	 Indemnitee
	  	9.3
	 Indemnitor
	  	9.3
	 Indirect Taxes
	  	5.6.2(b)
	 Insolvency Event
	  	10.4
	 Joint IP
	  	6.6.4
	 Joint Know-How
	  	6.6.4
	 Joint Patent
	  	6.6.4
	 Licensed Program Assets
	  	2.4
	 Licensed Program Confidential Information
	  	7.11
	 Licensed Program Inventory
	  	2.3.4
	 Licensed Program Know-How
	  	1.46(a)
	 Licensed Program Non-Specific IP
	  	7.2
	 Licensed Program Patents
	  	1.46(b)
	 Licensed Program Specific IP
	  	7.2
	 Licensed Program U.S. License Agreement
	  	Recitals
	 Master Collaboration Agreement
	  	Recitals
	 MHLW
	  	1.68
	 Negotiation Period
	  	4.2.2
	 [***]
	  	[***]
	 Notice Period
	  	4.2.2
	 Ongoing Clinical Trial
	  	2.1.3(a)
	 Ongoing Prothena Development Activities
	  	2.1.3(c)
	 Party or Parties
	  	Preamble
	 Patent Liaison
	  	6.7
	 Payee Party
	  	5.6.2(b)
	 Paying Party
	  	5.6.2(b)
	 Per Licensed Product Annual Net Sales
	  	5.3.1
	 Program
	  	Recitals

  
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treatment has been requested with respect to the omitted portions. 

			
	 Definition:
	  	 Section:

	 Prothena
	  	Preamble
	 Prothena Acquired Competing Compound
	  	4.4
	 Prothena Indemnitees
	  	9.1
	 Prothena Licensor
	  	8.3.3
	 Prothena Ongoing Program Activities
	  	2.1.3(d)
	 Prothena Reversion Antibodies
	  	10.8.1
	 Publishing Party
	  	7.8.1
	 Receiving Party
	  	7.1
	 Regulatory Milestone Payment
	  	5.4.1
	 Right of First Negotiation
	  	4.2.2
	 Sales Milestone Payment
	  	5.5.1
	 SEC
	  	7.4.1(a)
	 Securities Regulators
	  	7.6
	 Tax Benefit
	  	5.6.2(c)
	 Term
	  	10.1.1
	 Transition Plan
	  	2.3.6

 ARTICLE 2. 

DEVELOPMENT, MANUFACTURE AND COMMERCIALIZATION 

2.1    Development, Manufacturing and Commercialization. 

2.1.1    General. From and after the Effective Date, and subject to the terms and conditions of this Agreement,
(i) Celgene will have the sole right (and shall solely control, at its discretion), itself and/or with or through its Affiliates, Sublicensees or other Third Parties, to Develop, Manufacture and Commercialize Licensed Antibodies and Licensed
Products in the Field in the Territory, and (ii) Prothena and its Affiliates shall not have any right to, and shall not, conduct any Development, Manufacture or Commercialization of any Licensed Antibodies or Licensed Products in the Field in
the Territory. 
 2.1.2    Diligence. From and after the Effective Date, and subject to the terms and conditions
of this Agreement, Celgene, itself and/or with or through its Affiliates, Sublicensees or other Third Parties, will use Commercially Reasonable Efforts to (i) Develop and seek Regulatory Approval for at least one Licensed Product in the U.S.
and at least one Major Market, and (ii) following receipt of Regulatory Approval in in the U.S. or such Major Market, introduce at least one Licensed Product into commercial market in such country. 

2.1.3    Prothena Activities in Support of Licensed Program. Notwithstanding the provisions of Section 2.1.1,
as and to the extent requested by Celgene in writing, Prothena shall conduct the following activities as reasonably directed by Celgene: 

(a)    Ongoing Clinical Trials. If any Clinical Trial(s) that were being conducted by or on behalf of Prothena
under the Licensed Program pursuant to the Master Collaboration Agreement have not been completed as of the Effective Date (an “Ongoing Clinical Trial”), then, at Celgene’s written election, Prothena will, at its expense,
either wind-down and terminate such Ongoing Clinical Trial or continue to perform such Ongoing Clinical Trial. In the 

  
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 event Celgene elects that an Ongoing Clinical Trial should be wound-down and terminated, Prothena shall
cause such Ongoing Clinical Trial to be wound-down and terminated promptly. In the event that Celgene elects the Ongoing Clinical Trial to continue, then Prothena shall continue to be responsible for the performance of, and shall continue to
perform, such Ongoing Clinical Trial in accordance with (i) the Research Plan (as defined in the Master Collaboration Agreement) as in existence as of the Effective Date, (ii) the terms of the applicable Clinical Trial protocol as in
existence as of the Effective Date (as may be amended as required by Applicable Law and applicable guidance issued from time to time by the by the relevant Regulatory Authority) and (iii) otherwise in accordance with the reasonable directions
of Celgene, until completion of such Clinical Trial. In such case, the performance of such Clinical Trial by or on behalf of Prothena shall continue to be governed by the terms and conditions of the Master Collaboration Agreement as if the Licensed
Program were continuing under the Master Collaboration Agreement solely with respect to such Ongoing Clinical Trial, mutatis mutandis (including that Know-How conceived, created, discovered, first
generated, invented, first made or first reduced to practice, by or on behalf of Prothena or its Affiliates, whether solely or jointly with any Third Party, pursuant to the conduct of such Ongoing Clinical Trial, shall be Licensed Program Know-How hereunder); provided that, notwithstanding the provisions of the Master Collaboration Agreement, Celgene shall have the right to make decisions and determinations with respect to the conduct of such Ongoing
Clinical Trial, and Prothena shall comply with all such reasonable decisions and determinations, provided that Celgene consults with and reasonably considers Prothena’s comments with respect thereto prior to making any such decision or
determination. In addition, Celgene shall have the right, at any time, to notify Prothena to cease performance of an Ongoing Clinical Trial, and in such case, Prothena shall immediately wind-down any such Ongoing Clinical Trial. 

(b)    Transition Supply. If Prothena was supplying (or having supplied) any Licensed Antibody and/or
Licensed Product for any Clinical Trial(s) or other Development activities conducted with respect to the Licensed Program under the Master Collaboration Agreement, then, at Celgene’s written request, Prothena will be responsible for supplying,
and shall supply, to Celgene (or its designee) Licensed Antibody(ies) and/or Licensed Product(s), for use in Development by or on behalf of Celgene hereunder for a period not to exceed [***] ([***]) [***] (or such longer period of time as agreed to
by the Parties), as and to the extent requested by Celgene; provided that Celgene shall pay to Prothena a reasonable, fair value cost for such supply, which cost shall be negotiated in good faith and agreed to by the Parties prior to such supply. In
such case, at the request of Celgene, the Parties shall negotiate in good faith and enter into an appropriate supply agreement (including a quality agreement) for Prothena to supply (or have supplied) Licensed Antibody and/or Licensed Product, as
applicable, to Celgene (or its designee). Notwithstanding the foregoing, if Prothena has engaged a Third Party contract manufacturer for the supply of Licensed Antibodies and/or Licensed Products, and the agreement with such Third Party prohibits
the supply to Celgene in accordance with the foregoing (provided that Prothena used good faith efforts not to include such prohibition during negotiations), then in lieu of the foregoing supply obligation, Prothena shall take such actions as
reasonably requested by Celgene to facilitate the negotiations between Celgene and Prothena’s Third Party contract manufacturer of an appropriate supply agreement (including a quality agreement) for the supply of Licensed Antibody and/or
Licensed Product, as applicable, to Celgene (or its designee). 
 (c)    Other Continuing Development
Activities. Without limiting the other obligations of Prothena hereunder (including as set forth in this Section 2.1.3), in the event 

  
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treatment has been requested with respect to the omitted portions. 

 
that the Parties mutually agree in writing that Prothena or its Affiliates will conduct any other specific Development activities for Celgene after the Effective Date with respect to the Licensed
Program (in addition to those set forth in the foregoing provisions of this Section 2.1.3) (the “Ongoing Prothena Development Activities”), then, in such case, the Parties shall negotiate in good faith and enter into a separate
services agreement pursuant to which Prothena (or its Affiliates, as applicable) shall perform such Ongoing Prothena Development Activities. 

(d)    Prothena Ongoing Program Activities. Prothena’s obligations as set forth in this Section 2.1.3,
as applicable, are the “Prothena Ongoing Program Activities”. 
 2.1.4    Celgene Progress
Updates. During the Term until such time as Celgene has submitted a MAA for at least one Licensed Product in the United States and at least one country in the EU (or through centralized EU filing) for a Select Indication, Celgene and Prothena
shall meet at least [***] to discuss the progress of Celgene’s material Development and Commercialization activities with respect to Licensed Products pursuant to this Agreement. Such meeting shall be either in person or telephonically as
agreed to by the Parties. In addition, during the Term until such time as Celgene has submitted an MAA for at least one Licensed Product in the United States or at least one country in the EU (or through centralized EU filing) for a Select
Indication, at least [***] (or more frequently as agreed to by the Parties), Celgene shall submit to Prothena a written report summarizing the progress of Celgene’s material Development and Commercialization activities with respect to Licensed
Products pursuant to this Agreement since the last report. 
 2.1.5    JSC. For the avoidance of doubt, the JSC
(as defined in the Master Collaboration Agreement) and each Subcommittee (as defined in the Master Collaboration Agreement) shall no longer oversee or review any of the matters under this Agreement, and shall have no decision-making authority in
connection therewith. 
 2.2    Regulatory. 

2.2.1    Transfer of Existing Regulatory Materials. Subject to Section 2.2.2, Prothena shall assign and
transfer (and hereby does assign and transfer), or cause to be assigned and transferred to the extent not owned by Prothena, to Celgene (or its designee), promptly (but in all cases within [***] ([***]) days) after the Effective Date any and all
Regulatory Materials (including the Existing IND) for any Licensed Antibodies and/or Licensed Products held or generated by or on behalf of Prothena or its Affiliates (the “Existing Regulatory Materials”), including providing true,
accurate and complete hard and electronic copies thereof to Celgene. Thereafter Celgene (or its designee) shall have the sole right, in its discretion, to file, maintain and hold title to, all Existing Regulatory Materials. Notwithstanding the
foregoing, at the election of Celgene, Celgene may notify Prothena in writing that it does not desire to take assignment and transfer of certain Regulatory Materials (as so determined by Celgene) and in such case, Prothena shall not assign or
transfer to Celgene (or its designee) such designated Regulatory Materials. 
 2.2.2    Prothena Ownership for
Ongoing Clinical Trials. Notwithstanding the foregoing Section 2.2.1, in the event Prothena continues to be responsible for the performance of an Ongoing Clinical Trial pursuant to and in accordance with Section 2.1.3(a), Prothena will
retain ownership of any Existing Regulatory Materials (including the Existing IND) for the 

  
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treatment has been requested with respect to the omitted portions. 

 
corresponding Licensed Antibodies and Licensed Products related to such Ongoing Clinical Trial until completion of such Ongoing Clinical Trial, following which, the provisions of
Section 2.2.1 shall apply with respect to such Existing Regulatory Materials. 
 2.2.3    Safety
Information. Celgene shall have the right to report all safety information to Regulatory Authorities with respect to the Licensed Antibodies and/or Licensed Products in the Territory hereunder, provided that Prothena shall also have such right
with respect to safety data arising from any Ongoing Clinical Trial prior to the transfer of Existing Regulatory Materials to Celgene pursuant to Section 2.2.2. 

2.2.4    Right of Reference; Access to Data. Pending such time as the Existing Regulatory Materials are transferred
and assigned to Celgene (or its designee), or in the event of failure to transfer and assign any Existing Regulatory Materials to Celgene (or its designee), as required by Section 2.2.1 or 2.2.2 (as applicable), Celgene (and its designees)
shall have, and Prothena (on behalf of itself and its Affiliates) hereby grants to Celgene (and its designees), access and a right of reference (without any further action required on the part of Prothena or its Affiliates, whose authorization to
file this consent with any Regulatory Authority is hereby granted) to all such Existing Regulatory Materials and all data contained or referenced in any Existing Regulatory Materials for Celgene (and its designees) to exercise its rights and perform
its obligations hereunder. In all cases, Celgene (and its designees) shall have access to all data contained or referenced in any Existing Regulatory Materials, and Prothena shall ensure that Celgene (and its designees) are afforded such access.

 2.2.5    Regulatory Matters. In the event that Celgene determines that any regulatory filings for any Licensed
Antibodies and/or Licensed Products are required for any activities hereunder, including INDs, MAAs and other Regulatory Approvals (as applicable), then Celgene (or its designee) shall have the sole right, in its discretion, to seek to obtain and
maintain such regulatory filings (in its or its designee’s name). In addition, Celgene (or its designee) shall have the sole right to communicate and otherwise interact with Regulatory Authorities with respect to the Licensed Antibodies and/or
Licensed Products, including with respect to any Regulatory Materials in connection therewith. Prothena (and its Affiliates) shall have no right to, and shall not, make any regulatory filings related to any Licensed Antibodies and/or Licensed
Products or otherwise interact with any Regulatory Authorities with respect to the Licensed Antibodies and/or Licensed Products; provided that, as and to the extent reasonably requested by Celgene in writing, Prothena shall interact with Regulatory
Authorities in connection with Licensed Antibodies and/or Licensed Products with respect to matters related to the Licensed Program activities conducted by or on behalf of Prothena under the Master Collaboration Agreement or with respect to any
Prothena Ongoing Program Activities. Notwithstanding the foregoing, until such time as a given Existing Regulatory Material is assigned and transferred to Celgene in accordance with Section 2.2.1 or 2.2.2 (as applicable), Prothena shall be
responsible for all communications and interactions with Regulatory Authorities with respect to such Existing Regulatory Material; provided that, in connection with any such activities by Prothena, Prothena shall, to the extent reasonably requested
by Celgene, consult and coordinate with Celgene with respect thereto (including allowing Celgene to attend or participate in any meetings or other interactions with Regulatory Authorities to the extent such attendance is not prohibited or limited by
such Regulatory Authority) and Prothena shall accommodate and comply with any reasonable requests made by Celgene in connection therewith (including that Prothena shall submit to Celgene a copy of any proposed filings and

  
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treatment has been requested with respect to the omitted portions. 

 
correspondence with any Regulatory Authority for Celgene’s review and approval prior to submission thereof). At the request of Celgene, Prothena shall reasonably assist Celgene in
communications and filings with Regulatory Authorities with respect to the Licensed Antibodies and/or Licensed Products. 

2.2.6    Pharmacovigilance. At the written request of Celgene, within [***] ([***]) days after such request,
Prothena and Celgene (or its designee(s)) will enter into a pharmacovigilance agreement in order to, among other things, coordinate safety matters and share of safety information with respect to Licensed Products. 

2.3    Assistance; Technology Transfer. 

2.3.1    General. Prothena shall (and shall cause its Affiliates to) cooperate with Celgene (and its designees) and
provide reasonable assistance to Celgene (and its designees) to enable Celgene (and its designees) to Develop, Manufacture and Commercialize Licensed Antibodies and Licensed Products, as and to the extent requested reasonably by Celgene, including
(i) conducting a technology transfer to Celgene with respect to the Licensed Program Know-How and Prothena Licensed Collaboration Know-How, (ii) providing
Celgene (and its designees) reasonable assistance with respect to regulatory and Manufacturing transition matters related to Licensed Antibodies and Licensed Products and (iii) providing Celgene (and its designees) with reasonable access by
teleconference or in-person (as requested by Celgene) to Prothena personnel (and personnel of its Affiliates and Third Party contractors) involved in the Development or Manufacture of Licensed Antibodies and
Licensed Products to assist with the transition and answer questions related to Licensed Antibodies, Licensed Products and Diagnostic Products. 

2.3.2    Additional Specific Transition Assistance. Without limiting the provisions of Section 2.3, as soon as
reasonably practicable following the Effective Date (but in all cases, within [***] ([***]) days after the Effective Date or such other period of time as agreed to by the Parties), and thereafter during the Term as may be reasonably requested by
Celgene from time to time, Prothena shall (i) disclose to Celgene (and its designees) in English (including by providing hard and electronic copies thereof) all Licensed Program Know-How and Prothena
Licensed Collaboration Know-How, including any materials and documentation (including data and protocols) included therein and any other physical embodiments thereof, (ii) transfer to Celgene (and its
designees) all Licensed Program Biological and Chemical Materials, as well as [***] and Celgene and its designees shall have the full right to utilize all of the foregoing in connection with the Development, Manufacture or Commercialization of
Licensed Antibodies and Licensed Products, and (iii) assist Celgene (and its designees) in responding to regulatory inquiries with respect to Licensed Program Antibodies and Licensed Program Products. 

2.3.3    Manufacturing Technology Transfer. Without limiting the provisions of Sections 2.3 and 2.3.2, as soon as
reasonably practicable following the Effective Date (but in all cases, within [***] ([***]) days after the Effective Date or such other period of time as agreed to by the Parties), Prothena shall transfer, and thereafter continue, during the Term as
may be 

  
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treatment has been requested with respect to the omitted portions. 

 reasonably requested by Celgene from time to time, the transfer (from Prothena, its Affiliates or its Third
Party contract manufacturers) to Celgene (and its designees), copies in English (in writing and in an electronic format) of all data, information and other Know-How in the Control of Prothena or its Affiliates
([***]) that is related to the Manufacture of any Licensed Antibodies or Licensed Products, in order to enable Celgene (and its designees) to Manufacture the Licensed Antibodies and Licensed Products, including to replicate the process employed by
or on behalf of Prothena to Manufacture any Licensed Antibodies and Licensed Products. Such transfer shall include all [***]. In addition, at the reasonable request of Celgene from time to time, Prothena shall make its employees and consultants
(including personnel of its Affiliates and Third Party contract manufacturers) available to Celgene (and its designees) to provide reasonable consultation and technical assistance in order to ensure an orderly transition of the manufacturing
technology and operations to Celgene (and its designees) and to assist Celgene (and its designees) in its Manufacture of any Licensed Antibodies and Licensed Products. 

2.3.4    Inventory Transfer. At the written request of Celgene, Prothena shall promptly assign and transfer to
Celgene (or its designee) and deliver to Celgene (or its designee) (at a location to be specified by Celgene to Prothena), any or all (as and to the extent requested by Celgene) inventory of Licensed Antibodies and Licensed Products held by or on
behalf of Prothena or its Affiliates as of the Effective Date (including any such inventory held at any contract manufacturer or any other location); provided that Celgene shall pay to Prothena a reasonable, fair value cost for such transferred
inventory, which cost shall be negotiated in good faith and agreed to by the Parties prior to such transfer (the “Licensed Program Inventory”). 

2.3.5    Assignment of Certain Existing Agreements. 

(a)    At the written request of Celgene, Prothena shall (or shall cause its Affiliates to, as applicable), to the extent
legally permissible (provided that, to the extent consent is required from the relevant counterparty, Prothena shall (or shall cause its Affiliates to, as applicable) use reasonable efforts to obtain such consent) (i) assign to Celgene (or its
designee) any or all (as designated by Celgene) Existing Program Agreements and/or (ii) assist Celgene (or its Affiliate) in entering into new agreements directly with the counterparties to the Existing Program Agreements to cover the subject
matter of such Existing Program Agreements, as applicable, in each case of (i) and/or (ii), as and to the extent requested by Celgene in writing. If any Existing Program Agreement is assigned to Celgene, Prothena shall be solely responsible
for, and shall indemnify and hold harmless Celgene and all other Celgene Indemnitees from and against any costs and other Third Party Damages arising from, or relating to, any such Existing Program Agreement as a result of, or in connection with,
events or occurrences prior to the date of such assignment (including, for clarity, any payments that accrued prior to the date of such assignment, but which do not become payable until after the date of such assignment). 

(b)    [***] 

  
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 [***]. 

2.3.6    Transition Plan. In order to facilitate the transition as set forth in this Section 2.3, at the
request of Celgene, the Parties shall work together in good faith and establish a transition plan setting forth certain additional reasonable transition activities to be undertaken by or on behalf of Prothena in order to fully transition the
Development, Manufacture and Commercialization of Licensed Antibodies and Licensed Products to Celgene (and its designees) (the “Transition Plan”). Once established, Prothena shall use commercially reasonable efforts to [***]
perform its activities under the Transition Plan. 
 2.4    Covenant. Except as otherwise expressly permitted
under this Agreement, commencing on the Effective Date until the end of the Term, Prothena shall not and shall cause its Affiliates not to (a) assign, transfer, convey, encumber(through a lien, charge, security interest, mortgage or similar
encumbrance) or dispose of, or enter into any agreement with any Third Party to assign, transfer, convey, encumber (through a lien, charge, security interest, mortgage or similar encumbrance) or dispose of, any [***] (collectively, the
“Licensed Program Assets”), except to the extent such assignment, transfer, conveyance, encumbrance or disposition would not conflict with, be inconsistent with or adversely affect in any respect any of the rights or licenses
granted to Celgene hereunder, (b) license or grant to any Third Party, or agree to license or grant to any Third Party, any rights to any Licensed Program Assets if such license or grant could conflict with, be inconsistent with or adversely
affect in any respect any of the rights or licenses granted to Celgene hereunder, or (c) [***] the Licensed Program Assets to any Third Party if such [***] could impair or conflict in any respect with any of the rights or licenses granted to Celgene
hereunder. 
 2.5    Other Antibodies and Products Developed by Celgene. Notwithstanding anything to the contrary
contained herein, if Celgene (or any of its Affiliates), alone or with any Third Party, determines to Develop, Manufacture or Commercialize any Antibodies (or any product containing an Antibody), other than Licensed Antibodies or Licensed Products,
then Celgene may do so in its sole discretion, without any obligations to Prothena with respect thereto, and Prothena shall have no rights in connection therewith, provided that Celgene’s or its Affiliates’ conduct of any such activities
shall not modify or obviate Celgene’s obligations under this Agreement. 
 2.6    Licensed Program U.S. License
Agreement. The Parties hereby agree and acknowledge that this Agreement supersedes the Licensed Program U.S. License Agreement in its entirety and any activities conducted under the Licensed Program U.S. License Agreement shall be deemed to have
been conducted under this Agreement. 

  
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treatment has been requested with respect to the omitted portions. 

 ARTICLE 3. 

ANTITRUST AND COMPETITION LAW COMPLIANCE 

3.1    Antitrust Compliance. For the avoidance of doubt, the Parties shall continue to comply with Section 3.2
of the Master Collaboration Agreement, and such provisions shall apply to this Agreement as if set forth directly herein, mutatis mutandis. 

ARTICLE 4. 
 EXCLUSIVITY

 4.1    Prothena Exclusivity. During the Term, Prothena shall not and shall ensure that its
Affiliates shall not, anywhere in the world: (i) alone or with or through any Third Party, research [***], Develop, Manufacture or Commercialize (a) the Licensed Target or any Competing Compound, or (b) any diagnostic product intended
for use, or Developed or approved for use with, the Licensed Target (including any diagnostic product intended for use, or Developed or approved for use with, any Competing Compound), in each case, other than Prothena’s performance of the
Prothena Ongoing Program Activities (including engaging its Affiliates or Third Party subcontractors to perform the Prothena Ongoing Program Activities in accordance with this Agreement) as specifically set forth in Section 2.1.3; (ii) grant a
license, sublicense or other rights to any Third Party to conduct any of the activities in the foregoing clause (i), other than Prothena’s performance of the Prothena Ongoing Program Activities (including engaging its Affiliates or Third Party
subcontractors to perform the Prothena Ongoing Program Activities in accordance with this Agreement) as specifically set forth in Section 2.1.3; or (iii) transfer, assign, convey or otherwise sell (a) any Competing Compound or any
diagnostic product intended for use, or (b) Developed or approved for use with, the Licensed Target (including any diagnostic product intended for use, or Developed or approved for use with any Competing Compound). As used herein, the term
“Competing Compound” means [***]. 
 4.2    Prothena Exception for Active Immunotherapeutic
Approaches. 
 4.2.1    Exception for Active Immunotherapeutic Approaches. Notwithstanding the provisions of
Section 4.1, but subject to the provisions of Section 4.2.2, Prothena and its Affiliates (themselves, but not with or through any Third Parties) may conduct research, development, manufacture and commercialization of Active
Immunotherapeutic Approaches outside of this Agreement; provided that no Licensed Antibodies or Licensed Products are utilized in the conduct of any such activities (including no use of a Licensed Antibody or Licensed Product for an Active
Immunotherapeutic Approach). As used herein, “Active Immunotherapeutic Approaches” means [***]. 

4.2.2    Celgene Right of First Negotiation. During the Term, in the event that Prothena or its Affiliates
intends to, directly or indirectly, sublicense, assign, transfer, convey or grant other rights, however structured, to a Third Party with respect to any Active Immunotherapeutic Approaches (including any rights with respect to the Development or

  
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treatment has been requested with respect to the omitted portions. 

 
Commercialization of any Active Immunotherapeutic Approaches (each, a “Grant”), [***] will [***]. [***] will [***] (a “[***]”). If [***], [***] will [***] which
[***] will [***]. If [***], the Parties will [***]. Until [***] or the [***], as applicable, [***]. If [***] that it [***], then [***]. For the avoidance of doubt, this Section 4.2.2 [***] For clarity, [***]. 

4.3    Master Collaboration Agreement. For the avoidance of doubt, the provisions of Article 5 of the Master
Collaboration Agreement shall not limit in any way the provisions of this Article 4. 
 4.4    Exceptions for Change
of Control. Notwithstanding the provisions of Section 4.1, if following the Effective Date, Prothena undergoes a Change of Control with a Third Party who (itself or through any of its affiliates existing prior to the date of the Change of
Control) owns or has rights to a Competing Compound (but excluding any Licensed Antibody or Licensed Product) that is in ongoing clinical development or being commercialized by such Third Party (or its affiliate) as of the date of the Change of
Control (a “Prothena Acquired Competing Compound”), then Prothena (including the acquiring Person in the Change of Control (and such acquiring Person’s affiliates)) shall not be in breach of the provisions of
Section 4.1 as a result of [***]; provided that (i) such activities are conducted independently of the activities of this 

  
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treatment has been requested with respect to the omitted portions. 

 
Agreement and without use of any Prothena IP ([***]) and (ii) no personnel who are conducting any activities pursuant to this Agreement (or have conducted activities pursuant to the Master
Collaboration Agreement) are involved in the conduct of such activities with respect to the Prothena Acquired Competing Compound. 

4.5    Celgene Exclusivity. 

4.5.1    Celgene Exclusivity. During the period from the Effective Date until the five (5) year anniversary of
the Effective Date (the “Celgene Exclusivity Term”), neither Celgene nor its Affiliates will, anywhere in the world, alone or with or through any Third Party, either (a) sell any Competing Antibody that has an approved label
for treatment of an Indication for which Celgene or its Affiliates has conducted a Registration Enabling Clinical Trial for a Licensed Product hereunder (as set forth in the protocol for such Registration Enabling Clinical Trial) or (b) conduct
a Registration Enabling Clinical Trial for any Competing Antibody for treatment of an Indication (as set forth in the protocol for such Registration Enabling Clinical Trial) for which Celgene has conducted a Registration Enabling Clinical Trial for
a Licensed Product hereunder (as set forth in the protocol for such Registration Enabling Clinical Trial) (provided that, for the avoidance of doubt, this Section 4.5.1 shall not prohibit (i) use of an Competing Antibody as a comparator in
a Registration Enabling Clinical Trial or (ii) Celgene or any of its Affiliates providing proprietary products (that are not Competing Antibodies) to a Third Party for such Third Party’s use in a clinical trial of Competing Antibodies), in
each case of (a) and (b), other than Celgene’s exercise of its rights and performance of its obligations with respect to Licensed Antibodies and Licensed Products pursuant to this Agreement (including engaging Third Party subcontractors to
perform the such rights and obligations in accordance with this Agreement). As used herein, the term “Competing Antibody” means any Antibody that Targets the Licensed Target, including any product that incorporates any such
Antibody; provided that Competing Antibody shall not include (a) any Antibody (or any product that incorporates any such Antibody) that was Developed or Commercialized by or on behalf of Celgene or any of its Affiliates prior to the Effective
Date or (b) any Related Antibodies, or other improvements or modifications, to the Antibody in the foregoing clause (a) or products that incorporate such Related Antibodies or improvements or modifications. 

4.5.2    Exceptions for Change of Control. Notwithstanding the provisions of Section 4.5.1, if during the
Celgene Exclusivity Term, Celgene (or any of its Affiliates) undergoes a Change of Control with a Third Party who (itself or through any of its affiliates existing prior to the date of the Change of Control) owns or has rights to a Competing
Antibody (but excluding any Licensed Antibody or Licensed Product) that is in ongoing clinical development or being commercialized by such Third Party (or its affiliate) as of the date of the Change of Control (a “Celgene Acquired Competing
Antibody”), then Celgene and its Affiliates (including the acquiring Person in the Change of Control (and such acquiring Person’s affiliates)) shall not be in breach of the provisions of Section 4.5.1 as a result of [***];
provided that (i) such activities are conducted independently of the activities of this Agreement and without use of any Prothena IP 

  
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treatment has been requested with respect to the omitted portions. 

 
([***]) and (ii) no personnel who are conducting any Registration Enabling Clinical Trial activities pursuant to this Agreement are involved in the conduct of Registration Enabling Clinical
Trial activities with respect to the Celgene Acquired Competing Antibody. 
 ARTICLE 5. 

FINANCIAL TERMS 

5.1    Option Exercise Fee. Subject to Section 3.2 of the Master Collaboration Agreement, the Parties
acknowledge and agree that Celgene will pay the Phase 1 Option Exercise Fee (as defined in the Master Collaboration Agreement) for the Licensed Program in accordance with the Master Collaboration Agreement. 

5.2    Reimbursement of Certain CMC Expenses. Subject to Section 3.2 of the Master Collaboration Agreement,
Celgene will reimburse Prothena for the reasonable, documented and verifiable out-of-pocket costs that were incurred by Prothena under the Master Collaboration
Agreement, after the End of Phase 1 Date (as defined in the Master Collaboration Agreement) for the Licensed Program but prior to the Effective Date of this Agreement, for chemistry, manufacturing and controls (CMC) activities conducted by Prothena
specifically for preparation for any Registration Enabling Clinical Trials of Licensed Product; provided that (a) such amounts and such activities were approved in writing in advance by Celgene prior to Prothena undertaken such activities and
(b) in all cases, Celgene shall not be obligated to reimburse Prothena for any such amounts in excess of $[***] ([***]). Subject to Section 3.2 of the Master Collaboration Agreement, Prothena shall promptly after the Effective Date issue
an invoice to Celgene for the amounts set forth in this Section 5.2, and Celgene shall pay to Prothena the undisputed portion of such invoice within [***] ([***]) days after receipt of such invoice.  

5.3    Royalties. 

5.3.1    Licensed Product Royalties. Subject to the terms of this Section 5.3 (and subject further to
Section 5.6), Celgene shall pay Prothena royalties on Annual Net Sales, on a Licensed Product-by-Licensed Product basis during the applicable Royalty Term, equal to
the following portions of Annual Net Sales of the applicable Licensed Product multiplied by the applicable royalty rate set forth below for such portion of Annual Net Sales during the applicable Royalty Term for each such Licensed Product, which
royalties shall be paid in accordance with Section 5.3.7 (the “Per Licensed Product Annual Net Sales”). For clarity, the royalties (and royalty tiers) shall be calculated separately on a Licensed
Product-by-Licensed Product basis.  

  
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treatment has been requested with respect to the omitted portions. 

			
	 Per Licensed Product Annual Net Sales

for a Given Licensed Product in a Given

Calendar Year             
                               
	  	Royalty Rate
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a
given Licensed Product in a given Calendar Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%
	 Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar
Year above [***]
	  	[***]%

 The applicable royalty rate set forth in the table above will apply only to that portion of the Per Licensed Product Annual
Net Sales of a given Licensed Product during a given Calendar Year that falls within the indicated range. For clarity, (i) if no royalty is payable on a given unit of Licensed Product (e.g., following the Royalty Term for such Licensed Product
in a given country), then the Net Sales of such unit of Licensed Product shall not be included for purposes of determining the royalties or royalty tiers and (ii) Net Sales of a given Licensed Product will not be combined with Net Sales of any
other Licensed Product for purposes of determining the foregoing royalties or royalty tiers. Only one royalty shall be payable by Celgene to Prothena for each sale of a Licensed Product. 

By way of example, if Per Licensed Product Annual Net Sales of a given Licensed Product by Celgene, its Affiliates and Sublicensees were $[***] for a given
Calendar Year, then the royalties payable with respect to such Per Licensed Product Annual Net Sales for such Licensed Product for such Calendar Year, subject to adjustment as set forth in this Section 5.3, would be: [***]. 

  
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treatment has been requested with respect to the omitted portions. 

 5.3.2    Royalty Term. Celgene’s royalty obligations to
Prothena under Section 5.3.1 shall apply on a Licensed Product-by-Licensed Product and
country-by-country basis only during the applicable Royalty Term for such Licensed Product in such country. Following expiration of the applicable Royalty Term for a
given Licensed Product in a given country, as applicable, no further royalties will be payable in respect of sales of such Licensed Product in such country and thereafter the license granted to Celgene hereunder with respect to such Licensed Product
in such country will automatically become fully paid-up, perpetual, irrevocable and royalty-free. 

5.3.3    Reductions. 

(a)    Reductions for No Valid Claim. The royalty amounts payable with respect to Per Licensed Product Annual Net
Sales shall be reduced on a Licensed Product-by-Licensed Product and country-by-country
basis, to [***] percent ([***]%) of the amounts otherwise payable pursuant to Section 5.3.1 during any portion of the applicable Royalty Term in which both: (i) [***] and (ii) [***]. 

(b)    Royalty Reduction for Biosimilar Product. If, on a Licensed Product-by-Licensed Product and country-by-country and Calendar
Quarter-by-Calendar Quarter basis, 

(i)    [***]; or 

(ii)    [***]; 

then the royalties payable with respect to Per Licensed Product Annual Net Sales of such Licensed Product pursuant to Section 5.3.1 in
such country during such Calendar Quarter shall be reduced to [***], of the royalties otherwise payable pursuant to Section 5.3.1. [***]. 

5.3.4    Royalty Offset for Third Party Payments. If Celgene (or any of its Affiliates or Sublicensees) obtains a
right or license under intellectual property of a Third Party (whether prior to, or after, the Effective Date), where the research, development, making, using, selling, offering for sale, or importing of any Licensed Product (or any Licensed
Antibody contained in 

  
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treatment has been requested with respect to the omitted portions. 

 
such Licensed Product) by or on behalf of Celgene (or any of its Affiliates or Sublicensees) would result in a payment to such Third Party, then Celgene may deduct from the royalty payments that
would otherwise have been due under Section 5.3.1 with respect to Per Licensed Product Annual Net Sales in a particular Calendar Quarter, an amount equal to [***] percent ([***]%) of [***] (“Celgene Third Party Payments”)
during such Calendar Quarter. Notwithstanding the foregoing, in no event shall the royalties payable on Per Licensed Product Annual Net Sales be reduced by more than [***] percent ([***]%) in any Calendar Quarter by operation of this
Section 5.3.4; [***]. 
 5.3.5    Cumulative Effect of Royalty Reductions and Offsets. In no event
shall the royalty reductions or offsets described in Sections 5.3.3(a), 5.3.3(b) and 5.3.4, alone or together, reduce the royalties payable by Celgene for a given Calendar Quarter pursuant to Section 5.3.1 to less than [***] percent ([***]%) of
the amounts otherwise payable by Celgene for a given Calendar Quarter pursuant to Section 5.3.1. [***] 

5.3.6    Compulsory Licenses. If a compulsory license is granted to a Third Party with respect to a Licensed
Product in any country in the Territory with a royalty rate lower than the royalty rate provided by Section 5.3.1 (as adjusted pursuant to Section 5.3.3), then the royalty rate to be paid by Celgene on Per Licensed Product Annual Net Sales
in such country under Section 5.3.1 shall be reduced [***]. 
 5.3.7    Payment of Royalties. Celgene shall:
(a) within [***] ([***]) days following the end of each Calendar Quarter in which a royalty payment pursuant to Section 5.3.1 accrues, provide to Prothena a report specifying for such Calendar Quarter (i) the number of Licensed
Products sold that are subject to such royalty, (ii) the Per Licensed Product Annual Net Sales that are subject to such royalty, (iii) the applicable royalty rate under this Agreement, (iv) the royalty calculation and royalties
payable in U.S. Dollars and (v) any reduction to the royalty applied by Celgene pursuant to any one or more of Sections 5.3.3 and 5.3.4; and (b) make the royalty payments owed to Prothena hereunder in accordance with such royalty report in
arrears, within [***] ([***]) days from the end of the Calendar Quarter in which such payment accrues. 

5.4    Regulatory Milestones. 

5.4.1    Regulatory Milestones. Subject to the terms of this Section 5.4 (and subject further to
Section 5.6), Celgene will notify Prothena within [***] ([***]) days following the first 

  
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treatment has been requested with respect to the omitted portions. 

 
achievement by Celgene under this Agreement and after the Effective Date of each milestone event described below in this Section 5.4 with respect to the first (and only the first) Licensed
Product to achieve such milestone event under this Agreement, and Celgene shall thereafter pay the applicable amounts set forth below associated with the applicable milestone event in accordance with Section 5.4.2 (each, a “Regulatory
Milestone Payment”): 
  

			
	 Regulatory Approval Milestone Event
	  	 Regulatory Milestone Payment

	 1.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for the first Select Indication in the U.S. issued by the FDA; [***] (the “First U.S. Approval Milestone”)
	  	[***] Dollars ($[***])
		
	 2.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for the first Select Indication in the EU issued by the EMA; [***]
	  	[***] Dollars ($[***])
		
	 3.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for the first Select Indication in Japan issued by the MHLW; [***]
	  	[***] Dollars ($[***])
		
	 4.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for a second Select Indication [***] in the U.S. issued by the FDA; [***]
	  	[***] Dollars ($[***])
		
	 5.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for a second Select Indication [***] in the EU issued by the EMA; [***]
	  	[***] Dollars ($[***])
		
	 6.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for a second Select Indication [***] in Japan issued by the MHLW; [***]
	  	[***] Dollars ($[***])

  
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treatment has been requested with respect to the omitted portions. 

 Each of the foregoing milestones in this Section 5.4.1 shall be payable a maximum of one (1) time
as set forth in the foregoing chart regardless of the number of Licensed Products achieving the applicable milestone event (i.e., a maximum of six (6) Regulatory Milestone Payments may be made pursuant to this Section 5.4.1), and no
Regulatory Milestone Payment shall be due hereunder for subsequent or repeated achievement of such milestone event. For the avoidance of doubt, the maximum amount payable by Celgene pursuant to this Section 5.4.1 is One Hundred Eighty-Seven
Million Five Hundred Thousand Dollars ($187,500,000) assuming that each of the milestone events in this Section 5.4.1 were achieved. 

5.4.2    Invoice and Payment of Regulatory Milestone Payments. Following receipt of notification by Celgene to
Prothena that Celgene has achieved the applicable milestone event triggering a Regulatory Milestone Payment hereunder, Prothena shall invoice Celgene for the applicable Regulatory Milestone Payment, and Celgene shall pay such Regulatory Milestone
Payment within [***] ([***]) days after receipt of the invoice therefor. 

  
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treatment has been requested with respect to the omitted portions. 

 5.5    Sales Milestones. 

5.5.1    Sales Milestones. Subject to the terms of this Section 5.5 (and subject further to Section 5.6),
Celgene will notify Prothena within [***] ([***]) days after the end of the Calendar Quarter during which a given milestone event described below in this Section 5.5 was first achieved by Celgene under this Agreement and after the Effective
Date with respect to the Licensed Products, and Celgene shall thereafter pay the applicable amounts set forth below associated with the applicable milestone event in accordance with Section 5.5.2 (each, a “Sales Milestone
Payment”): 
  

			
	 Sales Milestone Event
	  	 Sales Milestone Payment

	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])
		
	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])
		
	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])
		
	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])

 Each of the foregoing milestones in this Section 5.5.1 shall be payable a maximum of one (1) time as
set forth in the foregoing chart regardless of the number of times the applicable milestone event was achieved (i.e., a maximum of four (4) Sales Milestone Payments may be made pursuant to this Section 5.5.1), and no Sales Milestone
Payment shall be due hereunder for subsequent or repeated achievement of such milestone event. For the avoidance of doubt, the maximum amount payable by Celgene pursuant to this Section 5.5.1 is Three Hundred Seventy-Five Million Dollars
($375,000,000) assuming that each of the milestone events in this Section 5.5.1 were achieved. 

  
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treatment has been requested with respect to the omitted portions. 

 5.5.2    Invoice and Payment of Sales Milestone Payments.
Following receipt of notification by Celgene to Prothena that Celgene has achieved the applicable milestone event triggering a Sales Milestone Payment hereunder, Prothena shall invoice Celgene for the applicable Sales Milestone Payment, and Celgene
shall pay such Sales Milestone Payment within [***] ([***]) days after receipt of the invoice therefor. 

5.6    Additional Payment Terms. 

5.6.1    Currency. All payments hereunder shall be made in U.S. Dollars by wire transfer to a bank designated in
writing by Prothena. Conversion of sales recorded in local currencies to Dollars shall be performed in a manner consistent with Accounting Standards and Celgene’s normal practices used to prepare its audited financial statements for internal
and external reporting purposes. 
 5.6.2    Taxes; Withholding. 

(a)    Generally. Each Party will pay, any and all income taxes levied on account of all payments it receives under
this Agreement except as otherwise provided in this Section 5.6.2. 
 (b)    Tax Withholding. Each Party
shall be entitled to deduct and withhold from any amounts payable under this Agreement such taxes as are required to be deducted or withheld therefrom under any provision of Applicable Law. The Party that is required to make such withholding (the
“Paying Party”) will (i) deduct those taxes from such payment, (ii) timely remit the taxes to the proper taxing authority, and (iii) send evidence of the obligation together with proof of tax payment to the other
Party (the “Payee Party”) on a timely basis following that tax payment; provided, however, that before making any such deduction or withholding, the Paying Party shall give the Payee Party notice of the intention to make such
deduction or withholding (such notice shall include an explanation of the reason for and the calculation of the proposed deduction or withholding and shall be given before such deduction or withholding is required in order for such Payee Party to
obtain reduction of or relief from such deduction or withholding). Each Party agrees to reasonably cooperate with the other Party in claiming refunds or exemptions from such deductions or withholdings under any relevant agreement or treaty which is
in effect to ensure that any amounts required to be withheld pursuant to this Section 5.6.2(b) are reduced in amount to the fullest extent permitted by Applicable Law. In addition, the Parties shall cooperate in accordance with Applicable Laws
to minimize indirect taxes (such as value added tax, sales tax, consumption tax and other similar taxes (“Indirect Taxes”)) in connection with this Agreement. 

(c)    Tax Gross Up. Notwithstanding the foregoing, if (a) any Party redomiciles, assigns its rights or
obligations or extends its rights under this Agreement, (b) as a result of such redomiciliation, assignment or extension, such Party (or its assignee) is required by Applicable Law to [***], or such redomiciliation, assignment or extension
results in [***] 

  
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treatment has been requested with respect to the omitted portions. 

 
[***], and (c) such [***] exceed the amount of [***] that would have been applicable but for such redomiciliation, assignment or extension, then any such amount payable shall [***] so that,
after making all required [***], as the case may be, the Payee Party (or its assignee) [***]. The [***] (A) [***] to the extent such [***] but for [***], and (B) [***]. For purposes of the preceding sentence, “Tax Benefit” shall
mean any cash refund or credit for Taxes resulting in a reduction in the amount of Taxes otherwise owed by the Payee Party as a result of [***] relating to payments by the Paying Party, as reasonably determined by Payee Party. Solely for purposes of
this Section 5.6.2(c), a Party’s “domicile” shall include its jurisdiction of incorporation or tax residence and a “redomiciliation” shall include a reincorporation or other action resulting in a change in tax residence
of the applicable Party or its assignee, or resulting in the attribution of any amounts payable to a branch or permanent establishment located outside the country of tax residence of the applicable Party or its assignee. 

(d)    Tax Documentation. Prothena has provided a properly completed and duly executed IRS Form W-8BEN-E to Celgene. Prior to the receipt of any payment under this Agreement, each recipient Party (and any other recipient of payments under this Agreement) shall, to the
extent it is legally permitted to, provide to the other Party, at the time or times reasonably requested by such other Party or as required by Applicable Law, such properly completed and duly executed documentation (for example, IRS Forms W-8 or W-9 or foreign equivalents) as will permit payments made under this Agreement to be made without, or at a reduced rate of, withholding for taxes. 

5.7    Other Global License Agreements. For the avoidance of doubt, a Licensed Product hereunder will
only be eligible for milestone and royalty payments under this Agreement, and shall not be eligible for, or counted towards, milestone or royalty payments under any other Global License Agreement (i.e., a given Licensed Product will be eligible for,
and counted towards, milestone and royalty payments only under one Global License Agreement). 
 5.8    U.S. License
Agreement. Notwithstanding the provisions of Sections 5.3, 5.4 and 5.5, in the event that Celgene (or its Affiliate) has previously paid any royalty payments or milestone payments under the Licensed Program U.S. License Agreement, then Celgene
shall not be required to make payments of any royalties or milestones payable hereunder for the same net sales or same milestone event (i.e., royalties and milestones shall be payable a maximum of one time, if payable, whether achieved under this
Agreement or under the Licensed Program U.S. License Agreement). By way of example, (i) if [***] 

  
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treatment has been requested with respect to the omitted portions. 

 [***], 

and/or (ii) if a given Sales Milestone Payment (as defined in the Licensed Program U.S. License Agreement) was paid under the Licensed Program U.S.
License Agreement, then no Sales Milestone Payment shall be due hereunder for the achievement of the same milestone event. 

5.9    Records Retention by Celgene; Review by Prothena. 

5.9.1    Records. With respect to royalty and milestone payments to be made under Sections 5.3 or 5.5 of this
Agreement, Celgene agrees to keep and shall procure that its Affiliates keep, for at least [***] ([***]) years from the end of the Calendar Year to which they pertain, complete and accurate records of sales by Celgene or its Affiliates (including
sales by Sublicensees), as the case may be, of each Licensed Product, in sufficient detail to allow the accuracy of the payments made hereunder to be confirmed. 

5.9.2    Review. Subject to the other terms of this Section 5.9.2, during the Term, at the request of
Prothena, which shall not be made more frequently than [***], upon at least [***] ([***]) days’ prior written notice from Prothena, [***], Celgene shall permit an independent, nationally-recognized certified public accountant selected by
Prothena and reasonably acceptable to Celgene to inspect (during regular business hours) the relevant records required to be maintained by Celgene under Section 5.9.1; provided that such audit right shall not apply to records beyond [***]
([***]) years from the end of the Calendar Year to which they pertain. In every case the accountant must have previously entered into a confidentiality agreement with both Parties having confidentiality obligations and
non-use obligations no less restrictive than those set forth in Article 7 and limiting the disclosure and use of such information by such accountant to authorized representatives of the Parties and the
purposes germane to Section 5.9.1. Results of any such review shall be binding on both Parties absent manifest error. The accountant shall report to Prothena only whether the particular amount being audited was accurate, and if not, the amount
of any discrepancy, and the accountant shall not report any other information to Prothena. Prothena shall treat the results of any such accountant’s review of Celgene’s records as Confidential Information of Celgene subject to the terms of
Article 7. If any review reveals a deficiency or overpayment in the calculation and/or payment of royalties or Sales Milestone Payments by Celgene, then (a) Celgene or Prothena as applicable shall promptly pay (or refund, as applicable) the
other Party the amount of such deficiency or overpayment, as applicable, and (b) if such deficiency is by more than the greater of (i) [***] or (ii) [***], Celgene shall, within [***] ([***]) days after receipt of an invoice therefor, pay the
reasonable out-of-pocket costs and expenses incurred by Prothena for the independent accountant in connection with the review. 

5.9.3    Records Final. Upon the expiration of [***] ([***]) years following the end of a given Calendar Year,
subject and without prejudice to the determination of any review commenced prior to such [***] pursuant to Section 5.9.2, the calculation of royalties and Sales Milestone Payments payable with respect to such Calendar Year shall be binding and
conclusive upon Prothena, and Celgene (and its Affiliates) shall be released from any liability or accountability with respect to such royalties for such Calendar Year. 

  
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treatment has been requested with respect to the omitted portions. 

 5.10    Prothena Third Party Agreements. Notwithstanding
anything to the contrary herein, but subject to Section 2.3.5(b), Prothena shall be solely responsible for all costs and payments of any kind (including all upfront fees, annual payments, milestone payments and royalty payments) arising under
any agreements between Prothena (or any of its Affiliates) and any Third Party (including under any In-License Agreement or other Existing Program Agreement), which costs or payments arise in connection with,
or as a result of, the activities hereunder, including the Development, Manufacture or Commercialization of Licensed Antibodies or Licensed Products unless and until such agreements have been assigned to Celgene pursuant to Section 2.3.5. 

5.11    Diagnostic Products. Notwithstanding anything to the contrary contained herein, [***]. 

5.12    Additional Provisions. Notwithstanding anything to the contrary herein, the terms and provisions of this
Article 5 are subject to Section 11.7 of the Master Collaboration Agreement and Sections 10.7 and 10.10 of this Agreement. 
 ARTICLE
6. 
 LICENSES; INTELLECTUAL PROPERTY 

6.1    License to Celgene. Subject to the terms and conditions of this Agreement, Prothena hereby grants to
Celgene an exclusive right and license, with the right to grant sublicenses (through multiple tiers), under the Prothena IP to research, develop (including Develop), make (including Manufacture), have made (including have Manufactured), use, offer
for sale, sell, import, Commercialize and otherwise exploit Licensed Antibodies and Licensed Products, including Diagnostic Products, in the Field in the Territory. 

6.2    License to Celgene for Other Targets. In the event that, during the Term, Celgene modifies a Licensed
Program Antibody in the course of its Development activities hereunder such that such Licensed Program Antibody specifically binds to a target other than (i) the Licensed Target or (ii) any other Collaboration Target (e.g., a bispecific
antibody), then, at the request of Celgene, Celgene and Prothena shall negotiate in good faith a license under intellectual property of Prothena or its Affiliates, as applicable, that is specific to such other target or Antibodies to such other
target. 
 6.3    Rights Retained by the Parties. For purposes of clarity, each Party retains all rights under Know-How and Patents Controlled by such Party not expressly granted to the other Party pursuant to this Agreement. In addition, Prothena retains the right to perform the Prothena Ongoing Program Activities in
accordance with this Agreement. 
 6.4    No Implied Licenses. Except as explicitly set forth in this Agreement,
the Master Collaboration Agreement, any U.S. License Agreement or any other Global License Agreement, neither Party shall be deemed by estoppel or implication to have granted to the other Party any license or other right to any intellectual property
of such Party. 

  
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treatment has been requested with respect to the omitted portions. 

 6.5    Insolvency. In the event that this Agreement is terminated
due to the rejection of this Agreement by or on behalf of Prothena due to an Insolvency Event, all licenses and rights to licenses granted under or pursuant to this Agreement by Prothena to Celgene are and shall otherwise be deemed to be licenses of
rights to “intellectual property”. The Parties agree that Celgene, as a licensee of such rights under this Agreement, shall retain and may fully exercise all of its rights and elections under any applicable insolvency statute, and that
upon commencement of an Insolvency Event by or against Prothena, Celgene shall be entitled to a complete duplicate of or complete access to (as Celgene deems appropriate), any such intellectual property and all embodiments of such intellectual
property. Such intellectual property and all embodiments thereof shall be promptly delivered to Celgene (i) upon any such commencement of a bankruptcy proceeding (or other Insolvency Event) upon written request therefore by Celgene, unless
Prothena elects to continue to perform all of its obligations under this Agreement or (ii) if not delivered under (i) above, upon the rejection of this Agreement by or on behalf of Prothena, then upon written request therefore by Celgene.
The provisions of this Section 6.5 shall be (1) without prejudice to any rights Celgene may have arising under any applicable insolvency statute or other Applicable Law and (2) effective only to the extent permitted by Applicable Law.

 6.6    Ownership. 

6.6.1    Inventorship. Notwithstanding the provisions of Section 11.7.1, inventorship of Know-How shall be determined by application of U.S. patent law pertaining to inventorship, and, except as provided for in Sections 6.6.2, 6.6.3 and 6.6.4, ownership of
Know-How shall be determined by inventorship. 
 6.6.2    Ownership of
Collaboration IP and Celgene IP. 
 (a)    Prothena. As between the Parties (including their respective
Affiliates), Prothena will retain all right, title and interest in and to all Prothena Licensed Collaboration IP, except to the extent that any such rights are licensed or granted to Celgene under this Agreement or the Master Collaboration
Agreement. Prothena shall [***] that all Patents, Know-How and other intellectual property (other than Licensed Program IP and Celgene IP, if any) utilized in the performance of the Licensed Program under the
Master Collaboration Agreement falls within the Prothena Licensed Collaboration IP and is and remains during the Term Controlled by Prothena such that Prothena has the full rights to grant the rights and licenses to the Prothena Licensed
Collaboration IP to Celgene hereunder (including that such Patents, Know-How and other intellectual property remains unencumbered such that Prothena is able to grant such rights and licenses to Celgene).
 
 (b)    Celgene. As between the Parties (including their respective Affiliates), Celgene (or its
Affiliate) will retain all right, title and interest in and to all Celgene IP, including all rights to Prosecute and Maintain, and enforce any such Celgene IP, and no rights or licenses are granted to Prothena hereunder with respect to any Celgene
IP. 

  
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treatment has been requested with respect to the omitted portions. 

 6.6.3    Ownership of Licensed Program IP. 

(a)    Prothena. As between the Parties (including their respective Affiliates), Prothena will solely own
and Control all Licensed Program IP. Celgene shall, and hereby does, assign to Prothena all of Celgene’s interest in any and all Licensed Program Know-How that falls within Section 1.46(a)(iii) and
all Licensed Program Patents claiming such Licensed Program Know-How. Celgene shall, and shall require its Affiliates to, take all reasonable actions and execute all documents necessary to effect the intent of
the preceding sentence. As between the Parties (and their respective Affiliates) and any Third Party, Prothena will solely own and Control all Licensed Program IP; provided that if (a) [***] and (b) [***]. 

(b)    If any Licensed Program IP is created, conceived, discovered, first generated, invented, first made or first
reduced to practice pursuant to the Master Collaboration Agreement by any Third Party that is in contractual privity with or otherwise engaged by Prothena or its Affiliates, Prothena [***] include in such agreement with such Third Party an
obligation to [***] to Prothena [***] such Licensed Program IP to enable Prothena to grant to Celgene a license thereunder as provided in this Agreement for the duration of this Agreement. 

6.6.4    Joint IP. The Parties shall each own an equal, undivided interest in: (a) any and all Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to practice, in each case, jointly by or on behalf of Prothena or its Affiliates, on the one hand, and Celgene
or its Affiliates, on the other hand, pursuant to the conduct of activities under this Agreement at any time during the Term (the “Joint Know-How”), and (b) any Patents that claim
any Joint Know-How (the “Joint Patents”, together with Joint Know-How the “Joint IP”). Each Party shall assign, and
hereby assigns, to the other Party, a joint equal and undivided interest in and to such Joint IP (provided, however, that for clarity, the foregoing joint ownership rights with respect to Joint IP shall not be construed as granting, conveying or
creating any license or other rights to any of the other Party’s other intellectual property, unless otherwise expressly set forth in this Agreement), and at the request of a Party, the other Party will execute such documents (including any
necessary assignments) to effect such joint ownership of such Joint IP. Each Party shall have the right to disclose (except as otherwise set forth in Section 7.2) and exploit the Joint IP without a duty of seeking consent or accounting to the
other Party except as expressly provided in this Agreement; provided that, such rights shall be subject to the rights and licenses granted to Celgene and Prothena hereunder (or under the Master Collaboration Agreement, any other Global License
Agreement or any U.S. License Agreement), including the obligations of Prothena as set forth in Article 4. The Parties hereby acknowledge and agree that any and all Joint IP (as defined in the Licensed Program U.S. License Agreement) shall be deemed
to be Joint IP under this Agreement, and from and after the Effective Date, the provisions of this Agreement shall apply with respect to all such Joint IP (as defined in the Licensed Program U.S. License Agreement). 

  
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treatment has been requested with respect to the omitted portions. 

 6.7    Patent Liaisons. Promptly after the Effective Date, each
Party shall appoint an individual to act as a patent liaison for such Party (each, a “Patent Liaison”). The Patent Liaisons shall be the primary point of contact for the Parties regarding intellectual property-related activities and
matters contemplated by this Agreement, as and to the extent requested by Celgene from time to time. The name and contact information for each Party’s Patent Liaison, as well as any replacement(s) chosen by such Party, in its sole discretion,
from time to time, shall be promptly provided to the other Party in accordance with Section 11.2. 

6.8    Prosecution and Maintenance of Prothena Licensed Collaboration Patents and Licensed Program
Patents. Following the Effective Date, the provisions of this Section 6.8 shall apply with respect to the Prothena Licensed Collaboration Patents and Licensed Program Patents. 

6.8.1    Prothena Platform Patents. Prothena shall [***] Prosecute and Maintain the Prothena Platform
Patents. All such Prosecution and Maintenance by Prothena shall be through patent counsel [***]. Prothena shall keep Celgene informed as to material developments with respect to the Prosecution and Maintenance of such Patents including by providing
copies of all substantive office actions, examination reports, communications or any other substantive documents to or from any patent office, including notice of all interferences, reissues, re-examinations,
inter partes reviews, derivations, post grant proceedings, oppositions or requests for patent term extensions. Prothena shall also provide Celgene with a reasonable opportunity to comment substantively on the Prosecution and Maintenance of such
Prothena Platform Patents prior to taking material actions (including the filing of initial applications), and will in good faith consider any comments made by and actions recommended by Celgene, provided, however, that Celgene provides its comments
reasonably in advance of any applicable filing deadlines. 
 6.8.2    Other Prothena Licensed
Collaboration Patents and Licensed Program Patents. 
 (a)    [***] First Right. [***] shall have the first
right (but not the obligation) to Prosecute and Maintain the Prothena Licensed Collaboration Patents (other than Prothena Platform Patents) and Licensed Program Patents using patent counsel of [***] choosing ([***]). [***] shall keep [***] informed
as to material developments with respect to the Prosecution and Maintenance of such Patents including by providing copies of all substantive office actions, examination reports, communications or any other substantive documents to or from any patent
office, including notice of all interferences, reissues, re-examinations, inter partes reviews, derivations, post grant proceedings, oppositions or requests for patent term extensions. [***] shall also provide
[***] with a reasonable opportunity to comment substantively on the Prosecution and Maintenance of such Prothena Licensed Collaboration Patents (other than Prothena Platform Patents) and Licensed Program Patents prior to taking material actions
(including the filing of initial applications), and will in good faith consider any comments madeby and actions recommended by [***], provided, however, that [***] does so consistent with any applicable filing deadlines. 

  
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treatment has been requested with respect to the omitted portions. 

 (b)    [***] Back-Up
Right. If [***] in any country decides not to file a Prothena Licensed Collaboration Patent (other than Prothena Platform Patents) or Licensed Program Patent or intends to allow such Patent to lapse or become abandoned without having first filed
a substitute, it shall notify and consult with [***] of such decision or intention at least [***] ([***]) days prior to the date upon which the subject matter of such Patent shall become unpatentable or such Patent shall lapse or become abandoned,
and, if after such consultation between the Parties, [***] still intends not to file such Prothena Licensed Collaboration Patent (other than Prothena Platform Patents) or Licensed Program Patent, [***] shall thereupon have the right (but not the
obligation) to assume the Prosecution and Maintenance thereof at [***] expense with counsel of its choice. [***] 

6.8.3    Cooperation in Prosecution and Maintenance. 

(a)    Further Assurances. If Celgene determines to undertake the Prosecution and Maintenance of a Prothena
Licensed Collaboration Patent or Licensed Program Patent (other than a Prothena Platform Patent) in accordance with this Section 6.8, Prothena agrees to make its employees, agents and consultants reasonably available to Celgene (and to
Celgene’s authorized attorneys, agents or representatives) to enable Celgene to undertake such Prosecution and Maintenance. In addition, Prothena shall (and shall cause its Affiliates and its and their employees, agents and consultants to)
provide reasonable assistance to Celgene (and to Celgene’s authorized attorneys, agents or representatives) to enable Celgene to undertake such Prosecution and Maintenance, including by executing powers of attorney and other documents for
Celgene to undertake such Prosecution and Maintenance. 
 (b)    Assistance. The Parties shall reasonably
cooperate with one another with respect to the Prosecution and Maintenance of the Prothena Licensed Collaboration Patents and Licensed Program Patents for which either Party is responsible for Prosecution and Maintenance pursuant to this
Section 6.8. [***], the Parties shall cooperate with one another to [***], in each case that are applicable to the Licensed Target or Licensed Program Antibody, as applicable, if practicable to [***]. 

6.8.4    Costs of Prosecution and Maintenance. Except as otherwise expressly set forth in this Section 6.8.4,
each Party shall be responsible for all costs and expenses associated with its Prosecution and Maintenance activities under this Section 6.8 with respect to Prothena Licensed Collaboration Patents and Licensed Program Patents for which it is
responsible pursuant to Sections 6.8.1 or 6.8.2, as applicable. Notwithstanding the foregoing provisions of this Section 6.8.4, [***] 

  
 42 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 [***]. If any Prothena Licensed Collaboration Patents or Licensed Program Patents claim or cover [***] and
such Prothena Licensed Collaboration Patent or Licensed Program Patent, as applicable, is [***], then Prothena shall [***], and [***] for the Prosecution and Maintenance of such Prothena Licensed Collaboration Patent or Licensed Program Patent, as
applicable, pursuant to Section [***] shall [***]. 
 6.9    Enforcement of Prothena Licensed
Collaboration Patents and Licensed Program Patents. 
 6.9.1    Notice. If any Party learns of an infringement
or threatened infringement by a Third Party of any Prothena Licensed Collaboration Patent or Licensed Program Patent, in each case other than a Prothena Platform Patent, in the Territory (including in connection with any Biosimilar Application
referencing a Licensed Product (regardless of whether such notice or copy is provided under any Applicable Laws) including under the BPCIA or the United States Patient Protection and Affordable Care Act or its successor provisions, or any similar
provisions in a country outside the United States, as applicable) such Party shall promptly notify the other Party and shall provide such other Party with available evidence of such infringement, and following such notification, the Parties shall
confer. 
 6.9.2    [***] First Right. Subject to the remaining provisions of this Section 6.9.2, [***]
shall have the first right, but not the obligation, to institute, prosecute, and control any action or proceeding (which may include settlement or otherwise seeking to secure the abatement of such infringement) with respect to any infringement of
any (i) Prothena Licensed Collaboration Patent or (ii) Licensed Program Patent, in each case other than a Prothena Platform Patent, (including in connection with any Biosimilar Application referencing a Licensed Product (regardless of
whether such notice or copy is provided under any Applicable Laws), including under the BPCIA or the United States Patient Protection and Affordable Care Act or its successor provisions, or any similar provisions in a country outside the United
States, as applicable), by counsel of its own choice, in [***]’s own name [***] and under [***]’s direction and control, including the right to control the defense of any challenges to such Patents as a counterclaim in such infringement
proceeding as well as the defense of declaratory judgment actions. Prothena retains all rights to enforce the Prothena Platform Patents against any actual or threatened infringement. 

6.9.3    [***] Back-Up Right. If [***] determines not to institute an
action or proceeding with respect to a given infringement of any Prothena Licensed Collaboration Patent or Licensed Program Patent pursuant to Section 6.9.3, it shall notify and consult with [***] of such decision, and, subject to the remaining
provisions of this Section 6.9.3, [***] 

  
 43 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 [***] shall thereupon have the right (but not the obligation) to institute an action or proceeding with
respect to such infringement of such Prothena Licensed Collaboration Patent or Licensed Program Patent, as applicable, at [***]’s expense with counsel of its choice. Notwithstanding the foregoing provisions of this Section 6.9.3, if [***] has
any reasonable grounds for believing that [***]’s exercise of its backup enforcement right with respect to any Patent as set forth in this Section 6.9.3 [***], then [***] shall not be permitted to enforce such Patent without the prior consent
of [***], in [***]’s discretion. 
 6.9.4    [***]. Notwithstanding the foregoing Sections 6.9.2 and 6.9.3,
the Parties must agree in writing prior to either Party initiating any action or proceeding with respect to any infringement of any Prothena Licensed Collaboration Patent or Licensed Program Patent with respect to any [***]. 

6.9.5    Joinder. In the case of any enforcement action or proceeding set forth in Section [***] controlled by
Celgene, Prothena will (and will cause its Affiliates to) join any such action or proceeding as a party at Celgene’s expense (and Prothena will use commercially reasonable efforts to cause any Third Party as necessary to join such action or
proceeding as a party) if doing so is necessary for the purposes of establishing standing or is otherwise required by Applicable Law to pursue such action or proceeding. Prothena may, at its option, participate in such enforcement action or
proceeding at its own expense. In the case of any enforcement action or proceeding controlled by Prothena pursuant to Section [***], Celgene may, at its option, participate in such enforcement action or proceeding at its own expense. Celgene
will join any such action or proceeding controlled by Prothena as a party at Prothena’s expense (and Celgene will use commercially reasonable efforts to cause any Third Party as necessary to join such action or proceeding as a party) if doing
so is necessary for the purposes of establishing standing or is otherwise required by Applicable Law to pursue such action or proceeding. Celgene will bear all costs and expenses incurred by it arising out of such enforcement action or proceeding
controlled by Celgene, and Prothena will bear all costs and expenses incurred by it arising out of such enforcement action or proceeding controlled by Prothena. 

6.9.6    Consultation; Cooperation. The enforcing Party will keep the
non-enforcing Party regularly informed of the status and progress of such enforcement efforts with respect to any Prothena Licensed Collaboration Patent or Licensed Program Patent, in each case other than a
Prothena Platform Patent. The enforcing Party shall consult with the non-enforcing Party and will take comments of the non-enforcing Party into good faith consideration
with respect to the infringement or claim construction of any claim in any such Prothena Licensed Collaboration Patent or Licensed Program Patent. The non-enforcing Party will provide to the enforcing Party
reasonable cooperation in such enforcement, at such enforcing Party’s request and expense. 

6.9.7    Settlement. A settlement or consent judgment or other voluntary final disposition of a suit with respect
to the Prothena Licensed Collaboration Patents or Licensed Program Patents, in each case other than a Prothena Platform Patent, under this Section 6.9 may be entered into without the consent of the Party not bringing suit; provided, however,
that any such settlement, consent judgment or other disposition of any action or proceeding by the Party bringing 

  
 44 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
suit under this Section 6.9 shall not, without the prior written consent of the Party not bringing suit, such consent not to be unreasonably withheld, (i) impose [***] liability or
obligation on the Party not bringing suit or any of its Affiliates, (ii) conflict with [***] of the subject matter claimed in the applicable Prothena Licensed Collaboration Patents or Licensed Program Patents, (iii) [***], include the grant of
any license, covenant or other rights to any Third Party that would conflict with [***] the rights or licenses granted to Celgene under this Agreement, the Master Collaboration Agreement, any other Global License Agreement or any U.S. License
Agreement, or (iv) [***]. 
 6.9.8    Costs and Recoveries. Except as otherwise set forth in this
Section 6.9.8, each Party shall bear all of its costs incurred in connection with its activities under this Section 6.9.8. Any damages or other monetary awards recovered in any action, suit or proceeding brought under this
Section 6.9.8 to the extent related to any Prothena Licensed Collaboration Patents or Licensed Program Patents shall be shared as follows: 

(a)    the amount of such recovery actually received by the Party controlling such action shall first be applied to
reimburse costs and expenses incurred by each Party in connection with such action (including, for this purpose, [***] counsel); and 

(b)    any remaining proceeds shall be (i) for any action controlled by Celgene, retained by, or provided to,
Celgene [***], and (ii) for any action controlled by Prothena, retained by, or provided to, Prothena [***]. 

6.9.9    Biosimilar Applications. Notwithstanding the foregoing provisions of this Section 6.9, if either
Party receives a copy of a Biosimilar Application referencing a Licensed Product, whether or not such notice or copy is provided under any Applicable Laws (including under the BPCIA, the United States Patient Protection and Affordable Care Act, or
its successor provisions, or any similar provisions in a country outside the United States, as applicable), or otherwise becomes aware that such a Biosimilar Application has been submitted to a Regulatory Authority for marketing authorization (such
as in an instance described in 42 U.S.C. §262(l)(2)), the remainder of this Section 6.9.9 shall apply. Such Party shall promptly, but in any event within [***] ([***]) Business Days, notify the other Party. The owner of the relevant
Patents shall then seek permission to view the Biosimilar Application, information regarding the process or processes used to manufacture the product that is the subject of the Biosimilar Application, and related confidential information from the
filer of the Biosimilar Application if necessary under 42 U.S.C. §262(l)(1)(B)(iii). If either Party receives any equivalent or similar communication or notice in the United States or any other jurisdiction, the Party receiving such
communication or notice shall within [***] ([***]) Business Days notify the other Party of such communication or notice to the 

  
 45 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
extent permitted by Applicable Laws. Regardless of the Party that is the “reference product sponsor,” as defined in 42 U.S.C. §262(l)(1)(A), for purposes of such Biosimilar
Application: 
 (a)    [***] the outside counsel and in-house counsel who shall
receive confidential access to the Biosimilar Application, information regarding the process or processes used to manufacture the product that is the subject of the Biosimilar Application, and any related confidential information pursuant to 42
U.S.C. §262(l)(1)(B)(ii). 
 (b)    In each case, after consulting with [***] and considering [***]’s
comments in good faith, [***] shall have the right to (a) list any patents, including those Patents within the Prothena IP, as required pursuant to 42 U.S.C. §262(l)(3)(A) or 42 U.S.C. §262(l)(7), (b) respond to any
communications with respect to such lists from the filer of the Biosimilar Application, (c) negotiate with the filer of the Biosimilar Application as to whether to utilize a different mechanism for information exchange other than that specified
in 42 U.S.C. §262(l)(1), and (d) as to the Patents that will be subject to the litigation procedure as described in 42 U.S.C. §262(l)(4), decide which Patent or Patents shall be selected for litigation under 42 U.S.C.
§262(l)(5)(B)(i)(II), and commence such litigation under 42 U.S.C. §262(l)(6). [***] 
 (c)    [***] shall
have the right, after consulting with [***], to identify Patents, including those Patents within the Prothena IP, or respond to relevant communications under any equivalent or similar listing to those described in the preceding clause (b) in
any other jurisdiction outside of the United States. [***].  
 (d)    [***] shall cooperate with [***]’s
reasonable requests in connection with the foregoing activities to the extent required or permitted by Applicable Laws. [***] shall consult with [***] prior to identifying any Patents within the Prothena IP to a Third Party as contemplated by this
Section 6.9.9. [***] shall consider in good faith advice and suggestions with respect thereto received from [***], and notify [***] of any such lists or communications promptly after they are made. 

(e)    Each Party shall within [***] ([***]) Business Days after receiving any notice of commercial marketing provided by
the filer of a Biosimilar Application pursuant to 42 U.S.C. §262(l)(8)(A), notify the other Party. To the extent permitted by Applicable Law, [***] shall have the first right, but not the obligation, to seek an injunction against such
commercial marketing as permitted pursuant to 42 U.S.C. §262(l)(8)(B) and to file an action for infringement. [***]. Except as otherwise provided in this Section 6.9.9, any such action shall be subject to the terms and conditions of
Section 6.9.1 through 6.9.8. 
 (f)    The Parties recognize that procedures other than those set forth above in
this Section 6.9.9 may apply with respect to Biosimilar Applications. In the event that the Parties determine that certain provisions of Applicable Laws in the United States or in any other country in the Territory apply to actions taken by the
Parties with respect to Biosimilar 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
Applications under this Section 6.9.8 in such country, the Parties shall comply with any such Applicable Laws in such country (and any relevant and reasonable procedures established by
Parties) in exercising their rights and obligations with respect to Biosimilar Applications under this Section 6.9.9. Notwithstanding the provisions of this Section 6.9.9, nothing in this Section 6.9.9 shall grant any rights to
Prothena with respect to any Celgene IP. 
 6.10    Patent Term Extensions. Prothena shall reasonably cooperate
with Celgene, including providing reasonable assistance to Celgene (including executing any documents as may reasonably be required), in efforts to seek and obtain patent term restoration or supplemental protection certificates or the like or their
equivalents in any country in the Territory, where applicable to Prothena Licensed Collaboration Patents or Licensed Program Patents or any other Patents Controlled by Celgene (or any of its Affiliates), in each case other than a Prothena Platform
Patent, including as may be available to the Parties under the provisions of the U.S. Drug Price Competition and Patent Term Restoration Act of 1984 or comparable laws outside the United States of America, in each case, in connection with any
Licensed Product. In the event that elections with respect to obtaining such patent term restoration or supplemental protection certificates or the like or their equivalents are to be made in connection therewith, [***] shall have the right to make
the election and [***]. Without limiting the foregoing, [***]. 
 6.11    Regulatory Data Protection. [***] (or
its designee) shall have the sole right to list, with the applicable Regulatory Authorities in the Territory, all applicable Patents (including any Prothena Licensed Collaboration Patents or Licensed Program Patents) for any Licensed Product,
including all so called “Purple Book” listings required under the U.S. Public Health Service Act, and all similar listings in any other relevant countries, [***]. For the avoidance of doubt, [***] will retain final decision-making
authority as to the listing of all applicable Patents for any Licensed Product, regardless of which Party owns such Patent, and [***] shall reasonably assist [***] in connection therewith. 

6.12    Matters Involving Joint Patents. The Prosecution and Maintenance, and the enforcement and
defense, of any Joint Patents shall be jointly managed by the Parties through independent patent counsel (mutually agreed to by the Parties) jointly representing the Parties, including any costs and recoveries regarding same. Prior to either Party
publishing any Joint Know-How, the Parties will discuss if a Joint Patent claiming such Joint Know-How should be filed. 

6.13    Common Interest Agreement. At the request of either Party, the Parties shall negotiate in good faith to
enter into a common interest agreement to govern their discussion of Patent matters. 
 6.14    License Filing.
At the request of [***], [***] shall, and shall cause its Affiliates to, assist in any license registration processes with applicable Governmental Authorities that may be available for the protection of [***]’s interests in this Agreement. 

  
 47 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 6.15    Defense of Claims Brought by Third Parties. If a Party
becomes aware of any actual or potential claim that the Development, Manufacture or Commercialization of a Licensed Antibody or Licensed Product by or on behalf of Celgene pursuant to this Agreement infringes the intellectual property rights of any
Third Party, such Party shall promptly notify the other Party. In any such instance, the Parties shall as soon as practicable thereafter meet to discuss in good faith regarding the best response to such notice; provided that Celgene shall have the
final decision-making authority in connection therewith. Except as set forth in Section 9.2 (and without limiting Celgene’s rights under Section 9.2), Celgene shall have the sole right, but not the obligation, to defend and dispose of
(including through settlement or license) such claim. [***] by or on behalf of [***] (or any of its Affiliates or Sublicensees) in connection with [***] to the extent relating to the Development, Manufacture or Commercialization of a Licensed
Antibody or Licensed Product, shall be [***], and [***]. 
 ARTICLE 7. 

CONFIDENTIALITY 

7.1    Nondisclosure. Each Party agrees that a Party (the “Receiving Party”)
receiving Confidential Information of the other Party (the “Disclosing Party”) pursuant to this Agreement shall (a) maintain in confidence such Confidential Information using not less than the efforts such Receiving Party uses
to maintain in confidence its own proprietary information of similar kind and value, but in no event less than a reasonable degree of efforts, (b) not disclose such Confidential Information to any Third Party without the prior written consent
of the Disclosing Party, except for disclosures expressly permitted pursuant to this Article 7, and (c) not use such Confidential Information for any purpose except those permitted by this Agreement, including, in the case of Celgene, the
exercise of the rights and licenses granted to Celgene hereunder (it being understood that this clause (c) shall not create or imply any rights or licenses not expressly granted under this Agreement). The obligations of confidentiality, non-disclosure and non-use under this Section 7.1 shall be in full force and effect during the Term and for a period of [***] ([***]) years thereafter. The Receiving
Party will return all copies of or destroy (and certify such destruction in writing) the Confidential Information of the Disclosing Party disclosed or transferred to it by the other Party pursuant to this Agreement, within [***] ([***]) days after
the termination or expiration of this Agreement; provided, however, that a Party may retain (i) Confidential Information of the other Party to exercise rights and licenses which expressly survive such termination or expiration pursuant to this
Agreement, and (ii) one (1) copy of all other Confidential Information in archives solely for the purpose of establishing the contents thereof. Without limiting the foregoing, [***] will keep confidential, and will cause its Affiliates
and its and their employees, consultants, licensees, sublicensees, professional advisors and Affiliates to keep confidential, [***] on confidentiality terms at least as protective as the confidentiality provisions of this Agreement (without regard
to Section 7.3). 
 7.2    Licensed Program Specific Confidential Information. Notwithstanding anything to
the contrary contained herein, the Parties agree and acknowledge that any Licensed Program 

  
 48 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
Specific IP shall be deemed to be Confidential Information of Celgene (without regard to Section 7.3), and Celgene shall be deemed to be the Disclosing Party with respect to the Licensed
Program Specific IP. As used herein, (a) the term “Licensed Program Specific IP” means, (i) [***], (ii) [***], and (iii) [***]; and (b) the term “Licensed Program
Non-Specific IP” means all Prothena Platform Technology within the Prothena Licensed Collaboration Know-How, and other Prothena Licensed Collaboration Know-How and Licensed Program Know-How other than Licensed Program Specific IP. For clarity, Licensed Program Non-Specific IP shall be
deemed to be the Confidential Information of Prothena. 
 7.3    Exceptions. 

7.3.1    General. The obligations in Section 7.1 shall not apply with respect to any portion of the
Confidential Information of the Disclosing Party that the Receiving Party can show by competent written proof: 

(a)    was known to the Receiving Party or any of its Affiliates, without any obligation to keep it confidential or any
restriction on its use, prior to disclosure by the Disclosing Party; 
 (b)    is subsequently disclosed to the
Receiving Party or any of its Affiliates by a Third Party lawfully in possession thereof and without any obligation to keep it confidential or any restriction on its use; 

(c)    is published by a Third Party or otherwise becomes publicly available or enters the public domain, either before
or after it is disclosed to the Receiving Party, without any breach by the Receiving Party of its obligations hereunder; 

(d)    is published by a Party in accordance with Section 7.8 without any breach by such Party of its obligations
hereunder; or 
 (e)    is independently developed by or for the Receiving Party or its Affiliates without reference to
or reliance upon the Disclosing Party’s Confidential Information. 
 Any combination of features or disclosures shall not be deemed to
fall within the foregoing exclusions merely because individual features are published or available to the general public or in the rightful possession of the Receiving Party unless the combination itself and principle of operation are published or
available to the general public or in the rightful possession of the Receiving Party. 

  
 49 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.4    Authorized Disclosure. 

7.4.1    Disclosure. Notwithstanding Section 7.1, the Receiving Party may disclose Confidential Information
belonging to the Disclosing Party in the following instances: 
 (a)    subject to Section 7.6, to comply with
Applicable Law (including the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) or any national securities exchange) or with judicial process (including prosecution or defense of litigation), if, in the
reasonable opinion of the Receiving Party’s counsel, such disclosure is necessary for such compliance or for such judicial process (including prosecution or defense of litigation); 

(b)    is disclosed to governmental or other regulatory agencies in order to obtain Patents or to gain or maintain
approval to conduct Clinical Trials or to market Licensed Product under this Agreement, in each case, in accordance with this Agreement, but such disclosure shall only be to the extent reasonably necessary to obtain Patents or authorizations, and
provided that reasonable steps are taken to ensure confidential treatment of such Confidential Information (if available); 

(c)    to any of its officers, employees, consultants, agents or Affiliates (including, (i) [***], (ii) in the case of
either Party, to such Party’s subcontractors for purpose of such subcontractor performing obligations of such Party under this Agreement) as it deems necessary or advisable in the course of conducting activities in accordance with this
Agreement in order to carry out its responsibilities or exercise its rights under this Agreement (including the exercise of the rights and licenses granted to the relevant Party hereunder), and (iii) in the case of either Party, to such
Party’s actual or potential acquirers; provided that each such disclosee is bound by written confidentiality obligations and non-use obligations no less restrictive than those set forth in this Article 7
to maintain the confidentiality thereof and not to use such Confidential Information except as expressly permitted by this Agreement; provided, however, that, in each of the above situations in this Section 7.4.1(c), the Receiving Party shall
remain responsible for any failure by any Person who receives Confidential Information from such Receiving Party pursuant to this Section 7.4.1(c) to treat such Confidential Information as required under this Article 7; and 

(d)    disclosure, solely on a “need to know basis” to its advisors (including attorneys and accountants) in
connection with activities hereunder; provided that, prior to any such disclosure, each disclosee must be bound by written obligations of confidentiality, non-disclosure and
non-use no less restrictive than the obligations set forth in this Article 7 (provided, however, that in the case of legal advisors, no written agreement shall be required), which for the avoidance of doubt,
will not permit use of such Confidential Information for any purpose except those expressly permitted by this Agreement; provided, however, that, in each of the above situations in this Section 7.4.1(d), the Receiving Party shall remain
responsible for any failure by any Person who receives Confidential Information from such Receiving Party pursuant to this Section 7.4.1(d) to treat such Confidential Information as required under this Article 7. 

7.4.2    Terms of Disclosure. If and whenever any Confidential Information is disclosed in accordance with this
Section 7.4, such disclosure shall not cause any such information to cease to be Confidential Information except to the extent that such disclosure results in a public disclosure of such information (other than by breach of this Agreement).
Where reasonably possible and subject to Section 7.6, the Receiving Party shall notify the Disclosing Party of the Receiving Party’s intent to make any disclosures pursuant to Section 7.4.1(a) sufficiently prior to making such
disclosure so as to allow the Disclosing Party adequate time to take whatever action it may deem appropriate to protect the confidentiality of the information, and the Receiving Party 

  
 50 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
will provide reasonable assistance to the Disclosing Party with respect thereto; provided that, in such event, the Receiving Party will use reasonable measures to ensure confidential treatment of
such information and shall only disclose such Confidential Information of the Disclosing Party as is necessary for the purposes of Section 7.4.1(a), as applicable. 

7.4.3    Licensed Program Specific IP. [***] shall not disclose the Licensed Program Specific IP without the prior
written consent of [***], other than pursuant to Section 7.4.1. 
 7.5    Terms of this Agreement. The
Parties agree that this Agreement and the terms hereof shall be deemed to be Confidential Information of both Prothena and Celgene, and each Party agrees not to disclose any of them without the prior written consent of the other Party, except that
each Party may disclose any of them in accordance with the provisions of Sections 7.4 and/or 7.6, as applicable. 

7.6    Securities Filings; Disclosure under Applicable Law. Each Party acknowledges and agrees that the
other Party may submit this Agreement to (or file this Agreement with) the SEC or any national securities exchange in any jurisdiction (collectively, the “Securities Regulators”), or to other Persons as may be required by Applicable
Law, and if a Party does submit this Agreement to (or file this Agreement with) any Securities Regulators, or other Persons as may be required by Applicable Law, such Party agrees to consult with the other Party with respect to the preparation and
submission of a confidential treatment request for this Agreement. Notwithstanding the foregoing, if a Party is required by Applicable Law or any Securities Regulator to make a disclosure of the terms of this Agreement in a filing or other
submission as required by Applicable Law or Securities Regulator, and (a) such Party has provided copies of the disclosure to the other Party reasonably in advance of such filing or other disclosure under the circumstances, (b) such Party
has promptly notified the other Party in writing of such requirement and any respective timing constraints, and (c) such Party has given the other Party a reasonable time under the circumstances from the date of notice by such Party of the
required disclosure to comment upon and request confidential treatment for such disclosure, then such Party will have the right to make such disclosure at the time and in the manner reasonably determined by its counsel to be required by Applicable
Law or Securities Regulator. Notwithstanding the foregoing, it is hereby understood and agreed that if a Party seeks to make a disclosure as required by Applicable Law or Securities Regulator as set forth in this Section 7.6, and the other
Party provides comments within the respective time periods or constraints specified herein or within the respective notice, the Party seeking to make such disclosure or its counsel, as the case may be, will in good faith consider incorporating such
comments.  
 7.7    Publicity. 

7.7.1    Press Release; Public Statements. Subject to Section 7.4, 7.6 and this Section 7.7, Prothena
agrees not (and shall cause its Affiliates not to) to issue any press release or other public statement disclosing this Agreement, the activities hereunder, or the transactions contemplated hereby, unless such press release or other public statement
is approved by Celgene in writing; provided that Prothena shall be authorized to make any disclosure, without the approval of Celgene, that is required by Applicable Laws (including the U.S. Securities Act of 1933, as amended, and the U.S.
Securities Exchange Act of 1934, as amended) or the rules of any Securities 

  
 51 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
Regulator, or by judicial process, subject to and in accordance with Sections 7.4 and 7.6, as applicable. Without limiting the foregoing, and subject to the foregoing proviso, in the event that
Prothena desires to issue an initial press release regarding the execution of this Agreement, Prothena shall have the right to do so provided that (i) [***] and (ii) [***]. For the avoidance of doubt, [***]. 

7.7.2    Additional Restrictions on Disclosure. Without limiting any other restrictions on disclosure set forth in
this Article 7 with respect to any press release or other public statement proposed to be made by Prothena, if such press release or public statement discloses, with respect to such Licensed Program, [***], such press release or other public
statement may not be issued without Celgene’s prior written consent, except, for such disclosures by Prothena as required by Applicable Law or Securities Regulators (solely and to the extent Prothena’s counsel determines such disclosure is
required by Applicable Law or Securities Regulators); provided that (i) in such case Prothena shall use reasonable efforts to afford Celgene a reasonable period of time to review any such disclosure and any comments made by Celgene will be
considered in good faith and (ii) any information that has been previously publicly disclosed in accordance with this Agreement may be disclosed again as long as such disclosure does not exceed the scope of such prior public disclosure. Subject
to the foregoing, in the event Celgene proposes that Prothena use specific wording or language with respect thereto, Prothena shall in good faith consider incorporating such wording or language. 

7.7.3    Previously Issued Public Statements. The contents of any press release or other public statement that has
been reviewed and approved by a reviewing Party may be re-released by the publishing Party or by such reviewing Party without a requirement for re-approval. 

7.8    Permitted Publications of Results. 

7.8.1    Publication. In the event Prothena (the “Publishing Party”) desires to publish or present
any information (including publications in journals, posters, presentations at conferences and abstracts submitted in advance of conferences) with respect to the results of the Licensed Program (including the results of a Phase 1 Clinical Trial
under the Licensed Program), or with respect to the Licensed Target, any Licensed Antibody or Licensed Product, the Publishing Party shall provide Celgene with a copy of such proposed publication or presentation no less than [***] ([***]) days
(provided that the other Party shall use Commercially Reasonable Efforts to accommodate a shorter time period if required due to circumstances outside of the Publishing Party’s control) prior to its intended submission for publication or public
disclosure. For the avoidance of doubt, the foregoing shall apply with respect to each proposed publication or presentation regardless of whether a prior publication or presentation was provided (e.g., if an abstract is provided in accordance with
this Section 7.8.1 and the Publishing Party wishes to publish the corresponding full manuscript, the full manuscript must be provided to Celgene 

  
 52 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
pursuant to this Section 7.8.1). Celgene shall respond in writing promptly and in no event later than [***] ([***]) days after receipt of the proposed material (provided that the other Party
shall use Commercially Reasonable Efforts to accommodate a shorter time period if notified by the Publishing Party and required due to circumstances outside of the Publishing Party’s control), with one or more of the following: 

(a)    comments on the proposed material, which the Publishing Party shall consider in good faith; and/or 

(b)    a specific statement of concern, based upon the need to seek patent protection or to block publication or public
disclosure (including publications in journals, posters, presentations at conferences and abstracts submitted in advance of conferences) if Celgene reasonably determines that the proposed disclosure is intellectual property that should be maintained
as a trade secret to protect the Licensed Target or any Licensed Antibody and/or Licensed Product, in which event the Publishing Party agrees not to submit such publication or make such presentation that contains such information until: 

(i)    with respect to publication or presentation of Licensed Program
Non-Specific IP, Celgene is given [***], to seek patent protection for any such Licensed Program Non-Specific IP in such publication or presentation which it believes is
patentable or to resolve any other issues, or 
 (ii)    with respect to publication or presentation of Licensed
Program Specific IP, [***] for Celgene to (x) enable further development and optimization of such Licensed Program Specific IP (including related Licensed Antibodies and Licensed Products), (y) seek patent protection for any such Licensed
Program Specific IP in such publication or presentation which it believes is patentable or (z) resolve any other issues; and/or 

(c)    an identification of Celgene’s Confidential Information that is contained in the material reviewed, which the
Publishing Party shall remove, if requested by Celgene. 
 Notwithstanding the foregoing or anything to the contrary contained herein, the
restrictions set forth in this Section 7.8.1 shall not apply to publications or presentations by Celgene (or its Affiliates or sublicensees) and Celgene (and its Affiliates and sublicensees) shall be free to make publications and presentations
with respect to results of the Licensed Program, the Licensed Target, Licensed Antibody and/or Licensed Product without the prior review or consent of Prothena. 

7.8.2    Re-Publication;
Re-Presentation. The contents of any publication or presentation that has been reviewed and approved by a reviewing Party may be re-released by the Publishing Party
or the reviewing Party without a requirement for re-approval. 
 7.9    Use
of Names. Except as otherwise expressly set forth herein, no Party (or its respective Affiliates) shall use the name, trademark, trade name or logo of the other Party or its Affiliates, or its or their respective employee(s) in any publicity,
promotion, news release or other public disclosure relating to this Agreement or its subject matter, without the prior written 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
permission of the other Party; provided that such permission shall not be required to the extent use thereof may be required by Applicable Law, including the rules of any securities exchange or
market on which a Party’s (or its Affiliate’s) securities are listed or traded. 
 7.10    Clinical Trials
Registry. Celgene (and its Affiliates and designees) shall have the right to publish registry information and summaries of data and results from any Clinical Trials conducted in connection with activities under this Agreement, on its clinical
trials registry or on a government-sponsored database such as www.clinicaltrials.gov, without requiring the consent of Prothena. The Parties shall reasonably cooperate if required or reasonably requested by Celgene in order to facilitate any such
publication by Celgene (and its Affiliates and designees). 
 7.11    Relationship to Master Collaboration Agreement
and Licensed Program U.S. License Agreement. Except as otherwise expressly stated in this Article 7, this Agreement supersedes the provisions of Article 8 of the Master Collaboration Agreement and the provisions of Article 7 of the Licensed
Program U.S. License Agreement with respect to any Confidential Information related to the Licensed Program, the Licensed Target, Licensed Antibodies or Licensed Products (the “Licensed Program Confidential Information”); provided
that, except as otherwise set forth herein, all “Confidential Information” of the “Disclosing Party” thereunder that is Licensed Program Confidential Information shall be deemed Confidential Information of the Disclosing Party
hereunder and shall be subject to the terms and conditions of this Agreement and the “Receiving Party” shall be bound by and obligated to comply with such terms and conditions as if they were the Receiving Party hereunder, subject in all
cases to Section 7.2. The foregoing shall not be interpreted as a waiver of any remedies available to the “Disclosing Party” as a result of any breach, prior to the Effective Date, by the “Receiving Party”, of its
obligations pursuant to Article 8 of the Master Collaboration Agreement or pursuant to Article 7 of the Licensed Program U.S. License Agreement, as applicable.

ARTICLE 8. 

REPRESENTATIONS AND WARRANTIES; COVENANTS 

8.1    Representations and Warranties of Both Parties. Each Party hereby represents and warrants to the other
Party, as of the Effective Date, that: 
 (a)    such Party is duly organized, validly existing and in good standing
under the Applicable Law of the jurisdiction of its formation and has full corporate power and authority to enter into this Agreement, and to carry out the provisions hereof; 

(b)    such Party has taken all necessary corporate action on its part to authorize the execution and delivery of this
Agreement and the performance of its obligations hereunder; 
 (c)    this Agreement has been duly executed and
delivered on behalf of such Party, and constitutes a legal, valid, binding obligation, enforceable against it in accordance with its terms, except to the extent that enforcement of the rights and remedies created hereby is subject to
(i) bankruptcy, insolvency, reorganization, moratorium and other similar laws of general application affecting the rights and remedies of creditors, or (ii) laws governing specific performance, injunctive relief and other equitable
remedies; 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (d)    the execution, delivery and performance of this Agreement by
such Party does not breach or conflict with any agreement or any provision thereof, or any instrument or understanding, oral or written, to which such Party (or any of its Affiliates) is a party or by which such Party (or any of its Affiliates) is
bound, nor violate any Applicable Law of any Governmental Authority having jurisdiction over such Party (or any of its Affiliates); 

(e)    no government authorization, consent, approval, license, exemption of or filing or registration with any court or
governmental department, commission, board, bureau, agency or instrumentality, domestic or foreign, under any Applicable Law currently in effect, is or will be necessary for, or in connection with, the transaction contemplated by this Agreement, or
for the performance by it of its obligations under this Agreement, except (i) as may be required to conduct Clinical Trials or to seek or obtain Regulatory Approvals or applicable Regulatory Materials or (ii) as set forth in
Section 3.2 of the Master Collaboration Agreement; and 
 (f)    it has obtained all necessary authorizations,
consents and approvals of any Third Party that is required to be obtained by it as of the Effective Date for, or in connection with, the transaction contemplated by this Agreement, or for the performance by it of its obligations under this
Agreement, except (i) as may be required to conduct Clinical Trials or to seek or obtain Regulatory Approvals or applicable Regulatory Materials or (ii) as set forth in Section 3.2 of the Master Collaboration Agreement. 

8.2    Representations and Warranties of Prothena. Except as set forth on Schedule 8.2, Prothena hereby
represents and warrants to Celgene, as of the Effective Date, that:5 

(a)    Schedules 1.46(b) and 1.63 contain a complete and accurate list of all Patents included in the
Prothena IP that claim or cover any Licensed Target, Licensed Antibodies or Licensed Products, including the composition or use of any of the foregoing, and Prothena Controls all such Patents. Except for the Prothena IP, (i) Prothena and its
Affiliates do not own or control (by license or otherwise), as of the Effective Date, any Patent or Know-How that is necessary or useful to Develop, Manufacture or Commercialize the Licensed Target, Licensed
Antibodies or Licensed Products and (ii) no other Know-How or Patents arose from, or were used in, the performance of the Licensed Program under the Master Collaboration Agreement. To Prothena’s and
its Affiliates’ actual knowledge, all issued Patents within the Prothena IP are in full force and effect, and are not invalid or unenforceable, in whole or in part; 

(b)    no claim has been issued or served, or written threat of a claim or litigation made by any Person, against
Prothena or its Affiliates that alleges that any Prothena IP is invalid or unenforceable; 
 (c)    neither Prothena
nor its Affiliates own or otherwise control (through license or otherwise) any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target the Licensed Target, other than the Licensed Program
Antibodies (all of which are set forth on Schedule 1.44) and the Licensed Program Products; 
  

 

	5 	 [***] 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (d)    [***]; 

(e)    neither Prothena nor its Affiliates are subject to any payment obligations to Third Parties as a result of the
execution or performance of this Agreement, or the research, development, manufacture or commercialization of the Licensed Target or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target
the Licensed Target; 
 (f)    Prothena has the full right and authority to grant all of the rights and licenses
granted to Celgene (or purported to be granted to Celgene) hereunder; and neither Prothena nor its Affiliates have granted any right or license to any Third Party relating to any of the Prothena IP or any other Licensed Program Asset, Licensed
Target or Antibody (or any products constituting, incorporating, comprising or containing any such Antibody) that Targets the Licensed Target, that would conflict with [***] any of the rights or licenses granted to Celgene hereunder; 

(g)    Prothena is the sole and exclusive owner of the Prothena IP, except for the Prothena Licensed Collaboration IP
that is exclusively licensed to Prothena (or its Affiliates) pursuant to the In-License Agreements set forth on Schedule 1.39. All Affiliates of Prothena have exclusively licensed or assigned all of
their right, title and interest in and to the Prothena IP to Prothena. Neither Prothena nor its Affiliates have granted any mortgage, pledge, claim, security interest, lien or other charge of any kind on the Prothena IP or other Licensed Program
Asset, and the Prothena IP and the other Licensed Program Assets are free and clear of any mortgage, pledge, claim, security interest, lien or charge of any kind; 

(h)    neither Prothena nor its Affiliates have received any written notice of any claim that any Patent or Know-How (including any trade secret right) owned or controlled by a Third Party would be infringed or misappropriated by the Development, Manufacture, or Commercialization of the Licensed Target, Licensed Antibody
or Licensed Product; 
 (i)    to Prothena’s and its Affiliates’ actual knowledge, (i) the Development
and Manufacture of the Licensed Target, any Licensed Antibody or Licensed Product, as conducted by or on behalf of Prothena or its Affiliates prior to the Effective Date, has not violated, infringed or misappropriated any intellectual property or
proprietary right of any Third Party and (ii) [***]; 
 (j)    there are no claims, judgments, settlements,
litigations, suits, actions, disputes, arbitration, judicial or legal administrative or other proceedings or governmental investigations pending or, to Prothena’s or its Affiliates’ knowledge, threatened against Prothena or its Affiliates
which would reasonably be expected to adversely affect or restrict the ability of Prothena to consummate or perform the transactions contemplated under this Agreement, or which would affect the Prothena IP or other Licensed Program Assets, or
Prothena’s Control thereof, or the Licensed Target or any Licensed Antibody or Licensed Product; 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (k)    neither Prothena nor its Affiliates have issued a claim against
a Third Party alleging that a Third Party is infringing or has infringed or misappropriated any Prothena IP, and, to Prothena’s and its Affiliates’ actual knowledge, no issued Patents within the Prothena IP are being infringed and no trade
secrets within the Prothena IP are being misappropriated by any Third Party; 
 (l)    neither Prothena nor its
Affiliates have employed or otherwise used in any capacity, the services of any Person suspended, proposed for debarment or debarred under United States law, including under 21 U.S.C. § 335a, or any foreign equivalent thereof, with respect to
the Licensed Target, the Licensed Antibodies or Licensed Products or otherwise in performing any portion of the Licensed Program. All Manufacture and Development (including non-clinical studies and Clinical
Studies) related to the Licensed Target, Licensed Antibodies or Licensed Products conducted by or on behalf of Prothena or its Affiliates prior to the Effective Date (including the conduct of the Licensed Program under the Master Collaboration
Agreement) has been conducted in accordance with all Applicable Laws (including, to the extent applicable, GCP, GLP and GMP); 

(m)    neither Prothena nor its Affiliates have entered into any agreement under which Prothena or its Affiliates
(i) has obtained a license or sublicense of rights from a Third Party to the Licensed Target, or to any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target the Licensed Target, or to
any Prothena IP, except for the In-License Agreements set forth on Schedule 1.39, or (ii) has granted a license, sublicense, option or right to a Third Party that remains in effect as of the
Effective Date to research, develop, manufacture or commercialize the Licensed Target or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target the Licensed Target, except (1) with
respect to licenses or rights granted pursuant to the agreements set forth on Schedule 1.39 that were entered into in the ordinary course of business [***] performing activities on behalf of Prothena [and (2) [***]]6. The agreements set forth on Schedule 1.39 do not conflict with [***] the rights or licenses granted to Celgene hereunder;7 

(n)    other than the Existing Program Agreements, Prothena (or its Affiliates, as applicable) has not entered into any
agreement relating to the Development, Manufacture, Commercialization or other exploitation of the Licensed Target, Licensed Antibodies or Licensed Products, or the Prothena IP;  

(o)    with respect to each Existing Program Agreement and In-License Agreement,
(i) it is in full force and effect; (ii) Prothena (or its Affiliate, as applicable) is not in breach thereof; (iii) Prothena (or its Affiliate, as applicable) has not received any notice from the 

 

	6 	 [***] 

	7 	 [***] 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
counterparty to such Existing Program Agreement or In-License Agreement, as applicable, of Prothena’s (or its Affiliate’s, as applicable) breach
or notice of threatened breach by Prothena (or its Affiliate, as applicable) thereof and (iv) Prothena has provided Celgene with a true, correct and complete copy of each Existing Program Agreement and
In-License Agreement; 
 (p)    Prothena has disclosed to Celgene all material
information and data, and all material correspondences to/from any Regulatory Authority, existing as at the Effective Date in the possession or control of Prothena or its Affiliates, in each case related to the Licensed Program, Licensed Target,
Licensed Antibodies or Licensed Products; 
 (q)    the Licensed Program Inventory to be provided to Celgene hereunder
was (and at all times up until delivery of such Licensed Program Inventory hereunder shall remain) manufactured, packaged, labeled, tested, stored and handled in accordance with all Applicable Laws (including GMPs), and specifications therefor, and
such Licensed Program Inventory is not adulterated or misbranded under Applicable Law and is not an article that could not, under the provisions of the Applicable Law, be introduced into interstate commerce. All such Licensed Program Inventory is
free and clear of all encumbrances (including through lien, charge, security interest, mortgage, encumbrance or otherwise); and 

(r)    other than the Existing IND, Prothena has not obtained, or filed, any INDs, MAAs or Regulatory Approvals or any
other form of regulatory application for approval of Clinical Trials, marketing or other purpose, for any Licensed Antibodies or Licensed Products and, to Prothena’s and it Affiliates’ actual knowledge, no other Person has obtained, or
filed for, any such INDs, MAAs or Regulatory Approvals. The Existing IND is in full force and good standing, and neither Prothena nor its Affiliates have received any notice in writing, or otherwise has knowledge of any facts, which have, or
reasonably could have, led Prothena to believe that the Existing IND is not currently in, or may not remain in, good standing with the FDA or other applicable Regulatory Authority. 

8.3    Additional Representations, Warranties and Covenants of Prothena. Prothena hereby further represents,
warrants and covenants to Celgene that: 
 8.3.1    With respect to the
In-License Agreements, (a) Prothena (or its Affiliates, as applicable) shall not breach, or commit any acts or permit the occurrence of any omissions that would cause the breach or termination, of any In-License Agreement and (b) Prothena shall (or shall cause its Affiliates to, as applicable) satisfy all of its obligations under each In-License Agreement in all
material respects and shall, or shall cause its Affiliates to, as applicable, maintain each In-License Agreement in full force and effect. Prothena shall, or shall cause its Affiliates to, as applicable,
enforce its rights under each In-License Agreement to the extent necessary to preserve Celgene’s rights under this Agreement. Prothena shall not, and shall cause its Affiliates not to, [***] if doing so
[***] under this Agreement. Prothena will provide Celgene with prompt written notice of any claim of a breach of which it is aware under any of the In-License Agreements or notice of termination of any In-License Agreement. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 8.3.2    With respect to the Existing Program Agreements,
(a) Prothena (or its Affiliate, as applicable) shall not breach, or commit any acts or permit the occurrence of any omissions that would cause the breach or termination, of any Existing Program Agreement and (b) Prothena shall (or shall
cause its Affiliates to, as applicable) satisfy all of its obligations under each Existing Program Agreement in all material respects and shall, or shall cause its Affiliates to, as applicable, maintain each Existing Program Agreement in full force
and effect, unless Prothena otherwise obtains Celgene’s prior written consent (such consent not to be unreasonably withheld). Prothena shall, or shall cause its Affiliates to, as applicable, enforce its rights under each Existing Program
Agreement to the extent necessary to preserve Celgene’s rights under this Agreement. Prothena shall not, and shall cause its Affiliates not to, [***] under this Agreement. Except as set forth in Section 2.3.5, Prothena shall not, and shall
cause its Affiliates not to assign or otherwise transfer any Existing Program Agreement. Prothena will provide Celgene with prompt written notice of any claim of a breach of which it is aware under any of the Existing Program Agreements or notice of
termination of any Existing Program Agreement. 
 8.3.3    In-License
Agreements. [***] on case-by-case basis, Prothena shall (or shall cause its Affiliates to, as applicable) execute a written agreement, in a form reasonably
acceptable to Celgene, with each Third Party that is a counterparty to the applicable In-License Agreement (each such counterparty, a “Prothena Licensor”) within [***] ([***]) days after the
date of such request, pursuant to which (a) in the event of an early termination of such In-License Agreement, at the request of Celgene, such Prothena Licensor shall grant a direct license to Celgene
with respect to the intellectual property licensed to Prothena under such In-License Agreement, on the same terms under which such Prothena Licensor grants such license to Prothena (or its Affiliate, as
applicable) under such In-License Agreement, (b) such Prothena Licensor agrees to and acknowledges the rights granted to Celgene hereunder with respect to any intellectual property licensed to Prothena
(or its Affiliate, as applicable) under such In-License Agreement, including the rights as set forth in this Section 8.3.3, and (c) [***]. 

8.3.4    Notwithstanding anything to the contrary contained herein, [***]. 

8.3.5    Prothena shall promptly notify Celgene in writing if any Patents in the Prothena IP that claim or cover any
Licensed Target, Licensed Antibodies or Licensed Products, including the composition or use of any of the foregoing, becomes known to Prothena that are not listed on Schedule 1.46(b) or 1.63. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 8.4    Representations and Warranties of Celgene. Except as set
forth on Schedule 8.4, Celgene hereby represents and warrants to Prothena, as of the Effective Date, that: 

8.4.1    there are no claims, judgments, settlements, litigations, suits, actions, disputes, arbitration, judicial or
legal administrative or other proceedings or governmental investigations pending or, to Celgene’s actual knowledge, threatened against Celgene which would reasonably be expected to adversely affect or restrict the ability of Celgene to
consummate or perform the transactions contemplated under this Agreement. 
 8.5    Covenants. 

8.5.1    Mutual Covenants. Each Party hereby covenants to the other Party that: 

(a)    such Party and its Affiliates shall perform its activities pursuant to this Agreement in compliance (and shall
ensure compliance by any of its subcontractors) with all Applicable Laws, including, to the extent applicable, GCP, GLP and GMP. 

8.5.2    Prothena Covenants. Prothena hereby covenants to Celgene that: 

(a)    Neither Prothena nor its Affiliates shall grant any right or license to any Third Party relating to any of the
intellectual property rights it owns or Controls (including the Prothena IP and other Licensed Program Assets), or otherwise with respect to any Licensed Antibody, Licensed Product or Diagnostic Product which conflict with, [***] any of the rights
or licenses granted to Celgene hereunder; and 
 (b)    Except with respect to the performance of the Prothena Ongoing
Program Activities in accordance with Section 2.1.3 (or as otherwise expressly agreed to by Celgene in writing, including as set forth in Section 2.1.3(c)), neither Prothena nor its Affiliates shall use (and neither shall grant any Third
Party the right to use) any Licensed Antibodies, Licensed Products or Diagnostic Products for any purposes in the Territory. 

8.6    Disclaimer. EXCEPT AS OTHERWISE EXPRESSLY PROVIDED IN THIS AGREEMENT, NEITHER PARTY MAKES ANY
REPRESENTATIONS OR EXTENDS ANY WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED (AND EACH PARTY HEREBY EXPRESSLY DISCLAIMS ANY AND ALL REPRESENTATIONS AND WARRANTIES NOT EXPRESSLY PROVIDED IN THIS AGREEMENT), INCLUDING WITH RESPECT TO ANY PATENTS OR KNOW-HOW, OR MATERIALS, INCLUDING WARRANTIES OF VALIDITY OR ENFORCEABILITY, MERCHANTABILITY, FITNESS FOR A PARTICULAR USE OR PURPOSE, PERFORMANCE, AND NONINFRINGEMENT OF ANY THIRD PARTY PATENTS OR OTHER INTELLECTUAL
PROPERTY RIGHTS. WITHOUT LIMITING THE FOREGOING, NEITHER PARTY MAKES ANY REPRESENTATION, WARRANTY OR GUARANTEE THAT THE LICENSED PROGRAM WILL BE SUCCESSFUL, OR THAT ANY OTHER PARTICULAR RESULTS WILL BE ACHIEVED WITH RESPECT TO THE LICENSED PROGRAM,
THE LICENSED TARGET, ANY LICENSED ANTIBODY OR ANY LICENSED PRODUCT HEREUNDER. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 ARTICLE 9. 

INDEMNIFICATION; INSURANCE 

9.1    Indemnification by Celgene. Celgene shall indemnify, defend and hold harmless Prothena and its Affiliates
and its and their respective directors, officers, employees, agents, successors and assigns (collectively, the “Prothena Indemnitees”), from and against any and all Third Party Damages to the extent arising out of or relating to,
directly or indirectly, any Third Party Claim based upon: 
 (a)    the gross negligence or willful misconduct of
Celgene or its Affiliates or its or their respective directors, officers, employees or agents, in connection with Celgene’s performance of its obligations under this Agreement; 

(b)    any breach by Celgene of any of its representations, warranties, covenants, agreements or obligations under this
Agreement; or 
 (c)    any claim for personal injury or death arising out of the Development, Manufacture or
Commercialization of the Licensed Antibodies and Licensed Products in the Territory by or on behalf of Celgene or its Affiliates or Sublicensees during the Term; 

in each case (a)-(c), provided, however, that such indemnity shall not apply to the extent Prothena has an indemnification obligation pursuant to
Section 9.2(a) or (b) for such Third Party Damages. 
 9.2    Indemnification by Prothena. Prothena
shall indemnify, defend and hold harmless Celgene, its Affiliates and its and their respective directors, officers, employees, agents, successors and assigns (collectively, the “Celgene Indemnitees”), from and against any and all
Third Party Damages to the extent arising out of or relating to, directly or indirectly, any Third Party Claim based upon: 

(a)    the gross negligence or willful misconduct of Prothena or its Affiliates or its or their respective directors,
officers, employees or agents, in connection with Prothena’s performance of its obligations under this Agreement; 

(b)    any breach by Prothena of any of its representations, warranties, covenants, agreements or obligations under this
Agreement; or 
 (c)    any claim for personal injury or death arising out of the Development, Manufacture or
Commercialization of the Licensed Antibodies (including Reversion Antibodies) and Licensed Products (including products containing Reversion Antibodies) by or on behalf of Prothena or its Affiliates or sublicensees; 

in each case (a)-(c), provided, however, that such indemnity shall not apply to the extent Celgene has an indemnification obligation pursuant
to Section 9.1(a) or (b) for such Third Party Damages. 
 9.3    Procedure. If a Party is seeking
indemnification under Section 9.1 or 9.2, as applicable (the “Indemnitee”), it shall inform the other Party (the “Indemnitor”) of the claim 

  
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treatment has been requested with respect to the omitted portions. 

 
giving rise to the obligation to indemnify pursuant to Section 9.1 or 9.2, as applicable, as soon as reasonably practicable after receiving notice of the claim (provided, however, any delay
or failure to provide such notice shall not constitute a waiver or release of, or otherwise limit, the Indemnitee’s rights to indemnification under Section 9.1 or 9.2, as applicable, except to the extent that such delay or failure
materially prejudices the Indemnitor’s ability to defend against the relevant claims). The Indemnitor shall have the right to assume the defense of any such claim for which the Indemnitee is seeking indemnification pursuant to Section 9.1
or 9.2, as applicable. The Indemnitee shall cooperate with the Indemnitor and the Indemnitor’s insurer as the Indemnitor may reasonably request, and at the Indemnitor’s cost and expense. The Indemnitee shall have the right to participate,
at its own expense and with counsel of its choice, in the defense of any claim or suit that has been assumed by the Indemnitor. The Indemnitor shall not settle any claim without the prior written consent of the Indemnitee, not to be unreasonably
withheld; provided, however, that the Indemnitor shall not be required to obtain such consent if the settlement (i) involves only the payment of money and will not result in the Indemnitee (or other Prothena Indemnitees or Celgene Indemnitees,
as applicable) becoming subject to injunctive or other similar type of relief, (ii) does not require an admission by the Indemnitee (or other Prothena Indemnitees or Celgene Indemnitees, as applicable) and (iii) does not adversely affect
the rights or licenses granted to the Indemnitee (or its Affiliate) under this Agreement. The Indemnitee shall not settle or compromise any such claim without the prior written consent of the Indemnitor, which it may provide in its sole discretion.
If the Parties cannot agree as to the application of Section 9.1 or 9.2, as applicable, to any claim, pending resolution of the dispute pursuant to Section 11.7 the Parties may conduct separate defenses of such claims, with each Party
retaining the right to claim indemnification from the other Party in accordance with Section 9.1 or 9.2, as applicable, upon resolution of the underlying claim. In each case, the Indemnitee shall reasonably cooperate with the Indemnitor, and
shall make available to the Indemnitor all pertinent information under the control of the Indemnitee, which information shall be subject to Article 7. 

9.4    Insurance. During the Term and for a period of [***] ([***]) years thereafter, each Party shall maintain, at
its cost, a program of insurance and/or self-insurance against liability and other risks associated with its activities and obligations under this Agreement (including, with respect to its Clinical Trials), and its indemnification obligations
hereunder, in such amounts, subject to such deductibles and on such terms as are customary for such Party for the activities to be conducted by it under this Agreement. It is understood that such insurance shall not be construed to create a limit on
either Party’s liability with respect to its indemnification obligations under this Article 9, or otherwise. 

9.5    LIMITATION OF LIABILITY. NEITHER PROTHENA NOR CELGENE, NOR ANY OF THEIR RESPECTIVE AFFILIATES, WILL BE
LIABLE TO THE OTHER PARTY OR ITS AFFILIATES UNDER OR IN CONNECTION WITH THIS AGREEMENT FOR ANY INDIRECT, INCIDENTAL, CONSEQUENTIAL, SPECIAL OR PUNITIVE OR EXEMPLARY DAMAGES (INCLUDING LOST PROFITS OR LOST REVENUES), WHETHER LIABILITY IS ASSERTED IN
CONTRACT, TORT (INCLUDING NEGLIGENCE AND STRICT PRODUCT LIABILITY), INDEMNITY, CONTRIBUTION OR OTHERWISE, AND IRRESPECTIVE OF WHETHER THAT PARTY OR ANY REPRESENTATIVE OF THAT PARTY HAS BEEN ADVISED OF, OR OTHERWISE MIGHT HAVE ANTICIPATED THE
POSSIBILITY OF, ANY SUCH LOSS OR DAMAGE. NOTWITHSTANDING THE FOREGOING, NOTHING IN THIS SECTION 9.5 IS INTENDED TO OR SHALL LIMIT OR RESTRICT THE INDEMNIFICATION RIGHTS OR OBLIGATIONS OF ANY PARTY UNDER SECTIONS 9.1 OR 9.2 IN CONNECTION WITH ANY
THIRD PARTY CLAIMS [***]. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 ARTICLE 10. 

TERM AND TERMINATION 

10.1    Term; Expiration. 

10.1.1    Term. Subject to Section 3.2 of the Master Collaboration Agreement, this Agreement shall become
effective on the Effective Date and, unless earlier terminated in accordance with this Article 10, shall remain in effect until it expires as follows (the “Term”): 

(a)    on a Licensed Product-by-Licensed
Product and country-by-country basis, this Agreement shall expire on the date of the expiration of the Royalty Term with respect to such Licensed Product in such
country; and 
 (b)    in its entirety upon the expiration of all applicable Royalty Terms under this Agreement with
respect to all Licensed Products in all countries in the Territory. 
 10.1.2    Effect of Expiration. After the
expiration of the Term pursuant to Section 10.1.1 above, the following terms shall apply: 
 (a)    Licenses
after Licensed Product Expiration. After expiration of the Term with respect to a given Licensed Product in a given country pursuant to Section 10.1.1(a), the licenses set forth in Section 6.1 with respect to such Licensed Product (and
the Licensed Antibody contained therein) and related Diagnostic Products in such country will automatically become fully paid-up, perpetual, irrevocable and royalty-free. 

(b)    Licenses after Expiration of Agreement. After expiration of the Term with respect to this Agreement in its
entirety pursuant to Section 10.1.1(b), all licenses set forth in Section 6.1 will automatically become fully paid-up, perpetual, irrevocable and royalty-free. 

10.2    Termination for Breach. 

10.2.1    Material Breach. This Agreement may be terminated by a Party for the material breach by the other Party of
this Agreement provided that the breaching Party has not cured such breach within ninety (90) days after the date of written notice to the breaching Party of such breach (or thirty (30) days in the case of a breach as a result of non-payment of any amounts due under this Agreement) (the “Cure Period”), which notice shall describe such breach in reasonable detail and shall state the
non-breaching Party’s intention to terminate this Agreement. For clarity, but subject to Section 10.2.2, the Cure Period for any allegation made as to a material breach under this Agreement will run
from the date that written notice was first provided to the breaching Party by the non-breaching Party. Any such termination of this Agreement under this Section 10.2.1 shall become effective at the end
of the Cure Period, unless the breaching Party has cured such breach prior to the expiration of such Cure Period, or, if such breach is not susceptible 

  
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to cure within the Cure Period, then such Cure Period shall be extended for an additional [***] ([***]) days so long as the breaching Party continues to use commercially reasonable efforts to
cure such material breach during such extension period. For the avoidance of doubt, termination of this Agreement pursuant to this Section 10.2.1 shall terminate the Master Collaboration Agreement solely with respect to the Licensed Program but
shall not terminate the Master Collaboration Agreement with respect to any other Programs or any U.S. License Agreement or other Global License Agreement for any other Program.

10.2.2    Disagreement as to Material Breach. Notwithstanding Section 10.2.1, if the Parties in good faith
disagree as to whether there has been a material breach of this Agreement pursuant to Section 10.2.1, then: (a) the Party that disputes that there has been a material breach may contest the allegation by referring such matter, within
[***], for resolution to the Executive Officers, who shall meet promptly to discuss the matter and determine, within [***], whether or not a material breach has occurred pursuant to Section 10.2.1; provided that if the Executive Officers are
unable to resolve such dispute within such [***] ([***]) [***] period after it is referred to them, the matter will be resolved as provided in Section 11.7; (b) the relevant Cure Period with respect thereto will be tolled from the date the
breaching Party notifies the non-breaching Party of such dispute and through the resolution of such dispute in accordance with the applicable provisions of this Agreement; (c) subject to
Section 10.10, during the pendency of such dispute, all of the terms and conditions of this Agreement shall remain in effect and the Parties shall continue to perform all of their respective obligations hereunder; and (d) if it is
ultimately determined that the breaching Party committed such material breach, then the breaching Party shall have the right to cure such material breach, after such determination, within the Cure Period (as may be extended in accordance with
Section 10.2.1) which shall commence as of the date of such determination. 
 10.3    Voluntary Termination.
Celgene may terminate this Agreement at will, in its sole discretion, in its entirety upon sixty (60) days’ prior written notice to Prothena at any time. 

10.4    Termination for Bankruptcy. If either Party makes a general assignment for the benefit of, or an
arrangement or composition generally with, its creditors, appoints or suffers appointment of an examiner or of a receiver or trustee over all or substantially all of its property, passes a resolution for its winding up or files a petition under any
bankruptcy or insolvency act or law or has any such petition filed against it which is not dismissed, discharged, bonded or stayed within ninety (90) days after the filing thereof (each, an “Insolvency Event”), the other Party
may terminate this Agreement in its entirety, effective immediately upon written notice to such Party, provided that, in connection therewith, the provisions of Section 6.5 shall apply. 

10.5    Termination for Patent Challenge. Prothena shall have the right to terminate this Agreement upon
written notice if Celgene or any Affiliate of Celgene challenges the validity, scope or enforceability of or otherwise opposes any Patent included in the Prothena IP that is licensed to Celgene under this Agreement, in each case through a formal
proceeding (other than as may be necessary or reasonably required to assert a cross-claim or a counter-claim or to respond to a court request or order or administrative law, request or order). If a Sublicensee of Celgene with respect to any Prothena
IP challenges the validity, scope or enforceability of or otherwise opposes any Patent included in such Prothena IP under which such Sublicensee is sublicensed, in 

  
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each case through a formal proceeding (other than as may be necessary or reasonably required to assert a cross-claim or a counter-claim or to respond to a court request or order or administrative
law, request or order) then Celgene shall, upon written notice from Prothena, terminate such sublicense. 

10.6    Effects of Expiration or Termination; Additional Remedies.

10.6.1    Termination by Prothena Pursuant to Section 10.2, 10.4 or 10.5,
or by Celgene Pursuant to Section 10.3. In the event this Agreement is terminated by Prothena pursuant to Section 10.2, 10.4 or 10.5, or by Celgene pursuant to Section 10.3, upon the effective date of such
termination: 
 (a)    the Master Collaboration Agreement (if not previously expired or terminated) shall also
terminate automatically with respect to the Licensed Program (but not any other Program); 
 (b)    except as set forth
in this Section 10.6.1, or Sections 10.8 or 10.9, all rights and licenses granted herein shall terminate; 

(c)    any and all Collaboration Specific IP shall thereafter no longer be deemed to be Collaboration Specific IP; 

(d)    each Party shall return or destroy all Confidential Information of the other Party as required by Article 7; and

 (e)    notwithstanding the foregoing provisions of this Section 10.6.1, the licenses granted to Celgene
hereunder shall survive for [***] ([***]) [***] following the effective date of termination in order for Celgene (and its Affiliates, Sublicensees and distributors), at Celgene’s discretion, during the [***] ([***])-[***] period immediately
following the effective date of termination, to (i) finish or otherwise wind-down any ongoing Clinical Trials with respect to any Licensed Antibodies, Licensed Products or Diagnostic Products hereunder and (ii) finish and sell any [***]
Licensed Antibodies, Licensed Products or Diagnostic Products remaining in inventory (provided that Celgene shall pay royalties on Annual Net Sales of such Licensed Products sold by Celgene during such period (provided that the applicable Royalty
Term is still ongoing) as an to the extent Celgene would otherwise be required to pay such royalties as set forth in Section 5.3); provided that, for clarity, Celgene shall have no obligation to undertake such activities, in each case of
(i) and (ii), as and to the extent determined by Celgene. 
 10.6.2    Termination by Celgene Pursuant to
Section 10.2 or 10.4. In the event this Agreement is terminated by Celgene pursuant to Section 10.2 or 10.4, upon the effective date of such termination: 

(a)    the Master Collaboration Agreement (if not previously expired or terminated) shall also terminate automatically
with respect to the Licensed Program (but not any other Program); 

  
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 (b)    except as set forth in this Section 10.6.2 or Sections 10.8
or 10.9, all rights and licenses granted herein shall terminate; 
 (c)    any and all Collaboration Specific IP hall
thereafter no longer be deemed to be Collaboration Specific IP; 
 (d)    each Party shall return or destroy all
Confidential Information of the other Party as required by Article 7; and 
 (e)    notwithstanding the foregoing
provisions of this Section 10.6.2, the licenses granted to Celgene hereunder shall survive for [***] ([***]) [***] following the effective date of termination in order for Celgene (and its Affiliates, Sublicensees and distributors), at
Celgene’s discretion, during the [***] ([***])-[***] period immediately following the effective date of termination, to (i) finish or otherwise wind-down any ongoing Clinical Trials with respect to any Licensed Antibodies, Licensed
Products or Diagnostic Products hereunder and (ii) finish and sell [***] any Licensed Antibodies, Licensed Products or Diagnostic Products remaining in inventory (provided that Celgene shall pay royalties on Annual Net Sales of such Licensed
Products sold by Celgene during such period (provided that the applicable Royalty Term is still ongoing) as an to the extent Celgene would otherwise be required to pay such royalties as set forth in Section 5.3); provided that, for clarity,
Celgene shall have no obligation to undertake such activities, in each case of (i) and (ii), as and to the extent determined by Celgene. 

10.7    Certain Additional Remedies of Celgene in Lieu of Termination. In the event that (i) Celgene notifies
Prothena in writing of a material breach of this Agreement by Prothena, and (ii) Celgene would have the right to terminate this Agreement pursuant to Section 10.2, then in lieu of Celgene terminating pursuant to Section 10.2, and
without limiting any other rights or remedies of Celgene, Celgene may elect to have this Agreement continue in full force and effect by providing written notice thereof to Prothena; provided, however, that if Celgene so elects to continue this
Agreement, then from and after such time as Celgene delivers such written notice to Prothena, any and all amounts thereafter payable by Celgene hereunder (including Regulatory Milestone Payments, Sales Milestone Payments and royalties) shall be
reduced by [***]. 
 10.8    Prothena Reversion Antibodies. If this Agreement terminates, except for any
termination by Celgene pursuant to Section 10.2 or 10.4, then the provisions of this Section 10.8 (and for the avoidance of doubt, the provisions of this Section 10.8 shall not apply in the case of termination by Celgene pursuant to
Section 10.2 or 10.4). 
 10.8.1    Reversion. All Licensed Program Antibodies that were the subject of
Clinical Trials conducted by Celgene pursuant to this Agreement shall be automatically and immediately deemed “Prothena Reversion Antibodies”. Celgene shall grant and hereby grants to Prothena a
non-exclusive, royalty-free, license in the Territory, with the right to grant sublicenses through multiple tiers, under any Patents and/or Know-How Controlled by
Celgene or its Affiliates as of the termination effective date claiming or covering [***], into the Prothena Reversion Antibodies as they exist as of such termination effective date, solely as necessary to research, Develop, Manufacture, use,
import, offer for sale, sell, and Commercialize Prothena Reversion Antibodies [***] in the Field in the Territory; [***]. 

  
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treatment has been requested with respect to the omitted portions. 

 10.8.2    Effects of Reversion. With respect to each Prothena
Reversion Antibody: 
 (a)    Except to the extent not permitted pursuant to any agreements between Celgene and a Third
Party, Celgene shall provide to Prothena, within a reasonable time, at Prothena’s request (provided that such request was made within [***] ([***]) days after the effective date of termination), subject to [***], copies of (i) [***] Clinical
Trial data and results generated by or on behalf of Celgene or its Affiliates in the Development of Prothena Reversion Antibodies pursuant to this Agreement, and (ii) [***] relating to the manufacture of such Prothena Reversion Antibodies; in each
case, to the extent in Celgene’s possession as of the termination effective date [***]. For clarity, Prothena shall have the right to use the foregoing [***] solely in connection with the exercise of Prothena’s rights under
Section 10.8.1; 
 (b)    Celgene shall transfer within a reasonable time to Prothena, at Prothena’s request
(provided that such request was made within [***] ([***]) days after the effective date of termination), [***], [***] Regulatory Filings [***] for the Prothena Reversion Antibodies [***] by Celgene or its Affiliates as of the termination effective
date; [***]; 
 (c)    Celgene shall otherwise cooperate reasonably with Prothena to provide a transfer of the
materials described in the foregoing provisions of this Section 10.8.2, [***]; 
 (d)    As and to the extent a
Third Party is Manufacturing such Prothena Reversion Antibody for Celgene or its Affiliate, Celgene shall use reasonable efforts, at Prothena’s request (provided that such request was made within [***] ([***]) days after the effective date of
termination) [***], to [***]. Additionally, at Prothena’s request (provided that such request was made within [***] ([***]) days after the effective date of termination), Celgene shall transfer to Prothena [***] such Prothena Reversion Antibody
owned by Celgene and then in Celgene’s possession, for a price equal to [***]; 
 (e)    To the extent that
Celgene or its Affiliate owns any trademark(s) and/or domain names that [***] a Prothena Reversion Antibody that [***] for the Commercialization of a Prothena Reversion Antibody (as [***], but not including any marks that include, in whole or part,
any corporate 

  
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name or logo of Celgene or its Affiliate), Prothena shall have the right to [***]. Prothena shall exercise such right by written notice to Celgene within [***] ([***]) days after such Licensed
Antibody or Licensed Product becomes a Prothena Reversion Antibody; and 
 (f)    If Celgene or its Affiliate has
obtained a license from a Third Party and Prothena is a sublicensee under such license pursuant to Section 10.8.1, then [***]. Notwithstanding the provisions of Section 10.8.1, Prothena shall not get a sublicense of any Third Party
intellectual property pursuant to Section 10.8.1 unless such sublicense is allowed pursuant to and in accordance with the agreement between Celgene and such Third Party. 

10.9    Surviving Provisions. 

10.9.1    Accrued Rights; Remedies. Termination or expiration of this Agreement for any reason shall be without
prejudice to any rights that shall have accrued to the benefit of any Party prior to such termination or expiration, and any and all damages or remedies (whether in law or in equity) arising from any breach hereunder, each of which shall survive
termination or expiration of this Agreement. Such termination or expiration shall not relieve any Party from obligations which are expressly indicated to survive termination or expiration of this Agreement. Except as otherwise expressly set forth in
this Agreement, the termination provisions of this Article 10 are in addition to any other relief and remedies available to either Party under this Agreement and at Applicable Law. 

10.9.2    Survival. Without limiting the provisions of Section 10.9.1, the rights and obligations of the
Parties set forth in the following Sections and Articles of this Agreement shall survive the expiration or termination of this Agreement, in addition to those other terms and conditions that are expressly stated to survive termination or expiration
of this Agreement: [Article 1 (to the extent the definitions are used in other surviving provisions), Section 2.3.5(a) (solely as to the last sentence therein) Article 5 (as to payment obligations accrued prior to the effectiveness of
termination or expiration of this Agreement), Section 6.3, Section 6.4, Section 6.5, Section 6.6, Section 6.12 (solely if there is no U.S. License Agreement or other Global License Agreement covering the applicable Joint
Patents), Article 7, Section 8.6, Article 9, Section 10.1.2, Section 10.6, Section 10.8, Section 10.9, Section 10.10, Section 10.11, and Article 11.].8 

10.10    Milestone Payments. Notwithstanding anything to the contrary contained herein, in the event notice of
termination of this Agreement is given prior to achievement of a given milestone set forth in Section 5.4 or 5.5, Celgene shall not be obligated to make any Regulatory Milestone Payment or Sales Milestone Payment to Prothena with respect to any
milestone achieved following the notice of such termination. 
  

 

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 10.11    Relationship to Other Agreements. Termination of this
Agreement shall not affect in any way the terms or provisions of any other then-existing executed Global License Agreements or U.S. License Agreements. 

ARTICLE 11. 

MISCELLANEOUS 

11.1    Severability. If any one or more of the terms or provisions of this Agreement is held by a court of
competent jurisdiction to be void, invalid or unenforceable in any situation in any jurisdiction, such holding shall not affect the validity or enforceability of the remaining terms and provisions hereof or the validity or enforceability of the
invalid, void or unenforceable term or provision in any other situation or in any other jurisdiction, and the term or provision shall be considered severed from this Agreement solely for such situation and solely in such jurisdiction, unless the
invalid, void or unenforceable term or provision is of such essential importance to this Agreement that it is to be reasonably assumed that the Parties would not have entered into this Agreement without the invalid, void or unenforceable term or
provision. If the final judgment of such court declares that any term or provision hereof is invalid, void or unenforceable, the Parties agree to (a) reduce the scope, duration, area or applicability of the term or provision or to delete
specific words or phrases to the minimum extent necessary to cause such term or provision as so reduced or amended to be enforceable, and (b) make a good faith effort to replace any invalid, void or unenforceable term or provision with a valid
and enforceable one such that the objectives contemplated by the Parties when entering this Agreement may be realized. 

11.2     Notices. Any notice required or permitted to be given by this Agreement shall be in writing and in English
and shall be (a) delivered by hand or by overnight courier with tracking capabilities, (b) mailed postage prepaid by first class, registered, or certified mail, or (c) delivered by facsimile followed by delivery via either of the
methods set forth in Sections 11.2(a) and (b), in each case, addressed as set forth below unless changed by notice so given: 
 If to
Celgene: 
 Celgene Switzerland LLC 

AON House 
 30 Woodbourne Ave.

 Pembroke HM 08, Bermuda 

Attention:        [***] 

With copies to: 
 Celgene
Corporation 
 86 Morris Avenue 

Summit, New Jersey 07901 U.S.A. 

Attention:        General Counsel 

Facsimile:        (908) 673-2771 

  
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treatment has been requested with respect to the omitted portions. 

 If to Prothena: 

Prothena Biosciences Limited 

Adelphi Plaza 
 Upper
George’s Street 
 Dun Laoghaire, Co. Dublin A96 T927 

Ireland 
 Attention:
        Company Secretary 
 Facsimile:         +353-1-686-5675 

With copies to: 
 Prothena
Biosciences Inc. 
 331 Oyster Point Boulevard 

South San Francisco, CA, 94080 

U.S.A. 

Attention:        Vice President, Business Development 

Facsimile:        +1
650-837-8560 
 Any such notice shall be deemed given on the date received,
except any notice received after 5:30 p.m. (in the time zone of the receiving party) on a Business Day or received on a non-Business Day shall be deemed to have been received on the next Business Day. A Party
may add, delete, or change the person or address to which notices should be sent at any time upon written notice delivered to the other Parties in accordance with this Section 11.2. 

11.3    Force Majeure. A Party shall not be liable for delay or failure in the performance of any of its
obligations hereunder if such delay or failure is due to a cause beyond the reasonable control of such Party, including acts of God, fires, earthquakes, acts of war, terrorism, or civil unrest, or hurricane or other inclement weather (“Force
Majeure”); provided, however, that the affected Party promptly notifies the other Party and further provided that the affected Party shall use its commercially reasonable efforts to avoid or remove such causes of non-performance and to mitigate the effect of such occurrence, and shall continue performance in accordance with the terms of this Agreement whenever such causes are removed. When such circumstances arise, the
Parties shall negotiate in good faith any modifications of the terms of this Agreement that may be necessary or appropriate in order to arrive at an equitable solution. 

11.4    Assignment. 

11.4.1    Generally. Except as expressly permitted herein, this Agreement may not be assigned or transferred by any
Party, nor may any Party assign or transfer any rights or obligations created by this Agreement, except as expressly permitted hereunder without the prior written consent of the other Party, which consent will not be unreasonably withheld. 

11.4.2    Celgene. Notwithstanding the limitations in Section 11.4.1, and subject to Section 5.6.2 and
the remaining provisions of this Section 11.4.2, Celgene may assign or transfer 

  
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this Agreement, or any rights or obligations hereunder in whole or in part, to (a) one or more Affiliates (provided, however, that Celgene shall remain fully and unconditionally liable and
responsible to the non-assigning Party hereto for the performance and observance of all such duties and obligations by such Affiliate); or (b) its successor in interest in connection with its merger,
consolidation, or sale of all or substantially all of its assets or that portion of its business pertaining to the subject matter of this Agreement. 

11.4.3    Prothena. Notwithstanding the limitations in Section 11.4.1, and subject to Section 5.6.2 and
the remaining provisions of this Section 11.4.3, Prothena may assign or transfer this Agreement, or any rights or obligations hereunder in whole or in part, to (a) one or more Affiliates (provided, however, Prothena shall remain fully and
unconditionally liable and responsible to the non-assigning Party hereto for the performance and observance of all such duties and obligations by such Affiliate); or (b) its successor in interest in
connection with its merger, consolidation, or sale of all or substantially all of its assets. 

11.4.4    Intellectual Property of Acquirer. Notwithstanding anything to the contrary in this Agreement, if a Party
is acquired by a Third Party after the Effective Date, then with respect to any intellectual property rights controlled by the Third Party acquiring party or its affiliates (other than one of the Parties to this Agreement or its Affiliates
immediately prior to such acquisition) involved in any assignment of this Agreement by such Party to such Third Party acquirer, such intellectual property rights shall not be included in the technology and intellectual property rights licensed to
the other Party hereunder to the extent held immediately prior to such transaction by such acquirer or its affiliate (other than the relevant Party to this Agreement or its Affiliates immediately prior to such acquisition), and developed outside the
scope of activities conducted with respect to the Collaboration, any Program, any U.S. License Agreement or any Global License Agreement. The Prothena IP shall also exclude any intellectual property developed by such Third Party acquirer after such
acquisition; provided that (i) such intellectual property is developed independently of the activities under this Agreement, the Collaboration, any Program, the Collaboration Agreement, any U.S. License Agreement or any Global License Agreement
[***], (ii) Prothena and its Affiliates put in place firewalls and other protections to [***] and (iii) [***]. 

11.4.5    All Other Assignments Null and Void. The terms of this Agreement will be binding upon and will inure to
the benefit of the successors, heirs, administrators and permitted assigns of the applicable Party. Any purported assignment in violation of this Section 11.4 will be null and void ab initio. 

11.5    Waivers and Modifications. The failure of any Party to insist on the performance of any obligation
hereunder shall not be deemed to be a waiver of such obligation. Waiver of any breach of any provision hereof shall not be deemed to be a waiver of any other breach of such provision or any other provision on such occasion or any succeeding
occasion. No waiver, modification, release, or amendment of any obligation under or provision of this Agreement shall be valid or effective unless in writing and signed by the Parties. 

  
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treatment has been requested with respect to the omitted portions. 

 11.6    WAIVER OF JURY TRIAL. EXCEPT AS LIMITED BY APPLICABLE
LAW, EACH PARTY HERETO HEREBY IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM (WHETHER BASED IN CONTRACT, TORT OR OTHERWISE) ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE ACTIONS OF ANY PARTY HERETO IN
THE NEGOTIATION, ADMINISTRATION, PERFORMANCE AND ENFORCEMENT HEREOF. 
 11.7    Choice of Law; Dispute
Resolution. 
 11.7.1    Choice of Law. This Agreement shall be governed by, enforced and construed in
accordance with the laws of the State of New York without reference to any rules of conflict of laws or renvoi and excluding the United Nations Convention on Contracts for the International Sales of Goods; provided, however, that with respect to
matters involving the validity or infringement of intellectual property rights in a given country, such matter may be brought in the applicable country (in accordance with Section 11.7.3) and the Applicable Laws of the applicable country shall
apply (subject to Section 6.6.1). 
 11.7.2    Exclusive Dispute Resolution Mechanism. The Parties agree
that the procedures set forth in Section 11.7.3 will be the exclusive mechanism for resolving any dispute (whether in contract, tort or otherwise), controversy or claim between the Parties arising out of or in connection with this Agreement,
any Party’s rights or obligations under this Agreement, breach of this Agreement or the transactions contemplated by this Agreement (each, a “Dispute”); provided that decisions that are subject to the decision making authority
of a given Party, as expressly set forth in this Agreement, will not be subject to the provisions of Section 11.7.3 so long as such decisions are made in accordance with this Agreement. 

11.7.3    Jurisdiction. 

(a)    Except as otherwise set forth in this Section 11.7.3, the sole jurisdiction and venue for all actions, suits
and proceedings arising out of any Dispute (except in respect of an Excluded Claim, where jurisdiction is non-exclusive) will be the state and federal courts located in the Borough of Manhattan in New York,
New York, USA. Each Party hereby irrevocably and unconditionally (a) consents to submit to the exclusive jurisdiction of the state and federal courts located in the Borough of Manhattan in New York, New York, USA for any action, suit or
proceeding arising out of such Dispute, and (b) waives any objection to the laying of venue of any action, suit or proceeding arising out of such Dispute in the state and federal courts of the Borough of Manhattan in New York, New York, USA and
agrees not to plead or claim in any such court that any such action, suit or proceeding brought in any such court has been brought in an inconvenient forum. Each of the Parties agrees that process may be served upon it in the manner specified in
Section 11.2 and irrevocably waives and covenants not to assert or plead any objection which it might otherwise have to such jurisdiction, or to such manner of service of process. It shall be a condition precedent to the commencement of any
action in court or other tribunal (save an action for an interim injunction or provisional relief) in respect of any Dispute relating to this Agreement that the Parties have sought to resolve the Dispute by either Party notifying the other

  
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Party in writing for resolution to the Executive Officers who shall meet (whether in person or via teleconference) within [***] ([***]) [***] of such notice to seek resolution in good faith. If
the Executive Officers are unable to resolve the Dispute at such meeting, either Party may pursue any remedy available to such Party at law or in equity, subject to the terms and conditions of this Agreement, including this Section 11.7.3. 

(b)    Notwithstanding the provisions of Section 11.7.3(a), either Party may, without waiving any remedy under this
Agreement, seek from any court having jurisdiction any equitable relief, including any injunctive or provisional relief and specific performance to protect the rights or property of that Party. Such remedies will not be deemed to be the exclusive
remedies for a breach of this Agreement but will be in addition to all other remedies available at law or equity. In addition, notwithstanding the provisions of Section 11.7.3(a) either Party may bring an action in any court having jurisdiction
to enforce an award rendered pursuant to Section 11.7.3(a). 
 (c)    Until final resolution of the dispute
through judicial determination, (i) this Agreement will remain in full force and effect and (ii) the time periods for cure as to any termination will be tolled. The Parties further agree that any payments made pursuant to this Agreement
pending resolution of the dispute shall be refunded if a court determines that such payments are not due. 
 (d)    As
used in this Section 11.7, the term “Excluded Claim” means a dispute, controversy or claim that concerns (i) the validity or infringement of a Patent, trademark or copyright, or (ii) any antitrust, anti-monopoly or
competition law or regulation, whether or not statutory. 
 11.8    Relationship of the Parties. Prothena and
Celgene are independent contractors under this Agreement. Nothing contained herein is intended or is to be construed so as to constitute (a) Prothena as a partner, agent, or joint venturer of Celgene or (b) Celgene as a partner, agent or
joint venturer of Prothena. Neither Prothena nor Celgene, respectively, shall have any express or implied right or authority to assume or create any obligations on behalf of or in the name of Celgene or Prothena, respectively, or to bind Celgene or
Prothena, respectively, to any contract, agreement, or undertaking with any Third Party. 
 11.9    Third Party
Beneficiaries. There are no express or implied Third Party beneficiaries hereunder. The provisions of this Agreement are for the exclusive benefit of the Parties, and no other person or entity shall have any right or claim against any Party by
reason of these provisions or be entitled to enforce any of these provisions against any Party. 
 11.10    Entire
Agreement. This Agreement, together with the attached Exhibits and Schedules and the Master Collaboration Agreement, contains the entire agreement by the Parties with respect to the subject matter hereof and supersedes any prior express or
implied agreements, understandings and representations, either oral or written, which may have related to the subject matter hereof in any way, including any and all term sheets relating to the transactions contemplated by this Agreement and
exchanged between the Parties prior to the Effective Date. In the event of a conflict between the provisions of this Agreement and the Master Collaboration Agreement with respect to the Licensed Program, the provisions of this Agreement shall
control. 

  
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treatment has been requested with respect to the omitted portions. 

 11.11    Counterparts. This Agreement may be executed in
counterparts with the same effect as if both Parties had signed the same document. All such counterparts shall be deemed an original, shall be construed together, and shall constitute one and the same instrument. Any such counterpart, to the extent
delivered by means of a fax machine or by .pdf, .tif, .gif, .jpeg or similar attachment to electronic mail (any such delivery, an “Electronic Delivery”) shall be treated in all manner and respects as an original executed counterpart
and shall be considered to have the same binding legal effect as if it were the original signed version thereof delivered in person. No Party hereto shall raise the use of Electronic Delivery to deliver a signature or the fact that any signature or
agreement or instrument was transmitted or communicated through the use of Electronic Delivery as a defense to the formation of a contract, and each Party forever waives any such defense, except to the extent that such defense relates to lack of
authenticity. 
 11.12    Equitable Relief; Cumulative Remedies. Notwithstanding anything to the contrary herein,
the Parties shall be entitled to seek equitable relief, including injunction and specific performance, as a remedy for any breach of this Agreement. Such remedies shall not be deemed to be the exclusive remedies for a breach of this Agreement but
shall be in addition to all other remedies available at law or equity. The Parties further agree not to raise as a defense or objection to the request or granting of such relief that any breach of this Agreement is or would be compensable by an
award of money damages. No remedy referred to in this Agreement is intended to be exclusive, but each shall be cumulative and in addition to any other remedy referred to in this Agreement or otherwise available under Applicable Law. 

11.13    Interpretation. 

11.13.1    Generally. This Agreement has been diligently reviewed by and negotiated by and among the Parties, and in
such negotiations each of the Parties has been represented by competent (in-house or external) counsel, and the final agreement contained herein, including the language whereby it has been expressed,
represents the joint efforts of the Parties and their counsel. Accordingly, in interpreting this Agreement or any provision hereof, no presumption shall apply against any Party as being responsible for the wording or drafting of this Agreement or
any such provision, and ambiguities, if any, in this Agreement shall not be construed against any Party, irrespective of which Party may be deemed to have authored the ambiguous provision. 

11.13.2    Definitions; Interpretation. The definitions of the terms herein shall apply equally to the singular and
plural forms of the terms defined and where a word or phrase is defined herein, each of its other grammatical forms shall have a corresponding meaning. Whenever the context may require, any pronoun shall include the corresponding masculine,
feminine, and neuter forms. The word “will” shall be construed to have the same meaning and effect as the word “shall.” The word “any” shall mean “any and all” unless otherwise clearly indicated by context.
The words “including,” “includes,” “include,” “for example,” and “e.g.” and words of similar import will be deemed to be followed by the words “without limitation.” The word “or”
is disjunctive but not necessarily exclusive. The words “hereof,” “herein” and “herewith” and words of similar import shall, unless otherwise stated, be construed to refer to this Agreement as a whole and not to any
particular provision of this Agreement. Unless the context requires otherwise or otherwise specifically provided, (i) all references herein to Articles, Sections, Schedules or Exhibits shall be construed to refer to Articles, Sections,
Schedules and Exhibits of this Agreement and (ii) reference in any Section to any subclauses are references to such subclauses of such Section. 

  
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treatment has been requested with respect to the omitted portions. 

 11.13.3    Subsequent Events. Unless the context requires
otherwise, (i) any definition of or reference to any agreement, instrument, or other document herein shall be construed as referring to such agreement, instrument, or other document as from time to time amended, supplemented, or otherwise
modified (subject to any restrictions on such amendments, supplements, or modifications set forth herein), (ii) any reference to any Applicable Law herein shall be construed as referring to such Applicable Law as from time to time enacted, repealed,
or amended, and (iii) any reference herein to any Person shall be construed to include the Person’s successors and assigns (subject to Section 11.4). 

11.13.4    Headings. Headings, captions and the table of contents are for convenience only and are not to be used
in the interpretation of this Agreement. 
 11.13.5    Prior Drafts. No prior draft of this Agreement nor any
course of performance or course of dealing shall be used in the interpretation or construction of this Agreement. 

11.13.6    Independent Significance. Although the same or similar subject matters may be addressed in different
provisions of this Agreement, the Parties intend that, except as reasonably apparent on the face of the Agreement or as expressly provided in this Agreement, each such provision shall be read separately, be given independent significance and not be
construed as limiting any other provision of this Agreement (whether or not more general or more specific in scope, substance or content). 

11.14    Further Assurances. Each Party shall execute, acknowledge and deliver such further instruments, and do all
such other ministerial, administrative or similar acts, as may be reasonably necessary or appropriate in order to carry out the expressly stated purposes and the clear intent of this Agreement. 

11.15    Extension to Affiliates. Subject to Sections 5.6.2 and 11.4, Celgene shall have the right to extend the
rights, licenses, immunities and obligations granted in this Agreement to one or more of its Affiliates. All applicable terms and provisions of this Agreement shall apply to any such Affiliate to which this Agreement has been extended to the same
extent as such terms and provisions apply to Celgene. Celgene shall remain fully liable for any acts or omissions of such Affiliates. 

[Signature Page Follows] 

  
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treatment has been requested with respect to the omitted portions. 

 IN WITNESS WHEREOF, and intending to be legally bound hereby, the Parties have caused this GLOBAL LICENSE
AGREEMENT to be executed by their respective duly authorized officers as of the Effective Date. 
  

									
	PROTHENA BIOSCIENCES LIMITED	 		 	CELGENE SWITZERLAND LLC
					
	By:	 	
                     
                                        
	 		 	By:	 	
                     
                                        

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

  
 [Signature Page to
Global License Agreement] 
 [***] Certain information in this document has been omitted and filed separately with the Securities and
Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 Schedule 1.27 

Existing IND 

  
 i 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.28 

Existing Program Agreements  

  
 ii 

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treatment has been requested with respect to the omitted portions. 

 Schedule 1.39 

In-License Agreements and Other Third Party Agreements 

  
 iii 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.44 

Licensed Program Antibodies 

  
 iv 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.47(b) 

Licensed Program Patents 

  
 v 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.49 

Licensed Target 

  
 vi 

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treatment has been requested with respect to the omitted portions. 

 Schedule 1.63 

Prothena Licensed Collaboration Patents 

  
 vii 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.65 

Prothena Platform Technology 

[***] 

  
 viii 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 8.2 

Exceptions to Prothena Representations and Warranties 

  
 ix 

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treatment has been requested with respect to the omitted portions. 

 Schedule 8.4 

Exceptions to Celgene Representations and Warranties 

  
 x 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Exhibit B 

Form of U.S. License Agreement 

(See Attached) 

  
 [***] Certain information
in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 U.S. LICENSE AGREEMENT 

by and among 
 PROTHENA
BIOSCIENCES LIMITED 
 and 

CELGENE SWITZERLAND LLC 

Dated as of             , 20     

  
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treatment has been requested with respect to the omitted portions. 

 TABLE OF CONTENTS1 

 

					
	 	  	  
	 
		  			
		  			

  
  

	1 	 To be inserted in final version. 

  
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treatment has been requested with respect to the omitted portions. 

 LIST OF SCHEDULES2 

 

			
	 SCHEDULE 1.28
	 	 EXISTING PROGRAM AGREEMENTS

	 SCHEDULE 1.40
	 	 IN-LICENSE AGREEMENTS AND OTHER THIRD PARTY
AGREEMENTS

	 SCHEDULE 1.45
	 	 LICENSED PROGRAM ANTIBODIES

	 SCHEDULE 1.47(b)
	 	 LICENSED PROGRAM PATENTS

	 SCHEDULE 1.49
	 	 LICENSED TARGET

	 SCHEDULE 1.64
	 	 PROTHENA LICENSED COLLABORATION PATENTS

	 SCHEDULE 1.66
	 	 PROTHENA PLATFORM TECHNOLOGY

	 SCHEDULE 8.2
	 	 EXCEPTIONS TO PROTHENA REPRESENTATIONS AND WARRANTIES

	 SCHEDULE 8.4
	 	 EXCEPTIONS TO CELGENE REPRESENTATIONS AND WARRANTIES

  

	2 	 All Schedules to be completed prior to execution of the Agreement. 

  
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treatment has been requested with respect to the omitted portions. 

 U.S. LICENSE AGREEMENT 

This U.S. LICENSE AGREEMENT (this “Agreement”) is entered into and made effective as of
             , 20     (the “Effective Date”) by and between Prothena Biosciences Limited, an Irish limited company (“Prothena”)
and Celgene Switzerland LLC, a Delaware limited liability company (“Celgene”)3. Celgene and Prothena are each referred to herein by name or as a “Party”
or, collectively, as the “Parties”. 
 RECITALS 

WHEREAS, Prothena and Celgene entered into that certain Master Collaboration Agreement, dated as of March 19, 2018 (the
“Master Collaboration Agreement”), pursuant to which, among other things, Prothena has conducted research and development programs with respect to certain targets (each, a “Program”) and Celgene has an exclusive
option to obtain an exclusive license to research, develop, manufacture and commercialize Antibodies that Target such targets; 

WHEREAS, pursuant to the terms of the Master Collaboration Agreement, upon exercise by Celgene of its IND Option (as defined in the
Master Collaboration Agreement) with respect to a given Program, the Parties are obligated to enter into a U.S. License Agreement with respect to such Program; and 

WHEREAS, Celgene has exercised its IND Option (as def in the Master Collaboration Agreement) with respect to the Licensed Program, and,
as such, the Parties are entering into this Agreement pursuant to which, among other things, Prothena grants to Celgene exclusive rights and licenses with respect to the research, development, manufacture and commercialization of Licensed Antibodies
and Licensed Products in the Territory, on the terms and subject to the conditions set forth herein. 
 NOW, THEREFORE, in
consideration of the foregoing and the mutual agreements set forth below, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties hereby agree as follows: 

ARTICLE 1. 
 DEFINITIONS

 Unless specifically set forth to the contrary herein, the following terms shall have the respective meanings set forth below. Capitalized terms used,
but not defined, herein will have the meanings ascribed to them in the Master Collaboration Agreement. 

1.1    “Accounting Standards” means U.S. generally accepted accounting principles
(“GAAP”) or, to the extent that Celgene adopts International Financial Reporting Standards (“IFRS”), then “Accounting Standards” shall mean IFRS, in either case consistently applied. 

 
  

	3 	 [***] 

  
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treatment has been requested with respect to the omitted portions. 

 1.2    “Affiliate” means any Person which, directly or
indirectly through one or more intermediaries, controls, is controlled by or is under common control with a Party. For purposes of this definition, the term “control” (including, with correlative meanings, the terms “controlled
by” and “under common control with”) as used with respect to a Person means (a) direct or indirect ownership of fifty percent (50%) or more of the voting securities or other voting interest of any Person (including attribution
from related parties), or (b) the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of such Person, whether through ownership of voting securities, by contract, as a general
partner, as a manager, or otherwise. 
 1.3    “Annual Net Sales” means, on a Licensed Product-by-Licensed Product basis, total Net Sales by Celgene, its Affiliates and Sublicensees in the Territory of such Licensed Product in a particular Calendar Year,
calculated in accordance with Accounting Standards consistently applied. 
 1.4    “Antibody” means any
[***] antibody (including [***]), [***] whether human, humanized, chimeric, murine, synthetic or from any other source. 

1.5    “Applicable Law” or “Applicable Laws” means all applicable laws, statutes,
rules, regulations, orders, judgments or ordinances having the effect of law of any national, multinational, federal, state, provincial, county, city or other political subdivision, including, to the extent applicable, GCP, GLP and GMP, as well as
all applicable data protection and privacy laws, rules and regulations, including, to the extent applicable, the United States Department of Health and Human Services privacy rules under the Health Insurance Portability and Accountability Act
(“HIPAA”) and the Health Information Technology for Economic and Clinical Health Act and the EU Data Protection Directive (Council Directive 95/46/EC) and applicable laws implementing the EU Data Protection Directive and, when in
force, the General Data Protection Regulation (2016/679). 
 1.6    “Biomarker” means a parameter or
characteristic in a patient or Patient Sample, the measurement of which is useful (a) for purposes of selecting appropriate therapies or patient populations or monitoring disease susceptibility, severity or state, or monitoring therapies for
such patient and/or (b) for predicting the outcome of a particular treatment of such patient. 

1.7    “Biosimilar Application” means an application or submission filed with a Regulatory Authority for
marketing authorization of a Biosimilar Product. 
 1.8    “Biosimilar Product” means,
with respect to a given Licensed Product, a biological product (a) that contains (i) an identical active ingredient(s) as the Licensed Antibody in such Licensed Product, or (ii) a “highly similar” active ingredient(s) to the
Licensed Antibody in such Licensed Product, as the phrase “highly similar” is used in 42 U.S.C. § 262(i)(2), and subject to the factors set forth in FDA’s Guidance for Industry, “Quality Considerations in Demonstrating
Biosimilarity to a Reference Protein Product,” (February 2012), at Section VI, or 

  
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any successor FDA guidance thereto, (b) for which Regulatory Approval is obtained by referencing Regulatory Materials of such Licensed Product, (c) is approved for use in such country
(or region) pursuant to a Regulatory Approval process governing approval of interchangeable or biosimilar biologics as described in 42 U.S.C. §§ 262, or a similar process for Regulatory Approval in any country (or region) outside the
United States, or any other similar provision that comes into force, or is the subject of a notice with respect to such Licensed Product under 42 U.S.C. § 262(l)(2) or any other similar provision that comes into force in such country (or
region), and (d) is sold in the same country as such Licensed Product by any Third Party that is not a Sublicensee of Celgene or its Affiliates with respect to the Prothena IP and did not purchase such product in a chain of distribution that
included any of Celgene or any of its Affiliates or its Sublicensees. 
 1.9    “BPCIA” means Biologics
Price Competition and Innovation Act of 2009, as amended. 
 1.10    “Business Day” means a day on
which banking institutions in New York City, New York, are open for business, excluding any Saturday or Sunday. 

1.11    “Calendar Quarter” means the period beginning on the Effective Date and ending on the last day of
the calendar quarter in which the Effective Date falls, and thereafter each successive period of three (3) consecutive calendar months ending on the last day of March, June, September, or December, respectively; provided that the final Calendar
Quarter shall end on the last day of the Term. 
 1.12    “Calendar Year” means the period beginning on
the Effective Date and ending on December 31 of the calendar year in which the Effective Date falls, and thereafter each successive period of twelve (12) consecutive calendar months beginning on January 1 and ending on December 31;
provided that the final Calendar Year shall end on the last day of the Term. 
 1.13    “Celgene IP”
means Patents and Know-How owned or otherwise controlled (through license or otherwise, but excluding through grant of a license from Prothena to Celgene pursuant to this Agreement) by Celgene or any of its
Affiliates (including any Know-How that is, created, conceived, discovered, first generated, invented, first made or first reduced to practice by or on behalf of Celgene or any of its Affiliates pursuant to
the conduct of activities under this Agreement). For the avoidance of doubt, Celgene IP excludes (i) Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced
to practice by or on behalf of Prothena, solely or jointly with a Third Party; (ii) Joint Program IP (as defined under the Master Collaboration Agreement); (iii) [***], and (iv) Joint IP. 

1.14    “Celgene Phase 1 Portion Participation Right” means the Celgene Phase 1 Portion Participation
Right (as defined in the Master Collaboration Agreement) for the Licensed Program. 
 1.15    “Change of
Control” in respect of a Person (an “Acquired Person”) shall be deemed to have occurred upon any of the following occurring after the Effective Date: (i) any Person or group of Persons that is not an Affiliate of such
Acquired Person becomes the beneficial 

  
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owner (directly or indirectly) of more than fifty percent (50%) of the voting shares; (ii) such Acquired Person consolidates with or merges into or with another Person that is not an
Affiliate of such Acquired Person pursuant to a transaction in which more than fifty percent (50%) of the voting shares of the acquiring or resulting entity outstanding immediately after such consolidation or merger is not held by the holders of the
outstanding voting shares of such Acquired Person immediately preceding such consolidation or merger; and/or (iii) that Acquired Person sells or transfers to another Person that is not an Affiliate of such Acquired Person all or substantially
all of its assets. 
 1.16    “Clinical Trial” means a human clinical trial, including any Phase 1
Clinical Trial, Phase 2 Clinical Trial or Registration Enabling Clinical Trial, any study incorporating more than one of these phases, or any human clinical trial commenced after Regulatory Approval. 

1.17    “Commercialization” means any and all activities directed to the commercialization of a product
(which may include related diagnostic products, if applicable), including commercial manufacturing (including Manufacturing) and commercial supply of a product, marketing, detailing, promotion, market research, distributing, order processing,
handling returns and recalls, booking sales, customer service, administering and commercially selling such product, importing, exporting and transporting such product for commercial sale, and seeking of pricing and reimbursement of a product (if
applicable), whether before or after Regulatory Approval has been obtained (including making, having made, using, importing, selling and offering for sale such product (or related diagnostic product, if applicable)), as well all regulatory
compliance with respect to the foregoing. For clarity, “Commercialization” does not include any Clinical Trial commenced after Regulatory Approval. When used as a verb, “Commercialize” means to engage in Commercialization.

 1.18    “Commercially Reasonable Efforts” means, with respect to Celgene in relation to an
obligation under this Agreement with respect to a Licensed Antibody or Licensed Product, such efforts that are consistent with the efforts and resources normally used by Celgene in the exercise of its commercially reasonable business practices
relating to performance of an obligation for a similar pharmaceutical compound or product (including the research, development, manufacture and commercialization of a pharmaceutical compound or product), as applicable, at a similar stage in its
research, development or commercial life as the relevant Licensed Antibody or Licensed Product, and that has commercial and market potential similar to the relevant Licensed Antibody or Licensed Product, taking into account issues of intellectual
property coverage, safety and efficacy, stage of development, product profile, competitiveness of the marketplace, proprietary position, regulatory exclusivity, anticipated or approved labeling, present and future market and commercial potential,
the likelihood of receipt of Regulatory Approval, profitability (including pricing and reimbursement status achieved or likely to be achieved), amounts payable to licensors of patents or other intellectual property rights, [***], and legal issues.

 1.19    “Confidential Information” means, with respect to a Party, all confidential and proprietary
information and materials, including Know-How, marketing plans, strategies, and customer lists, in each case, that are disclosed by or on behalf of such Party to the other Party pursuant to this Agreement,
regardless of whether any of the foregoing are marked “confidential” or “proprietary” or communicated to the other Party by or on behalf of the disclosing Party in oral, written, visual, graphic or electronic form. 

  
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treatment has been requested with respect to the omitted portions. 

 1.20    “Control”, “Controls” or
“Controlled” means, with respect to any intellectual property (including Know-How) or Confidential Information, the ability of a Party or its Affiliates, as applicable, (whether through
ownership or license (other than a license granted in this Agreement)) to grant to the other Party the licenses or sublicenses as provided herein, or to otherwise disclose such intellectual property or Confidential Information to the other Party,
without violating the terms of any then-existing agreement with any Third Party at the time such Party or its Affiliates, as applicable, would be required hereunder to grant the other Party such license or sublicenses as provided herein or to
otherwise disclose such intellectual property or Confidential Information to the other Party. 

1.21    “Cover”, “Covering” or “Covered” means, with reference to a
Patent claim, that such Patent claim has a Valid Claim that claims the [***], and that the sale of a Licensed Antibody (or product incorporating such Licensed Antibody) would infringe such Valid Claim in the country in which such activity occurs
without a license thereto (or ownership thereof); provided, that with respect to method of use, such method of use is for an Indication for which Regulatory Approval has been received (as set forth on the approved labeling for the applicable
Licensed Product incorporating such Licensed Antibody) for such Licensed Antibody in such country. 

1.22    “Derivative” means, with respect to a Licensed Target, all [***] thereof. 

1.23    “Development” means (i) research activities (including drug discovery, identification and/or
synthesis) with respect to a product (which may include related diagnostic products, if applicable), and/or (ii) preclinical and clinical drug development activities, and other development activities, with respect to a product (which may
include related diagnostic products, if applicable), including test method development and stability testing, toxicology, formulation, process development, qualification and validation, manufacture scale-up,
development-stage manufacturing (including Manufacturing), quality assurance/quality control, Clinical Trials (including Clinical Trials and other studies commenced after Regulatory Approval), statistical analysis and report writing, the preparation
and submission of INDs and MAAs, regulatory affairs with respect to the foregoing and all other activities necessary or useful or otherwise requested or required by a Regulatory Authority or as a condition or in support of obtaining or maintaining a
Regulatory Approval. When used as a verb, “Develop” means to engage in Development. 

1.24    “Diagnostic Product” means, on a Licensed Product-by-Licensed Product basis, any diagnostic product (which may include a Licensed Antibody or Licensed Product being used as a diagnostic product) which is necessary or reasonably useful (a) for
the [***] in a patient or Patient Sample, and/or (b) to [***] in a patient or Patient Sample, and/or (c) to [***] to achieve improved safety or effectiveness, in each case of (a), (b) and (c), which is intended for use or is Developed or
approved for use in connection with a therapeutic Licensed Antibody or Licensed Product (which may include [***]).  

  
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 1.25    “Dollars” or “$” means the
legal tender of the United States. 
 1.26    “EU” means all countries that are officially recognized
as member states of the European Union at any particular time. 
 1.27    “Executive Officers” means
Prothena’s Chief Executive Officer and Celgene’s Executive Vice President, Research and Early Development (or such Executive Vice President’s designee). 

1.28    “Existing Program Agreements” means any agreement between Prothena (or its Affiliates, as
applicable) and any Third Party solely related to the Development or Manufacture of any Licensed Antibodies or Licensed Products, in effect as of the Effective Date, as set forth on Schedule 1.28. 

1.29    “Field” means any and all uses or purposes, including the treatment, prophylaxis, palliation,
diagnosis or prevention of any human or animal disease, disorder or condition. 
 1.30    “First Commercial
Sale” means, on a Licensed Product-by-Licensed Product basis in the Territory, the first sale of such Licensed Product in the Territory for use or consumption
by the general public (following receipt of all Regulatory Approvals that are required in order to sell such Licensed Product in the Territory) and for which any of Celgene or its Affiliates or Sublicensees has invoiced sales of Licensed Products in
the Territory; provided, however, that the following shall not constitute a First Commercial Sale: (a) any sale to an Affiliate or Sublicensee, unless the Affiliate or Sublicensee is the last Person in the distribution chain of the Licensed
Product; or (b) any use of such Licensed Product in Clinical Trials or non-clinical development activities with respect to such Licensed Product by or on behalf of a Party, or disposal or transfer of such
Licensed Product for a bona fide charitable purpose, compassionate use or samples. 
 1.31    “Global License
Agreement” means each Global License Agreement entered into between the Parties (or their respective Affiliates, as applicable) pursuant to the Master Collaboration Agreement. 

1.32    “Good Clinical Practices” or “GCP” means the applicable then-current ethical and
scientific quality standards for designing, conducting, recording, and reporting trials that involve the participation of human subjects as are required by applicable Regulatory Authorities or Applicable Law in the relevant jurisdiction, including
in the United States, Good Clinical Practices established through FDA guidances, and, outside the United States, Guidelines for Good Clinical Practice – ICH Harmonized Tripartite Guideline (ICH E6). 

1.33    “Good Laboratory Practices” or “GLP” means the applicable then-current good
laboratory practice standards as are required by applicable Regulatory Authorities or Applicable Law in the relevant jurisdiction, including in the United States, those promulgated or endorsed by the FDA in U.S. 21 C.F.R. Part 58, or the equivalent
thereof as promulgated or endorsed by the applicable Regulatory Authorities outside of the United States. 

  
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treatment has been requested with respect to the omitted portions. 

 1.34    “Good Manufacturing Practices” or
“GMP” means all applicable standards relating to manufacturing practices for fine chemicals, intermediates, bulk products and/or finished pharmaceutical products, as are required by applicable Regulatory Authorities or Applicable
Law in the relevant jurisdiction, including, as applicable, (a) all applicable requirements detailed in the FDA’s current Good Manufacturing Practices regulations, U.S. 21 C.F.R. Parts 210 and 211, (b) all applicable requirements detailed
in the EMA’s “The Rules Governing Medicinal Products in the European Community, Volume IV, Good Manufacturing Practice for Medicinal Products”, and (c) all Applicable Laws promulgated by any Governmental Authority having
jurisdiction over the manufacture of the applicable compound or pharmaceutical product, as applicable. 

1.35    “Governmental Authority” means any (a) federal, state, local, municipal, foreign or other
government, (b) governmental or quasi-governmental authority of any nature (including any governmental division, subdivision, department, agency, bureau, branch, office, commission, council, board, instrumentality, officer, official,
representative, organization, unit, body or entity and any court or other tribunal), (c) multinational governmental organization or body or (d) entity or body exercising, or entitled to exercise, any executive, legislative, judicial,
administrative, regulatory, police, military or taxing authority or power of any nature. 

1.36    “IND” means an investigational new drug application (including any amendment or supplement
thereto) submitted to the FDA pursuant to U.S. 21 C.F.R. Part 312, including any amendments thereto. References herein to IND shall include, to the extent applicable, any comparable filing(s) outside the U.S. for the investigation of any product in
any other country or group of countries (such as a Clinical Trial Application in the EU). 
 1.37    “IND Option
Exercise Fee” shall mean the IND Option Exercise Fee (as defined in the Master Collaboration Agreement) for the Licensed Program. 

1.38    “Indication” means an entirely separate and distinct disease or medical condition in humans (i)
[***], and/or (ii) [***]. For clarity, (a) [***], (b) [***] and (c) [***]. 
 1.39    “Initiation”
means, with respect to a given Clinical Trial, the administration of the first dose of Licensed Product to the first properly enrolled subject in such Clinical Trial in accordance with the protocol for such Clinical Trial. 

1.40    “In-License Agreements” means any agreement between
Prothena (or its Affiliates, as applicable) and any Third Party pursuant to which such Third Party licenses to Prothena (or its Affiliates, as applicable) any Patents or Know-How included in the Prothena IP,
including those set forth on Schedule 1.40. 

  
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treatment has been requested with respect to the omitted portions. 

 1.41    
“Know-How” means all proprietary (a) information, techniques, technology, practices, trade secrets, inventions, methods (including methods of use or administration or dosing), knowledge,
data, results and software and algorithms, including pharmacological, toxicological and clinical test data and results, compositions of matter, chemical structures and formulations, sequences, processes, formulae, techniques, research data, reports,
standard operating procedures, batch records, manufacturing data, analytical and quality control data, analytical methods (including applicable reference standards), assays and research tools, in each case, whether patentable or not; and
(b) tangible manifestations thereof, including any and all of the foregoing relating to Licensed Program Biological and Chemical Materials. 

1.42    “Licensed Antibody” means (a) any Licensed Program Antibody and (b) any other Antibody
that is a variant, fragment, derivative or other modification of a Licensed Program Antibody that (i) Targets the Licensed Target, (ii) is made by or on behalf of Celgene or its Affiliates or Sublicensees during the Term in the course of
its activities performed under this Agreement and (iii) is claimed (or was claimed in an issued Patent that has subsequently expired) as a composition of matter in a Licensed Program Patent set forth on Schedule 1.47(b), Prothena
Licensed Collaboration Patent set forth on Schedule 1.64, or Joint Program Patent (as defined in the Master Collaboration Agreement) as applicable, or any substitutions, divisionals, continuations, continuations-in-part, reissues, renewals, registrations, confirmations, re-examinations, extensions, supplementary protection certificates and the like of any such
Licensed Program Patents, Prothena Licensed Collaboration Patents or Joint Program Patents (as defined in the Master Collaboration Agreement). 

1.43    “Licensed Product” means any product that constitutes, incorporates, comprises or contains a
Licensed Antibody, whether or not as the sole active ingredient, and in all forms, presentations, and formulations (including manner of delivery and dosage). For clarity, different forms, formulations, presentations or dosage strengths of a given
Licensed Product that constitute, incorporate, comprise or contain the same Licensed Antibody shall be considered the same Licensed Product for purposes of this Agreement. Licensed Products shall include, in all cases, any Licensed Program Product.

 1.44    “Licensed Program” means the Development program undertaken by or on behalf of Prothena
pursuant to the Master Collaboration Agreement with respect to the Licensed Target. 
 1.45    “Licensed
Program Antibody” means, with respect to the Licensed Program, (i) the Collaboration Candidates (as defined in the Master Collaboration Agreement) that Target the Licensed Target that were Developed under such Licensed Program pursuant
to the Master Collaboration Agreement, including those as set forth on Schedule 1.45 and (ii) all Related Antibodies with respect to any Antibody described in the foregoing clause (i) provided that such Related Antibodies are
claimed (or were claimed in an issued Patent that has subsequently expired) as a composition of matter in a Licensed Program Patent set forth on Schedule 1.47(b), a Prothena Licensed Collaboration Patent set forth on Schedule 1.64, or
a Joint Program Patent (as defined in the Master Collaboration Agreement) as applicable, or any substitutions, divisionals, continuations, continuations-in-part,
reissues, renewals, registrations, confirmations, 

  
 11 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
re-examinations, extensions, supplementary protection certificates and the like of any such Licensed Program Patents or Prothena Licensed Collaboration Patents. For the avoidance of doubt,
Licensed Program Antibodies are included within the definition of Licensed Antibody. 
 1.46    “Licensed
Program Biological and Chemical Materials” means, with respect to the Licensed Program, any and all compositions of matter, cells, cell lines, assays, animal models, imaging agents, Patient Samples, Biomarkers and any other physical,
biological or chemical material, that are Controlled by Prothena or its Affiliates and [***] the Licensed Target or Licensed Program Antibodies (or the Development, Manufacture or Commercialization thereof), including physical embodiments of the
Licensed Program Antibodies and any diagnostics related to such Licensed Program Antibodies, in each case, (i) created, conceived, discovered, first generated, invented, first made or first reduced to practice by or on behalf of Prothena or its
Affiliates, whether solely or jointly with any Third Party, in such Licensed Program under the Master Collaboration Agreement or (ii) otherwise utilized by or on behalf of Prothena or its Affiliates in the Licensed Program under the Master
Collaboration Agreement. To the extent the Licensed Program Biological and Chemical Materials were created, conceived, discovered, first generated, invented, first made or first reduced to practice under the Licensed Program under the Master
Collaboration Agreement, such Licensed Program Biological and Chemical Materials shall be “Licensed Program Know-How” hereunder, and to the extent the Licensed Program Biological and Chemical
Materials were not created, conceived, discovered, first generated, invented, first made or first reduced to practice under the Licensed Program under the Master Collaboration Agreement, but were otherwise utilized in the development of the Licensed
Program under the Master Collaboration Agreement, such Licensed Program Biological and Chemical Materials shall be “Prothena Licensed Collaboration Know-How” hereunder. 

1.47    “Licensed Program IP” means, collectively: 

(a)    “Licensed Program Know-How” which means any and all Know-How that was created, conceived, discovered, first generated, invented, first made or first reduced to practice, in each case (i) by or on behalf of [***], (ii) by or on behalf of [***], or (iii) by
or on behalf of [***]. For the avoidance of doubt, Licensed Program Know-How (i) includes ‘Program Know-How’ (as defined in the Master Collaboration
Agreement) related to the Licensed Program but (ii) expressly excludes any Know-How created, conceived, discovered, first generated, invented, first made or first reduced to practice in the course of
activities performed under this Agreement and any Joint Program Know-How (as defined in the Master Collaboration Agreement); and 

  
 12 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (b)    “Licensed Program Patents” which means any
Patents in the Territory Controlled by Prothena or its Affiliates that claim or cover any Licensed Program Know-How, including the Patents set forth on Schedule 1.47(b). For the avoidance of
doubt, Licensed Program Patents, include ‘Program Patents’ (as defined in the Master Collaboration Agreement) related to the Licensed Program, but expressly exclude Joint Program Patents (as defined in the Master Collaboration Agreement).

 1.48    “Licensed Program Product” means, with respect to the Licensed Program, any product that
constitutes, incorporates, comprises or contains a Licensed Program Antibody, whether or not as the sole active ingredient, and in all forms, presentations, and formulations (including manner of delivery and dosage). For clarity, different forms,
formulations, presentations or dosage strengths of a given Licensed Program Product that constitutes, incorporates, comprises or contains the same Licensed Program Antibody shall be considered the same Licensed Program Product for purposes of this
Agreement. For the avoidance of doubt, Licensed Program Products are included within the definition of Licensed Products. 

1.49    “Licensed Target” means the target set forth on Schedule 1.49, including
Derivatives thereof. 
 1.50    “Manufacture” means all activities related to the manufacturing of a
product or diagnostic product or, in either case, any component or ingredient thereof, including test method development and stability testing, formulation, process development, manufacturing scale-up whether
before or after Regulatory Approval, manufacturing any product or diagnostic product in bulk or finished form for Development or Commercialization (as applicable), including filling and finishing, packaging, labeling, shipping and holding, in-process and finished product testing, release of a product or diagnostic product or, in either case, any component or ingredient thereof, quality assurance and quality control activities related to manufacturing
and release of a product or diagnostic product, and regulatory activities related to any of the foregoing. 

1.51    “Marketing Authorization Application” or “MAA” means a Marketing Authorization
Application, Biologics License Application or similar application, as applicable, and all amendments and supplements thereto, submitted to the FDA, or any equivalent filing in a country or regulatory jurisdiction other than the U.S. with the
applicable Regulatory Authority, to obtain marketing approval for a pharmaceutical or diagnostic product, in a country or in a group of countries. 

1.52    “Net Sales” means, in respect of a given Licensed Product, the total [***] amounts [***] for all
sales of such Licensed Product in the Territory for use in the Field by Celgene, its Affiliates or Sublicensees to Third Party customers (including to distributors), less the following deductions [***] so as to arrive at “net sales” under
Accounting Standards as reported by Celgene, its Affiliates or Sublicensees, as applicable, in such Person’s financial statements: 

(a)    [***]; 

  
 13 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (b)    [***]; 

(c)    [***]; 

(d)    [***]; and 

(e)    [***]. 
 There shall
be no double counting in determining the foregoing deductions from gross amounts invoiced to calculate Net Sales. The calculations set forth in this definition of “Net Sales” shall be determined in accordance with Accounting Standards.

 Sales or other transfers between Celgene and its Affiliates or Sublicensees, as well as any transfers or dispositions of any Licensed Products for (i)
[***], (ii) [***], (iii) [***] or (iv) [***], in each case, shall be excluded from the computation of Net Sales. 
 The calculations set forth in this
section shall be determined in accordance with Accounting Standards. If any Licensed Product is, or is sold as part of, a Combination Product, Net Sales shall be calculated assuming that the gross sale price of each unit is equal to the product of
(i) Net Sales of the Combination Product calculated as above (i.e., calculated as for a non-Combination Product), and (ii) the fraction [***], where: [***] 

  
 14 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 For purposes of this definition, “Combination Product” means any pharmaceutical product
that (a) contains two or more active ingredients, including both (1) a Licensed Antibody and (2) one or more other compounds (which may be Antibodies) but that are not a Licensed Antibody, either as a fixed dose product, co-formulated product or co-packaged product, and sold for a single price, and (b) is Developed or Commercialized, alone or together with a Third Party, by Celgene or any
of its Affiliates or Sublicensees. Any vehicles, adjuvants and excipients used in conjunction with any Licensed Antibody shall not be treated as active ingredients for the purposes of this definition. 

1.53    “Patents” means (a) all patents and patent applications in any country or supranational
jurisdiction worldwide, (b) any substitutions, divisionals, continuations, continuations-in-part, reissues, renewals, registrations, confirmations, re-examinations, extensions, supplementary protection certificates and the like of any such patents or patent applications, and (c) foreign counterparts of any of the foregoing. 

1.54    “Patient Sample” means tissue, fluid, or cells collected from a patient, or components of the
foregoing. 
 1.55    “Person” means any individual, partnership, joint venture, limited liability
company, corporation, firm, trust, association, unincorporated organization, governmental authority or agency, or any other entity not specifically listed herein. 

1.56    “Phase 1 Clinical Trial” means a human clinical trial of a product that would satisfy the
requirements of U.S. 21 C.F.R. Part 312.21(a) (as amended), or a similar clinical study prescribed by the Regulatory Authorities in a foreign country, and is intended to (a) determine the safety, pharmacokinetics and pharmacodynamic parameters
in healthy individuals or patients, and (b) following the foregoing clause (a), further evaluate safety and pharmacokinetics (including exploration of trends of a biomarker-based or clinical endpoint-based efficacy relationship to dose which
need not be designed to be statistically significant) of the product, whether or not in combination with concomitant treatment and which provides sufficient evidence of safety to be included in filings for a Phase 2 Clinical Trial or a Registration
Enabling Clinical Trial with Regulatory Authorities. 
 1.57    “Phase 1 Option” shall mean the Phase 1
Option (as defined in the Master Collaboration Agreement) for the Licensed Program. 
 1.58    “Phase 1 Option
Term” shall mean the Phase 1 Option Term (as defined in the Master Collaboration Agreement) for the Licensed Program. 

1.59    “Phase 2 Clinical Trial” means a human clinical trial of a product that would satisfy the
requirements of U.S. 21 C.F.R. Part 312.21(b), as amended, and is intended to explore a variety of doses, dose response, and duration of effect, and to generate evidence of clinical safety and effectiveness for a particular Indication or Indications
in a target patient population, or a similar clinical study prescribed by the relevant Regulatory Authorities in a country other than the United States. 

1.60    “Prosecution and Maintenance” or “Prosecute and Maintain” means, with regard to
a Patent, the preparation, filing, prosecution and maintenance of such Patent, as well as re-examinations, reissues, appeals, and requests for patent term adjustments and patent term

  
 15 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
extensions with respect to such Patent, together with the initiation or defense of interferences, oppositions, inter partes review, derivations,
re-examinations, post-grant proceedings and other similar proceedings (or other defense proceedings with respect to such Patent, but excluding the defense of challenges to such Patent as a counterclaim in an
infringement proceeding) with respect to the particular Patent, and any appeals therefrom. For clarification, “Prosecution and Maintenance” or “Prosecute and Maintain” shall not include any other enforcement actions taken with
respect to a Patent. 
 1.61    “Prothena IP” means the Prothena Licensed Collaboration Patents, the
Prothena Licensed Collaboration Know-How, the Licensed Program Patents and the Licensed Program Know-How, as well as Prothena’s (and its Affiliates’) right,
title and interest in and to the Joint IP and any Joint Program IP (as defined under the Master Collaboration Agreement). 

1.62    “Prothena Licensed Collaboration IP” means all Prothena Licensed Collaboration Know-How and Prothena Licensed Collaboration Patents 
 1.63    “Prothena
Licensed Collaboration Know-How” means any and all Know-How that is Controlled by Prothena or its Affiliates on or after the Effective Date that (a) is
necessary or [***] to research, develop, make, have made, import, use, offer to sell, sell or otherwise exploit any [***], Licensed Program Antibody or Licensed Program Product or (b) is or was [***], including (i) any diagnostics related
to any such Licensed Program Antibody or Licensed Program Product and (ii) Know-How conceived, created discovered, first generated, invented, first made or first reduced to practice by or on behalf of a
Prothena or its Affiliates, whether solely or jointly with any Third Party, in the course of activities performed under this Agreement; but expressly excluding Joint Know-How, Joint Program Know-How (as defined in the Master Collaboration Agreement) and Licensed Program Know-How. 

1.64    “Prothena Licensed Collaboration Patents” means any and all Patents in the Territory that are
Controlled by Prothena or its Affiliates on or after the Effective Date that claim or cover (a) any Licensed Target, any Licensed Program Antibody or any Licensed Program Product, or the research, development, making, having made, import, use,
offering to sell, selling or other exploitation of any of the foregoing, or (b) any Prothena Licensed Collaboration Know-How; but expressly excluding Joint Patents, Joint Program Patents (as defined in
the Master Collaboration Agreement) and Licensed Program Patents. Prothena Licensed Collaboration Patents shall include the Patents set forth on Schedule 1.64. 

1.65    “Prothena Platform Patent” means a Patent within the Prothena Licensed Collaboration Patents that
[***] claims the Prothena Platform Technology. 
 1.66    “Prothena Platform Technology” means [***],
which shall [***]; but in any case excluding [***]. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 1.67    “Registration Enabling Clinical Trial” means
(a) a human clinical trial of a product that would satisfy the requirements of U.S. 21 C.F.R. Part 312.21(c), as amended, and is intended to (i) establish that the product is safe and efficacious for its intended use, (ii) define
contraindications, warnings, precautions and adverse reactions that are associated with the product in the dosage range to be prescribed, and (iii) support Regulatory Approval for such product, or (b) a similar clinical study prescribed by
the relevant Regulatory Authorities in a country other than the United States. 
 1.68    “Regulatory
Approval” means all approvals, licenses and authorizations of the applicable Regulatory Authority necessary for the marketing and sale of a pharmaceutical or diagnostic product for a particular Indication in a country or region (including
separate pricing or reimbursement approvals, as necessary), and including the approvals by the applicable Regulatory Authority of any expansion or modification of the label for such Indication. 

1.69    “Regulatory Authority” means any national or supranational Governmental Authority, including the
U.S. Food and Drug Administration (and any successor entity thereto) (the “FDA”) in the U.S., the European Medicines Agency (and any successor entity thereto) (the “EMA”) in the EU and the Ministry of Health, Labour
and Welfare of Japan, or the Pharmaceuticals and Medical Devices Agency of Japan (or any successor to either of them) as the case may be (the “MHLW”) in Japan, or any health regulatory authority in any country or region that is a
counterpart to the foregoing agencies, in each case, that holds responsibility for development and commercialization of, and the granting of Regulatory Approval for, a pharmaceutical or diagnostic product, as applicable, in such country or region.

 1.70    “Regulatory-Based Exclusivity” means, on a Licensed Product-by-Licensed Product basis in the Territory, that Celgene or any of its Affiliates or Sublicensees has been granted the exclusive legal right by a Regulatory Authority in the Territory to market and
sell the Licensed Product in the Territory, in each case, such that market exclusivity is maintained for Celgene (or its Affiliate or Sublicensee, as applicable) in the Territory with respect to such Licensed Product as a result of such grant by
such Regulatory Authority. 
 1.71    “Regulatory Materials” means the regulatory registrations,
applications, authorizations and approvals (including approvals of MAAs, supplements and amendments, pre- and post-approvals, pricing and reimbursement approvals, and labeling approvals), Regulatory Approvals
and other submissions made to or with any Regulatory Authority for research, development (including the conduct of Clinical Trials), manufacture, or commercialization of a pharmaceutical or diagnostic product in a regulatory jurisdiction, together
with all related correspondence to or from any Regulatory Authority and all documents referenced in the complete regulatory chronology for each MAA, including all Drug Master Files (if any), INDs and supplemental biologics license applications
(sBLAs) and foreign equivalents of any of the foregoing. 
 1.72    “Related Antibody” means, with
respect to a given Antibody, any (a) [***], or (b) [***], and in each case of (a) and (b), that [***]. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 1.73    “Royalty Term” means, on a Licensed Product-by-Licensed Product basis in the Territory, the period of time commencing on the First Commercial Sale of such Licensed Product in the Territory and expiring upon the
latest of (a) the first date on which there is no Valid Claim of a Patent within the Licensed Program Patents, Prothena Licensed Collaboration Patents or Joint Program Patents (as defined in the Master Collaboration Agreement) in each case,
that Covers such Licensed Product in the Territory, (b) the expiration of Regulatory-Based Exclusivity for such Licensed Product in the Territory and (c) the ten (10) year anniversary of the date of First Commercial Sale of such
Licensed Product in the Territory. 
 1.74    “Select Indication” means each of the following separate
and distinct Indications: [***] such other Indications as the Parties may mutually agree in writing to be expressly included as a “Select Indication” for purposes of this Agreement; provided that such indication is identified as an
approved use for the applicable Licensed Product in the approved label for such Licensed Product in the applicable country. 

1.75    “Sublicensee” means, with respect to Celgene, a Third Party to whom Celgene has granted a
sublicense, either directly or indirectly, under the Prothena IP licensed to Celgene by Prothena pursuant to this Agreement, to Develop, Manufacture and/or Commercialize Licensed Antibodies and Licensed Products in the Field in the Territory, but
excluding any Third Party acting as a distributor and excluding Prothena and its Affiliates. 

1.76    “Target” means, with respect to a given Antibody and the Licensed Target, that such
Antibody [***]. For the purposes of the “Target” definition, “[***]” means [***]. 4 

1.77    “Territory” means the United States. 

1.78    “Third Party” means any Person other than Prothena or Celgene that is not an Affiliate of
Prothena or of Celgene. 
 1.79    “Third Party Claim” means any and all suits, claims, actions,
proceedings or demands brought by a Third Party. 
 1.80    “Third Party Damages” means all losses,
costs, claims, damages, judgments, liabilities and expenses payable to a Third Party by a Party (or the Prothena Indemnitees or Celgene Indemnitees, as applicable) under a Third Party Claim (including reasonable attorneys’ fees and other
reasonable out-of-pocket costs of litigation in connection therewith). 
  

 

	4 	 [***] For the purposes of the “Target” definition, “[***]” means [***]

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 1.81    “United States” or “U.S.”
means the United States of America and all of its territories and possessions. 
 1.82    “U.S. License
Agreement” shall mean each U.S. License Agreement entered into between the Parties (or their respective Affiliates, as applicable) pursuant to the Master Collaboration Agreement. When used in this Agreement, references to U.S. License
Agreements are references to U.S. License Agreements other than this Agreement. 
 1.83    “Valid
Claim” means a claim of a Patent within the Licensed Program Patents, Prothena Licensed Collaboration Patents, or Joint Program Patents (as defined in the Master Collaboration Agreement) in the Territory that has issued and has not expired,
lapsed, been cancelled or abandoned, or been dedicated to the public, disclaimed, or held unenforceable, invalid, revoked or cancelled by a court or administrative agency of competent jurisdiction in an order or decision from which no appeal has
been or can be taken, including through opposition, reexamination, reissue, disclaimer, inter partes review, post grant procedures or similar proceedings [***]. 

1.84    Additional Definitions. Each of the following terms has the meaning described in the corresponding
section of this Agreement indicated below: 
  

			
	 Definition:
	  	Section:
	 Acquired Person
	  	1.15
	 Active Immunotherapeutic Approaches
	  	4.2.1
	 Agreement
	  	Preamble
	 Celgene
	  	Preamble
	 Celgene Acquired Competing Antibody
	  	4.4.2
	 Celgene Exclusivity Term
	  	4.4.1
	 Celgene Indemnitees
	  	9.2
	 Celgene Proposed Terms
	  	4.2.2
	 Celgene Share
	  	6.8.2(d)
	 Celgene Third Party Payments
	  	5.2.4
	 Clinical Trial Preliminary Activities Outside Date
	  	10.5
	 Combination Product
	  	1.52
	 Competing Antibody
	  	4.4.1
	 Competing Compound
	  	4.1
	 Cure Period
	  	11.2.1
	 Disclosing Party
	  	7.1
	 Dispute
	  	11.7.2
	 Electronic Delivery
	  	12.11
	 Effective Date
	  	Preamble
	 EMA
	  	1.69
	 Excluded Claim
	  	11.7.3(d)
	 FDA
	  	1.69
	 [***]
	  	[***]
	 Force Majeure
	  	11.3
	 GAAP
	  	1.1
	 Grant
	  	4.2.2

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

			
	 Definition:
	  	Section:
	 Grant Notice
	  	4.2.2
	 HIPAA
	  	1.5
	 IFRS
	  	1.1
	 Indemnitee
	  	9.3
	 Indemnitor
	  	9.3
	 Indirect Taxes
	  	5.5.2(b)
	 Insolvency Event
	  	10.4
	 Joint IP
	  	6.6.4
	 Joint Know-How
	  	6.6.4
	 Joint Patents
	  	6.6.4
	 Licensed Program Assets
	  	2.5
	 Licensed Program Confidential Information
	  	7.11
	 Licensed Program Know-How
	  	1.46(a)
	 Licensed Program Non-Specific IP
	  	7.2
	 Licensed Program Patents
	  	1.46(b)
	 Licensed Program Specific IP
	  	7.2
	 Master Collaboration Agreement
	  	Recitals
	 MHLW
	  	
	 Negotiation Period
	  	4.2.2
	 [***]
	  	[***]
	 Notice Period
	  	4.2.2
	 Ongoing Prothena Development Activities
	  	2.3.3
	 Party or Parties
	  	Preamble
	 Patent Liaison
	  	6.7
	 Payee Party
	  	5.5.2(b)
	 Paying Party
	  	5.5.2(b)
	 Per Licensed Product Annual Net Sales
	  	5.2.1
	 Program
	  	Recitals
	 Prothena
	  	Preamble
	 Prothena Indemnitees
	  	9.1
	 Prothena Licensor
	  	8.3.3
	 Prothena Ongoing Program Activities
	  	2.3
	 Prothena Reversion Antibodies
	  	10.10.1
	 Publishing Party
	  	8.8.1
	 Receiving Party
	  	7.1
	 Regulatory Milestone Payment
	  	5.3.1
	 Right of First Negotiation
	  	4.2.2
	 Sales Milestone Payment
	  	5.4.1
	 SEC
	  	8.4.1(a)
	 Securities Regulators
	  	7.6
	 Tax Benefit
	  	5.5.2(c)
	 Term
	  	10.1.1
	 Transfer Date
	  	2.2.1(a)

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 ARTICLE 2. 

DEVELOPMENT, MANUFACTURE AND COMMERCIALIZATION 

2.1    Development, Manufacturing and Commercialization. 

2.1.1    General. From and after the Effective Date, and subject to the terms and conditions of this Agreement
(including Sections 2.2, 2.3, and 2.8), (i) Celgene will have the sole right (and shall solely control, at its discretion), itself and/or with or through its Affiliates, Sublicensees or other Third Parties, to Develop, Manufacture and Commercialize
Licensed Antibodies and Licensed Products in the Field in the Territory, and (ii) Prothena and its Affiliates shall not have any right to, and shall not, conduct any Development, Manufacture or Commercialization of any Licensed Antibodies or
Licensed Products in the Field in the Territory. 
 2.1.2    Diligence. From and after the end of the Phase 1
Option Term, and subject to the terms and conditions of this Agreement (including Sections 2.2, 2.3, and 2.8), Celgene, itself and/or with or through its Affiliates, Sublicensees or other Third Parties, will use Commercially Reasonable Efforts to
(i) [***], and (ii) [***].  
 2.1.3    Celgene Progress Updates. During the Term until such time as
Celgene has submitted a MAA for at least one Licensed Product in a Select Indication in the Territory, Celgene and Prothena shall meet at least [***] to discuss the progress of Celgene’s material Development and Commercialization activities
with respect to Licensed Products pursuant to this Agreement. Such meeting shall be either in person or telephonically as agreed to by the Parties. In addition, during the Term until such time as Celgene has submitted an MAA for at least one
Licensed Product for a Select Indication in the Territory, at least [***] (or more frequently as agreed to by the Parties), Celgene shall submit to Prothena a written report summarizing the progress of Celgene’s material Development and
Commercialization activities with respect to Licensed Products pursuant to this Agreement since the last report. 

2.2    Regulatory. 

2.2.1    Regulatory Materials. 

(a)    Subject to Section 2.3, and subject further to Section 2.6.1(b) of the Master Collaboration Agreement
with respect to the Licensed Program, until the end of the Phase 1 Option Term for the Licensed Program (the “Transfer Date”), Prothena shall have the right, in consultation with Celgene, to prepare, file and maintain all Regulatory
Materials (including any Regulatory Approvals) necessary for the Development and Manufacture of any Licensed Program Antibodies and/or Licensed Program Products in the Territory hereunder, and to interact with Regulatory Authorities in connection
with the Development and Manufacture of any Licensed Program Antibodies and/or Licensed Program Products in the Territory hereunder. Prothena will provide Celgene with a reasonable opportunity to comment substantively on all material Regulatory
Materials prior to filing or taking material action, and will reasonably and in good faith consider any comments and actions recommended by Celgene, including with respect to filing 

  
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treatment has been requested with respect to the omitted portions. 

 
strategy. In addition, Prothena will allow Celgene or its representative to attend any and all meetings with Regulatory Authorities to the extent such attendance is not prohibited or limited by
such Regulatory Authority. 
 (b)    Subject to Section 2.3, after the Transfer Date, Celgene shall have the
right, in consultation with Prothena, to prepare, file and maintain all Regulatory Materials (including any Regulatory Approvals) necessary for the Development, Manufacture and Commercialization of any Licensed Program Antibodies and/or Licensed
Program Products in the Territory hereunder, and to interact with Regulatory Authorities in connection with the Development, Manufacture and Commercialization of any Licensed Program Antibodies and/or Licensed Program Products in the Territory
hereunder. Celgene will provide Prothena with a reasonable opportunity to comment substantively on all material Regulatory Materials, but only if such Regulatory Materials directly impact regulatory matters with respect to Licensed Program
Antibodies and/or Licensed Program Products outside the Territory, prior to filing or taking material action, and will reasonably and in good faith consider any comments and actions recommended by Prothena, including with respect to filing strategy.
In addition, Celgene will allow Prothena or its representative to attend any and all meetings with Regulatory Authorities with respect to Licensed Program Antibodies and/or Licensed Program Products in the Territory to the extent such attendance is
not prohibited or limited by such Regulatory Authority, but only if such meeting directly impact regulatory matters with respect to Licensed Program Antibodies and/or Licensed Program Products outside the Territory. 

2.2.2    Safety Information. Prior to the Transfer Date, Prothena shall have the right to report all safety
information to Regulatory Authorities with respect to the Licensed Program Antibodies and/or Licensed Program Products in the Territory hereunder, and shall promptly provide Celgene with all information concerning the pharmaceutical safety of
Licensed Program Antibodies and/or Licensed Program Products in the Territory. After the Transfer Date, Celgene shall have the right to report all safety information to Regulatory Authorities with respect to the Licensed Program Antibodies and/or
Licensed Program Products in the Territory hereunder, and shall promptly provide Prothena with all such information concerning the pharmaceutical safety of Licensed Program Antibodies and/or Licensed Program Products in the Territory. 

2.2.3    Step-In Right of Celgene. In the event that Prothena
does not undertake any activities allocated to Prothena in the provisions of Section 2.2.1 or 2.2.2 in any respect, then, upon written notice from Celgene to Prothena, Celgene (or its designee) shall have the right to do so, and Prothena shall
provide Celgene with reasonable assistance in connection therewith. 
 2.2.4    Right of Reference; Access to
Data. Celgene (and its designees) shall have, and Prothena (on behalf of itself and its Affiliates) hereby grants to Celgene (and its designees), access and a right of reference (without any further action required on the part of Prothena or its
Affiliates, whose authorization to file this consent with any Regulatory Authority is hereby granted) to all Regulatory Materials with respect to the Licensed Program Antibodies and/or Licensed Program Products in the Territory that are Controlled
by Prothena (or its Affiliates) and all data contained or referenced in any such Regulatory Materials for Celgene (and its designees) solely to the extent necessary for Celgene to exercise its rights and perform its obligations hereunder. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 2.2.5    Additional Regulatory Activities by Celgene. For the
avoidance of doubt, without limiting any other rights or remedies of Celgene, Celgene shall have the right to undertake any regulatory activities, including to prepare, file and maintain all Regulatory Materials (including any Regulatory Approvals)
necessary for the Development, Manufacture and Commercialization of any Licensed Antibodies and/or Licensed Products in the Territory hereunder, and to interact with Regulatory Authorities in connection with the Development, Manufacture and
Commercialization of any Licensed Antibodies and/or Licensed Products in the Territory hereunder, to the extent such activities are not performed by Prothena. 

2.2.6    Pharmacovigilance. At the written request of Celgene, within [***] ([***]) days after such request,
Prothena and Celgene (or its designee(s)) will enter into a pharmacovigilance agreement in order to, among other things, coordinate safety matters and share of safety information with respect to Licensed Products. 

2.3    Prothena Ongoing Activities in Support of Licensed Program. 

2.3.1    Prothena Ongoing Program Activities. Notwithstanding the provisions of Section 2.1.1 or
Section 2.2.1, Prothena shall have the right to continue to conduct Development activities (and related activities, including as set forth in Section 2.5.1(b)(iv) of the Master Collaboration Agreement with respect to the Licensed Program)
for the Licensed Program under, and in accordance with, the Master Collaboration Agreement, through the first to occur of (i) the end of the Phase 1 Option Term for the Licensed Program, or (ii) Celgene’s exercise of the Celgene Phase
1 Portion Participation Right; provided, however, that if thereafter, in the event that Prothena desires to conduct any Development activities (or related activities) in the Territory that are not set forth in the Master Collaboration Agreement or
this Agreement, Prothena may only conduct such activities to the extent requested by Celgene in writing, or otherwise with the prior written consent of Celgene. 

2.3.2    Transition Supply. If Prothena was supplying (or having supplied) any Licensed Antibody and/or Licensed
Product for any Clinical Trial(s) or other Development activities conducted with respect to the Licensed Program under the Master Collaboration Agreement, then, at Celgene’s written request, Prothena will be responsible for supplying, and shall
supply, to Celgene (or its designee) Licensed Antibody(ies) and/or Licensed Product(s), for use in Development by or on behalf of Celgene hereunder for a period not to exceed [***] ([***]) [***] (or such longer period of time as agreed to by the
Parties), as and to the extent requested by Celgene; provided that Celgene shall pay to Prothena a reasonable, fair value cost for such supply, which cost shall be negotiated in good faith and agreed to by the Parties prior to such supply. In such
case, at the request of Celgene, the Parties shall negotiate in good faith and enter into an appropriate supply agreement (including a quality agreement) for Prothena to supply (or have supplied) Licensed Antibody and/or Licensed Product, as
applicable, to Celgene (or its designee). Notwithstanding the foregoing, if Prothena has engaged a Third Party contract manufacturer for the supply of Licensed Antibodies and/or Licensed Products, and the agreement with such Third Party prohibits
the supply to Celgene in accordance with the foregoing (provided that Prothena used good faith efforts not to include such prohibition during negotiations), then in lieu of the foregoing supply obligation, Prothena shall take such actions as
reasonably requested by Celgene to facilitate the negotiations between Celgene and Prothena’s Third Party contract manufacturer of an appropriate supply agreement (including a quality agreement) for the supply of Licensed Antibody and/or
Licensed Product, as applicable, to Celgene (or its designee). 

  
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treatment has been requested with respect to the omitted portions. 

 2.3.3    Other Continuing Development Activities. Without
limiting the other obligations of Prothena hereunder (including as set forth in this Section 2.3), in the event that the Parties mutually agree in writing that Prothena or its Affiliates will conduct any other specific Development activities
for Celgene after the Effective Date with respect to the Licensed Program (in addition to those set forth in the foregoing provisions of this Section 2.3) (the “Ongoing Prothena Development Activities”), then, in such case, the
Parties shall negotiate in good faith and enter into a separate services agreement pursuant to which Prothena (or its Affiliates, as applicable) shall perform such Ongoing Prothena Development Activities. 

Prothena’s obligations as set forth in the foregoing clauses 2.3.1 through 2.3.3, as applicable, are the “Prothena Ongoing
Program Activities”. 
 2.4    Assistance; Technology Transfer. Prothena shall (and shall cause
its Affiliates to) cooperate with Celgene (and its designees) and provide reasonable assistance to Celgene (and its designees) to enable Celgene (and its designees) to Develop, Manufacture and Commercialize Licensed Antibodies and Licensed Products,
as and to the extent requested reasonably by Celgene, including (i) conducting a technology transfer to Celgene with respect to the Licensed Program Know-How and Prothena Licensed Collaboration Know-How, (ii) providing Celgene (and its designees) reasonable assistance with respect to regulatory and Manufacturing transition matters related to Licensed Antibodies and Licensed Products and
(iii) providing Celgene (and its designees) with reasonable access by teleconference or in-person (as requested by Celgene) to Prothena personnel (and personnel of its Affiliates and Third Party
contractors) involved in the Development or Manufacture of Licensed Antibodies and Licensed Products to assist with the transition and answer questions related to Licensed Antibodies, Licensed Products and Diagnostic Products. 

2.5    Covenant. Except as otherwise expressly permitted under this Agreement, commencing on the Effective Date
until the end of the Term, Prothena shall not and shall cause its Affiliates not to (a) assign, transfer, convey, encumber (through a lien, charge, security interest, mortgage or similar encumbrance) or dispose of, or enter into any agreement
with any Third Party to assign, transfer, convey, encumber (through a lien, charge, security interest, mortgage or similar encumbrance) or dispose of, any [***] (collectively, the “Licensed Program Assets”), except to the extent
such assignment, transfer, conveyance, encumbrance or disposition would not conflict with, be inconsistent with or adversely affect in any respect any of the rights or licenses granted to Celgene hereunder, (b) license or grant to any Third
Party, or agree to license or grant to any Third Party, any rights to any Licensed Program Assets if such license or grant could conflict with, be inconsistent with or adversely affect in any respect any of the rights or licenses granted to Celgene
hereunder, or (c) [***] the Licensed Program Assets to any Third Party if such [***] could impair or conflict in any respect with any of the rights or licenses granted to Celgene hereunder. 

  
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treatment has been requested with respect to the omitted portions. 

 2.6    Other Antibodies and Products Developed by Celgene.
Notwithstanding anything to the contrary contained herein, if Celgene (or any of its Affiliates), alone or with any Third Party, determines to Develop, Manufacture or Commercialize any Antibodies (or any product containing an Antibody), other than
Licensed Antibodies or Licensed Products, then Celgene may do so in its sole discretion, without any obligations to Prothena with respect thereto, and Prothena shall have no rights in connection therewith, provided that Celgene’s or its
Affiliates’ conduct of any such activities shall not modify or obviate Celgene’s obligations under this Agreement. 

2.7    Non-Exercise of Phase 1 Option for Licensed Program. In the event
that Celgene does not exercise its Phase 1 Option for the Licensed Program in accordance with the Master Collaboration Agreement prior to the end of the Phase 1 Option Term for the Licensed Program, and Prothena desires (itself or with or through a
Third Party) to continue the Development of the Licensed Program Antibodies and Licensed Program Products in the Field in the Territory, then at the written request of Prothena, Celgene shall discuss in good faith the terms under which Celgene may
be willing to grant rights to Prothena under the Prothena IP for Prothena (itself or with or through a Third Party) to continue the Development of the Licensed Program Products in the Field in the Territory (including the Manufacture of Licensed
Program Antibodies and Licensed Program Products in connection therewith), and to thereafter Commercialize Licensed Program Antibodies and Licensed Program Products in the Field in the Territory; provided that, for the avoidance of doubt, the
provisions of Article 5 (other than Section 5.7) shall not apply with respect to any such activities. 

2.8    No Global License Agreement. For the avoidance of doubt, in the event that Celgene does not exercise its
Phase 1 Option for the Licensed Program for the Licensed Program, this Agreement shall remain in full force and effect unless and until this Agreement expires or is otherwise terminated in accordance with the terms hereof. 

ARTICLE 3. 
 ANTITRUST
AND COMPETITION LAW COMPLIANCE 
 3.1    Antitrust Compliance. For the avoidance of doubt, the Parties shall
continue to comply with Section 3.2 of the Master Collaboration Agreement, and such provisions shall apply to this Agreement as if set forth directly herein, mutatis mutandis. 

ARTICLE 4. 
 EXCLUSIVITY

 4.1    Prothena Exclusivity. During the Term, Prothena shall not and shall ensure that its Affiliates
shall not, anywhere in the world: (i) alone or with or through any Third Party, research [***], Develop, Manufacture or Commercialize (a) the Licensed Target or any Competing Compound, or (b) any diagnostic product intended for use,
or Developed or approved for use with, the Licensed Target (including any diagnostic product intended for use, or Developed or approved for use with, any Competing Compound), in each case, other than Prothena’s performance of the Prothena
Ongoing Program Activities (including engaging its Affiliates or Third Party subcontractors to perform the Prothena Ongoing Program Activities in accordance with this Agreement) as specifically set forth in Section 2.3; (ii) grant a license,
sublicense or other rights to any Third Party to conduct any of the activities 

  
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in the foregoing clause (i), other than Prothena’s performance of the Prothena Ongoing Program Activities (including engaging its Affiliates or Third Party subcontractors to perform the
Prothena Ongoing Program Activities in accordance with this Agreement) as specifically set forth in Section 2.3; or (iii) transfer, assign, convey or otherwise sell (a) any Competing Compound or any diagnostic product intended for
use, or (b) Developed or approved for use with, the Licensed Target (including any diagnostic product intended for use, or Developed or approved for use with, any Competing Compound). As used herein, the term “Competing
Compound” means [***]. 
 4.2    Prothena Exception for Active Immunotherapeutic Approaches. 

4.2.1    Exception for Active Immunotherapeutic Approaches. Notwithstanding the provisions of Section 4.1, but
subject to the provisions of Section 5.3.2, Prothena and its Affiliates (themselves, but not with or through any Third Parties) may conduct research, development, manufacture and commercialization of Active Immunotherapeutic Approaches outside
of this Agreement; provided that no Licensed Antibodies or Licensed Products are utilized in the conduct of any such activities (including no use of a Licensed Antibody or Licensed Product for an Active Immunotherapeutic Approach). As used herein,
“Active Immunotherapeutic Approaches” means [***]. 
 4.2.2    Celgene Right of First
Negotiation. During the Term, in the event that Prothena or its Affiliates intends to, directly or indirectly, sublicense, assign, transfer, convey or grant other rights, however structured, to a Third Party with respect to any Active
Immunotherapeutic Approaches (including any rights with respect to the Development or Commercialization of any Active Immunotherapeutic Approaches (each, a “Grant”), [***] will [***]. [***] will [***] (a “[***]”).
If [***], [***] will [***] which [***] will [***].    If [***], the Parties will [***]. Until [***] or the [***], as applicable, [***]. If [***] that it [***] [***], then [***]. For the avoidance of doubt, this Section 4.2.2
[***]. For clarity, [***]. 

  
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treatment has been requested with respect to the omitted portions. 

 4.3    Master Collaboration Agreement. For the avoidance of
doubt, the provisions of this Article 4 shall not limit in any way the provisions of Article 5 of the Master Collaboration Agreement. 

4.4    Celgene Exclusivity. 

4.4.1    Celgene Exclusivity. If Celgene does not exercise the Phase 1 Option for the Licensed Program prior to the
end of the Phase 1 Option Term, then, for a period of five (5) years following the expiration of such Phase 1 Option Term (the “Celgene Exclusivity Term”), neither Celgene nor its Affiliates will, anywhere in the Territory,
alone or with or through any Third Party, either (a) sell any Competing Antibody that has an approved label for treatment of an Indication for which Celgene or its Affiliates has conducted a Registration Enabling Clinical Trial for a Licensed
Product hereunder (as set forth in the protocol for such Registration Enabling Clinical Trial) or (b) conduct a Registration Enabling Clinical Trial for any Competing Antibody for treatment of an Indication (as set forth in the protocol for
such Registration Enabling Clinical Trial) for which Celgene has conducted a Registration Enabling Clinical Trial for a Licensed Product hereunder (as set forth in the protocol for such Registration Enabling Clinical Trial) (provided that, for the
avoidance of doubt, this Section 4.4.1 shall not prohibit (i) use of an Competing Antibody as a comparator in a Registration Enabling Clinical Trial or (ii) Celgene or any of its Affiliates providing proprietary products (that are not
Competing Antibodies) to a Third Party for such Third Party’s use in a clinical trial of Competing Antibodies), in each case of (a) and (b), other than Celgene’s exercise of its rights and performance of its obligations with respect
to Licensed Antibodies and Licensed Products pursuant to this Agreement (including engaging Third Party subcontractors to perform the such rights and obligations in accordance with this Agreement). As used herein, the term “Competing
Antibody” means any Antibody that Targets the Licensed Target, including any product that incorporates any such Antibody; provided that Competing Antibody shall not include (a) any Antibody (or any product that incorporates any such
Antibody) that was Developed or Commercialized by or on behalf of Celgene or any of its Affiliates prior to the Effective Date or (b) any Related Antibodies, or other improvements or modifications, to the Antibody in the foregoing clause
(a) or products that incorporate such Related Antibodies or improvements or modifications. 

4.4.2    Exceptions for Change of Control. Notwithstanding the provisions of Section 4.4.1, if during the
Celgene Exclusivity Term, Celgene (or any of its Affiliates) undergoes a Change of Control with a Third Party who (itself or through any of its affiliates existing prior to 

  
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the date of the Change of Control) owns or has rights to a Competing Antibody (but excluding any Licensed Antibody or Licensed Product) that is in ongoing clinical development or being
commercialized by such Third Party (or its affiliate) as of the date of the Change of Control (a “Celgene Acquired Competing Antibody”), then Celgene and its Affiliates (including the acquiring Person in the Change of Control (and
such acquiring Person’s affiliates)) shall not be in breach of the provisions of Section 4.4.1 as a result of [***]; provided that (i) such activities are conducted independently of the activities of this Agreement and without use of
any Prothena IP ([***]) and (ii) no personnel who are conducting any Registration Enabling Clinical Trial activities pursuant to this Agreement are involved in the conduct of Registration Enabling Clinical Trial activities with respect to the
Celgene Acquired Competing Antibody. 
 ARTICLE 5. 

FINANCIAL TERMS 

5.1    Option Exercise Fee. Subject to Section 3.2 of the Master Collaboration Agreement, the Parties
acknowledge and agree that Celgene will pay the IND Option Exercise Fee (as defined in the Master Collaboration Agreement) for the Licensed Program in accordance with the Master Collaboration Agreement. 

5.2    Royalties. 

5.2.1    Licensed Product Royalties. Subject to the terms of this Section 5.2 (and subject further to
Section 5.5), Celgene shall pay Prothena royalties on Annual Net Sales, on a Licensed Product-by-Licensed Product basis during the applicable Royalty Term, equal to
the following portions of Annual Net Sales of the applicable Licensed Product multiplied by the applicable royalty rate set forth below for such portion of Annual Net Sales during the applicable Royalty Term for each such Licensed Product, which
royalties shall be paid in accordance with Section 5.2.7 (the “Per Licensed Product Annual Net Sales”). For clarity, the royalties (and royalty tiers) shall be calculated separately on a Licensed
Product-by-Licensed Product basis.  
  

			
	 Per Licensed Product Annual Net Sales

for a Given Licensed Product in a Given

Calendar
Year                                         
 
	  	Royalty Rate
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%

  
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	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%
		
	Portion of Per Licensed Product Annual Net Sales of a given Licensed Product in a given Calendar Year above [***]	  	[***]%

 The applicable royalty rate set forth in the table above will apply only to that portion of the Per Licensed Product Annual
Net Sales of a given Licensed Product during a given Calendar Year that falls within the indicated range. For clarity, (i) if no royalty is payable on a given unit of Licensed Product (e.g., following the Royalty Term for such Licensed
Product), then the Net Sales of such unit of Licensed Product shall not be included for purposes of determining the royalties or royalty tiers and (ii) Net Sales of a given Licensed Product will not be combined with Net Sales of any other
Licensed Product for purposes of determining the foregoing royalties or royalty tiers. Only one royalty shall be payable by Celgene to Prothena for each sale of a Licensed Product. 

By way of example, if Per Licensed Product Annual Net Sales of a given Licensed Product by Celgene, its Affiliates and Sublicensees were $[***] for a given
Calendar Year, then the royalties payable with respect to such Per Licensed Product Annual Net Sales for such Licensed Product for such Calendar Year, subject to adjustment as set forth in this Section 5.2, would be: [***]. 

  
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treatment has been requested with respect to the omitted portions. 

 5.2.2    Royalty Term. Celgene’s royalty obligations to
Prothena under Section 5.2.1 shall apply on a Licensed Product-by-Licensed Product basis in the Territory only during the applicable Royalty Term for such Licensed
Product. Following expiration of the applicable Royalty Term for a given Licensed Product, as applicable, no further royalties will be payable in respect of sales of such Licensed Product in the Territory and thereafter the license granted to
Celgene hereunder with respect to such Licensed Product will automatically become fully paid-up, perpetual, irrevocable and royalty-free. 

5.2.3    Reductions. 

(a)    Reductions for No Valid Claim. The royalty amounts payable with respect to Per Licensed Product Annual Net
Sales shall be reduced on a Licensed Product-by-Licensed Product basis, to [***] percent ([***]%) of the amounts otherwise payable pursuant to Section 5.2.1 during
any portion of the applicable Royalty Term in which both: (i) [***] and (ii) [***]. 
 (b)    Royalty Reduction for
Biosimilar Product. If, on a Licensed Product-by-Licensed Product and Calendar
Quarter-by-Calendar Quarter basis in the Territory, 

(i)    [***]; or 

(ii)    [***]; 

then the royalties payable with respect to Per Licensed Product Annual Net Sales of such Licensed Product pursuant to Section 5.2.1
during such Calendar Quarter shall be reduced to [***], of the royalties otherwise payable pursuant to Section 5.2.1. [***]. 

5.2.4    Royalty Offset for Third Party Payments. If Celgene (or any of its Affiliates or Sublicensees) obtains a
right or license under intellectual property of a Third Party (whether prior to, or after, the Effective Date), where the research, development, making, using, selling, offering for sale, or importing of any Licensed Product (or any Licensed
Antibody contained in such Licensed Product) by or on behalf of Celgene (or any of its Affiliates or Sublicensees) would result in a payment to such Third Party, then Celgene may deduct from the royalty payments that would otherwise have been due
under Section 5.2.1 with respect to Per Licensed Product Annual Net Sales in a particular Calendar Quarter, an amount equal to [***] percent ([***]%) of [***] 

  
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treatment has been requested with respect to the omitted portions. 

 [***] (“Celgene Third Party Payments”) during such Calendar Quarter. Notwithstanding the
foregoing, in no event shall the royalties payable on Per Licensed Product Annual Net Sales be reduced by more than [***] percent ([***]%) in any Calendar Quarter by operation of this Section 5.2.4; [***]. 

5.2.5    Cumulative Effect of Royalty Reductions and Offsets. In no event shall the royalty reductions and offsets
described in Sections 5.2.3(a), 5.2.3(b) and 5.2.4, alone or together, reduce the royalties payable by Celgene for a given Calendar Quarter pursuant to Section 5.2.1 to less than [***] percent ([***]%) of the amounts otherwise payable by
Celgene for a given Calendar Quarter pursuant to Section 5.2.1. [***] 
 5.2.6    Compulsory Licenses. If a
compulsory license is granted to a Third Party with respect to a Licensed Product in the Territory with a royalty rate lower than the royalty rate provided by Section 5.2.1 (as adjusted pursuant to Section 5.2.3), then the royalty rate to
be paid by Celgene on Per Licensed Product Annual Net Sales under Section 5.2.1 shall be reduced [***]. 

5.2.7    Payment of Royalties. Celgene shall: (a) within [***] ([***]) days following the end of each Calendar
Quarter in which a royalty payment pursuant to Section 5.2.1 accrues, provide to Prothena a report specifying for such Calendar Quarter (i) the number of Licensed Products sold that are subject to such royalty, (ii) the Per Licensed
Product Annual Net Sales that are subject to such royalty, (iii) the applicable royalty rate under this Agreement, (iv) the royalty calculation and royalties payable in U.S. Dollars and (v) any reduction to the royalty applied by
Celgene pursuant to any one or more of Sections 5.2.3 and 5.2.4; and (b) make the royalty payments owed to Prothena hereunder in accordance with such royalty report in arrears, within [***] ([***]) days from the end of the Calendar Quarter in
which such payment accrues. 
 5.3    Regulatory Milestones. 

5.3.1    Regulatory Milestones. Subject to the terms of this Section 5.3 (and subject further to
Section 5.5), Celgene will notify Prothena within [***] ([***]) days following the first achievement by Celgene under this Agreement and after the Effective Date of each milestone event described below in this Section 5.3 with respect to
the first (and only the first) Licensed Product to achieve such milestone event under this Agreement, and Celgene shall 

  
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thereafter pay the applicable amounts set forth below associated with the applicable milestone event in accordance with Section 5.3.2 (each, a “Regulatory Milestone
Payment”): 
  

			
	 Regulatory Approval Milestone Event
	  	Regulatory Milestone Payment
	 1.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for the first Select Indication in the U.S. issued by the FDA; [***] (the “First U.S. Approval Milestone”)
	  	[***] Dollars ($[***])
		
	 2.  Receipt under this Agreement of all Regulatory Approvals for a Licensed Product
for a second Select Indication [***] in the U.S. issued by the FDA; [***]
	  	[***] Dollars ($[***])

 Each of the foregoing milestones in this Section 5.3.1 shall be payable a maximum of one (1) time as
set forth in the foregoing chart regardless of the number of Licensed Products achieving the applicable milestone event (i.e., a maximum of two (2) Regulatory Milestone Payments may be made pursuant to this Section 5.3.1), and no
Regulatory Milestone Payment shall be due hereunder for subsequent or repeated achievement of such milestone event. For the avoidance of doubt, the maximum amount payable by Celgene pursuant to this Section 5.3.1 is Ninety Million Dollars
($90,000,000) assuming that each of the milestone events in this Section 5.3.1 were achieved. 

5.3.2    Invoice and Payment of Regulatory Milestone Payments. Following receipt of notification by Celgene to
Prothena that Celgene has achieved the applicable milestone event triggering a Regulatory Milestone Payment hereunder, Prothena shall invoice Celgene for the applicable Regulatory Milestone Payment, and Celgene shall pay such Regulatory Milestone
Payment within [***] ([***]) days after receipt of the invoice therefor. 

  
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treatment has been requested with respect to the omitted portions. 

 5.4    Sales Milestones. 

5.4.1    Sales Milestones. Subject to the terms of this Section 5.4 (and subject further to Section 5.5),
Celgene will notify Prothena within [***] ([***]) days after the end of the Calendar Quarter during which a given milestone event described below in this Section 5.4 was first achieved by Celgene under this Agreement and after the Effective
Date with respect to the Licensed Products, and Celgene shall thereafter pay the applicable amounts set forth below associated with the applicable milestone event in accordance with Section 5.4.2 (each, a “Sales Milestone
Payment”): 
  

			
	 Sales Milestone Event
	  	Sales Milestone Payment
	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])
		
	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])
		
	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])
		
	First achievement of Per Licensed Product Annual Net Sales of the Licensed Products in any single Calendar Year exceeding [***] Dollars ($[***])	  	[***] Dollars ($[***])

 Each of the foregoing milestones in this Section 5.4.1 shall be payable a maximum of one (1) time as
set forth in the foregoing chart regardless of the number of times the applicable milestone event was achieved (i.e., a maximum of four (4) Sales Milestone Payments may be made pursuant to this Section 5.4.1), and no Sales Milestone
Payment shall be due hereunder for subsequent or repeated achievement of such milestone event. For the avoidance of doubt, the maximum amount payable by Celgene pursuant to this Section 5.4.1 is Three Hundred Seventy-Five Million Dollars
($375,000,000) assuming that each of the milestone events in this Section 5.4.1 were achieved. 

  
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treatment has been requested with respect to the omitted portions. 

 5.4.2    Invoice and Payment of Sales Milestone Payments.
Following receipt of notification by Celgene to Prothena that Celgene has achieved the applicable milestone event triggering a Sales Milestone Payment hereunder, Prothena shall invoice Celgene for the applicable Sales Milestone Payment, and Celgene
shall pay such Sales Milestone Payment within [***] ([***]) days after receipt of the invoice therefor. 

5.5    Additional Payment Terms. 

5.5.1    Currency. All payments hereunder shall be made in U.S. Dollars by wire transfer to a bank designated in
writing by Prothena. Conversion of sales recorded in local currencies to Dollars shall be performed in a manner consistent with Accounting Standards and Celgene’s normal practices used to prepare its audited financial statements for internal
and external reporting purposes. 
 5.5.2    Taxes; Withholding. 

(a)    Generally. Each Party will pay any and all income taxes levied on account of all payments it receives under
this Agreement except as otherwise provided in this Section 5.5.2. 
 (b)    Tax Withholding. Each Party
shall be entitled to deduct and withhold from any amounts payable under this Agreement such taxes as are required to be deducted or withheld therefrom under any provision of Applicable Law. The Party that is required to make such withholding (the
“Paying Party”) will (i) deduct those taxes from such payment, (ii) timely remit the taxes to the proper taxing authority, and (iii) send evidence of the obligation together with proof of tax payment to the other
Party (the “Payee Party”) on a timely basis following that tax payment; provided, however, that before making any such deduction or withholding, the Paying Party shall give the Payee Party notice of the intention to make such
deduction or withholding (such notice shall include an explanation of the reason for and the calculation of the proposed deduction or withholding and shall be given before such deduction or withholding is required in order for such Payee Party to
obtain reduction of or relief from such deduction or withholding). Each Party agrees to reasonably cooperate with the other Party in claiming refunds or exemptions from such deductions or withholdings under any relevant agreement or treaty which is
in effect to ensure that any amounts required to be withheld pursuant to this Section 5.5.2(b) are reduced in amount to the fullest extent permitted by Applicable Law. In addition, the Parties shall cooperate in accordance with Applicable Laws
to minimize indirect taxes (such as value added tax, sales tax, consumption tax and other similar taxes (“Indirect Taxes”)) in connection with this Agreement. 

(c)    Tax Gross-Up. Notwithstanding the foregoing, if (a) any Party
redomiciles, assigns its rights or obligations or extends its rights under this Agreement, (b) as a result of such redomiciliation, assignment or extension, such Party (or its assignee) is required by Applicable Law to [***] or such
redomiciliation, assignment or extension results in [***], and (c) such [***] exceed the amount of [***] that would have been applicable but for such redomiciliation, assignment or extension, then any such amount payable shall [***]

  
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 [***] so that, after making all required [***], as the case may be, the Payee Party (or its assignee) [***].
The [***] (A) [***] to the extent such [***] but for [***], and (B) [***]. For purposes of the preceding sentence, “Tax Benefit” shall mean any cash refund or credit for Taxes resulting in a reduction in the amount of Taxes
otherwise owed by the Payee Party as a result of [***] relating to payments by the Paying Party, as reasonably determined by Payee Party. Solely for purposes of this Section 5.5.2(c), a Party’s “domicile” shall include its
jurisdiction of incorporation or tax residence and a “redomiciliation” shall include a reincorporation or other action resulting in a change in tax residence of the applicable Party or its assignee, or resulting in the attribution of any
amounts payable to a branch or permanent establishment located outside the country of tax residence of the applicable Party or its assignee 

(d)    Tax Documentation. Prothena has provided a properly completed and duly executed IRS Form W-8BEN-E to Celgene. Prior to the receipt of any payment under this Agreement, each recipient Party (and any other recipient of payments under this Agreement) shall, to the
extent it is legally permitted to, provide to the other Party, at the time or times reasonably requested by such other Party or as required by Applicable Law, such properly completed and duly executed documentation (for example, IRS Forms W-8 or W-9 or foreign equivalents) as will permit payments made under this Agreement to be made without, or at a reduced rate of, withholding for taxes 

5.5.3    Other U.S. License Agreements. For the avoidance of doubt, a Licensed Product hereunder will only be
eligible for milestone and royalty payments under this Agreement, and shall not be eligible for, or counted towards, milestone or royalty payments under any other U.S. License Agreement (i.e., a given Licensed Product will be eligible for, and
counted towards, milestone and royalty payments only under one U.S. License Agreement). 
 5.6    Records Retention
by Celgene; Review by Prothena. 
 5.6.1    Records. With respect to royalty and milestone payments to be made
under Sections 5.2 or 5.4 of this Agreement, Celgene agrees to keep and shall procure that its Affiliates keep, for at least [***] ([***]) years from the end of the Calendar Year to which they pertain, complete and accurate records of sales by
Celgene or its Affiliates (including sales by Sublicensees), as the case may be, of each Licensed Product, in sufficient detail to allow the accuracy of the payments made hereunder to be confirmed. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 5.6.2    Review. Subject to the other terms of this
Section 5.6.2, during the Term, at the request of Prothena, which shall not be made more frequently than [***], upon at least [***] ([***]) days’ prior written notice from Prothena, [***], Celgene shall permit an independent,
nationally-recognized certified public accountant selected by Prothena and reasonably acceptable to Celgene to inspect (during regular business hours) the relevant records required to be maintained by Celgene under Section 5.6.1; provided that
such audit right shall not apply to records beyond [***] ([***]) years from the end of the Calendar Year to which they pertain. In every case the accountant must have previously entered into a confidentiality agreement with both Parties having
confidentiality obligations and non-use obligations no less restrictive than those set forth in Article 7 and limiting the disclosure and use of such information by such accountant to authorized
representatives of the Parties and the purposes germane to Section 5.6.1. Results of any such review shall be binding on both Parties absent manifest error. The accountant shall report to Prothena only whether the particular amount being
audited was accurate, and if not, the amount of any discrepancy, and the accountant shall not report any other information to Prothena. Prothena shall treat the results of any such accountant’s review of Celgene’s records as Confidential
Information of Celgene subject to the terms of Article 7. If any review reveals a deficiency or overpayment in the calculation and/or payment of royalties or Sales Milestone Payments by Celgene, then (a) Celgene or Prothena as applicable shall
promptly pay (or refund, as applicable) the other Party the amount of such deficiency or overpayment, as applicable, and (b) if such deficiency is by more than the greater of (i) [***] or (ii) [***], Celgene shall, within [***] ([***])
days after receipt of an invoice therefor, pay the reasonable out-of-pocket costs and expenses incurred by Prothena for the independent accountant in connection with the
review. 
 5.6.3    Records Final. Upon the expiration of [***] ([***]) years following the end of a given
Calendar Year, subject and without prejudice to the determination of any review commenced prior to such [***] pursuant to Section 5.6.2, the calculation of royalties and Sales Milestone Payments payable with respect to such Calendar Year shall
be binding and conclusive upon Prothena, and Celgene (and its Affiliates) shall be released from any liability or accountability with respect to such royalties for such Calendar Year. 

5.7    Prothena Third Party Agreements. Notwithstanding anything to the contrary herein, Prothena shall be solely
responsible for all costs and payments of any kind (including all upfront fees, annual payments, milestone payments and royalty payments) arising under any agreements between Prothena (or any of its Affiliates) and any Third Party (including under
any In-License Agreement or other Existing Program Agreement), which costs or payments arise in connection with, or as a result of, the activities hereunder, including the Development, Manufacture or
Commercialization of Licensed Antibodies or Licensed Products. 
 5.8    Diagnostic Products. Notwithstanding
anything to the contrary contained herein, [***]. 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 5.9    Additional Provisions. Notwithstanding anything to the
contrary herein, the terms and provisions of this Article 5 are subject to Section 11.7 of the Master Collaboration Agreement and Sections 10.9 and 10.12 of this Agreement. 

ARTICLE 6. 
 LICENSES;
INTELLECTUAL PROPERTY 
 6.1    License to Celgene. Subject to the terms and conditions of this Agreement,
Prothena hereby grants to Celgene an exclusive right and license, with the right to grant sublicenses (through multiple tiers), under the Prothena IP to research, develop (including Develop), make (including Manufacture), have made (including have
Manufactured), use, offer for sale, sell, import, Commercialize and otherwise exploit Licensed Antibodies and Licensed Products, including Diagnostic Products, in the Field in the Territory. 

6.2    License to Celgene for Other Targets. In the event that, during the Term, Celgene modifies a Licensed
Program Antibody in the course of its Development activities hereunder such that such Licensed Program Antibody specifically binds to a target other than (i) the Licensed Target or (ii) any other Collaboration Target (e.g., a bispecific
antibody), then, at the request of Celgene, Celgene and Prothena shall negotiate in good faith a license under intellectual property of Prothena or its Affiliates, as applicable, that is specific to such other target or Antibodies to such other
target. 
 6.3    Rights Retained by the Parties. For purposes of clarity, each Party retains all rights under Know-How and Patents Controlled by such Party not expressly granted to the other Party pursuant to this Agreement. In addition, Prothena retains the right to perform the Prothena Ongoing Program Activities in
accordance with this Agreement. 
 6.4    No Implied Licenses. Except as explicitly set forth in this Agreement,
the Master Collaboration Agreement, any other U.S. License Agreement or any Global License Agreement, neither Party shall be deemed by estoppel or implication to have granted to the other Party any license or other right to any intellectual property
of such Party. 
 6.5    Insolvency. In the event that this Agreement is terminated due to the rejection of this
Agreement by or on behalf of Prothena due to an Insolvency Event, all licenses and rights to licenses granted under or pursuant to this Agreement by Prothena to Celgene are and shall otherwise be deemed to be licenses of rights to “intellectual
property”. The Parties agree that Celgene, as a licensee of such rights under this Agreement, shall retain and may fully exercise all of its rights and elections under any applicable insolvency statute, and that upon commencement of an
Insolvency Event by or against Prothena, Celgene shall be entitled to a complete duplicate of or complete access to (as Celgene deems appropriate), any such intellectual property and all embodiments of such intellectual property. Such intellectual
property and all embodiments thereof shall be promptly delivered to Celgene (i) upon any such commencement of a bankruptcy proceeding (or other Insolvency Event) upon written request therefore by Celgene, unless Prothena elects to continue to
perform all of its obligations under this Agreement or (ii) if not delivered under (i) above, upon the rejection of this Agreement by or on behalf of Prothena, then upon written request therefore by Celgene. The provisions of this
Section 6.5 shall be (1) without prejudice to any rights Celgene may have arising under any applicable insolvency statute or other Applicable Law and (2) effective only to the extent permitted by Applicable Law. 

  
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treatment has been requested with respect to the omitted portions. 

 6.6    Ownership. 

6.6.1    Inventorship. Notwithstanding the provisions of Section 11.7.1, inventorship of Know-How shall be determined by application of U.S. patent law pertaining to inventorship, and, except as provided for in Sections 6.6.2, 6.6.3 and 6.6.4, ownership of
Know-How shall be determined by inventorship. 
 6.6.2    Ownership of
Collaboration IP and Celgene IP. 
 (a)    Prothena. As between the Parties (including their respective
Affiliates), Prothena will retain all right, title and interest in and to all Prothena Licensed Collaboration IP, except to the extent that any such rights are licensed or granted to Celgene under this Agreement or the Master Collaboration
Agreement. Prothena shall [***] that all Patents, Know-How and other intellectual property (other than Licensed Program IP and Celgene IP, if any) utilized in the performance of the Licensed Program under the
Master Collaboration Agreement falls within the Prothena Licensed Collaboration IP and is and remains during the Term Controlled by Prothena such that Prothena has the full rights to grant the rights and licenses to the Prothena Licensed
Collaboration IP to Celgene hereunder (including that such Patents, Know-How and other intellectual property remains unencumbered such that Prothena is able to grant such rights and licenses to Celgene). 

(b)    Celgene. As between the Parties (including their respective Affiliates), Celgene (or its Affiliate) will
retain all right, title and interest in and to all Celgene IP, including all rights to Prosecute and Maintain, and enforce any such Celgene IP, and no rights or licenses are granted to Prothena hereunder with respect to any Celgene IP. 

6.6.3    Ownership of Licensed Program IP. 

(a)    Prothena. As between the Parties (including their respective Affiliates), Prothena will solely own and
Control all Licensed Program IP. Celgene shall, and hereby does, assign to Prothena all of Celgene’s interest in any and all Licensed Program Know-How that falls within Section 1.47(a)(iii) and all
Licensed Program Patents claiming such Licensed Program Know-How. Celgene shall, and shall require its Affiliates to, take all reasonable actions and execute all documents necessary to effect the intent of the
preceding sentence. As between the Parties (and their respective Affiliates) and any Third Party, Prothena will solely own and Control all Licensed Program IP; provided that if (a) [***] and (b) [***]. 

  
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treatment has been requested with respect to the omitted portions. 

 (b)    If any Licensed Program IP is created, conceived, discovered,
first generated, invented, first made or first reduced to practice pursuant to the Master Collaboration Agreement by any Third Party that is in contractual privity with or otherwise engaged by Prothena or its Affiliates, Prothena [***] include in
such agreement with such Third Party an obligation to [***] to Prothena [***] such Licensed Program IP to enable Prothena to grant to Celgene a license thereunder as provided in this Agreement for the duration of this Agreement. 

6.6.4    Joint IP. The Parties shall each own an equal, undivided interest in: (a) any and all Know-How that is created, conceived, discovered, first generated, invented, first made or first reduced to practice, in each case, jointly by or on behalf of Prothena or its Affiliates, on the one hand, and Celgene
or its Affiliates, on the other hand, pursuant to the conduct of activities under this Agreement at any time during the Term (the “Joint Know-How”), and (b) any Patents that claim
any Joint Know-How (the “Joint Patents”, together with Joint Know-How the “Joint IP”). Each Party shall assign, and
hereby assigns, to the other Party, a joint equal and undivided interest in and to such Joint IP (provided, however, that for clarity, the foregoing joint ownership rights with respect to Joint IP shall not be construed as granting, conveying or
creating any license or other rights to any of the other Party’s other intellectual property, unless otherwise expressly set forth in this Agreement), and at the request of a Party, the other Party will execute such documents (including any
necessary assignments) to effect such joint ownership of such Joint IP. Each Party shall have the right to disclose (except as otherwise set forth in Section 7.2) and exploit the Joint IP without a duty of seeking consent or accounting to the
other Party except as expressly provided in this Agreement; provided that, such rights shall be subject to the rights and licenses granted to Celgene and Prothena hereunder (or under the Master Collaboration Agreement, any Global License Agreement
or any other U.S. License Agreement), including the obligations of Prothena as set forth in Article 4. 

6.7    Patent Liaisons. Prior to the end of the Phase 1 Option Term for the Licensed Program, the Patent Committee
under the Master Collaboration Agreement shall remain established, and shall continue to perform the functions set forth in Section 4.3 and Article 7 of the Master Collaboration Agreement with respect to the Prothena Licensed Collaboration
Patents and Licensed Program Patents. Following the end of the Phase 1 Option Term for the Licensed Program, the Patent Committee under the Master Collaboration Agreement shall no longer oversee or review any matters with respect to the Prothena
Licensed Collaboration Patents or Licensed Program Patents, and promptly following the end of the Phase 1 Option Term for the Licensed Program, each Party shall appoint an individual to act as a patent liaison for such Party pursuant to this
Agreement (each, a “Patent Liaison”). The Patent Liaisons shall be the primary point of contact for the Parties regarding intellectual property-related activities and matters contemplated by this Agreement, as and to the extent
requested by Celgene from time to time. The name and contact information for each Party’s Patent Liaison, as well as any replacement(s) chosen by such Party, in its sole discretion, from time to time, shall be promptly provided to the other
Party in accordance with Section 11.2. 

  
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treatment has been requested with respect to the omitted portions. 

 6.8    Prosecution and Maintenance of Prothena Licensed Collaboration
Patents and Licensed Program Patents. 
 6.8.1    Prior to End of the Phase 1 Option Term. Prior to the
expiration of the Phase 1 Option Term for the Licensed Program, the provisions of Section 7.7 of the Master Collaboration Agreement shall apply with respect to the Prothena Licensed Collaboration Patents and Licensed Program Patents.

 6.8.2    Following Phase 1 Option Term. Following the expiration of the Phase 1 Option Term for the Licensed
Program, the provisions of this Section 6.8.2 shall apply with respect to the Prothena Licensed Collaboration Patents and Licensed Program Patents.  

(a)    [***] First Right. Subject to Section 6.8.2(b), [***] shall be required to, and shall, Prosecute and
Maintain the Prothena Licensed Collaboration Patents and Licensed Program Patents in the Territory. All such Prosecution and Maintenance by [***] shall be through patent counsel reasonably acceptable to [***]. [***] shall keep [***] informed as to
material developments with respect to the Prosecution and Maintenance of such Patents including by providing copies of all substantive office actions, examination reports, communications or any other substantive documents to or from any patent
office, including notice of all interferences, reissues, re-examinations, inter partes reviews, derivations, post grant proceedings, oppositions or requests for patent term extensions. [***] shall also provide
[***] with a reasonable opportunity to comment substantively on the Prosecution and Maintenance of such Prothena Licensed Collaboration Patents and Licensed Program Patents prior to taking material actions (including the filing of initial
applications), and will in good faith incorporate any comments made by and actions recommended in good faith by [***], provided, however, that [***] provides its comments reasonably in advance of any applicable filing deadlines. 

(b)    [***] Back-Up Right. If [***] in the Territory decides not to file
a Prothena Licensed Collaboration Patent or Licensed Program Patent, in each case other than a Prothena Platform Patent, or intends to allow such Patent to lapse or become abandoned without having first filed a substitute, it shall notify and
consult with [***] of such decision or intention at least [***] ([***]) days prior to the date upon which the subject matter of such Patent shall become unpatentable or such Patent shall lapse or become abandoned, and [***] shall thereupon have the
right (but not the obligation) upon written notice to [***] to assume the Prosecution and Maintenance thereof at [***] expense with counsel of its choice ([***]). For clarity, the provisions of this Section 6.8.2(b) shall not limit
Prothena’s obligations to Prosecute and Maintain the Prothena Licensed Collaboration Patents and Licensed Program Patents in the Territory as set forth in Section 6.8.2(b). 

(c)    Cooperation in Prosecution and Maintenance. 

(i)    Further Assurances. If Celgene determines to undertake the Prosecution and Maintenance of a Prothena
Licensed Collaboration Patent or Licensed Program Patent in accordance with this Section 6.8.2, Prothena agrees to make its employees, agents and consultants reasonably available to Celgene (and to Celgene’s authorized attorneys, agents or
representatives) to enable Celgene to undertake such Prosecution and Maintenance. In addition, Prothena shall (and shall cause its Affiliates and its and their employees, agents and consultants 

  
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treatment has been requested with respect to the omitted portions. 

 
to) provide reasonable assistance to Celgene (and to Celgene’s authorized attorneys, agents or representatives) to enable Celgene to undertake such Prosecution and Maintenance, including by
executing powers of attorney and other documents for Celgene to undertake such Prosecution and Maintenance. 

(ii)    Assistance. The Parties shall reasonably cooperate with one another with respect to the Prosecution and
Maintenance of the Prothena Licensed Collaboration Patents and Licensed Program Patents for which either Party is responsible for Prosecution and Maintenance pursuant to this Section 6.8.2. [***], the Parties shall cooperate with one another to
[***], in each case that are applicable to the Licensed Target or Licensed Program Antibody, as applicable, if practicable to [***]. 

(d)    Costs of Prosecution and Maintenance. Except as otherwise expressly set forth in this Section 6.8.2,
each Party shall be responsible for all costs and expenses associated with its Prosecution and Maintenance activities under this Section 6.8.2 with respect to Prothena Licensed Collaboration Patents and Licensed Program Patents for which it is
responsible pursuant to Sections 6.8.2(a) or 6.8.2(b), as applicable. Notwithstanding the foregoing provisions of this Section 6.8.2, [***]. If any Prothena Licensed Collaboration Patents or Licensed Program Patents claim or cover [***] and
such Prothena Licensed Collaboration Patent or Licensed Program Patent, as applicable, is [***], and [***] for the Prosecution and Maintenance of such Prothena Licensed Collaboration Patent or Licensed Program Patent, as applicable, pursuant to
Section [***] shall [***]. 
 6.9    Enforcement of Prothena Licensed Collaboration Patents and Licensed Program
Patents. 
 6.9.1    Prior to the end of the Phase 1 Option Term. Prior to the end of the Phase 1 Option Term
for the Licensed Program, the provisions of Section 7.7 of the Master Collaboration Agreement shall apply with respect to the Prothena Licensed Collaboration Patents and Licensed Program Patents. 

6.9.2    Following Phase 1 Option Term. Following the end of the Phase 1 Option Term for the Licensed Program, the
provisions of this Section 6.9.2 shall apply with respect 

  
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treatment has been requested with respect to the omitted portions. 

 
to the Prothena Licensed Collaboration Patents and Licensed Program Patents in the Territory, and the provisions of Master Collaboration Agreement shall continue to apply with respect to the
Prothena Licensed Collaboration Patents and Licensed Program Patents outside the Territory. 
 (a)    Notice. If
any Party learns of an infringement or threatened infringement by a Third Party of any Prothena Licensed Collaboration Patent or Licensed Program Patent, in each case other than a Prothena Platform Patent, in the Territory (including in connection
with any Biosimilar Application referencing a Licensed Product (regardless of whether such notice or copy is provided under any Applicable Laws) including under the BPCIA or the United States Patient Protection and Affordable Care Act or its
successor provisions, or any similar provisions in a country outside the United States, as applicable) such Party shall promptly notify the other Party and shall provide such other Party with available evidence of such infringement, and following
such notification, the Parties shall confer. 
 (b)    [***] First Right. Subject to the remaining provisions of
this Section 6.9.2, [***] shall have the first right, but not the obligation, to institute, prosecute, and control any action or proceeding (which may include settlement or otherwise seeking to secure the abatement of such infringement) with
respect to any infringement of any (i) Prothena Licensed Collaboration Patent or (ii) Licensed Program Patent, in each case other than a Prothena Platform Patent, (including in connection with any Biosimilar Application referencing a
Licensed Product (regardless of whether such notice or copy is provided under any Applicable Laws), including under the BPCIA or the United States Patient Protection and Affordable Care Act or its successor provisions, or any similar provisions in a
country outside the United States, as applicable), by counsel of its own choice, in [***]’s own name [***] and under [***]’s direction and control, including the right to control the defense of any challenges to such Patents as a
counterclaim in such infringement proceeding as well as the defense of declaratory judgment actions. Prothena retains all rights to enforce the Prothena Platform Patents against any actual or threatened infringement. 

(c)    [***] Back-Up Right. If [***] determines not to institute an action
or proceeding with respect to a given infringement of any Prothena Licensed Collaboration Patent or Licensed Program Patent pursuant to Section 6.9.2(b), it shall notify and consult with [***] of such decision, and, subject to the remaining
provisions of this Section 6.9.2, [***] shall thereupon have the right (but not the obligation) to institute an action or proceeding with respect to such infringement of such Prothena Licensed Collaboration Patent or Licensed Program Patent, as
applicable, at [***]’s expense with counsel of its choice. Notwithstanding the foregoing provisions of this Section 6.9.2(c), if [***] has any reasonable grounds for believing that [***]’s exercise of its backup enforcement right with
respect to any Patent as set forth in this Section 6.9.2(c) [***], then [***] shall not be permitted to enforce such Patent without the prior consent of [***], in [***]’s discretion. 

(d)    [***]. Notwithstanding the foregoing Sections 6.9.2(b) and 6.9.2(c), the Parties must agree in writing
prior to either Party initiating any action or proceeding with respect to any infringement of any Prothena Licensed Collaboration Patent or Licensed Program Patent with respect to any [***]. 

  
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treatment has been requested with respect to the omitted portions. 

 (e)    Joinder. In the case of any enforcement action or
proceeding set forth in Section [***] controlled by Celgene, Prothena will (and will cause its Affiliates to) join any such action or proceeding as a party at Celgene’s expense (and Prothena will use commercially reasonable efforts to cause any
Third Party as necessary to join such action or proceeding as a party) if doing so is necessary for the purposes of establishing standing or is otherwise required by Applicable Law to pursue such action or proceeding. Prothena may, at its option,
participate in such enforcement action or proceeding at its own expense. In the case of any enforcement action or proceeding controlled by Prothena pursuant to Section [***], Celgene may, at its option, participate in such enforcement action
or proceeding at its own expense. Celgene will join any such action or proceeding controlled by Prothena as a party at Prothena’s expense (and Celgene will use commercially reasonable efforts to cause any Third Party as necessary to join such
action or proceeding as a party) if doing so is necessary for the purposes of establishing standing or is otherwise required by Applicable Law to pursue such action or proceeding. Celgene will bear all costs and expenses incurred by it arising out
of such enforcement action or proceeding controlled by Celgene, and Prothena will bear all costs and expenses incurred by it arising out of such enforcement action or proceeding controlled by Prothena. 

(f)    Consultation; Cooperation. The enforcing Party will keep the
non-enforcing Party regularly informed of the status and progress of such enforcement efforts with respect to any Prothena Licensed Collaboration Patent or Licensed Program Patent, in each case other than a
Prothena Platform Patent. The enforcing Party shall consult with the non-enforcing Party and will take comments of the non-enforcing Party into good faith consideration
with respect to the infringement or claim construction of any claim in any such Prothena Licensed Collaboration Patent or Licensed Program Patent. The non-enforcing Party will provide to the enforcing Party
reasonable cooperation in such enforcement, at such enforcing Party’s request and expense. In addition, Prothena shall (a) keep Celgene regularly informed of the status and progress of enforcement efforts with respect to any foreign
counterparts of such Prothena Licensed Collaboration Patents and Licensed Program Patents and (b) consult with Celgene and will take comments of Celgene into good faith consideration with respect to the infringement or claim construction of any
claim in any foreign counterparts of such Prothena Licensed Collaboration Patents and Licensed Program Patents. 

(g)    Settlement. A settlement or consent judgment or other voluntary final disposition of a suit with respect to
the Prothena Licensed Collaboration Patents or Licensed Program Patents, in each case other than a Prothena Platform Patent, under this Section 6.9.2 may be entered into without the consent of the Party not bringing suit; provided, however,
that any such settlement, consent judgment or other disposition of any action or proceeding by the Party bringing suit under this Section 6.9.2 shall not, without the prior written consent of the Party not bringing suit, such consent not to be
unreasonably withheld, (i) impose [***] liability or obligation on the Party not bringing suit or any of its Affiliates, (ii) conflict with [***] of the subject matter claimed in the applicable Prothena Licensed Collaboration Patents or
Licensed Program Patents, (iii) [***], include the grant of any license, covenant or other rights to any Third Party that would conflict with [***] the rights or licenses granted to Celgene under this Agreement, the Master Collaboration Agreement,
any Global License Agreement or any other U.S. License Agreement, or (iv) [***] 

  
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treatment has been requested with respect to the omitted portions. 

 [***]. 

(h)    Costs and Recoveries. Except as otherwise set forth in this Section 6.9.2, each Party shall bear all
of its costs incurred in connection with its activities under this Section 6.9.2. Any damages or other monetary awards recovered in any action, suit or proceeding brought under this Section 6.9.2 to the extent related to any Prothena
Licensed Collaboration Patents or Licensed Program Patents shall be shared as follows: 
 (i)    the amount of such
recovery actually received by the Party controlling such action shall first be applied to reimburse costs and expenses incurred by each Party in connection with such action (including, for this purpose, [***] counsel); and 

(ii)    any remaining proceeds shall be (A) for any action controlled by Celgene, retained by, or provided to,
Celgene [***], and (B) for any action controlled by Prothena, retained by, or provided to, Prothena [***]. 

(i)    Biosimilar Applications. Notwithstanding the foregoing provisions of this Section 6.9.2, if either
Party receives a copy of a Biosimilar Application referencing a Licensed Product, whether or not such notice or copy is provided under any Applicable Laws (including under the BPCIA, the United States Patient Protection and Affordable Care Act, or
its successor provisions, or any similar provisions in a country outside the United States, as applicable), or otherwise becomes aware that such a Biosimilar Application has been submitted to a Regulatory Authority for marketing authorization (such
as in an instance described in 42 U.S.C. §262(l)(2)), the remainder of this Section 6.9.2(i) shall apply. Such Party shall promptly, but in any event within [***] ([***]) Business Days, notify the other Party. The owner of the relevant
Patents shall then seek permission to view the Biosimilar Application, information regarding the process or processes used to manufacture the product that is the subject of the Biosimilar Application, and related confidential information from the
filer of the Biosimilar Application if necessary under 42 U.S.C. §262(l)(1)(B)(iii). If either Party receives any equivalent or similar communication or notice in the United States or any other jurisdiction, the Party receiving such
communication or notice shall within [***] ([***]) Business Days notify the other Party of such communication or notice to the extent permitted by Applicable Laws. Regardless of the Party that is the “reference product sponsor,” as defined
in 42 U.S.C. §262(l)(1)(A), for purposes of such Biosimilar Application: 
 (i)    [***] the outside counsel and in-house counsel who shall receive confidential access to the Biosimilar Application, information regarding the process or processes used to manufacture the product that is the subject of the Biosimilar Application,
and any related confidential information pursuant to 42 U.S.C. §262(l)(1)(B)(ii). 

  
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treatment has been requested with respect to the omitted portions. 

 (ii)    In each case, after consulting with [***] and considering
[***]’s comments in good faith, [***] shall have the right to (a) list any patents, including those Patents within the Prothena IP, as required pursuant to 42 U.S.C. §262(l)(3)(A) or 42 U.S.C. §262(l)(7), (b) respond to any
communications with respect to such lists from the filer of the Biosimilar Application, (c) negotiate with the filer of the Biosimilar Application as to whether to utilize a different mechanism for information exchange other than that specified
in 42 U.S.C. §262(l)(1), and (d) as to the Patents that will be subject to the litigation procedure as described in 42 U.S.C. §262(l)(4), decide which Patent or Patents shall be selected for litigation under 42 U.S.C.
§262(l)(5)(B)(i)(II), and commence such litigation under 42 U.S.C. §262(l)(6). [***] 
 (iii)    [***] shall
cooperate with [***]’s reasonable requests in connection with the foregoing activities to the extent required or permitted by Applicable Laws. [***] shall consult with [***] prior to identifying any Patents within the Prothena IP to a Third
Party as contemplated by this Section 6.9.2(i). [***] shall consider in good faith advice and suggestions with respect thereto received from [***], and notify [***] of any such lists or communications promptly after they are made. 

(iv)    Each Party shall within [***] ([***]) Business Days after receiving any notice of commercial marketing provided
by the filer of a Biosimilar Application pursuant to 42 U.S.C. §262(l)(8)(A), notify the other Party. To the extent permitted by Applicable Law, [***] shall have the first right, but not the obligation, to seek an injunction against such
commercial marketing as permitted pursuant to 42 U.S.C. §262(l)(8)(B) and to file an action for infringement. [***]. Except as otherwise provided in this Section 6.9.2(i), any such action shall be subject to the terms and conditions of
Section 6.9.2(a) through 6.9.2(h). 
 (v)    The Parties recognize that procedures other than those set forth
above in this Section 6.9.2(i) may apply with respect to Biosimilar Applications. In the event that the Parties determine that certain provisions of Applicable Laws in the United States apply to actions taken by the Parties with respect to
Biosimilar Applications under this Section 6.9.2(i), the Parties shall comply with any such Applicable Laws (and any relevant and reasonable procedures established by Parties) in exercising their rights and obligations with respect to
Biosimilar Applications under this Section 6.9.2(i). Notwithstanding the provisions of this Section 6.9.2(i), nothing in this Section 6.9.2(i) shall grant any rights to Prothena with respect to any Celgene IP. 

6.10    Patent Term Extensions. Prothena shall reasonably cooperate with Celgene, including providing reasonable
assistance to Celgene (including executing any documents as may reasonably be required), in efforts to seek and obtain patent term restoration or supplemental protection certificates or the like or their equivalents in the Territory, where
applicable to Prothena Licensed Collaboration Patents or Licensed Program Patents or any other Patents Controlled by Celgene (or any of its Affiliates), in each case other than a Prothena Platform Patent, including as may be available to the Parties
under the provisions of the U.S. Drug Price Competition and Patent Term Restoration Act of 1984, in connection with any Licensed Product. In the event that elections with respect to obtaining such patent term restoration or supplemental protection
certificates or the like or their equivalents are to be made in connection therewith, [***] shall have the right to make the election and [***]. Without limiting the foregoing, [***]. 

  
 45 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 6.11    Regulatory Data Protection. [***] (or its designee) shall
have the sole right to list, with the applicable Regulatory Authorities in the Territory, all applicable Patents (including any Prothena Licensed Collaboration Patents or Licensed Program Patents) for any Licensed Product, including all so called
“Purple Book” listings required under the U.S. Public Health Service Act, [***]. For the avoidance of doubt, [***] will retain final decision-making authority as to the listing of all applicable Patents for any Licensed Product, regardless
of which Party owns such Patent, and [***] shall reasonably assist [***] in connection therewith. 
 6.12    Matters
Involving Joint Patents. The Prosecution and Maintenance, and the enforcement and defense, of any Joint Patents shall be jointly managed by the Parties through independent patent counsel (mutually agreed to by the Parties) jointly
representing the Parties, including any costs and recoveries regarding same. Prior to either Party publishing any Joint Know-How, the Parties will discuss if a Joint Patent claiming such Joint Know-How should be filed. 
 6.13    Common Interest Agreement. At the request of
either Party, the Parties shall negotiate in good faith to enter into a common interest agreement to govern their discussion of Patent matters. 

6.14    License Filing. At the request of [***], [***] shall, and shall cause its Affiliates to, assist in any
license registration processes with applicable Governmental Authorities that may be available for the protection of [***]’s interests in this Agreement. 

6.15    Defense of Claims Brought by Third Parties. If a Party becomes aware of any actual or potential claim that
the Development, Manufacture or Commercialization of a Licensed Antibody or Licensed Product by or on behalf of Celgene pursuant to this Agreement infringes the intellectual property rights of any Third Party, such Party shall promptly notify the
other Party. In any such instance, the Parties shall as soon as practicable thereafter meet to discuss in good faith regarding the best response to such notice; provided that Celgene shall have the final decision-making authority in connection
therewith. Except as set forth in Section 9.2 (and without limiting Celgene’s rights under Section 9.2), Celgene shall have the sole right, but not the obligation, to defend and dispose of (including through settlement or license)
such claim. [***] or on behalf of [***] (or any of its Affiliates or Sublicensees) in connection with [***] to the extent relating to the Development, Manufacture or Commercialization of a Licensed Antibody or Licensed Product, shall be [***], and
[***]. 

  
 46 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 ARTICLE 7. 

CONFIDENTIALITY 

7.1    Nondisclosure. Each Party agrees that a Party (the “Receiving Party”)
receiving Confidential Information of the other Party (the “Disclosing Party”) pursuant to this Agreement shall (a) maintain in confidence such Confidential Information using not less than the efforts such Receiving Party uses
to maintain in confidence its own proprietary information of similar kind and value, but in no event less than a reasonable degree of efforts, (b) not disclose such Confidential Information to any Third Party without the prior written consent
of the Disclosing Party, except for disclosures expressly permitted pursuant to this Article 7, and (c) not use such Confidential Information for any purpose except those permitted by this Agreement, including, in the case of Celgene, the
exercise of the rights and licenses granted to Celgene hereunder (it being understood that this clause (c) shall not create or imply any rights or licenses not expressly granted under this Agreement). The obligations of confidentiality, non-disclosure and non-use under this Section 7.1 shall be in full force and effect during the Term and for a period of [***] ([***]) years thereafter. The Receiving
Party will return all copies of or destroy (and certify such destruction in writing) the Confidential Information of the Disclosing Party disclosed or transferred to it by the other Party pursuant to this Agreement, within [***] ([***]) days after
the termination or expiration of this Agreement; provided, however, that a Party may retain (i) Confidential Information of the other Party to exercise rights and licenses which expressly survive such termination or expiration pursuant to this
Agreement, (ii) one (1) copy of all other Confidential Information in archives solely for the purpose of establishing the contents thereof and (iii) Celgene may retain Confidential Information of Prothena in the event that the Parties (or
their respective Affiliates) enter into a Global License Agreement for the Licensed Program, and in such case, Celgene shall not be required to return or destroy any Confidential Information of Prothena. Without limiting the foregoing, [***]
will keep confidential, and will cause its Affiliates and its and their employees, consultants, licensees, sublicensees, professional advisors and Affiliates to keep confidential, [***] on confidentiality terms at least as protective as the
confidentiality provisions of this Agreement (without regard to Section 7.3). 
 7.2    Licensed Program
Specific Confidential Information. Notwithstanding anything to the contrary contained herein, the Parties agree and acknowledge that any Licensed Program Specific IP shall be deemed to be Confidential Information of Celgene (without regard to
Section 7.3), and Celgene shall be deemed to be the Disclosing Party with respect to the Licensed Program Specific IP. As used herein, (a) the term “Licensed Program Specific IP” means, (i) [***], (ii) [***], and (iii)
[***]; and (b) the term “Licensed Program Non-Specific IP” means all Prothena Platform Technology within the Prothena Licensed Collaboration
Know-How, and other Prothena Licensed Collaboration Know-How and Licensed Program Know-How other than Licensed Program Specific
IP.    For clarity, Licensed Program Non-Specific IP shall be deemed to be the Confidential Information of Prothena. 

  
 47 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.3    Exceptions. 

7.3.1    General. The obligations in Section 7.1 shall not apply with respect to any portion of the
Confidential Information of the Disclosing Party that the Receiving Party can show by competent written proof: 

(a)    was known to the Receiving Party or any of its Affiliates, without any obligation to keep it confidential or any
restriction on its use, prior to disclosure by the Disclosing Party; 
 (b)    is subsequently disclosed to the
Receiving Party or any of its Affiliates by a Third Party lawfully in possession thereof and without any obligation to keep it confidential or any restriction on its use; 

(c)    is published by a Third Party or otherwise becomes publicly available or enters the public domain, either before
or after it is disclosed to the Receiving Party, without any breach by the Receiving Party of its obligations hereunder; 

(d)    is published by a Party in accordance with Section 7.8 without any breach by such Party of its obligations
hereunder; or 
 (e)    is independently developed by or for the Receiving Party or its Affiliates without reference to
or reliance upon the Disclosing Party’s Confidential Information. 
 Any combination of features or disclosures shall not be deemed to
fall within the foregoing exclusions merely because individual features are published or available to the general public or in the rightful possession of the Receiving Party unless the combination itself and principle of operation are published or
available to the general public or in the rightful possession of the Receiving Party. 
 7.4    Authorized
Disclosure. 
 7.4.1    Disclosure. Notwithstanding Section 7.1, the Receiving Party may disclose
Confidential Information belonging to the Disclosing Party in the following instances: 
 (a)    subject to
Section 7.6, to comply with Applicable Law (including the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) or any national securities exchange) or with judicial process (including prosecution or
defense of litigation), if, in the reasonable opinion of the Receiving Party’s counsel, such disclosure is necessary for such compliance or for such judicial process (including prosecution or defense of litigation); 

(b)    is disclosed to governmental or other regulatory agencies in order to obtain Patents or to gain or maintain
approval to conduct Clinical Trials or to market Licensed Product under this Agreement, in each case, in accordance with this Agreement, but such disclosure shall only be to the extent reasonably necessary to obtain Patents or authorizations, and
provided that reasonable steps are taken to ensure confidential treatment of such Confidential Information (if available); 

  
 48 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (c)    to any of its officers, employees, consultants, agents or
Affiliates (including, (i) [***], (ii) in the case of either Party, to such Party’s subcontractors for purpose of such subcontractor performing obligations of such Party under this Agreement) as it deems necessary or advisable in the course of
conducting activities in accordance with this Agreement in order to carry out its responsibilities or exercise its rights under this Agreement (including the exercise of the rights and licenses granted to the relevant Party hereunder), and
(iii) in the case of either Party, to such Party’s actual or potential acquirers; provided that each such disclosee is bound by written confidentiality obligations and non-use obligations no less
restrictive than those set forth in this Article 7 to maintain the confidentiality thereof and not to use such Confidential Information except as expressly permitted by this Agreement; provided, however, that, in each of the above situations in this
Section 7.4.1(c), the Receiving Party shall remain responsible for any failure by any Person who receives Confidential Information from such Receiving Party pursuant to this Section 7.4.1(c) to treat such Confidential Information as
required under this Article 7; and 
 (d)    disclosure, solely on a “need to know basis” to its advisors
(including attorneys and accountants) in connection with activities hereunder; provided that, prior to any such disclosure, each disclosee must be bound by written obligations of confidentiality,
non-disclosure and non-use no less restrictive than the obligations set forth in this Article 7 (provided, however, that in the case of legal advisors, no written
agreement shall be required), which for the avoidance of doubt, will not permit use of such Confidential Information for any purpose except those expressly permitted by this Agreement; provided, however, that, in each of the above situations in this
Section 7.4.1(d), the Receiving Party shall remain responsible for any failure by any Person who receives Confidential Information from such Receiving Party pursuant to this Section 7.4.1(d) to treat such Confidential Information as
required under this Article 7. 
 7.4.2    Terms of Disclosure. If and whenever any Confidential Information is
disclosed in accordance with this Section 8.4, such disclosure shall not cause any such information to cease to be Confidential Information except to the extent that such disclosure results in a public disclosure of such information (other than
by breach of this Agreement). Where reasonably possible and subject to Section 7.6, the Receiving Party shall notify the Disclosing Party of the Receiving Party’s intent to make any disclosures pursuant to Section 8.4.1(a)
sufficiently prior to making such disclosure so as to allow the Disclosing Party adequate time to take whatever action it may deem appropriate to protect the confidentiality of the information, and the Receiving Party will provide reasonable
assistance to the Disclosing Party with respect thereto; provided that, in such event, the Receiving Party will use reasonable measures to ensure confidential treatment of such information and shall only disclose such Confidential Information of the
Disclosing Party as is necessary for the purposes of Section 8.4.1(a), as applicable. 
 7.4.3    Licensed
Program Specific IP. [***] shall not disclose the Licensed Program Specific IP without the prior written consent of [***], other than pursuant to Section 8.4.1  

7.5    Terms of this Agreement. The Parties agree that this Agreement and the terms hereof shall be deemed to be
Confidential Information of both Prothena and Celgene, and each Party agrees not to disclose any of them without the prior written consent of the other Party, except that each Party may disclose any of them in accordance with the provisions of
Sections 8.4 and/or 7.6, as applicable. 

  
 49 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.6    Securities Filings; Disclosure under Applicable
Law. Each Party acknowledges and agrees that the other Party may submit this Agreement to (or file this Agreement with) the SEC or any national securities exchange in any jurisdiction (collectively, the “Securities Regulators”),
or to other Persons as may be required by Applicable Law, and if a Party does submit this Agreement to (or file this Agreement with) any Securities Regulators, or other Persons as may be required by Applicable Law, such Party agrees to consult with
the other Party with respect to the preparation and submission of a confidential treatment request for this Agreement. Notwithstanding the foregoing, if a Party is required by Applicable Law or any Securities Regulator to make a disclosure of the
terms of this Agreement in a filing or other submission as required by Applicable Law or Securities Regulator, and (a) such Party has provided copies of the disclosure to the other Party reasonably in advance of such filing or other disclosure
under the circumstances, (b) such Party has promptly notified the other Party in writing of such requirement and any respective timing constraints, and (c) such Party has given the other Party a reasonable time under the circumstances from
the date of notice by such Party of the required disclosure to comment upon and request confidential treatment for such disclosure, then such Party will have the right to make such disclosure at the time and in the manner reasonably determined by
its counsel to be required by Applicable Law or Securities Regulator. Notwithstanding the foregoing, it is hereby understood and agreed that if a Party seeks to make a disclosure as required by Applicable Law or Securities Regulator as set forth in
this Section 7.6, and the other Party provides comments within the respective time periods or constraints specified herein or within the respective notice, the Party seeking to make such disclosure or its counsel, as the case may be, will in
good faith consider incorporating such comments. 
 7.7    Publicity. 

7.7.1    Press Release; Public Statements. Subject to Section 8.4, 7.6 and this Section 8.7, Prothena
agrees not to (and shall cause its Affiliates not to) issue any press release or other public statement disclosing this Agreement, the activities hereunder, or the transactions contemplated hereby, unless such press release or other public statement
is approved by Celgene in writing; provided that Prothena shall be authorized to make any disclosure, without the approval of Celgene, that is required by Applicable Laws (including the U.S. Securities Act of 1933, as amended, and the U.S.
Securities Exchange Act of 1934, as amended) or the rules of any Securities Regulator, or by judicial process, subject to and in accordance with Sections 8.4 and 7.6, as applicable. Without limiting the foregoing, and subject to the foregoing
proviso, in the event that Prothena desires to issue an initial press release regarding the execution of this Agreement, Prothena shall have the right to do so provided that (i) [***] and (ii) [***]. For the avoidance of doubt, [***]. 

7.7.2    Additional Restrictions on Disclosure. Without limiting any other restrictions on disclosure set forth in
this Article 7, with respect to any press release or other public statement proposed to be made by Prothena, if such press release or public 

  
 50 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
statement discloses, with respect to such Licensed Program, [***], such press release or other public statement may not be issued without Celgene’s prior written consent, except, for such
disclosures by Prothena as required by Applicable Law or Securities Regulators (solely and to the extent Prothena’s counsel determines such disclosure is required by Applicable Law or Securities Regulators); provided that (i) in such case
Prothena shall use reasonable efforts to afford Celgene a reasonable period of time to review any such disclosure and any comments made by Celgene will be considered in good faith and (ii) any information that has been previously publicly
disclosed in accordance with this Agreement may be disclosed again as long as such disclosure does not exceed the scope of such prior public disclosure. Subject to the foregoing, in the event Celgene proposes that Prothena use specific wording or
language with respect thereto, Prothena shall in good faith consider incorporating such wording or language. 

7.7.3    Previously Issued Public Statements. The contents of any press release or other public statement that has
been reviewed and approved by a reviewing Party may be re-released by the publishing Party or by such reviewing Party without a requirement for re-approval. 

7.8    Permitted Publications of Results. 

7.8.1    Publication. In the event Prothena (the “Publishing Party”) desires to publish or present
any information (including publications in journals, posters, presentations at conferences and abstracts submitted in advance of conferences) with respect to the results of the Licensed Program (including the results of a Phase 1 Clinical Trial
under the Licensed Program), or with respect to the Licensed Target, any Licensed Antibody or Licensed Product, the Publishing Party shall provide Celgene with a copy of such proposed publication or presentation no less than [***] ([***]) days
(provided that the other Party shall use Commercially Reasonable Efforts to accommodate a shorter time period if required due to circumstances outside of the Publishing Party’s control) prior to its intended submission for publication or public
disclosure. For the avoidance of doubt, the foregoing shall apply with respect to each proposed publication or presentation regardless of whether a prior publication or presentation was provided (e.g., if an abstract is provided in accordance with
this Section 7.8.1 and the Publishing Party wishes to publish the corresponding full manuscript, the full manuscript must be provided to Celgene pursuant to this Section 7.8.1). Celgene shall respond in writing promptly and in no event
later than [***] ([***]) days after receipt of the proposed material (provided that the other Party shall use Commercially Reasonable Efforts to accommodate a shorter time period if notified by the Publishing Party and required due to circumstances
outside of the Publishing Party’s control), with one or more of the following: 
 (a)    comments on the proposed
material, which the Publishing Party shall consider in good faith; and/or 
 (b)    a specific statement of concern,
based upon the need to seek patent protection or to block publication or public disclosure (including publications in journals, posters, presentations at conferences and abstracts submitted in advance of conferences) if Celgene

  
 51 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
reasonably determines that the proposed disclosure is intellectual property that should be maintained as a trade secret to protect the Licensed Target or any Licensed Antibody and/or Licensed
Product, in which event the Publishing Party agrees not to submit such publication or make such presentation that contains such information until: 

(i)    with respect to publication or presentation of Licensed Program
Non-Specific IP, Celgene is given [***], to seek patent protection for any such Licensed Program Non-Specific IP in such publication or presentation which it believes is
patentable or to resolve any other issues, or 
 (ii)    with respect to publication or presentation of Licensed
Program Specific IP, [***] for Celgene to (x) enable further development and optimization of such Licensed Program Specific IP (including related Licensed Antibodies and Licensed Products), (y) seek patent protection for any such Licensed
Program Specific IP in such publication or presentation which it believes is patentable or (z) resolve any other issues; and/or 

(c)    an identification of Celgene’s Confidential Information that is contained in the material reviewed, which the
Publishing Party shall remove, if requested by Celgene. 
 Notwithstanding the foregoing or anything to the contrary contained herein, the
restrictions set forth in this Section 7.8.1 shall not apply to publications or presentations by Celgene (or its Affiliates or sublicensees) and Celgene (and its Affiliates and sublicensees) shall be free to make publications and presentations
with respect to results of the Licensed Program, the Licensed Target, Licensed Antibody and/or Licensed Product without the prior review or consent of Prothena. 

7.8.2    Re-Publication;
Re-Presentation. The contents of any publication or presentation that has been reviewed and approved by a reviewing Party may be re-released by the Publishing Party
or the reviewing Party without a requirement for re-approval. 
 7.9    Use
of Names. Except as otherwise expressly set forth herein, no Party (or its respective Affiliates) shall use the name, trademark, trade name or logo of the other Party or its Affiliates, or its or their respective employee(s) in any publicity,
promotion, news release or other public disclosure relating to this Agreement or its subject matter, without the prior written permission of the other Party; provided that such permission shall not be required to the extent use thereof may be
required by Applicable Law, including the rules of any securities exchange or market on which a Party’s (or its Affiliate’s) securities are listed or traded. 

7.10    Clinical Trials Registry. Celgene (and its Affiliates and designees) shall have the right to publish
registry information and summaries of data and results from any Clinical Trials conducted in connection with activities under this Agreement, on its clinical trials registry or on a government-sponsored database such as www.clinicaltrials.gov,
without requiring the consent of Prothena. The Parties shall reasonably cooperate if required or reasonably requested by Celgene in order to facilitate any such publication by Celgene (and its Affiliates and designees). 

  
 52 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 7.11    Relationship to Master Collaboration Agreement. Except as
otherwise expressly stated in this Article 7, this Agreement supersedes the provisions of Article 8 of the Master Collaboration Agreement with respect to any Confidential Information related to the Licensed Program. the Licensed Target, Licensed
Antibodies or Licensed Products (the “Licensed Program Confidential Information”); provided that, except as otherwise set forth herein, all “Confidential Information” of the “Disclosing Party” thereunder
that is Licensed Program Confidential Information shall be deemed Confidential Information of the Disclosing Party hereunder and shall be subject to the terms and conditions of this Agreement and the “Receiving Party” shall be bound by and
obligated to comply with such terms and conditions as if they were the Receiving Party hereunder, subject in all cases to Section 7.2. The foregoing shall not be interpreted as a waiver of any remedies available to the “Disclosing
Party” as a result of any breach, prior to the Effective Date, by the “Receiving Party”, of its obligations pursuant to Article 8 of the Master Collaboration Agreement. 

7.12    Global License Agreement. Notwithstanding the foregoing provisions of this Article 7, if a Global License
Agreement is entered into with respect to the Licensed Program, then the provisions of such Global License Agreement shall control with respect to Confidential Information related to the Licensed Program in lieu of this Article 7. 

ARTICLE 8. 

REPRESENTATIONS AND WARRANTIES; COVENANTS 

8.1    Representations and Warranties of Both Parties. Each Party hereby represents and warrants to the other
Party, as of the Effective Date, that: 
 (a)    such Party is duly organized, validly existing and in good standing
under the Applicable Law of the jurisdiction of its formation and has full corporate power and authority to enter into this Agreement, and to carry out the provisions hereof; 

(b)    such Party has taken all necessary corporate action on its part to authorize the execution and delivery of this
Agreement and the performance of its obligations hereunder; 
 (c)    this Agreement has been duly executed and
delivered on behalf of such Party, and constitutes a legal, valid, binding obligation, enforceable against it in accordance with its terms, except to the extent that enforcement of the rights and remedies created hereby is subject to
(i) bankruptcy, insolvency, reorganization, moratorium and other similar laws of general application affecting the rights and remedies of creditors, or (ii) laws governing specific performance, injunctive relief and other equitable
remedies; 
 (d)    the execution, delivery and performance of this Agreement by such Party does not breach or conflict
with any agreement or any provision thereof, or any instrument or understanding, oral or written, to which such Party (or any of its Affiliates) is a party or by which such Party (or any of its Affiliates) is bound, nor violate any Applicable Law of
any Governmental Authority having jurisdiction over such Party (or any of its Affiliates); 
 (e)    no government
authorization, consent, approval, license, exemption of or filing or registration with any court or governmental department, commission, board, bureau, 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
agency or instrumentality, domestic or foreign, under any Applicable Law currently in effect, is or will be necessary for, or in connection with, the transaction contemplated by this Agreement,
or for the performance by it of its obligations under this Agreement, except (i) as may be required to conduct Clinical Trials or to seek or obtain Regulatory Approvals or applicable Regulatory Materials or (ii) as set forth in
Section 3.2 of the Master Collaboration Agreement; and 
 (f)    it has obtained all necessary authorizations,
consents and approvals of any Third Party that is required to be obtained by it as of the Effective Date for, or in connection with, the transaction contemplated by this Agreement, or for the performance by it of its obligations under this
Agreement, except (i) as may be required to conduct Clinical Trials or to seek or obtain Regulatory Approvals or applicable Regulatory Materials or (ii) as set forth in Section 3.2 of the Master Collaboration Agreement. 

8.2    Representations and Warranties of Prothena. Except as set forth on Schedule 8.2 Prothena
hereby represents and warrants to Celgene, as of the Effective Date, that: 5 

(a)    Schedules 1.47(b) and 1.64 contain a complete and accurate list of all Patents included in
the Prothena IP that claim or cover any Licensed Target, Licensed Antibodies or Licensed Products, including the composition or use of any of the foregoing, and Prothena Controls all such Patents. Except for the Prothena IP, (i) Prothena and
its Affiliates do not own or control (by license or otherwise), as of the Effective Date, any Patent or Know-How that is necessary or useful to Develop, Manufacture or Commercialize the Licensed Target,
Licensed Antibodies or Licensed Products and (ii) no other Know-How or Patents arose from, or were used in, the performance of the Licensed Program under the Master Collaboration Agreement. To
Prothena’s and its Affiliates’ actual knowledge, all issued Patents within the Prothena IP are in full force and effect, and are not invalid or unenforceable, in whole or in part; 

(b)    no claim has been issued or served, or written threat of a claim or litigation made by any Person, against
Prothena or its Affiliates that alleges that any Prothena IP is invalid or unenforceable; 
 (c)    neither Prothena
nor its Affiliates own or otherwise control (through license or otherwise) any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that Target the Licensed Target, other than the Licensed Program
Antibodies (all of which are set forth on Schedule 1.45) and the Licensed Program Products; 
 (d)    [***];

 (e)    neither Prothena nor its Affiliates are subject to any payment obligations to Third Parties as a result of
the execution or performance of this Agreement, or the research, development, manufacture or commercialization of the Licensed Target or any Antibodies (or any products constituting, incorporating, comprising or containing any such Antibody) that
Target the Licensed Target; 
  
  

	5 	 [***] 

  
 54 

[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (f)    Prothena has the full right and authority to grant all of the
rights and licenses granted to Celgene (or purported to be granted to Celgene) hereunder; and neither Prothena nor its Affiliates have granted any right or license to any Third Party relating to any of the Prothena IP or any other Licensed Program
Asset, Licensed Target or Antibody (or any products constituting, incorporating, comprising or containing any such Antibody) that Targets the Licensed Target, that would conflict with or [***] any of the rights or licenses granted to Celgene
hereunder; 
 (g)    Prothena is the sole and exclusive owner of the Prothena IP, except for the Prothena Licensed
Collaboration IP that is exclusively licensed to Prothena (or its Affiliates) pursuant to the In-License Agreements set forth on Schedule 1.40. All Affiliates of Prothena have exclusively licensed or
assigned all of their right, title and interest in and to the Prothena IP to Prothena. Neither Prothena nor its Affiliates have granted any mortgage, pledge, claim, security interest, lien or other charge of any kind on the Prothena IP or other
Licensed Program Asset, and the Prothena IP and the other Licensed Program Assets are free and clear of any mortgage, pledge, claim, security interest, lien or charge of any kind; 

(h)    neither Prothena nor its Affiliates have received any written notice of any claim that any Patent or Know-How (including any trade secret right) owned or controlled by a Third Party would be infringed or misappropriated by the Development, Manufacture, or Commercialization of the Licensed Target, Licensed Antibody
or Licensed Product; 
 (i)    to Prothena’s and its Affiliates’ actual knowledge, (i) the Development
and Manufacture of the Licensed Target, any Licensed Antibody or Licensed Product, as conducted by or on behalf of Prothena or its Affiliates prior to the Effective Date, has not violated, infringed or misappropriated any intellectual property or
proprietary right of any Third Party and (ii) [***]; 
 (j)    there are no claims, judgments, settlements,
litigations, suits, actions, disputes, arbitration, judicial or legal administrative or other proceedings or governmental investigations pending or, to Prothena’s or its Affiliates’ knowledge, threatened against Prothena or its Affiliates
which would reasonably be expected to adversely affect or restrict the ability of Prothena to consummate or perform the transactions contemplated under this Agreement, or which would affect the Prothena IP or other Licensed Program Assets, or
Prothena’s Control thereof, or the Licensed Target or any Licensed Antibody or Licensed Product; 
 (k)    neither
Prothena nor its Affiliates have issued a claim against a Third Party alleging that a Third Party is infringing or has infringed or misappropriated any Prothena IP, and, to Prothena’s and its Affiliates’ actual knowledge, no issued Patents
within the Prothena IP are being infringed and no trade secrets within the Prothena IP are being misappropriated by any Third Party; 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (l)    neither Prothena nor its Affiliates have employed or otherwise
used in any capacity, the services of any Person suspended, proposed for debarment or debarred under United States law, including under 21 U.S.C. § 335a, or any foreign equivalent thereof, with respect to the Licensed Target, the Licensed
Antibodies or Licensed Products or otherwise in performing any portion of the Licensed Program. All Manufacture and Development (including non-clinical studies and Clinical Studies) related to the Licensed
Target, Licensed Antibodies or Licensed Products conducted by or on behalf of Prothena or its Affiliates prior to the Effective Date (including the conduct of the Licensed Program under the Master Collaboration Agreement) has been conducted in
accordance with all Applicable Laws (including, to the extent applicable, GCP, GLP and GMP); 
 (m)    neither Prothena
nor its Affiliates have entered into any agreement under which Prothena or its Affiliates (i) has obtained a license or sublicense of rights from a Third Party to the Licensed Target, or to any Antibodies (or any products constituting,
incorporating, comprising or containing any such Antibody) that Target the Licensed Target, or to any Prothena IP, except for the In-License Agreements set forth on Schedule 1.40, or
(ii) has granted a license, sublicense, option or right to a Third Party that remains in effect as of the Effective Date to research, develop, manufacture or commercialize the Licensed Target or any Antibodies (or any products constituting,
incorporating, comprising or containing any such Antibody) that Target the Licensed Target, except (1) with respect to licenses or rights granted pursuant to the agreements set forth on Schedule 1.40 that were entered into in the
ordinary course of business [***] performing activities on behalf of Prothena [and (2) [***]6. The agreements set forth on Schedule 1.40 do not conflict with [***] the rights
or licenses granted to Celgene hereunder;7 
 (n)    other than
the Existing Program Agreements, Prothena (or its Affiliates, as applicable) has not entered into any agreement relating to the Development, Manufacture, Commercialization or other exploitation of the Licensed Target, Licensed Antibodies or Licensed
Products, or the Prothena IP; 
 (o)    with respect to each Existing Program Agreement and In-License Agreement, (i) it is in full force and effect; (ii) Prothena (or its Affiliate, as applicable) is not in breach thereof; (iii) Prothena (or its Affiliate, as applicable) has not received
any notice from the counterparty to such Existing Program Agreement or In-License Agreement, as applicable, of Prothena’s (or its Affiliate’s, as applicable) breach or notice of threatened breach by
Prothena (or its Affiliate, as applicable) thereof and (iv) Prothena has provided Celgene with a true, correct and complete copy of each Existing Program Agreement and In-License Agreement; 

(p)    Prothena has disclosed to Celgene all material information and data, and all material correspondences to/from any
Regulatory Authority, existing as at the Effective Date in the possession or control of Prothena or its Affiliates, in each case related to the Licensed Program, Licensed Target, Licensed Antibodies or Licensed Products; and 

 
  

	6 	 [***] 

	7 	 [***] 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 (q)    Prothena has not obtained, or filed, any INDs, MAAs or
Regulatory Approvals or any other form of regulatory application for approval of Clinical Trials, marketing or other purpose, for any Licensed Antibodies or Licensed Products and, to Prothena’s and its Affiliates’ actual knowledge, no
other Person has obtained, or filed for, any such INDs, MAAs or Regulatory Approvals. 
 8.3    Additional
Representations, Warranties and Covenants of Prothena. Prothena hereby further represents, warrants and covenants to Celgene that: 

8.3.1    With respect to the In-License Agreements, (a) Prothena (or its
Affiliates, as applicable) shall not breach, or commit any acts or permit the occurrence of any omissions that would cause the breach or termination, of any In-License Agreement and (b) Prothena shall (or
shall cause its Affiliates to, as applicable) satisfy all of its obligations under each In-License Agreement in all material respects and shall, or shall cause its Affiliates to, as applicable, maintain each In-License Agreement in full force and effect. Prothena shall, or shall cause its Affiliates to, as applicable, enforce its rights under each In-License Agreement to the
extent necessary to preserve Celgene’s rights under this Agreement. Prothena shall not, and shall cause its Affiliates not to, [***] if doing so [***] under this Agreement. Prothena will provide Celgene with prompt written notice of any claim
of a breach of which it is aware under any of the In-License Agreements or notice of termination of any In-License Agreement. 

8.3.2    With respect to the Existing Program Agreements, (a) Prothena (or its Affiliates, as applicable) shall not
breach, or commit any acts or permit the occurrence of any omissions that would cause the breach or termination, of any Existing Program Agreement and (b) Prothena shall (or shall cause its Affiliates to, as applicable) satisfy all of its
obligations under each Existing Program Agreement in all material respects and shall, or shall cause its Affiliates to, as applicable, maintain each Existing Program Agreement in full force and effect, unless Prothena otherwise obtains
Celgene’s prior written consent (such consent not to be unreasonably withheld). Prothena shall, or shall cause its Affiliates to, as applicable, enforce its rights under each Existing Program Agreement to the extent necessary to preserve
Celgene’s rights under this Agreement. Prothena shall not, and shall cause its Affiliates not to, [***] under this Agreement. Prothena shall not, and shall cause its Affiliates not to assign or otherwise transfer any Existing Program Agreement.
Prothena will provide Celgene with prompt written notice of any claim of a breach of which it is aware under any of the Existing Program Agreements or notice of termination of any Existing Program Agreement. 

8.3.3    In-License Agreements. [***] on case-by-case basis, Prothena shall (or shall cause its Affiliates to, as applicable) execute a written agreement, in a form reasonably acceptable to Celgene, with each Third Party that is a counterparty to
the applicable In-License Agreement (each such counterparty, a “Prothena Licensor”) within 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 
[***] ([***]) days after the date of such request, pursuant to which (a) in the event of an early termination of such In-License Agreement, at the
request of Celgene, such Prothena Licensor shall grant a direct license to Celgene with respect to the intellectual property licensed to Prothena under such In-License Agreement, on the same terms under which
such Prothena Licensor grants such license to Prothena (or its Affiliate, as applicable) under such In-License Agreement, (b) such Prothena Licensor agrees to and acknowledges the rights granted to
Celgene hereunder with respect to any intellectual property licensed to Prothena (or its Affiliate, as applicable) under such In-License Agreement, including the rights as set forth in this Section 8.3.3,
and (c) [***]. 
 8.3.4    Notwithstanding anything to the contrary contained herein, [***]. 

8.3.5    Prothena shall promptly notify Celgene in writing if any Patents in the Prothena IP that claim or cover any
Licensed Target, Licensed Antibodies or Licensed Products, including the composition or use of any of the foregoing, becomes known to Prothena that are not listed on Schedule 1.47(b) or 1.64. 

8.4    Representations and Warranties of Celgene. Except as set forth on Schedule 8.4, Celgene hereby
represents and warrants to Prothena, as of the Effective Date, that: 
 8.4.1    there are no claims, judgments,
settlements, litigations, suits, actions, disputes, arbitration, judicial or legal administrative or other proceedings or governmental investigations pending or, to Celgene’s actual knowledge, threatened against Celgene which would reasonably
be expected to adversely affect or restrict the ability of Celgene to consummate or perform the transactions contemplated under this Agreement. 

8.5    Covenants. 

8.5.1    Mutual Covenants. Each Party hereby covenants to the other Party that: 

(a)    such Party and its Affiliates shall perform its activities pursuant to this Agreement in compliance (and shall
ensure compliance by any of its subcontractors) with all Applicable Laws, including, to the extent applicable, GCP, GLP and GMP. 

8.5.2    Prothena Covenants. Prothena hereby covenants to Celgene that: 

(a)    Neither Prothena nor its Affiliates shall grant any right or license to any Third Party relating to any of the
intellectual property rights it owns or Controls (including the Prothena IP and other Licensed Program Assets), or otherwise with respect to any Licensed Antibody, Licensed Product or Diagnostic Product which conflict with, [***] any of the rights
or licenses granted to Celgene hereunder; and 

  
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treatment has been requested with respect to the omitted portions. 

 (b)    Except with respect to the performance of the Prothena Ongoing
Program Activities in accordance with Section 2.3 (or as otherwise expressly agreed to by Celgene in writing, including as set forth in Section 2.7), neither Prothena nor its Affiliates shall use (and neither shall grant any Third Party
the right to use) any Licensed Antibodies, Licensed Products or Diagnostic Products for any purposes in the Territory. 

8.6    Disclaimer. EXCEPT AS OTHERWISE EXPRESSLY PROVIDED IN THIS AGREEMENT, NEITHER PARTY MAKES ANY
REPRESENTATIONS OR EXTENDS ANY WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED (AND EACH PARTY HEREBY EXPRESSLY DISCLAIMS ANY AND ALL REPRESENTATIONS AND WARRANTIES NOT EXPRESSLY PROVIDED IN THIS AGREEMENT), INCLUDING WITH RESPECT TO ANY PATENTS OR KNOW-HOW, OR MATERIALS, INCLUDING WARRANTIES OF VALIDITY OR ENFORCEABILITY, MERCHANTABILITY, FITNESS FOR A PARTICULAR USE OR PURPOSE, PERFORMANCE, AND NONINFRINGEMENT OF ANY THIRD PARTY PATENTS OR OTHER INTELLECTUAL
PROPERTY RIGHTS. WITHOUT LIMITING THE FOREGOING, NEITHER PARTY MAKES ANY REPRESENTATION, WARRANTY OR GUARANTEE THAT THE LICENSED PROGRAM WILL BE SUCCESSFUL, OR THAT ANY OTHER PARTICULAR RESULTS WILL BE ACHIEVED WITH RESPECT TO THE LICENSED PROGRAM,
THE LICENSED TARGET, ANY LICENSED ANTIBODY OR ANY LICENSED PRODUCT HEREUNDER. 
 ARTICLE 9. 

INDEMNIFICATION; INSURANCE 

9.1    Indemnification by Celgene. Celgene shall indemnify, defend and hold harmless Prothena and its Affiliates
and its and their respective directors, officers, employees, agents, successors and assigns (collectively, the “Prothena Indemnitees”), from and against any and all Third Party Damages to the extent arising out of or relating to,
directly or indirectly, any Third Party Claim based upon: 
 (a)    the gross negligence or willful misconduct of
Celgene or its Affiliates or its or their respective directors, officers, employees or agents, in connection with Celgene’s performance of its obligations under this Agreement; 

(b)    any breach by Celgene of any of its representations, warranties, covenants, agreements or obligations under this
Agreement; or 
 (c)    any claim for personal injury or death arising out of the Development, Manufacture or
Commercialization of the Licensed Antibodies and Licensed Products in the Territory by or on behalf of Celgene or its Affiliates or Sublicensees during the Term; 

in each case (a)-(c), provided, however, that such indemnity shall not apply to the extent Prothena has an indemnification obligation pursuant to
Section 9.2(a) or (b) for such Third Party Damages. 
 9.2    Indemnification by Prothena.
Prothena shall indemnify, defend and hold harmless Celgene, its Affiliates and its and their respective directors, officers, employees, agents, successors and assigns (collectively, the “Celgene Indemnitees”), from and against any
and all Third Party 

  
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treatment has been requested with respect to the omitted portions. 

 
Damages to the extent arising out of or relating to, directly or indirectly, any Third Party Claim based upon: 

(a)    the gross negligence or willful misconduct of Prothena or its Affiliates or its or their respective directors,
officers, employees or agents, in connection with Prothena’s performance of its obligations under this Agreement; 

(b)    any breach by Prothena of any of its representations, warranties, covenants, agreements or obligations under this
Agreement; or 
 (c)    any claim for personal injury or death arising out of the Development, Manufacture or
Commercialization of the Licensed Antibodies (including Reversion Antibodies) and Licensed Products (including products containing Reversion Antibodies) by or on behalf of Prothena or its Affiliates or sublicensees; 

in each case (a)-(c), provided, however, that such indemnity shall not apply to the extent Celgene has an indemnification obligation pursuant
to Section 9.1(a) or (b) for such Third Party Damages. 
 9.3    Procedure. If a Party is
seeking indemnification under Section 9.1 or 9.2, as applicable (the “Indemnitee”), it shall inform the other Party (the “Indemnitor”) of the claim giving rise to the obligation to indemnify pursuant to
Section 9.1 or 9.2, as applicable, as soon as reasonably practicable after receiving notice of the claim (provided, however, any delay or failure to provide such notice shall not constitute a waiver or release of, or otherwise limit, the
Indemnitee’s rights to indemnification under Section 9.1 or 9.2, as applicable, except to the extent that such delay or failure materially prejudices the Indemnitor’s ability to defend against the relevant claims). The Indemnitor
shall have the right to assume the defense of any such claim for which the Indemnitee is seeking indemnification pursuant to Section 9.1 or 9.2, as applicable. The Indemnitee shall cooperate with the Indemnitor and the Indemnitor’s insurer
as the Indemnitor may reasonably request, and at the Indemnitor’s cost and expense. The Indemnitee shall have the right to participate, at its own expense and with counsel of its choice, in the defense of any claim or suit that has been assumed
by the Indemnitor. The Indemnitor shall not settle any claim without the prior written consent of the Indemnitee, not to be unreasonably withheld; provided, however, that the Indemnitor shall not be required to obtain such consent if the settlement
(i) involves only the payment of money and will not result in the Indemnitee (or other Prothena Indemnitees or Celgene Indemnitees, as applicable) becoming subject to injunctive or other similar type of relief, (ii) does not require an
admission by the Indemnitee (or other Prothena Indemnitees or Celgene Indemnitees, as applicable) and (iii) does not adversely affect the rights or licenses granted to the Indemnitee (or its Affiliate) under this Agreement. The Indemnitee shall
not settle or compromise any such claim without the prior written consent of the Indemnitor, which it may provide in its sole discretion. If the Parties cannot agree as to the application of Section 9.1 or 9.2, as applicable, to any claim,
pending resolution of the dispute pursuant to Section 11.7 the Parties may conduct separate defenses of such claims, with each Party retaining the right to claim indemnification from the other Party in accordance with Section 9.1 or 9.2,
as applicable, upon resolution of the underlying claim. In each case, the Indemnitee shall reasonably cooperate with the Indemnitor, and shall make available to the Indemnitor all pertinent information under the control of the Indemnitee, which
information shall be subject to Article 7. 

  
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treatment has been requested with respect to the omitted portions. 

 9.4    Insurance. During the Term and for a period
of [***] ([***]) years thereafter, each Party shall maintain, at its cost, a program of insurance and/or self-insurance against liability and other risks associated with its activities and obligations under this Agreement (including, with respect to
its Clinical Trials), and its indemnification obligations hereunder, in such amounts, subject to such deductibles and on such terms as are customary for such Party for the activities to be conducted by it under this Agreement. It is understood that
such insurance shall not be construed to create a limit on either Party’s liability with respect to its indemnification obligations under this Article 9, or otherwise. 

9.5    LIMITATION OF LIABILITY. NEITHER PROTHENA NOR CELGENE, NOR ANY OF THEIR RESPECTIVE AFFILIATES, WILL BE
LIABLE TO THE OTHER PARTY OR ITS AFFILIATES UNDER OR IN CONNECTION WITH THIS AGREEMENT FOR ANY INDIRECT, INCIDENTAL, CONSEQUENTIAL, SPECIAL OR PUNITIVE OR EXEMPLARY DAMAGES (INCLUDING LOST PROFITS OR LOST REVENUES), WHETHER LIABILITY IS ASSERTED IN
CONTRACT, TORT (INCLUDING NEGLIGENCE AND STRICT PRODUCT LIABILITY), INDEMNITY, CONTRIBUTION OR OTHERWISE, AND IRRESPECTIVE OF WHETHER THAT PARTY OR ANY REPRESENTATIVE OF THAT PARTY HAS BEEN ADVISED OF, OR OTHERWISE MIGHT HAVE ANTICIPATED THE
POSSIBILITY OF, ANY SUCH LOSS OR DAMAGE. NOTWITHSTANDING THE FOREGOING, NOTHING IN THIS SECTION 9.5 IS INTENDED TO OR SHALL LIMIT OR RESTRICT THE INDEMNIFICATION RIGHTS OR OBLIGATIONS OF ANY PARTY UNDER SECTIONS 9.1 OR 9.2 IN CONNECTION WITH ANY
THIRD PARTY CLAIMS [***]. 
 ARTICLE 10. 

TERM AND TERMINATION 

10.1    Term; Expiration. 

10.1.1    Term. Subject to Section 3.2 of the Master Collaboration Agreement, this Agreement shall become
effective on the Effective Date and, unless earlier terminated in accordance with this Article 10, shall remain in effect until it expires as follows (the “Term”): 

(a)    on a Licensed Product-by-Licensed
Product basis, this Agreement shall expire on the date of the expiration of the Royalty Term with respect to such Licensed Product; and 

(b)    in its entirety upon the expiration of all applicable Royalty Terms under this Agreement with respect to all
Licensed Products in the Territory. 
 10.1.2    Effect of Expiration. After the expiration of the Term pursuant
to Section 10.1.1 above, the following terms shall apply: 
 (a)    Licenses after Licensed Product
Expiration. After expiration of the Term with respect to a given Licensed Product pursuant to Section 10.1.1(a), the licenses set forth in Section 6.1 with respect to such Licensed Product (and the Licensed Antibody contained therein)
and related Diagnostic Products will automatically become fully paid-up, perpetual, irrevocable and royalty-free. 

  
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treatment has been requested with respect to the omitted portions. 

 (b)    Licenses after Expiration of Agreement. After expiration
of the Term with respect to this Agreement in its entirety pursuant to Section 10.1.1(b), all licenses set forth in Section 6.1 will automatically become fully paid-up, perpetual, irrevocable and
royalty-free. 
 10.2    Termination for Breach. 

10.2.1    Material Breach. This Agreement may be terminated by a Party for the material breach by the other Party of
this Agreement provided that the breaching Party has not cured such breach within ninety (90) days after the date of written notice to the breaching Party of such breach (or thirty (30) days in the case of a breach as a result of non-payment of any amounts due under this Agreement) (the “Cure Period”), which notice shall describe such breach in reasonable detail and shall state the
non-breaching Party’s intention to terminate this Agreement. For clarity, but subject to Section 10.2.2, the Cure Period for any allegation made as to a material breach under this Agreement will run
from the date that written notice was first provided to the breaching Party by the non-breaching Party. Any such termination of this Agreement under this Section 10.2.1 shall become effective at the end
of the Cure Period, unless the breaching Party has cured such breach prior to the expiration of such Cure Period, or, if such breach is not susceptible to cure within the Cure Period, then such Cure Period shall be extended for an additional [***]
([***]) days so long as the breaching Party continues to use commercially reasonable efforts to cure such material breach during such extension period. For the avoidance of doubt, termination of this Agreement pursuant to this Section 10.2.1
shall terminate the Master Collaboration Agreement solely with respect to the Licensed Program but shall not terminate the Master Collaboration Agreement with respect to any other Programs or any other U.S. License Agreement or Global License
Agreement for any other Program. 
 10.2.2    Disagreement as to Material Breach. Notwithstanding
Section 10.2.1, if the Parties in good faith disagree as to whether there has been a material breach of this Agreement pursuant to Section 11.2.1, then: (a) the Party that disputes that there has been a material breach may contest the
allegation by referring such matter, within [***], for resolution to the Executive Officers, who shall meet promptly to discuss the matter and determine, within [***], whether or not a material breach has occurred pursuant to Section 11.2.1;
provided that if the Executive Officers are unable to resolve such dispute within such [***] ([***]) [***] period after it is referred to them, the matter will be resolved as provided in Section 11.7; (b) the relevant Cure Period with respect
thereto will be tolled from the date the breaching Party notifies the non-breaching Party of such dispute and through the resolution of such dispute in accordance with the applicable provisions of this
Agreement; (c) subject to Section 10.12, during the pendency of such dispute, all of the terms and conditions of this Agreement shall remain in effect and the Parties shall continue to perform all of their respective obligations hereunder;
and (d) if it is ultimately determined that the breaching Party committed such material breach, then the breaching Party shall have the right to cure such material breach, after such determination, within the Cure Period (as may be extended in
accordance with Section 10.2.1) which shall commence as of the date of such determination. 
 10.3    Voluntary
Termination. Celgene may terminate this Agreement at will, in its sole discretion, in its entirety upon sixty (60) days’ prior written notice to Prothena at any time. 

  
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treatment has been requested with respect to the omitted portions. 

 10.4    Termination for Bankruptcy. If either Party makes a
general assignment for the benefit of, or an arrangement or composition generally with, its creditors, appoints or suffers appointment of an examiner or of a receiver or trustee over all or substantially all of its property, passes a resolution for
its winding up or files a petition under any bankruptcy or insolvency act or law or has any such petition filed against it which is not dismissed, discharged, bonded or stayed within ninety (90) days after the filing thereof (each, an
“Insolvency Event”), the other Party may terminate this Agreement in its entirety, effective immediately upon written notice to such Party, provided that, in connection therewith, the provisions of Section 6.5 shall apply. 

10.5    Termination for Failure to Commence Preliminary Activities in Support of Clinical Trial. In the event that
(i) Celgene does not exercise its Phase 1 Option for the Licensed Program in accordance with the Master Collaboration Agreement prior to the end of the Phase 1 Option Term for the Licensed Program and (ii) Celgene (or its Affiliates or
Sublicensees) does not, within [***] ([***]) months after the end of the Phase 1 Option Term for the Licensed Program (the “Clinical Trial Preliminary Activities Outside Date”), engage in any activities in support of an IND for a
Clinical Trial for a Licensed Product, then Prothena may terminate this Agreement in its entirety upon [***] ([***]) days’ prior written notice to Celgene; provided that such termination notice is provided within [***] ([***]) days after the
Clinical Trial Preliminary Activities Outside Date. Notwithstanding the foregoing, the Clinical Trial Preliminary Activities Outside Date shall be automatically extended by one day for each day that Celgene (or its Affiliates or Sublicensees, as
applicable) is delayed from engaging in activities in support of the commencement of a Clinical Trial for a Licensed Product caused by reasons outside the reasonable control of Celgene (or its Affiliates or Sublicensees, as applicable), including
delays caused by Regulatory Authorities (including regulatory or clinical hold). 
 10.6    Termination for Patent
Challenge. Prothena shall have the right to terminate this Agreement upon written notice if Celgene or any Affiliate of Celgene challenges the validity, scope or enforceability of or otherwise opposes any Patent included in the Prothena IP that
is licensed to Celgene under this Agreement, in each case through a formal proceeding (other than as may be necessary or reasonably required to assert a cross-claim or a counter-claim or to respond to a court request or order or administrative law,
request or order). If a Sublicensee of Celgene with respect to any Prothena IP challenges the validity, scope or enforceability of or otherwise opposes any Patent included in such Prothena IP under which such Sublicensee is sublicensed in each case
through a formal proceeding (other than as may be necessary or reasonably required to assert a cross-claim or a counter-claim or to respond to a court request or order or administrative law, request or order), then Celgene shall, upon written notice
from Prothena, terminate such sublicense. 
 10.7    Termination Upon Execution of Global License Agreement for
Licensed Program. This Agreement shall automatically terminate if the Parties (or their respective Affiliates, as applicable) enter into a Global License Agreement for the Licensed Program in accordance with the terms of the Master Collaboration
Agreement. 
 10.8    Effects of Expiration or Termination; Additional Remedies.

10.8.1    Termination by Prothena Pursuant to Section 10.2, 10.4, 10.5 or 10.6, or by Celgene Pursuant to
Section 10.3. In the event this Agreement is terminated by Prothena 

  
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pursuant to Section 10.2, 10.4 ,10.5 or 10.6, or by Celgene pursuant to Section 10.3, upon the effective date of such termination: 

(a)    the Master Collaboration Agreement (if not previously expired or terminated) shall also terminate automatically
with respect to the Licensed Program (but not any other Program); 
 (b)    except as set forth in this
Section 10.8.1 or Sections 10.10 or 10.11, all rights and licenses granted herein shall terminate; 
 (c)    any
and all Collaboration Specific IP shall thereafter no longer be deemed to be Collaboration Specific IP; 
 (d)    each
Party shall return or destroy all Confidential Information of the other Party as required by Article 7; and  

(e)    notwithstanding the foregoing provisions of this Section 10.8.1, the licenses granted to Celgene hereunder
shall survive for [***] ([***]) [***] following the effective date of termination in order for Celgene (and its Affiliates, Sublicensees and distributors), at Celgene’s discretion, during the [***] ([***])-[***] period immediately following the
effective date of termination, to (i) finish or otherwise wind-down any ongoing Clinical Trials with respect to any Licensed Antibodies, Licensed Products or Diagnostic Products hereunder and (ii) finish and sell any [***] Licensed
Antibodies, Licensed Products or Diagnostic Products remaining in inventory (provided that Celgene shall pay royalties on Annual Net Sales of such Licensed Products sold by Celgene during such period (provided that the applicable Royalty Term is
still ongoing) as an to the extent Celgene would otherwise be required to pay such royalties as set forth in Section 5.2); provided that, for clarity, Celgene shall have no obligation to undertake such activities, in each case of (i) and
(ii), as and to the extent determined by Celgene. 
 10.8.2    Termination by Celgene Pursuant to
Section 10.2 or 10.4. In the event this Agreement is terminated by Celgene pursuant to Section 10.2 or 10.4, upon the effective date of such termination: 

(a)    the Master Collaboration Agreement (if not previously expired or terminated) shall also terminate automatically
with respect to the Licensed Program (but not any other Program); 
 (b)    except as set forth in this
Section 10.8.2 or Sections 10.10 or 10.11, all rights and licenses granted herein shall terminate; 
 (c)    any
and all Collaboration Specific IP hall thereafter no longer be deemed to be Collaboration Specific IP; 
 (d)    each
Party shall return or destroy all Confidential Information of the other Party as required by Article 7; and 

  
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treatment has been requested with respect to the omitted portions. 

 (e)    notwithstanding the foregoing provisions of this
Section 10.8.2, the licenses granted to Celgene hereunder shall survive for [***] ([***]) [***] following the effective date of termination in order for Celgene (and its Affiliates, Sublicensees and distributors), at Celgene’s discretion,
during the [***] ([***])-[***] period immediately following the effective date of termination, to (i) finish or otherwise wind-down any ongoing Clinical Trials with respect to any Licensed Antibodies, Licensed Products or Diagnostic Products
hereunder and (ii) finish and sell [***] any Licensed Antibodies, Licensed Products or Diagnostic Products remaining in inventory (provided that Celgene shall pay royalties on Annual Net Sales of such Licensed Products sold by Celgene during
such period (provided that the applicable Royalty Term is still ongoing) as an to the extent Celgene would otherwise be required to pay such royalties as set forth in Section 5.2); provided that, for clarity, Celgene shall have no obligation to
undertake such activities, in each case of (i) and (ii), as and to the extent determined by Celgene. 

10.8.3    Termination Pursuant to Section 10.7. In the event this Agreement is terminated
pursuant to Section 10.7, upon the effective date of such termination, except as set forth in Section 10.11, all rights and licenses granted herein shall terminate. 

10.9    Certain Additional Remedies of Celgene in Lieu of Termination. In the event that (i) Celgene notifies
Prothena in writing of a material breach of this Agreement by Prothena, and (ii) Celgene would have the right to terminate this Agreement pursuant to Section 10.2, then in lieu of Celgene terminating pursuant to Section 10.2, and
without limiting any other rights or remedies of Celgene, Celgene may elect to have this Agreement continue in full force and effect by providing written notice thereof to Prothena; provided, however, that if Celgene so elects to continue this
Agreement, then from and after such time as Celgene delivers such written notice to Prothena, any and all amounts thereafter payable by Celgene hereunder or under any Global License Agreement entered into with respect to the Licensed Program
(including Regulatory Milestone Payments, Sales Milestone Payments and royalties) shall be reduced by [***]. 

10.10    Prothena Reversion Antibodies. If this Agreement terminates, except for any termination by Celgene
pursuant to Section 10.2 or 10.4 or termination pursuant to Section 10.7, then the provisions of this Section 10.10 (and for the avoidance of doubt, the provisions of this Section 10.10 shall not apply in the case of termination
by Celgene pursuant to Section 10.2 or 10.4 or termination pursuant to Section 10.7). 

10.10.1    Reversion. All Licensed Program Antibodies that were the subject of Clinical Trials conducted by
Celgene pursuant to this Agreement shall be automatically and immediately deemed “Prothena Reversion Antibodies”. Celgene shall grant and hereby grants to Prothena a non-exclusive,
royalty-free, license in the Territory, with the right to grant sublicenses through multiple tiers, under any Patents and/or Know-How Controlled by Celgene or its Affiliates as of the termination effective
date claiming or covering [***], into the Prothena Reversion Antibodies as they exist as of such termination effective date, solely as necessary to research, Develop, Manufacture, use, import, offer for sale, sell, and Commercialize Prothena
Reversion Antibodies [***] in the Field in the Territory; [***] 

  
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 [***]. 

10.10.2    Effects of Reversion. With respect to each Prothena Reversion Antibody: 

(a)    Except to the extent not permitted pursuant to any agreements between Celgene and a Third Party, Celgene shall
provide to Prothena, within a reasonable time, at Prothena’s request (provided that such request was made within [***] ([***]) days after the effective date of termination), subject to [***], copies of (i) [***] Clinical Trial data and results
generated by or on behalf of Celgene or its Affiliates in the Development of Prothena Reversion Antibodies pursuant to this Agreement, and (ii) [***] relating to the manufacture of such Prothena Reversion Antibodies; in each case, to the extent in
Celgene’s possession as of the termination effective date [***]. For clarity, Prothena shall have the right to use the foregoing [***] solely in connection with the exercise of Prothena’s rights under Section 10.10.1; 

(b)    Celgene shall transfer within a reasonable time to Prothena, at Prothena’s request (provided that such
request was made within [***] ([***]) days after the effective date of termination), [***], [***] Regulatory Filings in the Territory [***] for the Prothena Reversion Antibodies [***] by Celgene or its Affiliates as of the termination effective
date; [***]; 
 (c)    Celgene shall otherwise cooperate reasonably with Prothena to provide a transfer of the
materials described in the foregoing provisions of this Section 10.10.2, [***]; 
 (d)    As and to the extent a
Third Party is Manufacturing such Prothena Reversion Antibody for Celgene or its Affiliate, Celgene shall use reasonable efforts, at Prothena’s request (provided that such request was made within [***] ([***]) days after the effective date of
termination) [***], to [***]. Additionally, at Prothena’s request (provided that such request was made within [***] ([***]) days after the effective date of termination), Celgene shall transfer to Prothena [***] such Prothena Reversion Antibody
owned by Celgene and then in Celgene’s possession, for a price equal to [***]; 
 (e)    To the extent that
Celgene or its Affiliate owns any trademark(s) and/or domain names that [***] a Prothena Reversion Antibody in the Territory that [***] for the Commercialization of a Prothena Reversion Antibody (as [***], but not including any marks that include,
in whole or part, any corporate name or logo of Celgene or its Affiliate), Prothena shall have the right to [***] 

  
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treatment has been requested with respect to the omitted portions. 

 [***]. Prothena shall exercise such right by written notice to Celgene within [***] ([***]) days after such
Licensed Antibody or Licensed Product becomes a Prothena Reversion Antibody; and 
 (f)    If Celgene or its Affiliate
has obtained a license from a Third Party and Prothena is a sublicensee under such license pursuant to Section 10.10.1, then [***]. Notwithstanding the provisions of Section 10.10.1, Prothena shall not get a sublicense of any Third Party
intellectual property pursuant to Section 10.10.1 unless such sublicense is allowed pursuant to and in accordance with the agreement between Celgene and such Third Party. 

10.11    Surviving Provisions. 

10.11.1    Accrued Rights; Remedies. Termination or expiration of this Agreement for any reason shall be without
prejudice to any rights that shall have accrued to the benefit of any Party prior to such termination or expiration, and any and all damages or remedies (whether in law or in equity) arising from any breach hereunder, each of which shall survive
termination or expiration of this Agreement. Such termination or expiration shall not relieve any Party from obligations which are expressly indicated to survive termination or expiration of this Agreement. Except as otherwise expressly set forth in
this Agreement, the termination provisions of this Article 10 are in addition to any other relief and remedies available to either Party under this Agreement and at Applicable Law. 

10.11.2    Survival. Without limiting the provisions of Section 11.8.1, the rights and obligations of the
Parties set forth in the following Sections and Articles of this Agreement shall survive the expiration or termination of this Agreement, in addition to those other terms and conditions that are expressly stated to survive termination or expiration
of this Agreement: [Article 1 (to the extent the definitions are used in other surviving provisions), Article 5 (as to payment obligations accrued prior to the effectiveness of termination or expiration of this Agreement), Section 6.3,
Section 6.4, Section 6.5, Section 6.6, Section 6.12 (solely if there is no other U.S. License Agreement or Global License Agreement covering the applicable Joint Patents), Article 7, Section 8.6, Article 9,
Section 10.1.2, Section 10.8, Section 10.9, Section 10.10, Section 10.11, Section 10.12, Section 10.13, and Article 11].8 

10.12    Milestone Payments. Notwithstanding anything to the contrary contained herein, in the event notice of
termination of this Agreement is given prior to achievement of a given milestone set forth in Section 5.3 or 5.4, Celgene shall not be obligated to make any Regulatory Milestone Payment or Sales Milestone Payment to Prothena with respect to any
milestone achieved following the notice of such termination. 
  

 

	8 	 To be updated in final version 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 10.13    Relationship to Other Agreements. Termination of this
Agreement shall not affect in any way the terms or provisions of any other then-existing executed U.S. License Agreements or Global License Agreements. 

ARTICLE 11. 

MISCELLANEOUS 

11.1    Severability. If any one or more of the terms or provisions of this Agreement is held by a court of
competent jurisdiction to be void, invalid or unenforceable in any situation in any jurisdiction, such holding shall not affect the validity or enforceability of the remaining terms and provisions hereof or the validity or enforceability of the
invalid, void or unenforceable term or provision in any other situation or in any other jurisdiction, and the term or provision shall be considered severed from this Agreement solely for such situation and solely in such jurisdiction, unless the
invalid, void or unenforceable term or provision is of such essential importance to this Agreement that it is to be reasonably assumed that the Parties would not have entered into this Agreement without the invalid, void or unenforceable term or
provision. If the final judgment of such court declares that any term or provision hereof is invalid, void or unenforceable, the Parties agree to (a) reduce the scope, duration, area or applicability of the term or provision or to delete
specific words or phrases to the minimum extent necessary to cause such term or provision as so reduced or amended to be enforceable, and (b) make a good faith effort to replace any invalid, void or unenforceable term or provision with a valid
and enforceable one such that the objectives contemplated by the Parties when entering this Agreement may be realized. 

11.2    Notices. Any notice required or permitted to be given by this Agreement shall be in writing and in English
and shall be (a) delivered by hand or by overnight courier with tracking capabilities, (b) mailed postage prepaid by first class, registered, or certified mail, or (c) delivered by facsimile followed by delivery via either of the
methods set forth in Sections 11.2(a) and (b), in each case, addressed as set forth below unless changed by notice so given: 
 If to
Celgene: 
 Celgene Switzerland LLC 

AON House 
 30 Woodbourne Ave.

 Pembroke HM 08, Bermuda 

Attention:         [***] 

With copies to: 
 Celgene
Corporation 
 86 Morris Avenue 

Summit, NJ 07901 
 U.S.A. 

Attention:        General Counsel 

Facsimile:        (908) 673-2771 

  
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treatment has been requested with respect to the omitted portions. 

 If to Prothena: 

Prothena Biosciences Limited 

Adelphi Plaza 
 Upper
George’s Street 
 Dun Laoghaire, Co. Dublin A96 T927 

Ireland     

Attention:         Company Secretary 

Facsimile:
        +353-1-686-5675 

With copies to: 
 Prothena
Biosciences Inc. 
 331 Oyster Point Boulevard 

South San Francisco, CA, 94080 

U.S.A. 
 Attention: Vice
President, Business Development 
 Facsimile:         +1 650-837-8560 
 Any such notice shall be deemed given on the date received, except any notice received after 5:30
p.m. (in the time zone of the receiving party) on a Business Day or received on a non-Business Day shall be deemed to have been received on the next Business Day. A Party may add, delete, or change the person
or address to which notices should be sent at any time upon written notice delivered to the other Parties in accordance with this Section 11.2. 

11.3    Force Majeure. A Party shall not be liable for delay or failure in the performance of any of its
obligations hereunder if such delay or failure is due to a cause beyond the reasonable control of such Party, including acts of God, fires, earthquakes, acts of war, terrorism, or civil unrest, or hurricane or other inclement weather (“Force
Majeure”); provided, however, that the affected Party promptly notifies the other Party and further provided that the affected Party shall use its commercially reasonable efforts to avoid or remove such causes of non-performance and to mitigate the effect of such occurrence, and shall continue performance in accordance with the terms of this Agreement whenever such causes are removed. When such circumstances arise, the
Parties shall negotiate in good faith any modifications of the terms of this Agreement that may be necessary or appropriate in order to arrive at an equitable solution. 

11.4    Assignment. 

11.4.1    Generally. Except as expressly permitted herein, this Agreement may not be assigned or transferred by any
Party, nor may any Party assign or transfer any rights or obligations created by this Agreement, except as expressly permitted hereunder without the prior written consent of the other Party, which consent will not be unreasonably withheld. 

11.4.2    Celgene. Notwithstanding the limitations in Section 11.4.1, and subject to Section 5.5.2 and
the remaining provisions of this Section 11.4.2, Celgene may assign or transfer this Agreement, or any rights or obligations hereunder in whole or in part, to (a) one or more Affiliates (provided, however, that Celgene shall remain fully
and unconditionally liable and 

  
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treatment has been requested with respect to the omitted portions. 

 
responsible to the non-assigning Party hereto for the performance and observance of all such duties and obligations by such Affiliate); or (b) its
successor in interest in connection with its merger, consolidation, or sale of all or substantially all of its assets or that portion of its business pertaining to the subject matter of this Agreement. 

11.4.3    Prothena. Notwithstanding the limitations in Section 11.4.1, and subject to Section 5.5.2 and
the remaining provisions of this Section 11.4.3, Prothena may assign or transfer this Agreement, or any rights or obligations hereunder in whole or in part, to (a) one or more Affiliates (provided, however, that Prothena shall remain fully
and unconditionally liable and responsible to the non-assigning Party hereto for the performance and observance of all such duties and obligations by such Affiliate); or (b) its successor in interest in
connection with its merger, consolidation, or sale of all or substantially all of its assets. 

11.4.4    Intellectual Property of Acquirer. Notwithstanding anything to the contrary in this Agreement, if a Party
is acquired by a Third Party after the Effective Date, then with respect to any intellectual property rights controlled by the Third Party acquiring party or its affiliates (other than one of the Parties to this Agreement or its Affiliates
immediately prior to such acquisition) involved in any assignment of this Agreement by such Party to such Third Party acquirer, such intellectual property rights shall not be included in the technology and intellectual property rights licensed to
the other Party hereunder to the extent held immediately prior to such transaction by such acquirer or its affiliate (other than the relevant Party to this Agreement or its Affiliates immediately prior to such acquisition), and developed outside the
scope of activities conducted with respect to the Collaboration, any Program, any U.S. License Agreement or any Global License Agreement. The Prothena IP shall also exclude any intellectual property developed by such Third Party acquirer after such
acquisition; provided that (i) such intellectual property is developed independently of the activities under this Agreement, the Collaboration, any Program, the Collaboration Agreement, any U.S. License Agreement or any Global License Agreement
[***], (ii) Prothena and its Affiliates put in place firewalls and other protections to [***] and (iii) [***]. 

11.4.5    All Other Assignments Null and Void. The terms of this Agreement will be binding upon and will inure to
the benefit of the successors, heirs, administrators and permitted assigns of the applicable Party. Any purported assignment in violation of this Section 11.4 will be null and void ab initio. 

11.5    Waivers and Modifications. The failure of any Party to insist on the performance of any obligation
hereunder shall not be deemed to be a waiver of such obligation. Waiver of any breach of any provision hereof shall not be deemed to be a waiver of any other breach of such provision or any other provision on such occasion or any succeeding
occasion. No waiver, modification, release, or amendment of any obligation under or provision of this Agreement shall be valid or effective unless in writing and signed by the Parties. 

  
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treatment has been requested with respect to the omitted portions. 

 11.6    WAIVER OF JURY TRIAL. EXCEPT AS LIMITED BY APPLICABLE
LAW, EACH PARTY HERETO HEREBY IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM (WHETHER BASED IN CONTRACT, TORT OR OTHERWISE) ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE ACTIONS OF ANY PARTY HERETO IN
THE NEGOTIATION, ADMINISTRATION, PERFORMANCE AND ENFORCEMENT HEREOF. 
 11.7    Choice of Law; Dispute
Resolution. 
 11.7.1    Choice of Law. This Agreement shall be governed by, enforced and construed in
accordance with the laws of the State of New York without reference to any rules of conflict of laws or renvoi and excluding the United Nations Convention on Contracts for the International Sales of Goods; provided, however, that with respect to
matters involving the validity or infringement of intellectual property rights in a given country, such matter may be brought in the applicable country (in accordance with Section 11.7.3) and the Applicable Laws of the applicable country shall
apply (subject to Section 6.6.1). 
 11.7.2    Exclusive Dispute Resolution Mechanism. The Parties agree
that the procedures set forth in Section 11.7.3 will be the exclusive mechanism for resolving any dispute (whether in contract, tort or otherwise), controversy or claim between the Parties arising out of or in connection with this Agreement,
any Party’s rights or obligations under this Agreement, breach of this Agreement or the transactions contemplated by this Agreement (each, a “Dispute”); provided that decisions that are subject to the decision making authority
of a given Party, as expressly set forth in this Agreement, will not be subject to the provisions of Section 11.7.3 so long as such decisions are made in accordance with this Agreement. 

11.7.3    Jurisdiction. 

(a)    Except as otherwise set forth in this Section 11.7.3, the sole jurisdiction and venue for all actions, suits
and proceedings arising out of any Dispute (except in respect of an Excluded Claim, where jurisdiction is non-exclusive) will be the state and federal courts located in the Borough of Manhattan in New York,
New York, USA. Each Party hereby irrevocably and unconditionally (a) consents to submit to the exclusive jurisdiction of the state and federal courts located in the Borough of Manhattan in New York, New York, USA for any action, suit or
proceeding arising out of such Dispute, and (b) waives any objection to the laying of venue of any action, suit or proceeding arising out of such Dispute in the state and federal courts of the Borough of Manhattan in New York, New York, USA and
agrees not to plead or claim in any such court that any such action, suit or proceeding brought in any such court has been brought in an inconvenient forum. Each of the Parties agrees that process may be served upon it in the manner specified in
Section 12.2 and irrevocably waives and covenants not to assert or plead any objection which it might otherwise have to such jurisdiction, or to such manner of service of process. It shall be a condition precedent to the commencement of any
action in court or other tribunal (save an action for an interim injunction or provisional relief) in respect of any Dispute relating to this Agreement that the Parties have sought to resolve the Dispute by either Party notifying the other Party in
writing for resolution to the Executive Officers who shall meet (whether in person or via teleconference) within [***] ([***]) [***] of such notice to seek resolution in good faith. If the Executive Officers are unable to resolve the Dispute at such
meeting, either Party may pursue any remedy available to such Party at law or in equity, subject to the terms and conditions of this Agreement, including this Section 11.7.3. 

  
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treatment has been requested with respect to the omitted portions. 

 (b)    Notwithstanding the provisions of Section 11.7.3(a), either
Party may, without waiving any remedy under this Agreement, seek from any court having jurisdiction any equitable relief, including any injunctive or provisional relief and specific performance to protect the rights or property of that Party. Such
remedies will not be deemed to be the exclusive remedies for a breach of this Agreement but will be in addition to all other remedies available at law or equity. In addition, notwithstanding the provisions of Section 11.7.3(a) either Party may
bring an action in any court having jurisdiction to enforce an award rendered pursuant to Section 11.7.3(a). 

(c)    Until final resolution of the dispute through judicial determination, (i) this Agreement will remain in full
force and effect and (ii) the time periods for cure as to any termination will be tolled. The Parties further agree that any payments made pursuant to this Agreement pending resolution of the dispute shall be refunded if a court determines that
such payments are not due. 
 (d)    As used in this Section 11.7, the term “Excluded Claim”
means a dispute, controversy or claim that concerns (i) the validity or infringement of a Patent, trademark or copyright, or (ii) any antitrust, anti-monopoly or competition law or regulation, whether or not statutory. 

11.8    Relationship of the Parties. Prothena and Celgene are independent contractors under this Agreement. Nothing
contained herein is intended or is to be construed so as to constitute (a) Prothena as a partner, agent, or joint venturer of Celgene or (b) Celgene as a partner, agent or joint venturer of Prothena. Neither Prothena nor Celgene,
respectively, shall have any express or implied right or authority to assume or create any obligations on behalf of or in the name of Celgene or Prothena, respectively, or to bind Celgene or Prothena, respectively, to any contract, agreement, or
undertaking with any Third Party. 
 11.9    Third Party Beneficiaries. There are no express or implied Third
Party beneficiaries hereunder. The provisions of this Agreement are for the exclusive benefit of the Parties, and no other person or entity shall have any right or claim against any Party by reason of these provisions or be entitled to enforce any
of these provisions against any Party. 
 11.10    Entire Agreement. This Agreement, together with the attached
Exhibits and Schedules and the Master Collaboration Agreement, contains the entire agreement by the Parties with respect to the subject matter hereof and supersedes any prior express or implied agreements, understandings and representations, either
oral or written, which may have related to the subject matter hereof in any way, including any and all term sheets relating to the transactions contemplated by this Agreement and exchanged between the Parties prior to the Effective Date. In the
event of a conflict between the provisions of this Agreement and the Master Collaboration Agreement with respect to the Licensed Program, the provisions of this Agreement shall control. 

11.11    Counterparts. This Agreement may be executed in counterparts with the same effect as if both Parties had
signed the same document. All such counterparts shall be deemed an 

  
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treatment has been requested with respect to the omitted portions. 

 
original, shall be construed together, and shall constitute one and the same instrument. Any such counterpart, to the extent delivered by means of a fax machine or by .pdf, .tif, .gif, .jpeg or
similar attachment to electronic mail (any such delivery, an “Electronic Delivery”) shall be treated in all manner and respects as an original executed counterpart and shall be considered to have the same binding legal effect as if
it were the original signed version thereof delivered in person. No Party hereto shall raise the use of Electronic Delivery to deliver a signature or the fact that any signature or agreement or instrument was transmitted or communicated through the
use of Electronic Delivery as a defense to the formation of a contract, and each Party forever waives any such defense, except to the extent that such defense relates to lack of authenticity. 

11.12    Equitable Relief; Cumulative Remedies. Notwithstanding anything to the contrary herein, the Parties shall
be entitled to seek equitable relief, including injunction and specific performance, as a remedy for any breach of this Agreement. Such remedies shall not be deemed to be the exclusive remedies for a breach of this Agreement but shall be in addition
to all other remedies available at law or equity. The Parties further agree not to raise as a defense or objection to the request or granting of such relief that any breach of this Agreement is or would be compensable by an award of money damages.
No remedy referred to in this Agreement is intended to be exclusive, but each shall be cumulative and in addition to any other remedy referred to in this Agreement or otherwise available under Applicable Law. 

11.13    Interpretation. 

11.13.1    Generally. This Agreement has been diligently reviewed by and negotiated by and among the Parties, and in
such negotiations each of the Parties has been represented by competent (in-house or external) counsel, and the final agreement contained herein, including the language whereby it has been expressed,
represents the joint efforts of the Parties and their counsel. Accordingly, in interpreting this Agreement or any provision hereof, no presumption shall apply against any Party as being responsible for the wording or drafting of this Agreement or
any such provision, and ambiguities, if any, in this Agreement shall not be construed against any Party, irrespective of which Party may be deemed to have authored the ambiguous provision. 

11.13.2    Definitions; Interpretation. The definitions of the terms herein shall apply equally to the singular and
plural forms of the terms defined and where a word or phrase is defined herein, each of its other grammatical forms shall have a corresponding meaning. Whenever the context may require, any pronoun shall include the corresponding masculine,
feminine, and neuter forms. The word “will” shall be construed to have the same meaning and effect as the word “shall.” The word “any” shall mean “any and all” unless otherwise clearly indicated by context.
The words “including,” “includes,” “include,” “for example,” and “e.g.” and words of similar import will be deemed to be followed by the words “without limitation.” The word “or”
is disjunctive but not necessarily exclusive. The words “hereof,” “herein” and “herewith” and words of similar import shall, unless otherwise stated, be construed to refer to this Agreement as a whole and not to any
particular provision of this Agreement. Unless the context requires otherwise or otherwise specifically provided, (i) all references herein to Articles, Sections, Schedules or Exhibits shall be construed to refer to Articles, Sections,
Schedules and Exhibits of this Agreement and (ii) reference in any Section to any subclauses are references to such subclauses of such Section. 

  
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treatment has been requested with respect to the omitted portions. 

 11.13.3    Subsequent Events. Unless the context requires
otherwise, (i) any definition of or reference to any agreement, instrument, or other document herein shall be construed as referring to such agreement, instrument, or other document as from time to time amended, supplemented, or otherwise
modified (subject to any restrictions on such amendments, supplements, or modifications set forth herein), (ii) any reference to any Applicable Law herein shall be construed as referring to such Applicable Law as from time to time enacted, repealed,
or amended, and (iii) any reference herein to any Person shall be construed to include the Person’s successors and assigns (subject to Section 11.4). 

11.13.4    Headings. Headings, captions and the table of contents are for convenience only and are not to be used
in the interpretation of this Agreement. 
 11.13.5    Prior Drafts. No prior draft of this Agreement nor any
course of performance or course of dealing shall be used in the interpretation or construction of this Agreement. 

11.13.6    Independent Significance. Although the same or similar subject matters may be addressed in different
provisions of this Agreement, the Parties intend that, except as reasonably apparent on the face of the Agreement or as expressly provided in this Agreement, each such provision shall be read separately, be given independent significance and not be
construed as limiting any other provision of this Agreement (whether or not more general or more specific in scope, substance or content). 

11.14    Further Assurances. Each Party shall execute, acknowledge and deliver such further instruments, and do all
such other ministerial, administrative or similar acts, as may be reasonably necessary or appropriate in order to carry out the expressly stated purposes and the clear intent of this Agreement. 

11.15    Extension to Affiliates. Subject to Sections 5.5.2 and 11.4, Celgene shall have the right to extend the
rights, licenses, immunities and obligations granted in this Agreement to one or more of its Affiliates. All applicable terms and provisions of this Agreement shall apply to any such Affiliate to which this Agreement has been extended to the same
extent as such terms and provisions apply to Celgene. Celgene shall remain fully liable for any acts or omissions of such Affiliates. 

[Signature Page Follows] 

  
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treatment has been requested with respect to the omitted portions. 

 IN WITNESS WHEREOF, and intending to be legally bound hereby, the Parties have caused this
U.S. LICENSE AGREEMENT to be executed by their respective duly authorized officers as of the Effective Date. 
  

									
	PROTHENA BIOSCIENCES LIMITED	 		 	CELGENE SWITZERLAND LLC
					
	By:	 	
                     
                    
	 		 	By:	 	
                     
                    

	Name:	 	
                     
                    
	 		 	Name:	 	
                     
                    

	Title:	 	
                     
                    
	 		 	Title:	 	
                     
                    

  
 [Signature Page to
U.S. License Agreement] 
 [***] Certain information in this document has been omitted and filed separately with the Securities and
Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

 Schedule 1.28 

Existing Program Agreements  

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.40 

In-License Agreements and Other Third Party Agreements 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.45 

Licensed Program Antibodies 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.47(b) 

Licensed Program Patents 

  
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treatment has been requested with respect to the omitted portions. 

 Schedule 1.49 

Licensed Target 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.64 

Prothena Licensed Collaboration Patents 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 1.66 

Prothena Platform Technology 

[***] 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions. 

 Schedule 8.2 

Exceptions to Prothena Representations and Warranties 

  
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treatment has been requested with respect to the omitted portions. 

 Schedule 8.4 

Exceptions to Celgene Representations and Warranties 

  
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[***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential
treatment has been requested with respect to the omitted portions.

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