EX-10.19





 Exhibit 10.19 

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD
BE COMPETITIVELY HARMFUL IF PUBLICLY DISCLOSED. 
 EXCLUSIVE LICENSE AGREEMENT 

BETWEEN 

ICOSAVAX, INC. 

AND 

UNIVERSITY OF WASHINGTON 

FOR 

COMPUTATIONALLY DESIGNED NANOPARTICLES AND VACCINES BASED
UPON SUCH DESIGNS 
 UW COMOTION AGREEMENT
REF. [***] 












 TABLE OF CONTENTS 
  

					
	 Background
	  	 	1	 
	 1. Definitions
	  	 	2	 
	 2. License Grant
	  	 	7	 
	 3. Rights of University; Limitations
	  	 	9	 
	 4. Applications and Patents
	  	 	10	 
	 5. Commercialization
	  	 	11	 
	 6. Payments, Reimbursements, Reports, and Records
	  	 	12	 
	 7. Infringement
	  	 	14	 
	 8. Licensed Rights Validity
	  	 	15	 
	 9. Termination
	  	 	15	 
	 10. Release, Indemnification, and Insurance
	  	 	18	 
	 11. Warranties
	  	 	19	 
	 12. Damages
	  	 	20	 
	 13. General Provisions
	  	 	20	 
	 Exhibit A
	  	 	27	 
	 Exhibit B
	  	 	34	 
	 Exhibit C
	  	 	35	 
	 Exhibit D
	  	 	36	 














 CONFIDENTIAL 
  

 EXCLUSIVE LICENSE AGREEMENT 

This Exclusive License Agreement (this “Agreement”), effective as of the date of last signature (the “Effective
Date”), is made and entered into between the University of Washington, a public institution of higher education and an agency of the state of Washington, (“University”), and Icosavax, Inc., a for profit corporation under
the laws of Delaware (“Company”). 
 BACKGROUND 

A.    Certain innovations relating to computationally designed two-component icosahedral
protein nanoparticles; two-component tetrahedral protein nanoparticles; and methods of multivalent antigen presentation on designed protein nanomaterials were made in the University laboratory of
Dr. David Baker, a faculty member in the Department of Biochemistry and an employee of the Howard Hughes Medical Institute (“HHMI”), and in the University laboratory of Dr. Neil King (“Principal
Investigator”), who was a research associate in the Baker laboratory and now is a faculty member in the Department of Biochemistry. In addition, other inventions relating to nanoparticle vaccine candidates for respiratory syncytial virus
were made via a collaboration by Drs. Baker and King working at University and the laboratory of Dr. Antonio Lanzavecchia at the Institute for Research In Biomedicine (“IRB”), located in Switzerland. 

B.    HHMI assigned its rights in such innovations to University, subject to the HHMI License (as defined herein). University now
solely owns certain intellectual property rights in such innovations, and co-owns certain intellectual property rights in such innovations with IRB, as listed in Exhibit A
“Start-Up License Schedule” to this Agreement. University and IRB have executed an interinstitutional agreement, dated September 19, 2017, that authorizes University to assume sole
responsibility for both the patent prosecution and licensing of co-owned patent applications 47969.01US1 /USSN 62/481,331. Thus, University has the right to license to others certain rights to use and practice
such intellectual property. University is willing to grant those rights so that such innovations may be developed for use in the public interest. 

C.    Company desires that University grant it an exclusive license under such intellectual property rights, and University is
willing to grant such a license, on the terms set forth in this Agreement. University desires Company to commercialize the intellectual property subject to this Agreement for commercial indications through Company and the exclusive license granted
hereunder. 
 D.    The innovations licensed under this Agreement were funded in part by the Bill and Melinda Gates Foundation
(“BMGF”) pursuant to those certain grant agreements between BMGF and University of Washington Foundation dated [***] entitled [***] and [***] entitled [***] (“BMGF Agreements”) and
pursuant to which University made certain global access commitments to BMGF. 
 E.    Company intends to enter into one or more
mutually agreeable sponsored research agreement(s) negotiated with University after the Effective Date for work on Indication Category(ies) to be done in the laboratory of Principal Investigator. Under such sponsored research agreement(s) Company
shall have an option to negotiate to include inventions and/or know-how arising from such University activities under the sponsored research agreement where the inventors are not HHMI employees under the
applicable 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
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 CONFIDENTIAL 
  

 
patent law as Licensed Patents and/or Licensed Know-How under this Agreement. For the avoidance of doubt, inclusion of such shall require payment of
additional license fees if not an Improvement (as defined below). 
 AGREEMENT 

The Parties agree as follows: 

1.    DEFINITIONS 

“Acquisition” means (a) the sale by Company of all, or substantially all of, its assets in transaction to a Third Party at
arm’s length, (b) the sale, transfer, or exchange by the shareholders, partners, or equity owners of Company of a majority interest in Company’s outstanding stock in an arm’s length transaction to a Third Party, or (c) the
merger of Company with a Third Party at arm’s length; provided, however, that in no event will (y) any bona fide equity financing for the primary purpose of raising capital for corporate purposes, or (z) any license, or any option to
obtain a license, relating to all or substantially all of Company’s rights (whether such rights pertain to this Agreement or to Company’s rights more generally) that is granted to a Third Party (whether or not collaborative or partnership
activities also will be conducted), be considered an Acquisition under this Agreement. For the avoidance of doubt, the Parties agree that any license or option to obtain a license, as stipulated in (z) above, shall be considered a Sublicense if
such license or option to obtain a license includes sublicensed rights under this Agreement. 
 “Acquisition Consideration” means all
consideration for an Acquisition (including, as an example only, any payment made to exercise an option to effect an Acquisition) for the first Acquisition to occur after the Effective Date (but does not include any consideration received for any
subsequent Acquisition). Any Acquisition Consideration is expressly excluded from Sublicense Consideration. 
 “Combination Product”
means a product sold in a form containing a Licensed Product and at least one other product, component, or ingredient which could be sold separate and apart from the Licensed Product and which is not required for the function of the Licensed
Product. 
 “Company Shares” means the Shares or any securities convertible or exchangeable for Shares. 

“Confidential Information” means any information or materials of a Party not generally known to the public, including any information
comprised of those materials and Company’s business plans or reports. Confidential Information does not include any information that: (a) is, or becomes, part of the public domain through no fault of receiving Party; (b) is known to
receiving Party prior to the disclosure by the disclosing Party, as evidenced by documentation; (c) is publicly released as authorized under this Agreement by University, its employees or agents; (d) is subsequently obtained on a non-confidential basis by receiving Party from a Third Party who is authorized to have and disclose such information; or (e) is independently developed by receiving Party without reliance on any portion of the
Confidential Information received from the disclosing Party and without any breach of this Agreement as evidenced by documentation. 

“Developing Countries” means the list of countries set forth on Exhibit C. 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	2















 CONFIDENTIAL 
  

 “Distributor” means a distributor, reseller or OEM to which a Licensed Party sells a
Licensed Product for resale of Licensed Product by the Distributor, and where Distributor has no other rights with respect to the Licensed Rights other than to resell or otherwise distribute Licensed Products (including but not limited to integrated
or bundled with other products or services), and for which resale or distribution such Licensed Party receives no further consideration (including but not limited to royalties and/or commissions) beyond the price for the initial sale of Licensed
Product to the Distributor. 
 “Event of Force Majeure” means an unforeseeable act that prevents or delays a Party from performing
one or more of its duties under this Agreement and that is outside of the reasonable control of the affected Party. An Event of Force Majeure includes acts of war or of nature, insurrection and riot, and labor strikes. An Event of Force Majeure does
not include a Party’s inability to obtain a Third Party’s consent to any act or omission, unless the inability was caused by a separate Event of Force Majeure. 

“Fair Market Value” means the average price at which the stock in question is publicly trading for twenty (20) days prior to the
announcement of its purchase by the Sublicensee(s), or, if the stock is not publicly traded, the value of such stock as determined in good faith by the board of directors of Company or Sublicensee. 

“Field of Use” means prophylactic and/or therapeutic treatments in a defined “Indication Category”, specifically: for (i) respiratory
syncytial virus (“RSV”) (the “First Indication Category”), (ii) [***] (the “Second Indication Category”), (iii) [***] (the “Third Indication Category”), (iv)
[***] (the “Fourth Indication Category”), and (v) [***] (the “Fifth Indication Category”). These viruses, bacteria and pathogens listed within each Indication Category represent a preliminary
indication of Company’s priorities and targeted indications within the broad category of commercially attractive vaccines. Accordingly, University grants Company the right, from time to time, to re-order
the priority of, and/or substitute a new replacement virus, bacteria and/or pathogen for any of the Indication Categories above by written notice to University (“Updated Indication Designation”) designating the new order of
Indication Categor(ies) and/or potential substitution (i.e., deletion of current and replacement with new) virus, bacteria and/or pathogen, subject to then-current availability (i.e., not exclusively licensed to a Third Party) of the replacement
virus, bacteria and/or pathogen (as applicable) and University’s willingness to license such rights. Parties agree that such Updated Indication Designation(s) shall be captured in a written amendment per Section 13.1 “Amendment and
Waiver”. 
 “Fully-Diluted Shares” means the total number of Shares issued and outstanding or reserved for issuance assuming the
exercise or conversion of all securities convertible into Shares.  
 “Improvements” means patentable inventions that
(a) are owned by University after the Effective Date and not encumbered by third party rights that would prevent delivery to Company, (b) would require a license under the exclusively Licensed Rights to practice, (c) were developed in
the laboratory of the Principal Investigator, and identified to UW CoMotion as Improvements falling under this license, and (d) do not include an HHMI employee as an inventor under the applicable patent law. 

“Licensed Know-How” means University knowledge or intangible work that: (a) was developed
in the laboratory of Principal Investigator, (b) exists as of the Effective Date, (c) is relevant to utilizing any of the Licensed Patents, (d) is unpublished, (e) is not subject to patent or copyright protection, and (f) is
not covered by Third Party rights that would prevent delivery to Company. 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	3















 CONFIDENTIAL 
  

 “Licensed Party” mean Company or any of its Sublicensees. 

“Licensed Patents” means (a) the patents and patent applications listed in Exhibit A1.1 “Licensed Patents”, all
(b) divisions, continuations, and claims in continuations-in-part that are entitled to claim priority to, or that share a common priority claim with, and are
directed to subject matter specifically described in, any item listed on Exhibit A1.1 “Licensed Patents”; (c) claims of extensions, renewals, substitutes, re-examinations and re-issues of any of the items in (a) or (b) that are directed to subject matter specifically described in any items listed on Exhibit A1.1; and (d) claims of foreign counterparts of any of the items in
(a), (b), or (c) that are directed to subject matter specifically described in any items listed on Exhibit A1.1, wherever and whenever filed. 

“Licensed Product” means any method, process, composition, product, service, or component part thereof that would, but for the granting
of the rights set forth in this Agreement, infringe a Valid Claim contained in the Licensed Patents. 
 “Licensed Rights” means all
rights granted to Company under Article 2 “License Grant” of this Agreement. 
 “Net Sales” means the gross amount received
by a Licensed Party from Distributors, customers, end users and other Third Parties for sales, leases, and other dispositions of Licensed Products, less [***]. On sales of Licensed Products by made in other than an arm’s length
transaction, the value of the Net Sales attributed to such transaction will be equal to the Net Sales that would have been received in an arm’s length transaction, based on sales of like quantity and quality of Licensed Products sold on or
about the time of the transaction. Net Sales does not include sale, lease, disposition or other transfer of Licensed Products among or between Company, Subsidiaries and Sublicensees for the purpose of subsequent resale to a Third Party, but does
include subsequent resale to such Third Party. For avoidance of doubt Net Sales are calculated on sales by a Licensed Party to Distributor, and not on the subsequent sale by Distributor. 

Net Sales of Combination Products will be calculated by multiplying actual Net Sales of such Combination Products by the fraction A/(A+B), where
“A” is the Net Sales price of the Licensed Product if sold or performed separately, and “B” is the Net Sales price of the other product, component or ingredient in the Combination Product if sold separately. If, on a country-by-country basis, the other product, component or ingredient in the Combination Product is not sold separately in said country, Net Sales for the purpose of
determining running royalties of the Combination Product shall be calculated by multiplying actual Net Sales of the Combination Product by the fraction A/C where “A” is the Net Sales price of the Licensed Product, if sold separately, and
“C” is the Net Sales price of the Combination Product. If, on a country-by-country basis, neither the Licensed Product, nor the other product, component or
ingredient in the Combination Product, is sold separately in said country, Net Sales for the purpose of determining running royalties of the Combination Product shall be determined in good faith by the Parties. A Combination Product may include a
Licensed Product and any separate product, component or ingredient or service developed by or in-licensed by a Licensed Party from a Third Party provided it is a Combination Product as defined in this
Agreement. 
 “New Patent Applications” means patents and patent applications which claim Improvements and that the Company elects
under Section 2.4 “Improvements” to include in the Licensed Patents. 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	4















 CONFIDENTIAL 
  

 “Parties” means University and Company and “Party” means either
University or Company. 
 “Patent Expenses” means all reasonable costs (including attorneys’ and application fees) incurred by
University in accordance with this Agreement to apply for, prosecute and maintain Licensed Patents, including but not limited to the costs of interferences, oppositions, inter partes review and
re-examinations. Costs for interferences, oppositions, inter partes review, re-examinations and other complex and expensive patent-related proceedings will be incurred
in consultation with Company, pursuant to the processes of Article 4 “Applications and Patents”. Patent Expenses also include reimbursement for in-house costs to apply for, prosecute and maintain
Licensed Patents; provided they are for activities that would otherwise have been performed by outside counsel at an equal or greater expense. 

“Performance Milestone” means any of the milestones described in Section A2 “Performance Milestones” of
attached Exhibit A “Start-Up License Schedule”. 
 “Performance Milestone Date”
means the date by which a Performance Milestone is to be achieved as set forth in Section A2 “Performance Milestones” of attached Exhibit A “Start-Up License Schedule”, as such date may be
extended pursuant to Section 5.1 “Performance Milestones” or as otherwise agreed upon by the Parties. 
 “Permitted
Sublicense” means any arm’s length agreement with a Third Party manufacturer, contract research organization or contract researcher/developer with whom a Licensed Party contracts for manufacture, research or development of
Licensed Products on Licensed Party’s behalf, and where such Third Party has no other rights with respect to the Licensed Rights other than to manufacture, research or develop on behalf of Licensed Party. 

“Permitted Sublicensee” means a Third Party holding a Permitted Sublicense. 

“Qualified Financing” means one or more offerings of equity securities (whether common or preferred stock, options, warrants or
notes convertible into common stock) issued for cash (or cash equivalents), the aggregate proceeds of which equals or exceeds the Qualified Offering Proceeds; provided that a Qualified Financing refers solely to the first offering (or offerings) in
which the Company raises the Qualified Offering Proceeds, whether occurring prior to, concurrent with or subsequent to the Effective Date. 

“Qualified Offering Proceeds” means [***]. 

“Sales Report” means a report in substantially the form set forth in Exhibit B “Royalty Report Form”. 

“Securities Act” means the Securities Act of 1933, as amended, and rules and regulations promulgated thereunder. 

“Securities Exchange Act” means the Securities Exchange Act of 1934, as amended, and rules and regulations promulgated thereunder. 


  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	5















 CONFIDENTIAL 
  

 “Shares” means shares of the Company’s common stock. 

“Sublicense” means the grant by a Licensed Party to a Third Party of any license, option, first right to negotiate, or other right
granted under the Licensed Rights, in whole or in part. The grant of the right to resell to a Distributor and the grant of a license or other right to use a Licensed Product to an end-user, where the end
user has no other rights with respect to the Licensed Rights other than to be an end user of the Licensed Product, will not be a Sublicense and will be treated solely under Net Sales. 

“Sublicensee” means a Third Party holding a Sublicense under the Licensed Rights. 

“Sublicense Consideration” means all consideration, including but not limited to [***]; but excluding [***] For avoidance
of doubt, consideration paid to Company by Sublicensees for the following shall not be deemed Sublicense Consideration: [***]. For clarity, University acknowledges and agrees that, if Company should enter into an agreement with a Third Party
that includes a Sublicense as part, but not all, of the subject matter of such agreement, then the total non-royalty consideration paid to Company under such Third Party agreement will not be deemed Sublicense
Consideration merely because a Sublicense is granted (since only a portion of the consideration received is for the grant of the Sublicense). 

Furthermore, to the extent that: (1) this Agreement has not been assigned by Company prior to the date Sublicense Consideration is received by
Company; and (2) Company has not raised more than [***] in equity financing prior to the date Sublicense Consideration is received by Company, amounts received by Company from a Third Party for [***], shall be excluded from
Sublicense Consideration, as stipulated in the paragraph above in (a)(ii). Company will provide to University a copy of the [***] together with a copy of the executed Sublicense as required by Section 2.3 “Sublicense Rights”.

 “Territory” means worldwide. 

“Third Party” means an individual or entity other than University and Company. 

“Valid Claim” means (a) a claim in an issued, unexpired United States or granted foreign patent included in the Licensed
Patents that: (i) has not been held invalid, unpatentable, or unenforceable by a decision of a court or other governmental agency of competent jurisdiction and not subject to appeal (ii) has not been admitted to be invalid or unenforceable
through reissue, inter partes review, disclaimer, or otherwise, (iii) has not been lost through an interference, reexamination, or reissue proceeding; or (b) a pending claim of a pending patent application included in the Licensed
Patents. 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	6















 CONFIDENTIAL 
  

 Additional Definitions. The following terms have the meanings set forth in the corresponding
sections of this Agreement, as described below. 
  

			
	 Defined Term
	  	 Section

	 “Accountants”
	  	 6.5.1

	 “Acquisition Fee”
	  	 A3.7

	 “Act”
	  	 13.3.3

	 “Agreement”
	  	 Preamble

	 “Assignee”
	  	 A3.5.1

	 “Claim”
	  	 10.2

	 “Company”
	  	 Preamble

	 “Dispute Notice”
	  	 13.4

	 “Effective Date”
	  	 Preamble

	 “First Indication Category”
	  	 Definition of Field of Use

	 “HHMI”
	  	 Background

	 “HHMI Claims”
	  	 10.2

	 “HHMI Indemnitees”
	  	 10.2

	 “HHMI License”
	  	 2.8

	 “Indemnitee”
	  	 10.2

	 “Indication Category”
	  	 Definition of Field of Use

	 “Initial Notice Period”
	  	 9.8

	 “IRB”
	  	 Background

	 “Operating Expenses”
	  	 Definition of Sublicense Consideration

	 “Operating Expense Budget”
	  	 Definition of Sublicense Consideration

	 “Option”
	  	 13.21

	 “Principal Investigator”
	  	 Background

	 “Second Indication Category”
	  	 Definition of Field of Use

	 “Sell-Off Period”
	  	 9.6

	 “Subsidiaries”
	  	 2.7

	 “Third Indication Category”
	  	 Definition of Field of Use

	 “University”
	  	 Preamble


 2.     LICENSE GRANT. Subject to the terms and
conditions of this Agreement: 
 2.1    Patent License. University hereby grants to Company an exclusive (subject only to
any rights of the government described in Section 2.6 “The United States Government’s Rights” and to rights of University described in Article 3 “Rights of University; Limitations” and to rights of HHMI described in
Section 2.8 “HHMI Research Use Rights”) license under the Licensed Patents to make, have made on Company’s behalf, use, offer to sell, sell, offer to lease or lease, import, or otherwise offer to dispose of Licensed Products in
the Territory in the Field of Use. Unless otherwise terminated under Article 9 “Termination”, the term of this patent license will begin on the Effective Date and will continue until all


  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	7















 CONFIDENTIAL 
  

 
Valid Claims expire or are held invalid or unenforceable by a court of competent jurisdiction from which no appeal can be taken. 

2.2    Know-How License. University hereby grants to Company a non-exclusive, worldwide license to use Licensed Know-How. Unless otherwise terminated under Article 9 “Termination”, the term of this license will begin on the
Effective Date and will continue until all rights under Licensed Patents are terminated. 
 2.3    Sublicense Rights.
Company has the right, exercisable during the term of this Agreement, to Sublicense its Licensed Rights under this Agreement. Company may not grant Sublicensees the right to enforce Licensed Rights. Company will remain responsible for its
obligations under this Agreement. Except for Permitted Sublicensees, Company will ensure that the Sublicense agreement: (a) contains terms and conditions that require Sublicensee to comply with the terms and conditions of this Agreement
applicable to Sublicensees, including a release substantially similar to that provided by Company in Section 10.1 “Company’s Release”; a warranty substantially similar to that provided by Company in Section 11.1
“Authority”; University disclaimers and exclusions of warranties under Sections 11.3 and 11.4 “No Known Infringement” and “Disclaimer”; and limitations of remedies and damages substantially similar to those provided by
Company in Sections 12.1 “Remedy Limitation” and 12.2 “Damage Cap”; (b) specifically incorporates provisions of this Agreement regarding obligations pertaining to indemnification, use of names and insurance. Each Sublicense
agreement must also contain obligations, terms and conditions in favor of HHMI or the HHMI Indemnitees, as applicable, that are substantially similar to those undertaken by Company in favor of HHMI or the HHMI Indemnitees, as applicable, under this
Agreement and intended for the protection of the HHMI Indemnitees, including, without limitation, the obligations, terms and conditions regarding indemnification, insurance and HHMI’s third party beneficiary status. Company will provide
University with a copy of the executed Sublicense, excluding any Permitted Sublicense agreement, within thirty (30) days after its execution. Company will not enter into any Sublicense agreement if the terms of such agreement are inconsistent
in any material respect with the material terms of this Agreement. Any Sublicense made in violation of this Section 2.3 “Sublicense Rights” will be void and will constitute an event of default that requires remedy under
Section 9.2 “Termination by University”. 
 2.4    Improvements. For a period of [***] months after
the Effective Date, University will provide reasonable written notice to Company of any Improvements to the Licensed Patents. Company will have the option, exercisable within ninety (90) days of receipt of University’s notice of such
Improvement, to add such Improvements to the Licensed Patents. If Company exercises its option to add Improvements to the Licensed Patents, the Licensed Patents thereafter will include the applicable New Patent Applications, and the Parties will
revise Exhibit A “Start-Up License Schedule” to include such Improvements. 

2.5    Limitation of Rights. No provision of this Agreement grants to Company, by implication, estoppel or otherwise,
any rights other than the rights expressly granted it in this Agreement under the Licensed Rights, including any license rights under any other University-owned or IRB-owned technology, copyright, know-how, patent applications, or patents, or any ownership rights in the Licensed Rights. 

2.6    The United States Government’s Rights. Inventions covered in the Licensed Patents arose, in whole
or in part, from federally supported research and the federal government of the United States of America has certain rights in and to such inventions as those rights are described in Chapter 18, Title 35


  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	8















 CONFIDENTIAL 
  

 
of the United States Code and accompanying regulations, including Part 401, Chapter 37 of the Code of Federal Regulation. The Parties’ rights and obligations under this Agreement to any
government-funded inventions, including the grant of license set forth in Section 2.1 “Patent License”, are subject to the applicable terms of the aforementioned United States laws. The U.S. Government is entitled, as a right,
under these Chapters: (a) to a nonexclusive, nontransferable, irrevocable, paid-up license to practice or have practiced for or on the behalf of the U.S. Government any of the federally funded
inventions throughout the world and (b) to exercise march in rights on the federally funded inventions. Company further agrees that, to the extent required by Title 35 Section 204 of the United States Code, it will substantially
manufacture in the United States of America all products embodying or produced through the use of any such federally funded invention. 

2.7    Rights to Wholly Owned Subsidiaries of Company. Company may extend rights granted to Company under this Agreement to
wholly owned subsidiaries (“Subsidiaries”) of Company, provided that (a) Company is responsible for all acts of such Subsidiaries as if they were acts of the Company, (b) such Subsidiary is bound in writing to perform all
obligations to University and HHMI of this Agreement other than making payments pursuant to Article 6 “Payments, Reimbursements, Reports, and Records”, as if such Subsidiary were Company, and (c) Company reports to University pursuant
to Section 13.10 “Notices” that such Subsidiary will be exercising rights under this Agreement prior to such Subsidiary exercising any such rights under this Agreement. For avoidance of doubt, Company may perform any obligation of
Subsidiary on Subsidiary’s behalf. 
 2.8    HHMI Research Use Rights. Company acknowledges that it has been informed
that the Licensed Patents were developed, at least in part, by employees of HHMI and that HHMI has a paid-up, non-exclusive, irrevocable license to exercise any
intellectual property rights with respect to the Licensed Patents for research purposes, with the right to sublicense to non-profit and governmental entities, but with no other rights to assign or sublicense
(the “HHMI License”). This license is explicitly made subject to the HHMI License. 
 3.    RIGHTS
OF UNIVERSITY; LIMITATIONS 
 3.1    University’s Rights. University
reserves all rights not expressly granted to Company under this Agreement. University retains for itself, IRB, and other not-for-profit research institutions, an
irrevocable, nonexclusive right to practice Licensed Rights for research, instructional or educational purposes. Expressly included, without limitation, within this University reservation of rights is the right to do the following in connection with
such research, instructional or educational purposes: (a) to use the Licensed Rights in sponsored research or collaborative research with any Third Party, but not for any commercial purpose, and only to the extent that no such Third Party is
granted any commercialization rights of any kind under the Licensed Rights or to commercialize Licensed Products, (b) to grant material transfer agreements that restrict the use of such materials to research, teaching or other scholarly
activities, and that the transferree has no rights greater than University or IRB, and has no further right to transfer such materials to any Third Party, and (c) to publish any information included in the Licensed Rights or any other
information that may result from University’s or IRB’s research. 
 3.2    Sublicensing Opportunities. If a Third
Party notifies University that it wishes to license any of the exclusively licensed Licensed Rights in any field or territory in which Company is unable or unwilling to develop and market a Licensed Product or for any field within the Field of Use
that University reasonably 

  

			
	 Icosavax, Inc. / University of Washington
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 UW CoMotion Ref. [***]
	  	
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 CONFIDENTIAL 
  

 
believes Company is not diligently pursuing, University will notify Company in writing of such Third Party’s wish to obtain such license, and Company will have good faith discussions with
such Third Party regarding the terms and conditions under which such Sublicense could be obtained. Company will not be obligated to provide such sublicense where it interferes with Company’s business strategy; however, Company will not
unreasonably withhold such Sublicense. 
 3.3    Reservation of Rights for Humanitarian Purposes. Consistent with 35 U.S.C.
§200 et seq., University retains the right to require Company to grant Sublicenses to responsible applicants in the Field of Use under the Licensed Patents on terms that are reasonable under the circumstances; or, if Company fails to grant a
license, to grant the license itself. The exercise of these rights by University will only be in exceptional circumstances and only if University determines (a) the action is necessary to meet health or safety needs that are not reasonably
satisfied by Company; or (b) the action is necessary to meet requirements for public use specified by federal regulations, and such requirements are not reasonably satisfied by Company. In addition, University retains the right to require
Company to grant Sublicenses in the Field of Use under the Licensed Patents on terms that are reasonable under the circumstances solely to allow the Licensed Products to be available and accessible at an affordable price in Developing Countries, or,
if Company fails to offer to grant a license on reasonable terms, to grant the license itself to meet global access obligations agreed to by University under the BMGF Agreements in connection with funding of research that led to the Licensed Patents
and such obligations are not reasonably satisfied by Company. University will not require the granting of a sublicense, and will not grant the license itself, unless the responsible applicant has first negotiated in good faith with Company. Company
shall be entitled to use the dispute resolution mechanisms of Section 13.4 “Escalation; Dispute Resolution”, including seeking an injunction from the court if mediation is unsuccessful, if Company wishes to dispute that University
should be entitled to exercise its rights under this Section 3.3. 
 4.     APPLICATIONS AND
PATENTS 
 4.1    Pre-Agreement Patent Filings. Company has
reviewed the Licensed Patents and as of the Effective Date is not aware of any basis to challenge or dispute the inventorship, validity, or enforceability of any of the claims made in the Licensed Patents. 

4.2    Patent Prosecution Decisions. University and Company will consult on the preparation, filing and prosecution of the
Licensed Patents (including, without limitation, on the selection of patent counsel). Patent counsel will be directed to deliver to Company all written and electronic communications to and from all patent offices and foreign counsel, and provide
summaries of oral communications with patent offices. Provided Company is in compliance with Section A3.8 “Patent Expense Payment” of Exhibit A “Start-Up License Schedule”, Company’s
directions regarding patent preparation, filing and prosecution will be followed unless detrimental to University’s intellectual property rights. University and Company will consult prior to deciding in which countries to pursue patent
protection and provided Company is in compliance with Section A3.8 “Patent Expense Payment”, patents will be filed in all countries Company designates. University acknowledges the key role and value of the Licensed Patent portfolio to
Company and the need for timely review and exchange of information between University and Company prior to Licensed Patent portfolio decisions. University will remain the client of record, and may at its own expense instruct patent counsel to take
actions necessary to protect University’s intellectual property rights, if in University’s reasonable opinion, Company actions will result in a loss of rights; provided that for any such actions, if Company declines to reimburse University
pursuant to Section A3.8 “Patent Expense Payment” 

  

			
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of Exhibit A “Start-Up License Schedule”, those applications and resultant patents will not be subject to this Agreement. In no event will
Company file a patent application where all of the inventors are under University policy obligated to assign their rights in such patent application to University. 

4.3    Assumption of Patent Prosecution and Maintenance. Provided Company is in compliance with Section A3.8 “Patent
Expense Payment” of Exhibit A “Start-Up License Schedule”, University will take all commercially reasonable steps to cause patents and patent applications within the Licensed Patents to be
diligently prosecuted and maintained. If Company is in compliance, and University, against Company’s instructions, decides to abandon or allow to lapse any patent application or any claim of any patent included in the Licensed Patents or not
pursue patent protection for any foreign patent mutually agreed upon by the Parties under Section 4.2 “Patent Prosecution Decisions”, University will notify Company at least sixty (60) days before such decision would be
effective, and Company will have the right to file, prosecute, and maintain, as applicable, such patent or patent application at Company’s expense provided Company shall keep University informed of such activity. Company may thereafter abandon
or allow to lapse any or all patents or patent applications for which it is responsible. Company will notify University of any abandoned or lapsed patents within thirty (30) days of such abandonment or lapse. 

5.    COMMERCIALIZATION 

5.1    Performance Milestones. Company will, directly or through its Subsidiaries or Sublicensees, use its commercially
reasonable efforts, consistent with sound and reasonable business practices and judgment, to commercialize the Licensed Rights and to make and sell Licensed Products as soon as practicable and to maximize sales thereof. Unless an extension is
provided due to an Event of Force Majeure during the term of this Agreement, Company shall perform, or shall cause to happen or be performed, the Performance Milestones in accordance with the Performance Milestone Dates. Upon the occurrence of an
Event of Force Majeure, the Performance Milestones and Performance Milestone Dates shall be equitably adjusted to accommodate the Event of Force Majeure. 

5.2    Renegotiation of Performance Milestones. If Company determines that it will be unable to achieve a Performance
Milestone for a given Indication Category by the applicable Performance Milestone Date, Company will so notify University in advance of the Performance Milestone Date, and, provided Company demonstrates it is diligently pursuing commercialization of
at least one Licensed Product for such Indication Category, Company shall have the option of either (1) negotiating in good faith an appropriate new Performance Milestone and/or related Performance Milestone Date to accommodate for the
reasonable length of the delay or (2) paying a fee to the University equal to [***] of the next due Financial Milestone payment for a one year of extension to all Performance Milestone Dates (not yet met) for such Indication Category. A
subsequent payment of another [***] of the next due Financial Milestone payment to add another one year extension to all Performance Milestones Dates (not yet met) for such Indication Category will be granted by University but no further
extensions shall be (automatically) granted under this payment mechanism. If in the case of (1) above, the Parties are unable to agree on a renegotiated Performance Milestone [***], then University may proceed with its termination rights
under Section 9.2 “Termination by University”, subject to both Company and University having the right to seek mediation under Section 13.4 “Escalation; Dispute Resolution”. For the avoidance of doubt, University’s
termination rights shall be on an Indication Category by Indication Category basis (e.g., any failure to achieve a Performance Milestone by the applicable Performance Milestone Date for one Indication


  

			
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Category shall not result in termination of another Indication Category that is in compliance with its Performance Milestones). 

5.3    Commercialization Reports. Throughout the term of this Agreement and during the
Sell-Off Period, and within thirty (30) days of December 31st of each year, Company will deliver to University written reports of Company’s and
Sublicensees’ efforts and plans to develop and commercialize the innovations covered by the Licensed Rights and to make and sell Licensed Products. Company will have no obligation to prepare commercialization reports in years where
(a) Company delivers to University a written Sales Report with active sales, and (b) Company has fulfilled all Performance Milestones. In relation to each of the Performance Milestones each commercialization report will include sufficient
information to demonstrate achievement of those Performance Milestones and will set out timeframes and plans for achieving those Performance Milestones which have not yet been met. 

5.4    Company Information. Once per year, until University no longer has Shares in Company, Company shall provide a current
capitalization chart to indicate the number of Shares University owns in Company, and total number of Shares and Fully Diluted Shares. Throughout the term of this Agreement, Company shall provide the names of, and sufficient contact information to
identify, any Permitted Sublicensees within thirty (30) days of University’s written request. Upon University’s inquiry, Company will provide information on funding rounds to date (type, date, and amount) and number of employees. 

6.    PAYMENTS, REIMBURSEMENTS, REPORTS, AND RECORDS

 6.1    Payments. Company will deliver to University the payments specified in Section A3 “Payments” of
attached Exhibit A “Start-Up License Schedule”. Company will make such payments by check, wire transfer, or any other mutually agreed-upon and generally accepted method of payment. All checks to
University will be made payable to “University of Washington” and will be mailed to the address specified in Section 13.10 “Notices” and will reference the University agreement number [***]. 

All wire or electronic fund transfers must be confirmed via email referencing the above agreement number to: ipfin@uw.edu 

 

			
	Wire transfers:	 	Electronic Fund Transfer (ACH):

 [***] 

6.2    Currency and Checks. All computations and payments made under this Agreement will be in United States dollars. The
exchange rate for the currency into dollars as reported in The Wall Street Journal as the New York foreign exchange mid-range rate on the last business day of the month in which the transaction
was entered into will be used for determining the dollar value of transactions conducted in non-United States dollar currencies. 

6.3    Late Payments. University may charge Company a late fee for all amounts owed to University that are more than thirty
(30) days overdue; provided that, for any portion of any such amount that is the subject of a bona fide, good faith dispute by Company (the mechanism of such dispute governed by Section 13.4 “Escalation; Dispute Resolution”), the
late fee shall not apply to such disputed portion unless and until the dispute is decided in University’s favor. The late fee will be computed as the [***], 

  

			
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compounded monthly, as set forth by The Wall Street Journal (Western edition) on the date on which the payment is due, of the outstanding, unpaid balance. The payment of a late fee will
not foreclose or limit University from exercising any other rights it may have as a consequence of the lateness of any payment. 

6.4    Sales Reports. Within sixty (60) days after the last day of each calendar quarter commencing the calendar quarter
after the Company effects its first commercial sale of a Licensed Product and during the term of this Agreement and the Sell-Off Period, Company will deliver to University the Sales Report setting forth the
number of and Net Sales amount (expressed in U. S. dollars) of all sales, leases, or other dispositions of Licensed Products, whether made by Company or a Sublicensee, during such calendar quarter. Included in each sales report will be the name of
each Distributor, and the number and type of Licensed Product sold, leased, or otherwise provided to such Distributor. After the first commercial sale of a Licensed Product in the Territory, Company will deliver a written Sales Report to University
even if Company is not required hereunder to pay to University a royalty payment during the calendar quarter. Company shall provide the names of Permitted Sublicensees within thirty (30) days at University’s written request. 

6.5    Books and Records. Throughout the term of this Agreement and for [***] years thereafter, Company, at its
expense, will keep and maintain and shall cause each Sublicensee other than Permitted Sublicensees to keep and maintain complete and accurate records of all sales, leases, and other dispositions of Licensed Products and all other records
related to this Agreement. 
 6.5.1    Audit Rights. Company will permit at the request of University (not
to be made more than once in any given calendar year), one or more independent, certified accountants selected by University and reasonably acceptable to Company (which acceptance shall not be unreasonably withheld or delayed)
(“Accountants”) to have access to Company’s records and books of account pertaining to calculation of Net Sales and payment of any other amounts owed under this Agreement. Accountants’ access will be during ordinary
working hours to audit Company’s records for any payment period ending prior to such request, the correctness of any Sales Report or payment made under this Agreement, or to obtain information as to the payments due for any period in the case
of failure of Company to report or make payment under the terms of this Agreement or to verify Company’s compliance with its payment obligations hereunder. Accountants will sign Company’s standard
non-disclosure agreement provided it is reasonable to the industry in which Company operates. Company shall cause each Sublicensee, other than Permitted Sublicensees, that manufactures, sells, leases, or
otherwise disposes of Licensed Products on behalf of Company to grant University the rights to inspect and audit Sublicensee’s records. 

6.5.2    Scope of Disclosure. Accountants will not disclose to University any information relating to the
business of Company except that which is necessary to inform University of: (a) the accuracy or inaccuracy of Company’s Sales Reports and payments; (b) compliance or noncompliance by Company with the terms and conditions of this
Agreement; or (c) the extent of any inaccuracy or noncompliance. A copy of the Accountants’ report will be provided to Company. 

6.5.3    Accountant Copies. If Accountants believe there is an inaccuracy in any of Company’s payments or
noncompliance by Company with any terms and conditions, Accountants will have 

  

			
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the right to make and retain copies (including photocopies) of any pertinent portions of the records and books of account. 

6.5.4    Costs of Audit. If Company’s payments calculated for any calendar quarter are under-reported by
more than [***], the costs of any audit and review initiated by University will be borne by Company; otherwise, University shall bear the costs of any audit initiated by University. 

7.    INFRINGEMENT 

7.1    Notice of Third Party’s Infringement. If a Party learns of substantial, credible evidence that a Third Party is
infringing exclusively Licensed Rights, that Party will promptly deliver written notice of the possible infringement to the other Party, describing in detail all relevant information to which that Party has access or control suggesting infringement
of the exclusively Licensed Rights. 
 7.2    Company’s Right to Enforce. During the term of this Agreement, Company
has the first right to respond to, defend, and prosecute in its own name, and at its own expense, actions or suits relating to the exclusively Licensed Rights. University may request in writing that Company take action against known infringer. If
required by law or otherwise legally necessary for such action to proceed, Company may request that University be joined as a party plaintiff and University will consider such request in good faith, such request not to be unreasonably denied,
provided that (a) Company must notify University at least ten (10) days before filing suit, and (b) Company will reimburse University for all reasonable legal fees and costs incurred by University in connection with such action.
Company will not settle any suits or actions in any manner relating to the Licensed Rights that is detrimental to the University or to the scope or validity of Licensed Rights, without obtaining the prior written consent of University, which consent
shall not be unreasonably withheld or delayed. 
 7.3    Distributions. Out of any Sublicense fees, royalties, damages,
awards, or settlement proceeds from any settlement or judgment for infringement of Licensed Rights, Company is allowed to first recover its reasonable attorney’s fees and other
out-of-pocket expenses directly related to any action, suit, or settlement for infringement of the Licensed Rights. Any payment by an alleged infringer that, under the
terms of the applicable settlement agreement or judgment, (a) constitutes consideration for Net Sales of infringing product (or an equivalent characterization in the nature of a product royalty) will be handled according to the payment
provisions in Section A3.2 “Running Royalty Payments”, and (b) constitutes consideration for the grant of a Sublicense (or an equivalent characterization) will be handled according to Section A3.6 “Sublicense Consideration”.
Any remaining proceeds will be distributed [***] to Company and [***] to University. 
 7.4    Limitation on
Infringement Actions. Excluded from the rights granted herein is the right to bring an infringement action against a not-for-profit entity for infringement of the
License Rights in carrying out not-for-profit research. 

7.5    University Right to Institute Action. If Company fails, within [***] of receiving of the University’s
written request to take action against an alleged infringer of exclusively Licensed Rights, to secure cessation of the infringement, institute suit against the infringer, or to provide to University satisfactory evidence that Company is engaged in
bona fide negotiations for the acceptance by infringer of a Sublicense to the relevant Licensed Rights, then University may, upon written notice to Company, assume 

  

			
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full right and responsibility to secure cessation of the infringement or institute suit against the infringer, or secure acceptance of a Sublicensee by Company from the alleged infringer in the
relevant Licensed Patents. If University, in accordance with the terms and conditions of this Agreement, chooses to institute suit against an alleged infringer, University may bring such suit in its own name (or, if required by law, in its and
Company’s name) and at its own expense, and Company will, but at University’s expense for Company’s direct associated expenses, fully and promptly cooperate and assist University in connection with any such suit. All license fees,
royalties, damages, awards, or settlement proceeds arising from such a University-initiated action will be solely for the account of University. 

7.6    No Obligation to Institute Action. Neither Company nor University is obligated under this Agreement to institute or
prosecute a suit against any alleged infringer of the Licensed Rights. 
 8.    LICENSED RIGHTS
VALIDITY 
 8.1    Notice and Investigation of Third Party Challenges. If any Third Party challenges the
validity or enforceability of any of the Licensed Rights, the Party having such information will immediately notify the other Party. 

8.2    Third Party Actions. In the event of a Third Party legal action challenging the validity or enforceability of any of
the exclusively Licensed Rights, Company in its sole discretion will have the right to assume and control the sole defense of the claim at Company’s expense. Company will not settle any suits or actions in any manner relating to the Licensed
Rights without obtaining the prior written consent of University, which consent shall not be unreasonably withheld or delayed; provided, however, that the Parties agree that loss of University’s intellectual property rights is a reasonable
reason to withhold consent. Further, if Company is not diligently protecting University’s intellectual property rights, or if Company does not elect to assume and control the sole defense of the Third Party legal action within [***]
after becoming aware of challenge, University will have the right to assume the defense of the action at its own expense. University will not settle any suits or actions in any manner relating to the Licensed Rights without considering in good faith
any comments from Company. 
 8.3    Enforceability of Licensed Rights. Notwithstanding challenge by any Third Party, any
Licensed Right will be enforceable under this Agreement until such Licensed Right is determined to be invalid. 

9.    TERMINATION 

9.1    End of Term. This Agreement will expire, unless terminated earlier as provided in this Article 9
“Termination”, without further action by the Parties, when all Licensed Rights have terminated pursuant to Article 2 “License Grant”, and all obligations due to University based on the exercise of such Licensed Rights have been
fulfilled. 
 9.2    Termination by University. If Company materially breaches or fails to perform one or more of its
material duties under this Agreement, University may deliver to Company a written notice of default, which notice will (a) state that it is a notice of default, (b) state that University intends to terminate this Agreement if the default
is not cured in ninety (90) days, and (c) identify the material duty or duties to which such default relates. Subject to Section 13.4 “Escalation; Dispute Resolution”, University may terminate this Agreement by delivering to
Company a written notice of termination if the default has not 

  

			
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been cured within ninety (90) days of the delivery to Company of the notice of default; provided, however, if Company can reasonably demonstrate to University that it is proceeding
diligently and in good faith to cure such default but cannot do so within such ninety (90) day period, University will extend such cure period for another ninety (90) day period, or such longer period approved by University. In addition,
University may terminate this Agreement in part pursuant to Section 5.2 “Renegotiation of Performance Milestones”. 

9.3    Events of Default. University may terminate this Agreement by delivering to Company a written notice of termination at
least ten (10) days prior to the date of termination if Company (i) permanently ceases operations; (ii) voluntarily files or has filed against it a petition under applicable bankruptcy or insolvency laws that Company fails to have
released within thirty (30) days after filing; (iii) proposes any dissolution, composition, or financial reorganization with creditors or if a receiver, trustee, custodian, or similar agent is appointed; (iv) makes a general
assignment for the benefit of creditors; or (v) if Company challenges the validity of the Licensed Patents. 

9.4    Disputing Events of Default. Notwithstanding the foregoing, if Company disputes that a default has occurred as
contemplated above or that a default has not been cured, Company may use the dispute resolution mechanism outlined in Section 13.4 “Escalation; Dispute Resolution”. 

9.5    Termination by Company. Company may terminate this Agreement at any time by delivering to University a written notice
of termination at least sixty (60) days prior to the effective date of termination. In addition, Company may propose to terminate certain of its Licensed Rights hereunder by delivering to University a written notice of termination accompanied
by a proposed written amendment to this Agreement at least sixty (60) days prior to the effective date of termination of such Licensed Rights. For clarity, such amendment will become effective upon execution of such amendment by University and
Company and shall not be unreasonably withheld or delayed. 
 9.6    Effect of Termination. Upon termination of this
Agreement, the Licensed Rights granted (including any and all rights granted under the Licensed Rights to Sublicensees including Permitted Sublicensees) will terminate. However, no end-user rights shall
terminate as a result of termination of this Agreement. Company’s obligations that have accrued prior to the effective date of termination or expiration of this Agreement (including but not limited to the obligations under Article 6
“Payments, Reimbursements, Reports, and Records” will survive termination of this Agreement. Sublicenses will terminate unless converted into a direct license with University pursuant to Section 9.8 “Sublicenses After
Termination”. Notwithstanding any such termination of this Agreement, subject to being in compliance with Article 6 of this Agreement at the time of termination, and subject to ongoing compliance with obligations under Article 6 and Article 10
“Release, Indemnification, and Insurance”, Company and any Sublicensees and Distributors may sell or otherwise dispose of existing inventory of Licensed Products for a period of [***] days after the effective date of termination of
this Agreement (“Sell-Off Period”), provided, however, that the terms of this Agreement shall apply to the Sell-Off Period as if this Agreement had not
terminated. Company will provide notification if Company, or any Sublicensees or Distributors, will be exercising their rights to continue selling inventory pursuant to the Sell-Off Period. 

9.7    Final Report to University. Within sixty (60) days after the end of the calendar quarter following either the
expiration or termination of either this Agreement or the Sell-Off Period, whichever is later, Company will submit a final Sales Report to University. Any payment obligations accrued prior to such


  

			
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termination or expiration, including those incurred but not yet paid, will become due and payable at the same time as this final Sales Report is due to University. 

9.8    Sublicenses After Termination. At any time within [***] following termination of this Agreement, Sublicensee
may notify University pursuant to Section 13.10 “Notices” that it wishes to enter into a direct license with University in order to retain its rights to the Licensed Rights granted to it under its Sublicense (such [***] period
following receipt of notice of termination, the “Initial Notice Period”). Following University’s receipt of Sublicensee’s notice, University shall offer Sublicensee a license agreement the terms of which will be
substantially similar to the terms of this Agreement; provided, however, that the offered scope of the direct license, licensed territory, and duration of the license grant will be the same as (not merely substantially similar to) the scope
of the license, licensed territory and duration of the license granted under this Agreement (unless the rights granted by Company to Sublicensee were a subset of rights under this Agreement, in which case the scope of the direct license, licensed
territory and duration of the license will be the same as the corresponding terms granted by Company to such Sublicensee). For the sake of clarity, the financial terms, including without limitation, the running royalty rate and milestone payments,
will be identical to the corresponding financial terms set forth in this Agreement, provided University shall consider in good faith reducing the non-running royalty financial payments where there are multiple
direct licensees or such direct licensee has a reduced scope compared with this Agreement. Notwithstanding the foregoing, each Sublicensee’s right to enter into such direct license will be conditioned upon: 

9.8.1    Written Notification to University. Such Sublicensee informing University in writing, pursuant to
Section 13.10 “Notices”, that it wishes to enter into such direct license with University, within the Initial Notice Period; 

9.8.2    Sublicensee in Good Standing. Such Sublicensee being in good standing with Company under its
Sublicense such that Sublicensee is not in material breach of the Sublicense; 
 9.8.3    Valid Sublicense.
Such Sublicense having been validly entered into by Company and Sublicensee pursuant to the terms of Section 2.3 “Sublicense Rights”; 

9.8.4    Sublicensee Certification that Conditions are Satisfied. Such Sublicensee using reasonable efforts to
certify or otherwise demonstrate that the conditions set forth in Subsections 9.8.1 “Written Notification to University”, 9.8.2 “Sublicensee In Good Standing”, and 9.8.3 “Valid Sublicense” have been met within
[***] of expiration of the Initial Notice Period (or within such longer period of time as University agrees is reasonable under the circumstances, based on the nature and extent of any documentation reasonably requested by University); and

 9.8.5    Time Limitations. Unless mutually agreed by the Parties in writing, execution of a direct
license with Sublicensee will be completed not later than [***] from the end of the Initial Notice Period. 
 Except as set forth in Subsection
9.8.5 “Time Limitations”, University may, at its sole discretion, waive any of the requirements in Subsections 9.8.1 through 9.8.4. If all of the conditions set forth in this Section 9.8 “Sublicenses After Termination” are
met, then Sublicensee will be granted such direct license by University. If any condition set forth in this Section 9.8 “Sublicenses After Termination” is not met, then 

  

			
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after expiration of any time period granted to Sublicensee with respect to meeting such condition (for example and to the extent applicable, the Initial Notice Period and/or the periods described
in Subsections 9.8.4 “Sublicensee Certification that Conditions are Satisfied” and 9.8.5 “Time Limitations”), Sublicensee will not practice Licensed Rights except as provided for in Section 9.6 “Effect of
Termination” and University will be free to license or not license Licensed Rights to such Sublicensee according to University’s sole discretion. 

10.    RELEASE, INDEMNIFICATION, AND INSURANCE 

10.1    Company’s Release. Company hereby releases University, IRB, and their regents, officers, employees,
and agents forever from any and all suits, actions, claims, liabilities, demands, damages, losses, or expenses (including reasonable attorneys’ and investigative expenses) relating to or arising out of (a) the manufacture, use, lease,
sale, or other disposition of a Licensed Product; or (b) the assigning or sublicensing of Company’s rights under this Agreement. 

10.2    Indemnification. Company will indemnify, defend, and hold harmless University, IRB and their regents, officers,
employees, and agents (each, an “Indemnitee”) from all Third Party suits, actions, claims, liabilities, demands, damages, losses, or expenses (including reasonable attorneys’ and investigative expenses), based on
University’s or IRB’s role in developing or licensing Licensed Rights and relating to or arising out of Company’s or Sublicensees’ exercise of any rights with respect to Licensed Products, including, without limitation, personal
injury, property damage, breach of contract and warranty and products-liability claims relating to a Licensed Product and claims brought by a Sublicensee (each, a “Claim”), provided that the Company will not have obligations to the
extent resulting from the University’s or IRB’s gross negligence or willful misconduct. In the event of a Claim, the Indemnitee against whom a Claim is brought will: (a) give Company written notice of the Claim within a reasonable
period of time after such Indemnitee receives notice thereof along with sufficient information for Company to identify the Claim; and (b) cooperate and provide such assistance (including, without limitation, testimony and access to
documentation within the possession or control of such Indemnitee) as Company may reasonably request in connection with Company’s defense, settlement and satisfaction of the Claim. Company will pay or reimburse all costs and expenses reasonably
incurred by such Indemnitee to provide any such cooperation and assistance. Any settlement that would admit liability on the part of University or IRB or that would involve any relief other than the payment of monetary damages will be subject to the
approval of University and/or IRB, such approval not to be unreasonably withheld. HHMI, and its trustees, officers, employees, and agents (collectively, “HHMI Indemnitees”), will be indemnified, defended by counsel acceptable to
HHMI, and held harmless by Company from and against any claim, liability, cost, expense, damage, deficiency, loss, or obligation, of any kind or nature (including, without limitation, reasonable attorneys’ fees and other costs and expenses of
defense) (collectively, “HHMI Claims”), based upon, arising out of, or otherwise relating to this Agreement or any Sublicense, including without limitation any cause of action relating to product liability. The previous sentence
will not apply to any HHMI Claim that is determined with finality by a court of competent jurisdiction to result solely from the gross negligence or willful misconduct of an HHMI Indemnitee. Notwithstanding any other provision of this Agreement,
Company’s obligation to defend, indemnify and hold harmless the HHMI Indemnitees under this paragraph will not be subject to any limitation or exclusion of liability or damages or otherwise limited in any way. 

10.3    Company’s Insurance. 

  

			
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 10.3.1    General Insurance Requirement. Throughout the term
of this Agreement, or during such period as the Parties will agree in writing, Company will maintain full force and effect commercial general liability (CGL) insurance and product liability insurance, with single claim limits at an amount customary
to Company’s business for activities and/or products of a similar nature. Such insurance policy will include coverage for claims that may be asserted by University or HHMI against Company under Section 10.2 “Indemnification”.
Such insurance policy will name the Board of Regents of the University of Washington and HHMI as an additional insured and will require the insurer to deliver written notice to University at the address set forth in Section 13.10
“Notices”, at least thirty (30) days prior to the termination of the policy. Company will deliver to University a copy of the certificate of insurance for such policy. 

10.3.2    Clinical Trial Liability Insurance. Within thirty (30) days prior to the initiation of human
clinical trials with respect to Licensed Product(s), Company will provide to University certificates evidencing the existence and amount of clinical trials liability insurance. Company will issue irrevocable instructions to its insurance agent and
to the issuing insurance company to notify University of any discontinuance or lapse of such insurance not less than thirty (30) days prior to the time that any such discontinuance is due to become effective. Company will provide University a
copy of such instructions upon their transmittal to the insurance agent and issuing insurance company. Company will further provide University, at least annually, proof of continued coverage. 

11.    WARRANTIES 

11.1    Authority. Each Party represents and warrants to the other Party that it has full power and authority to execute,
deliver, and perform this Agreement, and that no other proceedings by such Party are necessary to authorize the Party’s execution or delivery of this Agreement. 

11.2    Documents. University represents and warrants that: all University personnel, including employees, students,
consultants and contractors, who University is aware as of Effective Date have contributed to the Licensed Patents as of Effective Date have either (a) been party to a for-hire relationship with
University that affords University sufficient ownership of all Licensed Patents to provide this license of University’s rights to Company, or (b) executed assignment documents in favor of University as prescribed either by University
policies or by agreement with HHMI to provide University sufficient ownership of the Licensed Patents to provide this license of University’s rights to Company. Furthermore, in the interinstitutional agreement between University and IRB, IRB
represents that its inventors are obligated to assign to IRB all of the inventors’ rights in the Licensed Patents, and that IRB will use diligent efforts to cause its inventors to sign any additional papers as may be necessary to evidence such
assignment. 
 11.3     No Known Infringement. As of the Effective Date, to the best of University’s CoMotion
office’s knowledge, (a) no claim has been made or is threatened charging University or IRB with infringement of, or claiming that the Licensed Rights infringe any Third Party rights; and (b) no proceedings have been instituted, or are
pending or threatened, which challenge the University’s or IRB’s rights in respect to the Licensed Patents or other Licensed Rights. 

11.4    Disclaimer. EXCEPT FOR THE EXPRESS WARRANTIES SET FORTH IN SECTIONS 11.1 “AUTHORITY”, 


  

			
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11.2 “DOCUMENTS”, AND 11.3 “NO KNOWN INFRINGEMENT” UNIVERSITY DISCLAIMS AND EXCLUDES ALL WARRANTIES, EXPRESS AND IMPLIED, CONCERNING EACH LICENSED RIGHT AND EACH
LICENSED PRODUCT, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF NON-INFRINGEMENT AND THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. University innovation has been developed
as part of research conducted at University. University innovation is experimental in nature and is made available “AS IS,” without obligation by University to provide accompanying services or support except as specified in this Agreement.
The entire risk as to the quality and performance of University innovation is with Company. 
 11.5    Intellectual Property
Disclaimers. University expressly disclaims any warranties concerning and makes no representations: (a) that the Licensed Patent(s) will be approved or will issue; (b) concerning the validity or scope of any Licensed Right; or
(c) that the practice of Licensed Rights, or the manufacture, use, sale, lease or other disposition of a Licensed Product will not infringe or violate a Third Party’s patent, copyright, or other intellectual property right. 

12.    DAMAGES 

12.1    Remedy Limitation. EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, (A) IN NO EVENT WILL
UNIVERSITY OR IRB BE LIABLE FOR PERSONAL INJURY OR PROPERTY DAMAGES ARISING IN CONNECTION WITH THE ACTIVITIES CONTEMPLATED IN THIS AGREEMENT AND (B) IN NO EVENT WILL EITHER PARTY OR IRB BE LIABLE FOR
LOST PROFITS, LOST BUSINESS OPPORTUNITY, INVENTORY LOSS, WORK STOPPAGE, LOST DATA OR ANY OTHER RELIANCE OR EXPECTANCY, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, OF ANY KIND. 

12.2    Damage Cap. IN NO EVENT WILL UNIVERSITY’S TOTAL LIABILITY FOR THE BREACH OR NONPERFORMANCE OF
THIS AGREEMENT EXCEED [***] OF PAYMENTS PAID TO UNIVERSITY UNDER ARTICLE 6 “PAYMENTS, REIMBURSEMENTS, REPORTS, AND RECORDS”. THIS LIMITATION WILL APPLY TO CONTRACT,
TORT, AND ANY OTHER CLAIM OF WHATEVER NATURE. 
 13.    GENERAL PROVISIONS 

13.1    Amendment and Waiver. This Agreement may be amended from time to time only by a written instrument signed by the
Parties. No term or provision of this Agreement will be waived, and no breach excused, unless such waiver or consent is in writing and signed by the Party claimed to have waived or consented. No waiver of a breach will be deemed to be a waiver of a
different or subsequent breach. 
 13.2    Assignment. The rights and licenses granted by University in this Agreement are
personal to Company and Company will not assign its interest or delegate its duties under this Agreement without the written consent of University, which consent will not to be unreasonably withheld or delayed; any such assignment or delegation made
without written consent of University will not release Company from its obligations under this Agreement. Notwithstanding the foregoing, Company, without the prior approval of University, may assign all, but no less than all, of its rights and
delegate all, but no less than all, of its duties under this Agreement to a Third Party provided that: (a) the assignment is made to such Third Party as a part of and in connection with an Acquisition, (b) Company obtains from such Third
Party written agreement to honor all obligations under this Agreement accrued by Company before Acquisition and all obligations under this Agreement to accrue by such Third Party assignee after Acquisition, and (c)


  

			
	 Icosavax, Inc. / University of Washington
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 CONFIDENTIAL 
  

 
Company provides written notice to University of the Acquisition, together with a substitution of parties document or copy of the assignment confirming compliance with (b) above, no later
than thirty (30) days after the close of the Acquisition. Any assignment made in violation of this Section 13.2 is void and will constitute an act of breach that requires remedy under Section 9.2 “Termination by University”.
This Agreement will inure to the benefit of Company and University and their respective permitted assignees and trustees. 

13.3    Confidentiality. 

13.3.1    Form of Transfer. Confidential Information may be conveyed in tangible or intangible form.
Disclosing Party must clearly mark its Confidential Information “confidential”. If disclosing Party communicates Confidential Information in non-written form, it will reduce such communications to
writing, clearly mark it “confidential”, and provide a copy to receiving Party within thirty (30) days of original communication at the address in Section 13.10 “Notices”. Any business information delivered by Company
as required under this Agreement shall be deemed marked “confidential”, whether or not such confidential marking appears. 

13.3.2    No Unauthorized Disclosure of Confidential Information. Beginning on the Effective Date and
continuing throughout the term of this Agreement and thereafter for a period of [***], receiving Party will not disclose or otherwise make known or available to any Third Party any disclosing Party Confidential Information, without the
express prior written consent of disclosing Party. Notwithstanding the foregoing, receiving Party will be permitted to disclose Confidential Information of disclosing Party to (i) actual or potential investors, lenders, consultants, advisors,
collaborators, Sublicensees, or development partners, which disclosure will be made under conditions of confidentiality and limited use and (ii) its attorney or agent as reasonably required and (iii) to employees and trustees of HHMI who
have a need to know. In no event will receiving Party incorporate or otherwise use disclosing Party’s Confidential Information in connection with any patent application filed by or on behalf of receiving Party. Receiving Party will restrict the
use of disclosing Party’s Confidential Information to uses exclusively in accordance with the terms of this Agreement. Receiving Party will use reasonable procedures to safeguard disclosing Party’s Confidential Information. In the case
where Company is the receiving Party, Company’s confidentiality obligations will also apply equally to Sublicensees. 

13.3.3    Access to University Information. University is an agency of the state of Washington and is subject
to the Washington Public Records Act, RCW 42.56 et seq., (“Act”), and no obligation assumed by University under this Agreement will be deemed to be inconsistent with University’s obligations as defined under the Act and as
interpreted by University in its sole discretion. If University receives a request for public records under the Act for documents containing Company Confidential Information, and if University concludes that the documents are not otherwise exempt
from public disclosure, University will provide Company notice of the request before releasing such documents. Such notice will be provided in a timely manner to afford Company sufficient time to review such documents and/or seek a protective order,
at Company’s expense utilizing the procedures described in RCW 42.56.540. University will have no other obligation to protect Company Confidential Information from disclosure in response to a request for public records. 

  

			
	 Icosavax, Inc. / University of Washington
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 CONFIDENTIAL 
  

 13.3.4    Disclosure as Required by Law. Either Party will
have the right to disclose the other Party’s Confidential Information as required by law or valid court order, provided that such Party will inform the Party who owns such Confidential Information prior to such disclosure, will cooperate with
the owner Party’s efforts to limit or avoid disclosure, and will limit the scope and recipient of disclosure to that required by such law or court order. 

13.4    Escalation; Dispute Resolution. If (i) Company disputes that a default has occurred as contemplated in
Section 9.2 “Termination by University”, or that a default has not been cured, or (ii) Company wishes to dispute termination of this Agreement resulting from a failed renegotiation of a new Performance Milestone as contemplated
under Section 5.2 “Renegotiation of Performance Milestones”, or (iii) Company disputes in good faith any amounts that are owed to University under this Agreement, and a late fee for such disputed amount has been charged to
Company under Section 6.3 “Late Payments”, then Company may provide University with a written dispute notice (“Dispute Notice”). In the case of (i) and (ii) above such Dispute Notice must be received by
University prior to expiration of the 60-day cure period referenced in Section 9.2 “Termination by University”, stating the basis of Company’s disagreement with respect to such default or
cure. In the case of (iii) above such Dispute Notice must be received by University within thirty (30) days of being charged a late fee for such disputed amount. If Company disputes that a default has occurred as contemplated in
Section 9.3 “Events of Default”, then Company may provide University with a Dispute Notice within thirty (30) days of University sending the notice of termination referenced in Section 9.3 “Events of Default”. Upon
receipt of a Dispute Notice, University’s right to terminate this Agreement or demand payment of late fees will be suspended and all rights under this Agreement will continue unaffected provided the dispute resolution process in this
Section 13.4 “Escalation; Dispute Resolution” is being exercised. Any dispute will first be escalated to Company’s Chief Executive Officer or to a representative from Company’s Board of Directors, and to University’s
Vice President for Innovation Strategy, representatives of which will be instructed to work in good faith to attempt to reach a mutually acceptable resolution of the dispute that would avoid termination of this Agreement. If the representatives are
unable to reach such resolution of the dispute within thirty (30) days of delivery of the Dispute Notice, an independent, neutral mediator acceptable to both Parties (acting reasonably) will be appointed. The Parties will submit their dispute
to mediation according to such parameters as they may mutually agree in writing. The Parties agree to discuss their differences in good faith and to attempt in good faith, with facilitation by the mediator, to reach an amicable resolution of the
dispute within thirty (30) days after the mediator’s appointment. If the Parties are not able to agree on resolution of the dispute within such period, or within ninety (90) days of the Dispute Notice, whichever is earlier, including
agreeing on a new Performance Milestone pursuant to Section 5.2 “Renegotiation of Performance Milestones” if that is the subject of the dispute, then the dispute resolution process of this Section 13.4 “Escalation; Dispute
Resolution” will be complete and either Party may pursue any other action that is legally available to it. Notwithstanding the foregoing, no dispute affecting the rights or property of HHMI shall be subject to the dispute resolutions provisions
set forth above. 
 13.5    Consent and Approvals. Except as otherwise expressly provided in this Agreement, all consents
or approvals required under the terms of this Agreement must be in writing and will not be unreasonably withheld or delayed. 

13.6    Construction. The headings preceding and labeling the sections of this Agreement are for the purpose of
identification only and will not in any event be employed or used for the purpose of construction or interpretation of any portion of this Agreement. As used herein and where necessary, the 

  

			
	 Icosavax, Inc. / University of Washington
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 CONFIDENTIAL 
  

 
singular includes the plural and vice versa, and masculine, feminine, and neuter expressions are interchangeable, and the word “including” shall mean “including, without
limitation.” 
 13.7    Enforceability. If a court of competent jurisdiction adjudges a provision of this Agreement
unenforceable, invalid, or void, such determination will not impair the enforceability of any of the remaining provisions hereof and the provisions will remain in full force and effect. 

13.8    Third-Party Beneficiaries. Except as identified in Section 13.22 “Third Party Beneficiary” or other
parts of this Agreement referencing IRB, no provision of this Agreement, express or implied, confers upon any person other than the Parties to this Agreement, IRB, HHMI and Sublicensees (Sublicensees solely for purposes of enforcing Sections 9.8
“Sublicenses After Termination” and 13.22) any rights, remedies, obligations, or liabilities hereunder. No Sublicensee will have a right to enforce or seek damages under this Agreement other than as set forth in Section 13.22. The
Parties agree that no amendment or modification to Section 9.8 or Section 13.22 shall apply to a Sublicensee without the prior written consent of that Sublicensee, if such amendment occurs after the date of execution of the applicable
Sublicense. 
 13.9    Language. Unless otherwise expressly provided in this Agreement, all notices, reports, and other
documents and instruments that a Party elects or is required by the terms of this Agreement to deliver to the other Party will be in English. 

13.10    Notices. All notices, requests, and other communications that a Party is required or elects to deliver will be in
writing and will be delivered personally, or by facsimile or electronic mail (provided such delivery is confirmed), or by a recognized overnight courier service or by United States mail, first-class, certified or registered, postage prepaid, return
receipt requested, to the other Party at its address set forth below or to another address as a Party may designate by notice given under this Section 13.10: 

 

			
	If to University:	  	 UW CoMotion
 ATTN: Director, Innovation Development

4545 Roosevelt Way NE, Suite 400
 Seattle, WA 98105-4721

Facsimile No.: 206-685-4767

		
	If to Company:	  	 Icosavax, Inc.
 ATTN: Adam Simpson

600 University Street, Suite 2525
 Seattle, WA 98101



 13.11    Proprietary Markings. To the extent commercially feasible, Company will mark
all material forms of Licensed Products or packaging pertaining thereto made and sold by Company in the United States with patent marking conforming to 35 U.S.C. §287(a), as amended from time to time. All Licensed Product(s) shipped to or sold
in other countries will be marked in such a manner as to provide notice to potential infringers pursuant to the patent law and practice of the country of manufacture or sale. 

  

			
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 CONFIDENTIAL 
  

 13.12    Use of University’s Name and Trademarks or the Names
of University Faculty, Staff, or Students. No provision of this Agreement grants Company or Sublicensee any right or license to use the name or trademarks of University or IRB or the names or identities of any member of the faculty, staff, or
student body of University or IRB. Except as provided herein, Company will not use, and will not permit a Sublicensee to use, any such trademarks, names, or identities without University’s, IRB’s and, as the case may be, such member’s
prior written approval. Notwithstanding the foregoing, Company, University, and IRB may provide factual information regarding the existence of this Agreement. Company acknowledges that under HHMI policy, Company may not use the name of HHMI or of
any HHMI employee (including Dr. Baker) in a manner that reasonably could constitute an endorsement of a commercial product or service; but that use for other purposes, even if commercially motivated, is permitted provided that (1) the use
is limited to accurately reporting factual events or occurrences, and (2) any reference to the name of HHMI or any HHMI employees in press releases or similar materials intended for public release is approved by HHMI in advance. 

13.13    Publicity. In accordance with Section 13.12, University will have the right to report in its customary
publications and presentations that University and Company have entered into a license agreement for the technology covered by the Licensed Rights and University may use Company logos in such publications and presentations provided that University
does not modify Company’s logos and does not through such use imply any endorsement by Company of University. The Parties will cooperate with one another to review and respond to any press release or similar communication proposed by the other
Party regarding the non-confidential subject matter of this Agreement. The specific content and timing of such press releases or similar communication is subject to mutual agreement by the Parties, which will
not be unreasonably withheld. Further, University and Company will issue a joint press release regarding this Agreement, subject to both Parties’, and, if applicable in accordance with Section 13.12, HHMI’s, review and approval of the
specific content thereof, and such press release will include specific mention of the contributions of University personnel, in accordance with Section 13.12, and University in developing the technology in a prominent portion of the press
release. Company will provide University with appropriate quotes for such press release. University may post the press release in digital and print publications as well as on University’s own website. 

13.14    Relationship of Parties. In entering into, and performing their duties under, this Agreement, the Parties are acting
as independent contractors and independent employers. No provision of this Agreement will create or be construed as creating a partnership, joint venture, or agency relationship between the Parties. No Party will have the authority to act for or
bind the other Party in any respect. 
 13.15    Relationship with Principal Investigator(s). Company acknowledges
that Principal Investigator is employed by University and has certain pre-existing obligations to University, including obligations with respect to disclosure and ownership of intellectual property and
obligations arising from sponsored research agreements between University and Third Parties. Accordingly, Company agrees that to the extent that any consulting agreement between Company and Principal Investigator is inconsistent with any of
Principal Investigator’s obligations to University, including the reporting of all inventions developed while employed by University (regardless of where arising) and including contractual obligations arising under any sponsored research
agreements between University and Third Parties, then Principal Investigator’s obligations to University will prevail and to such extent any inconsistent provisions of such consulting agreement will be deemed inapplicable and unenforceable.


  

			
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 CONFIDENTIAL 
  

 13.16    Security Interest. In no event will Company grant, or permit any
person to assert or perfect, a security interest in the Licensed Rights; however, Company may grant or permit a security interest in the Company’s rights under this Agreement. 

13.17    Survival. The obligations specified in Article 6 “Payments, Reimbursements, Reports, and Records” will
survive termination of this Agreement provided Reports will not be required for any period in which there are no Net Sales other than the final report due under Section 9.7 “Final Report to University”. Article 1
“Definitions” and the obligations and rights set forth in Section 2.8 “HHMI Research Use Rights”, Section 5.3 “Commercialization Reports” (as applicable to any Sell-Off
Period), Article 9 “Termination”, Article 10 “Release, Indemnification, and Insurance”, Article 11 “Warranties”, Article 12 “Damages”, Section 13.3 “Confidentiality”, Section 13.4
“Escalation; Dispute Resolution”, but only with respect to any disputes arising before the effective date of termination or expiration), Section 13.17 “Survival”, Section 13.19 “Applicable Law”,
Section 13.20 “Forum Selection”, Section 13.21 “Entire Agreement”, and Section 13.22 “Third-Party Beneficiary” will survive the termination or expiration of this Agreement. 

13.18    Collection Costs and Attorneys’ Fees. If a Party fails to perform an obligation or otherwise
breaches one or more of the terms of this Agreement, the other Party may recover from the non-performing breaching Party all its costs (including actual attorneys’ and investigative fees) to enforce the
terms of this Agreement. 
 13.19    Applicable Law. The internal laws of the state of Washington will govern the validity,
construction, and enforceability of this Agreement, without giving effect to the conflict of laws principles thereof. 

13.20    Forum Selection. Any suit, claim, or other action to enforce the terms of this Agreement will be brought exclusively
in the state and federal courts of King County, Washington. Company hereby submits to the jurisdiction of that court and waives any objections it may have to that court asserting jurisdiction over Company or its assets and property. 

13.21    Entire Agreement. Company and University executed an exclusive option agreement (“Option”) for
certain Licensed Patents, with University reference [***], dated [***]. This Agreement (including all attachments, exhibits, and amendments) is the final and complete understanding between the Parties concerning licensing of the Licensed Rights.
This Agreement supersedes any and all prior or contemporaneous negotiations, representations, and agreements, whether written or oral, concerning the Licensed Rights. However, the obligations of nondisclosure for confidential information (such term
as defined in the Option) disclosed under the Option will survive. Confidential Information disclosed under this Agreement will be governed by the terms of this Agreement. This Agreement may not be modified in any manner, except by written
agreement signed by an authorized representative of both Parties. 
 13.22    Third Party Beneficiary. 

13.22.1    HHMI is not a party to this Agreement and has no liability to any licensee, sublicensee, or user of
anything covered by this Agreement, but HHMI is an intended third-party beneficiary of this Agreement and certain of its provisions are for the benefit of HHMI and are enforceable by HHMI in its own name. 

  

			
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 CONFIDENTIAL 
  

 13.22.2    Notwithstanding anything to the contrary in this
Agreement, each Sublicensee is an intended third party beneficiary of this Agreement, but solely for purposes of enforcing Section 9.8 “Sublicenses After Termination” in its own name. 

13.23    Counterparts. This Agreement may be executed in counterparts, each of which (including signature pages) will be
deemed an original, but all of which together will constitute one and the same instrument. A facsimile, scanned, or photocopied signature (and any signature duplicated in another similar manner) identical to the original will be considered an
original signature. 
 IN WITNESS WHEREOF, the Parties have caused this Agreement to be duly executed by their respective authorized
representatives. 
  

							
	University of Washington	 	Icosavax, Inc.
				
	By:	  	 /s/ Fiona Wills
	 	By:	 	 /s/ Adam K. Simpson

	Name:	  	Fiona Wills	 	Name:	 	Adam K. Simpson
	Title:	  	Director, Innovation Development	 	Title:	 	CEO
	Date:	  	6/29/2018	 	Date:	 	6/29/2018


  

			
	 Icosavax, Inc. / University of Washington
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 CONFIDENTIAL 
  

 Exhibit A 

Start-Up License Schedule 

A1.    Licensed Rights: 

 A1.1    Licensed Patents: [***] 

A2.    Performance Milestones (Section 5.1 “Performance Milestones”): Subject to Company’s right to renegotiation or
Company’s payment of a fee for extension as set forth in Article 5 “Commercialization” of the Agreement, Company will perform, or shall cause to happen or be performed, the following Performance Milestones: 

 

			
	 	  	Performance Milestone and Performance Milestone Date
for First Indication Category in the Field of Use
	 A2.1.1
 Performance

Milestone 1
	  	[***]
		
	 A2.1.2
 Performance

Milestone 2
	  	[***]
		
	 A2.1.3
 Performance

Milestone 3
	  	[***]
		
	 A2.1.4
 Performance

Milestone 4
	  	[***]
		
	 A2.1.5
 Performance

Milestone 5
	  	[***]
		
	 A2.1.6
 Performance

Milestone 6
	  	[***]
		
	 A2.1.7
 Performance

Milestone 7
	  	[***]

  

			
	 	  	Performance Milestone and Performance Milestone Date
for Second Indication Category in the Field of Use
	 A2.2.1
 Performance

Milestone 1
	  	[***]
		
	 A2.2.2
 Performance

Milestone 2
	  	[***]
		
	 A2.2.3
 Performance

Milestone 3
	  	[***]


  

			
	 Icosavax, Inc. / University of Washington
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 UW CoMotion Ref. [***]
	  	
	27















 CONFIDENTIAL 
  


			
	 A2.2.4
 Performance

Milestone 4
	  	[***]
		
	 A2.2.5
 Performance

Milestone 5
	  	[***]
		
	 A2.2.6
 Performance

Milestone 6
	  	[***]
		
	 A2.2.7
 Performance

Milestone 7
	  	[***]
		
	 	  	Performance Milestone and Performance Milestone Date
for Third Indication Category in the Field of Use
	 A2.3.1
 Performance

Milestone 1
	  	[***]
		
	 A2.3.2
 Performance

Milestone 2
	  	[***]
		
	 A2.3.3
 Performance

Milestone 3
	  	[***]
		
	 A2.3.4
 Performance

Milestone 4
	  	[***]
		
	 A2.3.5
 Performance

Milestone 5
	  	[***]
		
	 A2.3.6
 Performance

Milestone 6
	  	[***]
		
	 A2.3.7
 Performance

Milestone 7
	  	[***]
		
	 	  	Performance Milestone and Performance Milestone Date
for Fourth Indication Category in the Field of Use
	 A2.4.1
 Performance

Milestone 1
	  	[***]


  

			
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 CONFIDENTIAL 
  


			
	 A2.4.2
 Performance

Milestone 2
	  	[***]
		
	 A2.4.3
 Performance

Milestone 3
	  	[***]
		
	 A2.4.4
 Performance

Milestone 4
	  	[***]
		
	 A2.4.5
 Performance

Milestone 5
	  	[***]
		
	 A2.4.6
 Performance

Milestone 6
	  	[***]
		
	 A2.4.7
 Performance

Milestone 7
	  	[***]
		
	 	  	Performance Milestone and Performance Milestone Date
for Fifth Indication Category in the Field of Use
	 A2.5.1
 Performance

Milestone 1
	  	[***]
		
	 A2.5.2
 Performance

Milestone 2
	  	[***]
		
	 A2.5.3
 Performance

Milestone 3
	  	[***]
		
	 A2.5.4
 Performance

Milestone 4
	  	[***]
		
	 A2.5.5
 Performance

Milestone 5
	  	[***]
		
	 A2.5.6
 Performance

Milestone 6
	  	[***]
		
	 A2.5.7
 Performance

Milestone 7
	  	[***]


  

			
	 Icosavax, Inc. / University of Washington
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 CONFIDENTIAL 
  

 A3.    Payments (Section 6.1): 

A3.1    Annual Maintenance Fee. Company will pay to University an annual,
non-creditable, maintenance fee of [***] due on the second anniversary and all subsequent anniversaries of the Effective Date provided that no annual maintenance fee will be due in any year Company pays
minimum annual royalties. 
 A3.2    Running Royalty Payments. Company will pay to University within sixty
(60) days after the last day of each calendar quarter during the term of this Agreement an amount equal to [***] during such quarter as a running royalty payment. 

A3.2.1    Stacking or Third Party Royalty. If a Licensed Party is required to pay royalties to a Third Party
based on such Licensed Party’s manufacture, use, offer for sale, sale or import of Licensed Product, subject to one or more patents of such Third Party, then the royalty Company pays to University may be reduced [***] of the royalty
actually paid to the Third Party ; provided that [***] of Licensed Product, and provided that the royalty amount paid to the University shall not fall below [***] of Net Sales. 

A3.3    Minimum Annual Royalties. Company will pay minimum annual royalties for the term of this Agreement to
be creditable against running royalty payments for the preceding calendar year on a non-cumulative basis and to be due in full and payable on January 31st of each year beginning on January 31st following the
first full calendar year after the first commercial sale of a Licensed Product and continuing during the term of this Agreement according to the following schedule: 
  

			
	 Calendar Year
	  	Minimum Annual Royalty
	 Year [***] after first

commercial sale
	  	[***]
		
	 Year [***] after first

commercial sale
	  	[***]
		
	 Year [***] after first

commercial sale and each year

after
	  	[***]

 A3.3.1    If this Agreement is terminated prior to the payment of a minimum annual
royalty in any given year the amount due for that minimum annual royalty payment will be prorated on the basis of the number of full quarters that have elapsed prior to termination since the last payment of a minimum annual royalty. 

A3.4    Financial Milestone Payments. Company will pay to University the following non-cumulative, non-creditable, and non-refundable, one-time Performance Milestone achievement
payments for each of First Indication Category, Second Indication Category, Third Indication Category, Fourth Indication Category, and Fifth Indication Category within thirty (30) days of achieving the corresponding Performance Milestone,
whether achieved by Company or a Sublicensee: 

  

			
	 Icosavax, Inc. / University of Washington
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 CONFIDENTIAL 
  


			
	 	 	
Performance Milestone Achieved

	[***]	 	Performance Milestone 4 in A2.1.4, A2.2.4, A2.3.4, A2.4.4, or A2.5.4
		
	[***]	 	Performance Milestone 5 in A2.1.5, A2.2.5, A2.3.5, A2.4.5, or A2.5.5
		
	[***]	 	Performance Milestone 6 in A2.1.6, A2.2.6, A2.3.6, A2.4.6, or A2.5.6
		
	[***]	 	Cumulative Net Sales of [***] for First Indication Category, Second Indication Category, Third Indication Category, Fourth Indication Category, or Fifth Indication Category

 For the avoidance of doubt, total Financial Milestones for each Indication Category shall not exceed US
[***] and total Financial Milestones under this Agreement shall not exceed [***]. Each Financial Milestone shall be payable only once for the applicable Indication Category even if such milestone is achieved by more than one Licensed
Product. 
 A3.5    Equity. In consideration for the rights granted to Company hereunder, within thirty
(30) days after the Effective Date, Company will issue to University a number of Shares equal to [***] of Company’s Fully-Diluted Shares as of the Effective Date, such Shares to be issued pursuant to the Stock Subscription Agreement
attached hereto as Exhibit D. In addition, Company agrees to issue additional Shares to University sufficient to cause the University to own in aggregate [***] of Company’s Fully-Diluted Shares through such time as the Company has raised
Qualified Financing; provided, however, that if Company closes an equity financing that would result in its cumulative equity capital raised being in excess of the Qualified Offering Proceeds, any such excess capital (and resulting dilution) will be
ignored and the number of additional Shares to be issued to University will be calculated assuming Company had raised only such amount of equity capital as would result in its cumulative equity capital raised since incorporation being equal to the
Qualified Offering Proceeds. Any such additional Shares will be issued as of or immediately after such closing: 

A3.5.1    Participation Rights. If at any time after the execution and delivery of the Agreement, Company
proposes to sell any equity securities or securities that are convertible into equity securities of the Company (“Future Equity Financings”), then the University and/or its Assignee (as defined below) will have the right
[***]. In addition, Company acknowledges that, [***]. Company shall provide thirty (30) days advance written notice of each such financing, including reasonable details regarding the terms of the financing. The term
“Assignee” means (a) any entity to which the University’s participation rights under this section have been assigned either by the University or another entity, or (b) any entity that is controlled by the University.
This paragraph shall survive the termination of this Agreement as follows: such participation rights, including [***], shall expire on the earliest of: [***] 

A3.6    Sublicense Consideration. Within sixty (60) days of the end of each calendar quarter during the
term of this Agreement, Company will pay to University [***] any Sublicense Consideration received by Company during such calendar quarter unless reduced by achievement of Performance Milestones by Company or its Sublicensees prior to
execution of the particular Sublicense in accordance with the schedule below. Determination of the relevant Performance Milestone having been achieved for the purposes of determining the Sublicense Consideration percentage shall be based on the most
advanced Licensed Product candidate then in development in the applicable Indication Category for which Sublicense Consideration was received. A further reduction of the percentage of Sublicense Consideration payable to University under this
Agreement will be negotiated in good faith between the Parties where, in addition to the Sublicense of any 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
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	31















 CONFIDENTIAL 
  

 
rights granted to Company hereunder, Company or its Sublicensee also grants a Sublicensee a license or sublicense under a Third Party’s intellectual property rights that are or would be
infringed by Licensed Product(s) (treating pending patent applications as if they were issued patents), but only to the extent that the total aggregate consideration for such combined license is treated as Sublicense Consideration. 

 

					
	 	  	
Performance Milestone Has Been Achieved at

the Date of Execution of the Sublicense

related to the applicable Indication Category
	  	Sublicense
Consideration
Percentage
	 A3.6.1
 Milestone 1
	  	Performance Milestone 1 in A2.1.1, A2.2.1, A2.3.1, A2.4.1, or A2.5.1	  	[***]
			
	 A3.6.2
 Milestone 2
	  	Performance Milestone 2 in A2.1.2, A2.2.2, A2.3.2, A2.4.2, or A2.5.2	  	[***]
			
	 A3.6.3
 Milestone 3
	  	Performance Milestone 3 in A2.1.3, A2.2.3, A2.3.3, A2.4.3, or A2.5.3	  	[***]
			
	 A3.6.4
 Milestone 4
	  	Performance Milestone 4 in A2.1.4, A2.2.4, A2.3.4, A2.4.4, or A2.5.4	  	[***]
			
	 A3.6.5
 Milestone 5
	  	Performance Milestone 5 in A2.1.5, A2.2.5, A2.3.5, A2.4.5, or A2.5.5	  	[***]
			
	 A3.6.6
 Milestone 6
	  	Performance Milestone 6 in A2.1.6, A2.2.6, A2.3.6, A2.4.6, or A2.5.6	  	[***]
			
	 A3.6.7
 Milestone 7
	  	Performance Milestone 7 in A2.1.7, A2.2.7, A2.3.7, A2.4.7, or A2.5.7	  	[***]

 Notwithstanding the foregoing, achievement of Performance Milestones 1, 2 and 3 by the Company or its Sublicensee for
the First Indication Category shall reduce the initial Sublicense Consideration percentage to [***] for all subsequent Indication Categories, with further subsequent reductions for such applicable Indication Category occurring upon
achievement of Performance Milestones 3, 4, 5, 6, and 7 based on the schedule above. 
 A3.7    Acquisition
Fee. University will be paid within thirty (30) days of an Acquisition a fee (the “Acquisition Fee”) equal to [***] of the Acquisition Consideration if no Performance Milestones have been achieved by Company or
Sublicensee for any Indication Category; [***] of the Acquisition Consideration if Performance Milestone 1 has been achieved by Company or Sublicensee in at least one (1) Indication Category[***] of the Acquisition Consideration
if Performance Milestone 2 has been achieved by Company or Sublicensee in at least one (1) Indication Category; or [***] of the Acquisition Consideration if either (i) Performance Milestone 3 has been achieved by Company or
Sublicensee in at least one (1) Indication Category, or (ii) Company has raised cumulative equity capital equal to or in excess of the Qualified Offering Proceeds regardless of whether Milestones 1 through 3 above have been met. The
Acquisition Fee otherwise due under this Section A3.7 will be reduced and offset by the amount of consideration attributable to University’s Shares under Section A3.5 “Equity” above. For this purpose, the consideration attributable to
the Shares will be deemed to include all amounts paid at closing, placed in escrow, subject to earnout payments, or otherwise contemplated by the agreement relating to such Acquisition, to the extent such amounts are actually received by University.
The Company will act in good faith and will not intentionally seek to avoid payment of or reduce the Acquisition Fee by raising capital or achieving other Performance Milestones specifically for that purpose. 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	32















 CONFIDENTIAL 
  

 A3.8    Patent Expense Payment. Company will pay, or
reimburse University for paying, all Patent Expenses incurred on or after the Effective Date within thirty (30) days of its receipt of University’s invoice for such Patent Expenses. University reserves the right to request advance payments
for certain Patent Expenses, at University’s discretion. Company will, within 30 days from raising Qualified Financing or one year from the Effective Date, whichever comes first (the “Patent Reimbursement Date”), to the extent
not previously reimbursed to University by Company or a Third Party, reimburse University for all Patent Expenses incurred prior to the Effective Date. Such reimbursement by Company will be allocated into two (2) equal installments – one
(1) installment of half the amount due will be paid within thirty (30) days from the later of the Effective Date or Patent Reimbursement Date, and a second installment covering the remainder of such past Patent Expenses will be paid on the
one (1) year anniversary of the later of the Effective Date or Patent Reimbursement Date. The amount of unreimbursed Patent Expenses invoiced to University prior to the Effective Date is approximately [***] 

A3.8.1    Notwithstanding Sections 4.2 and 4.3 of this Agreement, if at any time Company is not fully reimbursing University for
Patent Expenses, or fails to provide advance payment when requested, University shall make patent filing, prosecution, and maintenance decisions, including choosing in which countries to prosecute patents, in its sole discretion and Company shall
have no rights to provide instruction or to take over patent prosecution. University shall reasonably consider input provided by Company, but have no obligation to act on such input. 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	33















 CONFIDENTIAL 
  

 Exhibit B 

[***] 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	34















 CONFIDENTIAL 
  

 Exhibit C 

[***] 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	35















 CONFIDENTIAL 
  

 Exhibit D 

Stock Subscription Agreement 
 [***] 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	36















 CONFIDENTIAL 
  

 Appendix A 

Defined Terms: 
 The following terms shall be defined as follows for purposes
of this Agreement: 
 The term “Agreement” means this Subscription Agreement, when executed by the University and the Company. 

The term “Notice” means, with respect to the University, the information required by an applicable section delivered personally, or by facsimile or
electronic mail (provided such delivery is confirmed), or by a recognized overnight courier service or by United States mail, first-class, certified or registered, postage prepaid, return receipt requested, to the other Party at its address set
forth below or to another address as a Party may designate by notice given pursuant to this article. 
 The term “Securities” means
                     shares of the common stock, par value [***] per share of the Company. 

The term “Company” means Icosavax, Inc., a Delaware corporation. 

The term “University” means University of Washington, a public institution of higher education and an agency of the state of Washington, acting through
UW CoMotion. 
 Address for Delivery of Stock Certificate: 

Treasury Office 
 University of Washington 

4311 – 11th Avenue NE, Suite 600 

Seattle, WA 98105-4608 
 With a copy to: 

UW CoMotion 
 University of Washington 

4545 Roosevelt Way NE, Suite 400 
 Seattle, WA
98105-4721 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	37















 CONFIDENTIAL 
  

 Appendix B 

Subject to the terms and conditions specified below, the Company hereby grants to the University a right of first offer with respect to
future sales by the Company of any of its common stock or any securities convertible or exchangeable for common stock (the “Company Shares”). Each time the Company proposes to offer any Company Shares in an offering (the
“Offered Shares”) other than an offering described in Section 5 hereof, the Company shall first offer such stock to the University in accordance with this Appendix B. 

1.    Notice. The Company shall deliver a Notice by mail, facsimile transmission or personal delivery
(“Company Notice”) to the University stating (i) its bona fide intention to offer or issue the Offered Shares, (ii) the number of Offered Shares, and (iii) the price at which it proposes to issue the Offered Shares.

 2.    Election. The University may elect within 30 days after receipt of the Company Notice to purchase,
at the price and on the terms specified in the Company Notice (or at such lower price as the Company accepts from other investors), [***] of the Offered Shares by giving written notice within such
30-day period to the Company. 
 3.    [***] 

4.    Subsequent Offerings. For the avoidance of doubt, if the University does not exercise its rights to
purchase, or if the Company terminates or withdraws the Offered Shares, and does not consummate an agreement for the sale of Offered Shares, the rights provided by this Appendix B shall continue to apply to any other Company Offering. 

5.    [***] 

6.    Expiration. The right of first offer granted under this Appendix B shall expire on the earliest of:
(i) the date the Company closes an initial public offering of its common stock or otherwise becomes a public reporting company under the Securities Exchange Act of 1934 (e.g., via reverse merger), (ii) the date Company closes a sale, lease, or
other disposition of all or substantially all of the Company’s assets or the Company’s merger into or consolidation with any other company or other entity, or any other company reorganization, in which Company’s outstanding voting
shares immediately prior to such transaction represents, immediately after such transaction, securities representing less than [***] of the voting power of the company or other entity surviving such transaction, or (iii) the date Company
enters into an agreement providing participation rights to preferred stockholders of the Company to the extent the Company offers the same rights to University. 

7.    Assignment. The right of first offer granted under this Appendix B shall be assignable in whole or in
part by the University to any entity. 

  

			
	 Icosavax, Inc. / University of Washington
 Exclusive License
Agreement
 UW CoMotion Ref. [***]
	  	
	38














 Amendment No. 1 to 

Exclusive License Agreement [***] 

This amendment number one (“Amendment No. 1”) to the Exclusive License Agreement [***]
(“Agreement”), such agreement effective as of June 29, 2018, by and between the University of Washington, a public institution of higher education and an agency of the state of Washington (“University”), and
Icosavax, Inc., a corporation organized under the laws of the state of Delaware (“Company”) (collectively, the “Parties”), is entered into by and between the Parties, effective as of July 9,
2019(“Amendment No. 1 Effective Date”). 
 WHEREAS, pursuant to the Agreement, the University granted to
the Company an exclusive license under the Licensed Patents and a non-exclusive license under the Licensed Know to make, have made on Company’s behalf, use, offer to sell, sell, offer to lease or lease,
import, or otherwise offer to dispose of Licensed Products in the Territory in certain Indication Categories (as such terms are defined in the Agreement); 

WHEREAS, some of the innovations licensed under the Agreement were funded in part by the Bill and Melinda Gates Foundation
(“BMGF”) pursuant to those certain grant agreements between BMGF and University of Washington Foundation dated [***] entitled “[***]” and [***] entitled “[***]” (“BMGF Agreements”) and pursuant
to which University made certain global access commitments to BMGF, and accordingly the University retains the right to require Company to grant Sublicenses in the Field of Use under the Licensed Patents on terms that are reasonable under the
circumstances solely to allow the Licensed Products to be available and accessible at an affordable price in Developing Countries (as such terms are defined in the BMGF Agreements), or, if Company fails to offer to grant a license on reasonable
terms, to grant the license itself to meet global access obligations agreed to by University under the BMGF Agreements in connection with funding of research that led to the Licensed Patents and such obligations are not reasonably satisfied by
Company (the “BMGF Reservation of Rights”); 
 WHEREAS, after the Effective Date, the University amended the BMGF
Agreements (“Additional BMGF Agreements”), pursuant to which amendments, among other things BMGF provided funding for Supplemental Projects (as such term is defined in the Additional BMGF Agreements), and, subject to certain
limitations, the University agreed to grant to BMGF a non-exclusive license with respect to developments funded by the Supplemental Projects to enable BMGF to achieve its global access goals (the “BMGF
Humanitarian License”); 
 WHEREAS, in the Additional BMGF Agreements, BMGF and the University agreed that the Indication
Categories listed prior to the Amendment No. 1 Effective Date in the definition of the Field of Use in the Agreement are not subject to the Humanitarian License; 

WHEREAS, pursuant to the Agreement, the University granted Company the right, from time to time, to
re-order the priority of, and/or substitute a new replacement virus, bacteria and/or pathogen for any of the Indication Categories listed in the definition of the Field of Use by written notice to University
designating the new order of Indication Categor(ies) and/or potential substitution (i.e., deletion of current and replacement with new) virus, bacteria and/or pathogen, subject to then-current availability (i.e., not


  
 1 













 
exclusively licensed to a Third Party) of the replacement virus, bacteria and/or pathogen (as applicable) and University’s willingness to license such rights; 

WHEREAS, the Parties now wish to amend the Agreement, effective as of the Amendment No. 1 Effective Date, to update Indication Categories
and add an additional Indication Category in the Field of Use, and to amend the Performance Milestones and Performance Milestone Dates, update Financial Milestone payments, update table of percentages on Sublicense Consideration, and to add
additional Licensed Patents; 
 WHEREAS, the Parties intend that the Indication Categories listed in the definition of the Field of Use
prior to this Amendment No. 1 will continue to be subject to the BMGF Reservation of Rights to the extent applicable, and the Indication Categories that are added to the definition of the Field of Use pursuant to this Amendment No. 1 may
be subject to the Humanitarian License, provided that the applicable conditions set forth in the Additional BMGF Agreements apply, including without limitation that University utilizes the Supplemental Projects funding to any such new Indication
Categories; and 
 WHEREAS, as of the date hereof, University has not, to the best of UW CoMotion’s knowledge, utilized funding from
BMGF, including without limitation Supplemental Projects funding, for research and/or development of vaccines for [***]. 
 WHEREFORE the
Parties, intending to be legally bound, acknowledge and agree as follows: 
 1.    The rights and obligations of the
Parties shall be governed by the terms and conditions of the Agreement, as heretofore amended by this Amendment No. 1. Capitalized terms not specifically defined herein shall have the meanings set forth in the Agreement. Capitalized terms
defined herein shall have the meanings set forth in this Amendment 1. 
 2.    “Field of Use” definition in
Section 1 of the Agreement (Definitions) shall be amended and restated as: 
 “Field of Use” means prophylactic and/or
therapeutic treatments in a defined “Indication Category”, specifically: for (i) respiratory syncytial virus (“RSV”) (the “First Indication Category”), (ii) [***] (the “Second Indication
Category”), (iii) [***] (the “Third Indication Category”), [***] (the “Fourth Indication Category”), (v) [***] (the “Fifth Indication Category”), and (vi) human metapneumovirus (the
“Sixth Indication Category”). These viruses, bacteria and pathogens listed within each Indication Category represent a preliminary indication of Company’s priorities and targeted indications within the broad category of
commercially attractive vaccines. Accordingly, University grants Company the right, from time to time, to re-order the priority of, and/or substitute a new replacement virus, bacteria and/or pathogen for any
of the Indication Categories above by written notice to University (“Updated Indication Designation”) designating the new order of Indication Categor(ies) and/or potential substitution (i.e., deletion of current and replacement with
new) virus, bacteria and/or pathogen, subject to then-current availability (i.e., not exclusively licensed to a Third Party) of the replacement virus, bacteria and/or pathogen (as applicable) and University’s willingness to license such rights.
The Parties agree that such Updated Indication Designation(s) shall be captured in a written amendment per Section 13.1 “Amendment and Waiver”. 

  
 2 













 3.    “Licensed
Know-How” definition in Section 1 of the Agreement (Definitions) shall be amended and restated as: 

“Licensed Know-How” means University knowledge or intangible work that:
(a) was developed in the laboratory of Principal Investigator, (b) exists as of the Amendment No. 1 Effective Date, (c) is relevant to utilizing any of the Licensed Patents, (d) is unpublished, (e) is not subject to
patent or copyright protection, and (f) is not covered by Third Party rights that would prevent delivery to Company. 

4.    Section 2.4 of the Agreement (Improvements) shall be amended and restated as: 

Improvements. For a period of [***] after the Amendment No. 1 Effective Date, University will provide reasonable written
notice to Company of any Improvements to the Licensed Patents. Company will have the option, exercisable within ninety (90) days of receipt of University’s notice of such Improvement, to add such Improvements to the Licensed Patents. If
Company exercises its option to add Improvements to the Licensed Patents, the Licensed Patents thereafter will include the applicable New Patent Applications, and the Parties will revise Exhibit A
“Start-Up License Schedule” to include such Improvements. 
 5.    A
new section, Section 3.4 of the Agreement (BMGF Humanitarian License), and related new exhibit, Exhibit E, shall be included as below and attached to this Amendment No. 1: 

BMGF Humanitarian License. Company acknowledges that, with respect to indications other than the First Indication Category (RSV), the
Second Indication Category ([***]), or the Third Indication Category ([***]), the University has agreed to the following grantback (the “Humanitarian License”) pursuant to the Additional BMGF Agreements, and the University will
retain rights under the Licensed Patents and License Know-How necessary to comply with the Humanitarian License for such other indications (where You is the University), subject to the terms and conditions
contained in Exhibit E: 
 Subject to applicable laws and for the purpose of achieving Global Access, You grant the Foundation a nonexclusive,
perpetual, irrevocable, worldwide, royalty-free, fully paid up, sublicensable license to make, use, sell, offer to sell, import, distribute, copy, create derivative works, publicly perform, and display Funded Developments and Essential Background
Technology. “Essential Background Technology” means Background Technology that is: (a) owned, controlled, or developed by You, or in-licensed with the right to sublicense; and (b) either
incorporated into a Funded Development or reasonably required to exercise the license to a Funded Development. If You demonstrate to the satisfaction of the Foundation that Global Access can best be achieved without this license, the Foundation and
You will make good faith efforts to modify or terminate this license, as appropriate. 
 Notwithstanding anything to the contrary, BMGF and University
agreed in the Additional BMGF Agreements that the original Indication Categories listed in the definition of the Field of Use in the Agreement as originally executed, i.e., the Indication Categories listed prior to the Amendment No. 1 Effective
Date, are not subject to the Humanitarian License. The Indication 

  
 3 













 
Categories that remain in the Field of Use as of the Amendment No. 1 Effective Date and that are not subject to the Humanitarian License are the First Indication Category (RSV), the Second
Indication Category ([***]), and the Third Indication Category ([***]). 
 6.    Section A1.1 of Exhibit A shall be
amended to include additional Licensed Patents: 
  

											
	 UW Reference #
	 	 Application Serial #
	 	 Filing Date
	 	 Type
	 	 Owner
	 	 Status

	 [***]
	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	 [***]
	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	 [***]
	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	 [***]
	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]

 7.    Section A2 of Exhibit A shall be amended and restated as: 

A2.    Performance Milestones (Section 5.1 “Performance Milestones”): Subject to Company’s right to
renegotiation or Company’s payment of a fee for extension as set forth in Article 5 “Commercialization” of the Agreement, Company will perform, or shall cause to happen or be performed, the following Performance Milestones: 

 

			
	 	  	Performance Milestone and Performance Milestone Date
for First Indication Category in the Field of Use
	 A2.1.1
 Performance

Milestone 1
	  	[***]
		
	 A2.1.2
 Performance

Milestone 2
	  	[***]
		
	 A2.1.3
 Performance

Milestone 3
	  	[***]
		
	 A2.1.4
 Performance

Milestone 4
	  	[***]
		
	 A2.1.5
 Performance

Milestone 5
	  	[***]


  
 4 














			
	A2.1.6 Performance Milestone 6	  	[***]
		
	A2.1.7 Performance Milestone 7	  	[***]
		
	 	  	Performance Milestone and Performance Milestone Date
for Second Indication Category in the Field of 
Use
		
	 A2.2.1

Performance

Milestone 1
	  	[***]
		
	 A2.2.2

Performance

Milestone 2
	  	[***]
		
	 A2.2.3

Performance

Milestone 3
	  	[***]
		
	 A2.2.4

Performance

Milestone 4
	  	[***]
		
	 A2.2.5

Performance

Milestone 5
	  	[***]
		
	 A2.2.6

Performance

Milestone 6
	  	[***]
		
	 A2.2.7

Performance

Milestone 7
	  	[***]


  
 5 














			
	 	  	Performance Milestone and Performance Milestone Date
for Third Indication Category in the Field of 
Use
	 A2.3.1

Performance

Milestone 1
	  	[***]
		
	 A2.3.2

Performance

Milestone 2
	  	[***]
		
	 A2.3.3

Performance

Milestone 3
	  	[***]
		
	 A2.3.4

Performance

Milestone 4
	  	[***]
		
	 A2.3.5

Performance

Milestone 5
	  	[***]
		
	 A2.3.6

Performance

Milestone 6
	  	[***]
		
	 A2.3.7

Performance

Milestone 7
	  	[***]
		
	 	  	Performance Milestone and Performance Milestone Date
for Fourth Indication Category in the Field of 
Use
	 A2.4.1

Performance

Milestone 1
	  	[***]


  
 6 














			
	 A2.4.2
 Performance

Milestone 2
	  	[***]
		
	 A2.4.3
 Performance

Milestone 3
	  	[***]
		
	 A2.4.4
 Performance

Milestone 4
	  	[***]
		
	 A2.4.5
 Performance

Milestone 5
	  	[***]
		
	 A2.4.6
 Performance

Milestone 6
	  	[***]
		
	 A2.4.7
 Performance

Milestone 7
	  	[***]
		
	 	  	Performance Milestone and Performance Milestone Date
for Fifth Indication Category in the Field of 
Use
	 A2.5.1

Performance

Milestone 1
	  	[***]
		
	 A2.5.2

Performance

Milestone 2
	  	[***]
		
	 A2.5.3

Performance

Milestone 3
	  	[***]


  
 7 














			
	 A2.5.4

Performance

Milestone 4
	  	 [***]

		
	 A2.5.5

Performance

Milestone 5
	  	 [***]

		
	 A2.5.6

Performance

Milestone 6
	  	 [***]

		
	 A2.5.7

Performance

Milestone 7
	  	 [***]

		
	 	  	
Performance Milestone and Performance Milestone Date
for Sixth Indication Category in the 
Field of Use

	 A2.6.1

Performance

Milestone 1
	  	 [***]

		
	 A2.6.2

Performance

Milestone 2
	  	 [***]

		
	 A2.6.3

Performance

Milestone 3
	  	 [***]

		
	 A2.6.4

Performance

Milestone 4
	  	 [***]

		
	 A2.6.5

Performance

Milestone 5
	  	 [***]

		
	 A2.6.6

Performance

Milestone 6
	  	 [***]



  
 8 














			
	 A2.6.7
 Performance

Milestone 7
	  	[***]

 8.    Section A3.4 of Exhibit A shall be amended and restated as: 

A3.4    Financial Milestone Payments. Company will pay to University the following non-cumulative, non-creditable, and non-refundable, one-time Performance Milestone achievement
payments for each of First Indication Category, Second Indication Category, Third Indication Category, Fourth Indication Category, Fifth Indication Category, and Sixth Indication Category within thirty (30) days of achieving the corresponding
Performance Milestone, whether achieved by Company or a Sublicensee: 
  

			
	 	 	
Performance Milestone Achieved

	[***]	 	Performance Milestone 4 in A2.1.4, A2.2.4, A2.3.4, A2.4.4, A2.5.4 or A2.6.4
		
	[***]	 	Performance Milestone 5 in A2.1.5, A2.2.5, A2.3.5, A2.4.5, A2.5.5 or A2.6.5
		
	[***]	 	Performance Milestone 6 in A2.1.6, A2.2.6, A2.3.6, A2.4.6, A2.5.6 or A2.6.6
		
	[***]	 	Cumulative Net Sales of [***] for First Indication Category, Second Indication Category, Third Indication Category, Fourth Indication Category, Fifth Indication Category, or Sixth Indication Category

 For the avoidance of doubt, total Financial Milestones for each Indication Category shall not exceed
[***] and total Financial Milestones under this Agreement shall not exceed [***]. Each Financial Milestone shall be payable only once for the applicable Indication Category even if such milestone is achieved by more than one Licensed Product. 

9.    The table in Section A3.6 of Exhibit A shall be amended and restated as: 

 

					
	 	  	
Performance Milestone Has Been Achieved at

the Date of Execution of the Sublicense
 related
to the applicable Indication Category
	  	Sublicense
Consideration
Percentage
	 A3.6.1
 Milestone 1
	  	Performance Milestone 1 in A2.1.1, A2.2.1, A2.3.1, A2.4.1, A2.5.1, or A2.6.1	  	[***]


  
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	 A3.6.2
 Milestone 2
	  	Performance Milestone 2 in A2.1.2, A2.2.2, A2.3.2, A2.4.2, A2.5.2, or A2.6.2	  	[***]
			
	 A 3.6.3
 Milestone 3
	  	Performance Milestone 3 in A2.1.3, A2.2.3, A2.3.3, A2.4.3, A2.5.3, or A2.6.3	  	[***]
			
	 A3.6.4
 Milestone 4
	  	Performance Milestone 4 in A2.1.4, A2.2.4, A2.3.4, A2.4.4, A2.5.4, or A2.6.4	  	[***]
			
	 A3.6.5
 Milestone 5
	  	Performance Milestone 5 in A2.1.5, A2.2.5, A2.3.5, A2.4.5, A2.5.5, or A2.6.5	  	[***]
			
	 A3.6.6
 Milestone 6
	  	Performance Milestone 6 in A2.1.6, A2.2.6, A2.3.6, A2.4.6, A2.5.6, or A2.6.6	  	[***]
			
	 A3.6.7
 Milestone 7
	  	Performance Milestone 7 in A2.1.7, A2.2.7, A2.3.7, A2.4.7, A2.5.7, or A2.6.7	  	[***]

 10. All other terms and conditions of the Agreement shall remain in full force and effect. 

11.    This Amendment No. 1 may be executed by facsimile, pdf, or duplicate originals, and may be executed in several
counterparts, all of which taken together will constitute effective execution. 
 [Signature Page Follows] 

  
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 IN WITNESS WHEREOF, the Parties have executed this Amendment No. 1 effective as of the
Amendment No. 1 Effective Date. 
  

									
	UNIVERSITY OF WASHINGTON 	 		  	ICOSAVAX, INC.
					
	By:	 	 /s/ Dennis Hanson
	 		  	By:	  	 /s/ Adam Simpson

	Name: Dennis Hanson	 		  	Name: Adam Simpson
	Title: Associate Director, Innovation Development	 		  	Title: Chief Executive Officer
	Date: 7/19/2019	 		  	Date: 7/19/2019


  
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 Amendment No. 2 to 

Exclusive License Agreement #[***] 

This amendment number two (“Amendment No. 2”) to the Exclusive License Agreement #[***], such agreement effective
as of June 29, 2018, as amended by Amendment No. 1 to Exclusive License Agreement #[***] effective as of July 19, 2019, (collectively, the “Agreement”) by and between the University of Washington, a public institution
of higher education and an agency of the state of Washington (“University”), and Icosavax, Inc., a corporation organized under the laws of the state of Delaware (“Company”) (collectively, the “Parties”), is entered into
by and between the Parties, effective as of November 13, 2020 (“Amendment No. 2 Effective Date”). 
 WHEREAS, pursuant
to the Agreement, the University granted to the Company an exclusive license under the Licensed Patents and a non-exclusive license under the Licensed Know to make, have made on Company’s behalf, use,
offer to sell, sell, offer to lease or lease, import, or otherwise offer to dispose of Licensed Products in the Territory in certain Indication Categories (as such terms are defined in the Agreement); 

WHEREAS, pursuant to Section 2.4 of the Agreement, the Parties agreed that, during a period of [***] after the Amendment
No. 1 Effective Date, University will provide reasonable written notice to Company of any Improvements to the Licensed Patents, and Company will have the option, exercisable within ninety (90) days of receipt of University’s notice of
such Improvement, to add such Improvements to the Licensed Patents; 
 WHEREAS, University has so notified Company of an Improvement to the
Licensed Patents; 
 WHEREAS, pursuant to Section 2.4 of the Agreement, the Parties agreed that, if Company exercises its option to add
Improvements to the Licensed Patents, the Licensed Patents thereafter will include the applicable New Patent Applications, and the Parties will revise Exhibit A “Start-Up License Schedule” to include
such Improvements; 
 WHEREAS, the Parties agree that Company has exercised its option to add such Improvements to the Licensed Patents, and
accordingly the Licensed Patents will include the applicable New Patent Applications; and 
 WHEREAS, the Parties would like to revise
Exhibit A “Start-Up License Schedule” to include such Improvements and New Patent Applications. 

WHEREFORE the Parties, intending to be legally bound, acknowledge and agree as follows: 

1.    The rights and obligations of the Parties shall be governed by the terms and conditions of the Agreement, as
heretofore amended by this Amendment No. 2. Capitalized terms not specifically defined herein shall have the meanings set forth in the Agreement. Capitalized terms defined herein shall have the meanings set forth in this Amendment No. 2.

 2.    Section A1.1 of Exhibit A of the Agreement shall be deleted and replaced with the following: 

  
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 “A1.1    Licensed Patents: 

[ 
  

											
	 [***]
	 	 [***]
	 	 [***]
	 	 [***]
	 	 [***]
	 	 [***]

	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]
	[***]	 	[***]	 	[***]	 	[***]	 	[***]	 	[***]

 ” 

3.    All other terms and conditions of the Agreement shall remain in full force and effect. 

4.    This Amendment No. 2 may be executed by facsimile, pdf, or duplicate originals, and may be executed in several
counterparts, all of which taken together will constitute effective execution. 
 [Signature Page Follows] 

  
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 IN WITNESS WHEREOF, the Parties have executed this Amendment No. 2 effective as of the
Amendment No. 2 Effective Date. 
  

									
	UNIVERSITY OF WASHINGTON 	 		  	ICOSAVAX, INC.
					
	By:	 	 /s/ Dennis Hanson
	 		  	By:	  	 /s/ Adam Simpson

	Name: Dennis Hanson	 		  	Name: Adam Simpson
	Title: Associate Director, Innovation Development	 		  	Title: CEO
	Date: 11/13/2020	 		  	Date: 11/13/2020


  
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