EX-10.17



 Exhibit 10.17 

FOIA CONFIDENTIAL TREATMENT REQUESTED 

RESEARCH COLLABORATION AGREEMENT 

BETWEEN 
 CYTOMX
THERAPEUTICS, INC. 
 AND 

IMMUNOGEN, INC. 

JANUARY 8, 2014 
 ***Certain
information contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 







 TABLE OF CONTENTS 

 

									
	 	  	 	  	 	  	Page	 
			
	1.	  	 DEFINITIONS
	  	 	1	  
			
	2.	  	 RESEARCH PROGRAM
	  	 	15	  
				
		  	2.1.	  	 Selection of Research Program Targets
	  	 	15	  
				
		  	2.2.	  	 Scope and Conduct of the Research Program
	  	 	18	  
				
		  	2.3.	  	 Work Plans
	  	 	18	  
				
		  	2.4.	  	 Governance of the Research Program
	  	 	20	  
				
		  	2.5.	  	 Alliance Managers
	  	 	21	  
				
		  	2.6.	  	 Conformance with Law
	  	 	21	  
				
		  	2.7.	  	 Personnel Matters
	  	 	22	  
				
		  	2.8.	  	 Debarment Certification
	  	 	22	  
				
		  	2.9.	  	 Records
	  	 	22	  
				
		  	2.10.	  	 Transfer and Use of Proprietary Materials
	  	 	22	  
			
	3.	  	 OPTION FOR LICENSE AND COMMERCIAL LICENSE GRANTS
	  	 	23	  
				
		  	3.1.	  	 Grants to ImmunoGen
	  	 	23	  
				
		  	3.2.	  	 Grants to CytomX
	  	 	26	  
				
		  	3.3.	  	 Section 365(n) of Bankruptcy Code
	  	 	29	  
				
		  	3.4.	  	 No Implied Rights
	  	 	29	  
			
	4.	  	 EXPENSES
	  	 	29	  
				
		  	4.1.	  	 Expenses
	  	 	29	  
			
	5.	  	 INTELLECTUAL PROPERTY
	  	 	29	  
				
		  	5.1.	  	 Inventions
	  	 	29	  


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

i 









									
		  	5.2.	  	 Filing, Prosecution and Maintenance of Patent Rights
	  	 	31	  
				
		  	5.3.	  	 Joint Research Agreement
	  	 	35	  
			
	6.	  	 CONFIDENTIALITY
	  	 	35	  
				
		  	6.1.	  	 Confidentiality
	  	 	35	  
				
		  	6.2.	  	 Authorized Disclosure
	  	 	36	  
				
		  	6.3.	  	 Public Announcements; Publications
	  	 	37	  
			
	7.	  	 REPRESENTATIONS AND WARRANTIES
	  	 	39	  
				
		  	7.1.	  	 Mutual Representations and Warranties
	  	 	39	  
				
		  	7.2.	  	 Representations and Warranties of CytomX
	  	 	39	  
				
		  	7.3.	  	 Representations and Warranties of ImmunoGen
	  	 	40	  
				
		  	7.4.	  	 Government Approvals
	  	 	40	  
				
		  	7.5.	  	 Further Covenants
	  	 	41	  
				
		  	7.6.	  	 Representation by Legal Counsel
	  	 	41	  
				
		  	7.7.	  	 Warranty Disclaimers
	  	 	41	  
			
	8.	  	 TERM AND TERMINATION
	  	 	41	  
				
		  	8.1.	  	 Term
	  	 	41	  
				
		  	8.2.	  	 Termination by Either Party for Cause
	  	 	42	  
				
		  	8.3.	  	 Termination on Insolvency
	  	 	42	  
				
		  	8.4.	  	 Effects of Expiration or Termination
	  	 	42	  
				
		  	8.5.	  	 Effect of Expiration of this Agreement
	  	 	44	  
				
		  	8.6.	  	 Remedies
	  	 	45	  
				
		  	8.7.	  	 Survival of Certain Obligations
	  	 	45	  


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

ii 









									
	9.	  	 LIMITATION ON LIABILITY, INDEMNIFICATION AND INSURANCE
	  	 	45	  
				
		  	9.1.	  	 No Consequential Damages
	  	 	45	  
				
		  	9.2.	  	 Indemnification by ImmunoGen
	  	 	45	  
				
		  	9.3.	  	 Indemnification by CytomX
	  	 	46	  
				
		  	9.4.	  	 Procedure
	  	 	46	  
				
		  	9.5.	  	 Insurance
	  	 	47	  
			
	10.	  	 MISCELLANEOUS
	  	 	48	  
				
		  	10.1.	  	 Assignment
	  	 	48	  
				
		  	10.2.	  	 Further Actions
	  	 	48	  
				
		  	10.3.	  	 Force Majeure
	  	 	48	  
				
		  	10.4.	  	 Notices
	  	 	49	  
				
		  	10.5.	  	 Amendment
	  	 	49	  
				
		  	10.6.	  	 Waiver
	  	 	49	  
				
		  	10.7.	  	 Severability
	  	 	50	  
				
		  	10.8.	  	 Descriptive Headings
	  	 	50	  
				
		  	10.9.	  	 Dispute Resolution
	  	 	50	  
				
		  	10.10.	  	 Patent Disputes and Disputes Relating to Article 6
	  	 	52	  
				
		  	10.11.	  	 Governing Law
	  	 	53	  
				
		  	10.12.	  	 Entire Agreement
	  	 	53	  
				
		  	10.13.	  	 Purpose and Scope
	  	 	53	  
				
		  	10.14.	  	 Counterparts
	  	 	53	  
				
		  	10.15.	  	 No Third Party Rights or Obligations
	  	 	53	  
				
		  	10.16.	  	 Interpretation
	  	 	53	  


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

iii 








 EXHIBITS 
 Exhibit
A – CytomX Research Program Target 
 Exhibit B – Form of Joint Press Release 

Exhibit C – Form of License Agreement where CytomX is licensing the ImmunoGen Technology upon exercise of the CytomX Option 

Exhibit D – Form of License where ImmunoGen is licensing the CytomX Technology upon exercise of an ImmunoGen Option 

Exhibit E – Form of Work Plan 
 Exhibit F –
Representatives to the Joint Research Committee 
 Schedule 1.104 – List of Cytotoxic Compound Patent Rights 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 

iv 








 RESEARCH COLLABORATION AGREEMENT 

This Research Collaboration Agreement (the “Agreement”) is entered into as of January 8, 2014 (the “Effective
Date”), by and between CytomX Therapeutics, Inc., a corporation organized and existing under the laws of Delaware and having a place of business at 343 Oyster Point Blvd., Suite 100, South San Francisco, California, 94080 United
States (“CytomX”) and ImmunoGen, Inc., a corporation organized and existing under the laws of Massachusetts and having a place of business at 830 Winter Street, Waltham, Massachusetts, 02451 (“ImmunoGen”).
CytomX and ImmunoGen may each be referred to herein individually as a “Party” and collectively as the “Parties.” 

WHEREAS, ImmunoGen is engaged in the development of novel, targeted anti-cancer therapeutic products using tumor-targeting monoclonal
antibodies to deliver cancer-cell killing agents and has developed and owns proprietary rights to certain Cytotoxic Compound and Linker (both as defined below) technology; 

WHEREAS, CytomX has developed and owns proprietary rights to certain technology relating to a proprietary platform to enable the development
of fully recombinant, protease-activated monoclonal antibodies, including Probodies (as defined below); and 
 WHEREAS, ImmunoGen and CytomX
desire to collaborate to discover and research novel Probodies and Probody drug conjugates active against certain designated targets and to provide for each Party to further research, develop, manufacture and commercialize Probody drug conjugates,
as provided for herein. 
 NOW THEREFORE, in consideration of the mutual promises and covenants set forth below and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the Parties hereby agree as follows: 
  

	1.	DEFINITIONS. 

 When used in this Agreement, the following capitalized terms shall have
the meanings set forth in this Article 1. 
 1.1. “ADC” means a compound that incorporates, is comprised of or
is otherwise derived from an Antibody (or other cell-binding moiety) conjugated to a Payload using a Linker, other than a PDC. 
 1.2.
“Affiliate” means, with respect to any Person, any other Person that controls, is controlled by or is under common control with such Person. A Person shall be regarded as in control of another entity if it owns or controls at least
fifty percent (50%) of the equity securities of the subject entity entitled to vote in the election of directors (or, in the case of an entity that is not a corporation, for the election of the corresponding managing authority), provided,
however, that the term “Affiliate” shall not include subsidiaries or other entities in which a Party or its Affiliates owns a majority of the ordinary voting 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 1 








 
power necessary to elect a majority of the board of directors or other managing authority, but is restricted from electing such majority by contract or otherwise, until such time as such
restrictions are no longer in effect. A Person shall be deemed an Affiliate only so long as it satisfies the foregoing definition. 
 1.3.
“Agreement PDC” means any PDC created or developed in the course of the Research Program. 
 1.4. “Agreement
Probody” means any Probody that is created or developed in the course of the Research Program to Target a Research Program Target. 

1.5. “Alliance Manager” is defined in Section 2.5 hereof. 

1.6. “Antibody” means a molecule which comprises or contains: (a) one or more immunoglobulin variable domains; or
(b) fragments, variants, modifications or derivatives of such immunoglobulin variable domains irrespective of origin or source, including but not limited to antigen binding portions including Fab, Fab’, F(ab’)2, Fv, dAb and CDR
fragments, single chain antibodies (scFv), chimeric antibodies, monospecific antibodies, diabodies and polypeptides (including humanized versions thereof) that contain at least a portion of an immunoglobulin that is sufficient to confer specific
antigen binding to the polypeptide. For clarity, as used in this Agreement, the term “Antibody” shall not include Probodies or PDCs. 

1.7. “Applicable Law” means the laws, statutes, rules, regulations, guidelines, or other requirements that may be in effect
from time to time and apply to a particular activity contemplated hereby, including any such laws, statutes, rules, regulations, guidelines or other requirements of the FDA or the EMA or any applicable securities regulatory authorities or national
securities exchanges or securities listing organizations. 
 1.8. “Bankruptcy Code” is defined in Section 3.3
hereof. 
 1.9. “Binding Obligation” means, with respect to a Party (a) any oral or written agreement or arrangement
that binds or legally affects such Party’s operations or property, including any assignment, license agreement, loan agreement, guaranty, or financing agreement; (b) the provisions of such Party’s charter, bylaws or other
organizational documents or (c) any order, writ, injunction, decree or judgment of any court or Governmental Authority entered against such Party or by which any of such Party’s operations or property are bound. 

1.10. Business Day” means a day other than a Saturday, a Sunday or other day on which banking institutions in Boston, Massachusetts
or San Francisco, California are required to be closed or are actually closed with legal authorization. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 2 








 1.11. “Calendar Quarter” means the respective periods of three
(3) consecutive calendar months ending on March 31, June 30, September 30 or December 31, for so long as this Agreement is in effect. 

1.12. “Calendar Year” means each successive period of twelve (12) calendar months commencing on January 1 and ending
on December 31. 
 1.13. “Commercially Reasonable Efforts” means, with respect to the efforts to be expended by a Party
with respect to any objective, those reasonable, good faith efforts to accomplish such objective as such Party would normally use to accomplish a similar objective under similar circumstances. 

1.14. “Confidential Information” of a Party means (a) with respect to ImmunoGen, (i) the identity of the ImmunoGen
Research Program Targets and (ii) the identification by ImmunoGen of any Target proposed by CytomX to be a Replacement Target as an ImmunoGen Excluded Target, (b) with respect to CytomX, (i) the identity of the CytomX Research Program
Target and (ii) the identification by CytomX of any Target proposed by ImmunoGen to be a Replacement Target as a CytomX Excluded Target, and (c) with respect to both Parties, all Know-How or other information, including proprietary
information and materials (whether or not patentable) regarding such Party’s technology, products, business or objectives, that is communicated in any way or form by or on behalf of such Party (in such capacity, the “Disclosing
Party”) to the other Party (in such capacity, the “Receiving Party”) or to any of the Receiving Party’s or its Affiliates’ employees, consultants or subcontractors (collectively,
“Representatives”), either prior to or after the Effective Date of this Agreement (including any information disclosed pursuant to the Confidentiality Agreement), and whether or not such Know-How or other information is identified
as confidential at the time of disclosure. The terms and conditions of this Agreement shall be deemed to be the Confidential Information of each Party. Confidential Information within the CytomX Program Technology shall be deemed to be the
Confidential Information of CytomX. Confidential Information within the ImmunoGen Program Technology shall be deemed to be the Confidential Information of ImmunoGen. Confidential Information within the Joint Improvements shall be deemed to be the
Confidential Information of each Party. Certain other information is designated as Confidential Information throughout this Agreement and is included in this definition. 

1.15. “Confidentiality Agreement” means that certain Mutual Confidential Disclosure Agreement between the Parties effective as
of March 21, 2013. 
 1.16. “Conjugation Probody Platform Improvements” is defined in Section 1.104 hereof.


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 3 








 1.17. “Control” or “Controlled” means, with respect to any
(a) item of information, including Know-How, (b) intellectual property right, or (c) Proprietary Material, the possession (whether by ownership interest or license, other than pursuant to this Agreement) by a Party of the ability to
grant to the other Party access to or a license under such item, right or material, as provided herein, without violating the terms of any agreement or other arrangements with any Third Party. 

1.18. “Covered Results” is defined in Section 6.3.2 hereof. 

1.19. “CytomX Activities” means the Work Plan Activities that are to be undertaken by CytomX or its Affiliates. 

1.20. “CytomX Agreement PDCs” means Agreement PDCs that Target the CytomX Research Program Target. 

1.21. “CytomX Background Technology” means any Proprietary Material, Patent Right, Know-How or other intellectual property
right that is (a) owned or Controlled by CytomX or any Affiliate of CytomX and (b) exists as of and/or was conceived prior to the Effective Date or is developed or obtained by CytomX or any of its Affiliates independently of this
Agreement without the use of ImmunoGen’s Confidential Information. For purposes of clarity, CytomX Background Technology includes CytomX Proprietary Materials, but does not include Agreement PDCs or ImmunoGen Probodies, although the Parties
acknowledge that CytomX Background Technology may be incorporated into Agreement PDCs and ImmunoGen Probodies. 
 1.22. “CytomX
Excluded Target” means any Target as to which (a) CytomX or an Affiliate of CytomX is pursuing a CytomX Internal Program with respect to such Target, (b) CytomX has granted, or is obligated to grant, an option or license to a
Third Party under any Patent Rights owned or Controlled by CytomX that are necessary or useful for the development, manufacture, use or sale of any compound or product that Targets such Target (as used in this definition, a “Third Party
Right”), (c) CytomX has entered into a bona fide written agreement or bona fide written term sheet with a Third Party that is in effect as of the date of CytomX’s receipt of a Proposed Target Notice from
ImmunoGen, that prohibits CytomX from including the applicable Proposed Target in the Research Program or granting to ImmunoGen a Development and Commercialization License for the Proposed Target on the terms and conditions of this Agreement or
(d) CytomX is in bona fide discussions with a Third Party with respect to a potential Third Party Right in which confidential information has been shared under the terms of a written confidential disclosure agreement entered into by
CytomX and such Third Party within the sixty (60)-day period immediately preceding the date of CytomX’s receipt of the applicable Proposed Target Notice from ImmunoGen. A Target shall be deemed a CytomX Excluded Target only so long as it
satisfies the foregoing definition. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 4 








 1.23. “CytomX Indemnified Party” is defined in Section 9.2 hereof.

 1.24. “CytomX Internal Product Candidate” means any cell-binding agent (which may or may not be a Probody), which may be
unconjugated or conjugated to a cell-killing or cell-modulating agent (other than a Cytotoxic Compound). 
 1.25. “CytomX Internal
Program” means a bona fide internal research, development or commercialization undertaken by CytomX with respect to a Target, with respect to which, as of the date of CytomX’s receipt from ImmunoGen of a Proposed Target
Notice for such Target (for purposes of this definition, the “Receipt Date”), a CytomX Internal Product Candidate Targeting such Target has been generated, and CytomX owns or has otherwise acquired rights to use such CytomX Internal
Product Candidate in the research or development of compounds for use in the Field and further provided that (a) as of the Receipt Date, CytomX has begun screening a panel of antibodies against such Target or has begun hybridoma discovery for
producing an antibody against such Target or is conducting research or pre-clinical studies in vitro or in vivo in any non-human species of such CytomX Internal Product Candidate in a sustained manner consistent with CytomX’s
other internal programs at similar stages of research and development or (b) as of or prior to the Receipt Date, CytomX or an Affiliate of CytomX had commenced process development activities in connection with a GLP toxicology study of such
CytomX Internal Product Candidate no more than two (2) years before the Effective Date. Notwithstanding the foregoing, if CytomX or an Affiliate of CytomX has in-licensed Patent Rights from a Third Party covering the manufacture, use or sale of
a cell-binding agent, then CytomX shall be deemed to be pursuing a CytomX Internal Program with respect to the Target to which such cell-binding agent is directed for the twelve (12)-month period immediately following the effective date of such
Third Party license, without any additional activities required on the part of CytomX or its Affiliates. 
 1.26. “CytomX License
Agreement” means the written license agreement in the form of Exhibit C attached hereto that will be entered into by the Parties upon CytomX’s exercise of the CytomX Option. 

1.27. “CytomX Licensed Intellectual Property” means any and all intellectual property (including Patent Rights and Know-How)
owned or Controlled by CytomX, including the CytomX Technology, that is necessary or useful for ImmunoGen to conduct the ImmunoGen Activities. Notwithstanding the foregoing, CytomX Licensed Intellectual Property shall not include Tools. 

1.28. “CytomX Licensed Product” means a PDC having a Payload that is a Cytotoxic Compound and Targeting a CytomX Licensed
Target. 
 1.29. “CytomX Licensed Target” is defined in Section 3.2.3 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 5 








 1.30. “CytomX Option” is defined in Section 3.2.1 hereof. 

1.31. “CytomX Option Exercise Cut-Off Date” is defined in Section 3.2.2 hereof. 

1.32. “CytomX Option Exercise Date” is defined in Section 3.2.2 hereof. 

1.33. “CytomX Patent Right” means any Patent Right comprised in the CytomX Technology. 

1.34. “CytomX Program Technology” means any Program Technology (other than Joint Program Technology) the inventors of which
are employees, agents or independent contractors of CytomX or any of its Affiliates. 
 1.35. “CytomX Proprietary Materials”
means biological materials (including any Probodies, Masks or Substrates) and other tangible research materials owned or Controlled by CytomX and provided by CytomX to ImmunoGen under this Agreement. Agreement PDCs and ImmunoGen Probodies, in and of
themselves, will not be considered to be CytomX Proprietary Materials, although the Parties acknowledge that CytomX Proprietary Materials may be incorporated into Agreement PDCs and ImmunoGen Probodies. 

1.36. “CytomX Research Program Target” means the Target selected by CytomX (other than an ImmunoGen Excluded Target) for
inclusion in the Research Program in accordance with Section 2.1 hereof. A Target ceases to be a CytomX Research Program Target once (a) it has become the subject of a Development and Commercialization License in accordance with
Section 3.2.2 hereof or (b) it has been dropped from the Research Program in accordance with Section 2.1.3 hereof. 

1.37. “CytomX TAP Platform Improvements” means any TAP Platform Improvements (other than TAP Platform Improvements comprised
in the Joint Program Technology) the inventors of which (alone or with others) area employees of, or others obligated to assign inventions to, CytomX or any of its Affiliates or Permitted Third Party Service Providers pursuant to the conduct of the
Research Program. 
 1.38. “CytomX Technology” means, collectively, the CytomX Background Technology and the CytomX Program
Technology. 
 1.39. “Cytotoxic Compound” means [***] Compounds and [***] Compounds. 

1.40. “Development and Commercialization License” means a license under the intellectual property rights (including Patent
Rights and Know-How) owned or Controlled by the licensor Party with respect to the Research Program Target specified in the applicable Option Exercise Notice as set forth in the applicable License Agreement. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 6 








 1.41. “Disclosing Party” is defined in Section 1.14 hereof. 

1.42. “Disclosure Letter” has the meaning ascribed to such term, with respect to each Development and Commercialization
License, as set forth in the applicable License Agreement. 
 1.43. “Dispute” is defined in Section 10.9 hereof.

 1.44. “Effective Date” is defined in the introduction to this Agreement. 

1.45. “EMA” means the European Medicines Agency, or any successor agency thereto. 

1.46. “Field” means all human therapeutic, prophylactic and diagnostic uses. 

1.47. “FD&C Act” means the United States Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 301 et seq.), as
amended, and the rules and regulations promulgated thereunder. 
 1.48. “FDA” means the United States Food and Drug
Administration or any successor agency thereto. 
 1.49. “GLP” means all good laboratory practices under Title 21 of
the United States Code of Federal Regulations, as amended from time to time. 
 1.50. “Governmental Authority” means any
court, agency, department, authority or other instrumentality of any national, state, county, city or other political subdivision. 
 1.51.
“[***] Compounds” means [***], including, without limitation, all analogs, variants, fragments or derivatives of any of the foregoing, in each case owned or Controlled by ImmunoGen. 

1.52. “ImmunoGen Activities” means the Work Plan Activities that are to be undertaken by ImmunoGen or its Affiliates. 

1.53. “ImmunoGen Agreement PDCs” means Agreement PDCs that Target the ImmunoGen Research Program Target(s). 

1.54. “ImmunoGen Background Technology” means any Proprietary Material, Patent Right, Know-How or other intellectual property
right that is (a) owned or Controlled by ImmunoGen or any Affiliate of ImmunoGen and (b) exists as of and/or was conceived prior to the Effective Date or is developed or obtained by ImmunoGen or any of its Affiliates independently
of this Agreement and without the use of CytomX’s Confidential Information. For purposes of clarity, ImmunoGen Background Technology includes ImmunoGen Proprietary Materials, but does not include Agreement PDCs, although the Parties acknowledge
that ImmunoGen Background Technology may be incorporated into Agreement PDCs. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 7 








 1.55. “ImmunoGen Excluded Target” means any Target as to which
(a) ImmunoGen or an Affiliate of ImmunoGen is pursuing an ImmunoGen Internal Program with respect to such Target, (b) ImmunoGen has granted, or is obligated to grant, an option or license to a Third Party under any Patent Rights owned or
Controlled by ImmunoGen that are necessary or useful for the development, manufacture, use or sale of any compound or product that Targets such Target (as used in this definition, a “Third Party Right”), (c) ImmunoGen has entered into
a bona fide written agreement or bona fide written term sheet with a Third Party that is in effect as of the date of ImmunoGen’s receipt of a Proposed Target Notice from CytomX, that prohibits ImmunoGen from including
the applicable Proposed Target in the Research Program or granting to CytomX a Development and Commercialization License for the Proposed Target on the terms and conditions of this Agreement, (d) ImmunoGen is in bona fide
discussions with a Third Party with respect to a Third Party Right in which confidential information has been shared under the terms of a written confidential disclosure agreement entered into by ImmunoGen and such Third Party within the sixty
(60)-day period immediately preceding the date of ImmunoGen’s receipt of the applicable Proposed Target Notice from CytomX or (e) [***]. A Target shall be deemed an ImmunoGen Excluded Target only so long as it satisfies the foregoing
definition. 
 1.56. “ImmunoGen Indemnified Party” is defined in Section 9.3 hereof. 

1.57. “ImmunoGen Internal Product Candidate” means any cell-binding agent (other than a Probody), which may be unconjugated or
conjugated to a cell-killing or cytostatic agent (which may or may not be a Cytotoxic Compound). 
 1.58. “ImmunoGen Internal
Program” means a bona fide internal research, development or commercialization undertaken by ImmunoGen with respect to a Target, with respect to which, as of the date of ImmunoGen’s receipt from CytomX of a Proposed Target
Notice for such Target (for purposes of this definition, the “Receipt Date”), an ImmunoGen Internal Product Candidate Targeting such Target has been generated, and ImmunoGen owns or has otherwise acquired rights to use such ImmunoGen
Internal Product Candidate in the research or development of compounds for use in the Field and further provided that (a) as of the Receipt Date, ImmunoGen has begun screening a panel of antibodies against such Target or has begun hybridoma
discovery for producing an antibody against such Target or is conducting research or pre-clinical studies in vitro or in vivo in any non-human species of such ImmunoGen Internal Product Candidate in a sustained manner consistent with
ImmunoGen’s other internal programs at similar stages of research and development or (b) as of or prior to the Receipt Date, ImmunoGen or an Affiliate of ImmunoGen had commenced process development activities in connection with a GLP
toxicology study of such ImmunoGen 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 8 








 
Internal Product Candidate no more than two (2) years before the Effective Date. Notwithstanding the foregoing, if ImmunoGen or an Affiliate of ImmunoGen has in-licensed Patent Rights from a
Third Party covering the manufacture, use or sale of a cell-binding agent, then ImmunoGen shall be deemed to be pursuing an ImmunoGen Internal Program with respect to the Target to which such cell-binding agent is directed for the twelve (12)-month
period immediately following the effective date of such Third Party license, without any additional activities required on the part of ImmunoGen or its Affiliates. 

1.59. “ImmunoGen License Agreement” means the written license agreement in the form of Exhibit D attached hereto
that will be entered into by the Parties upon ImmunoGen’s exercise of each ImmunoGen Option. 
 1.60. “ImmunoGen Licensed
Intellectual Property” means any and all intellectual property (including Patent Rights and Know-How) owned or Controlled by ImmunoGen, including the ImmunoGen Technology, that is necessary or useful for CytomX to conduct the CytomX
Activities. 
 1.61. “ImmunoGen Licensed Product” means a PDC having a Payload that is a Cytotoxic Compound and Targeting an
ImmunoGen Licensed Target. 
 1.62. “ImmunoGen Licensed Target” is defined in Section 3.1.3 hereof. 

1.63. “ImmunoGen Option” is defined in Section 3.1.1 hereof. 

1.64. “ImmunoGen Option Exercise Cut-Off Date” is defined in Section 3.1.2 hereof. 

1.65. “ImmunoGen Option Exercise Date” is defined in Section 3.1.2 hereof. 

1.66. “ImmunoGen Patent Right” means any Patent Right comprised in the ImmunoGen Technology. 

1.67. “ImmunoGen Probody(ies)” means the Agreement Probody(ies) Targeting the ImmunoGen Research Program Targets. 

1.68. “ImmunoGen Probody Platform Improvements” means any Probody Platform Improvements (other than Probody Platform
Improvements comprised in the Joint Program Technology) the inventors of which (alone or with others) area employees of, or others obligated to assign inventions to, ImmunoGen or any of its Affiliates or Permitted Third Party Service Providers
pursuant to the conduct of the Research Program. 
 1.69. “ImmunoGen Program Technology” means any Program Technology (other
than Joint Program Technology) the inventors of which are employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 9 








 1.70. “ImmunoGen Proprietary Materials” means any chemical (including any
Cytotoxic Compounds), biological (including any Antibodies) and other tangible research materials owned or Controlled by ImmunoGen and provided by ImmunoGen to CytomX under this Agreement. Agreement PDCs, in and of themselves, will not be considered
to be ImmunoGen Proprietary Materials, although the Parties acknowledge that ImmunoGen Proprietary Materials may be incorporated into Agreement PDCs. 

1.71. “ImmunoGen Research Program Target” means a Target selected by ImmunoGen (other than a CytomX Excluded Target) for
inclusion in the Research Program in accordance with Section 2.1 hereof. A Target ceases to be an ImmunoGen Research Program Target once (a) it has become the subject of a Development and Commercialization License in accordance with
Section 3.1.2 hereof or (b) it has been dropped from the Research Program in accordance with Section 2.1.3 hereof. 

1.72. “ImmunoGen Technology” means, collectively, the ImmunoGen Background Technology and the ImmunoGen Program Technology.

 1.73. “Improvement” is defined in Section 1.104 hereof. 

1.74. “IND” means an Investigational New Drug Application, as defined in the FD&C Act, that is required to be filed with
the FDA before beginning clinical testing of a Licensed Product in human subjects, or an equivalent foreign filing. 
 1.75.
“Indemnified Party” is defined in Section 9.4.1 hereof. 
 1.76. “Indemnifying Party” is
defined in Section 9.4.1 hereof. 
 1.77. “Independent Patent Counsel” means an outside patent counsel
reasonably acceptable to both Parties who (and whose firm) is not at the time of the dispute, and was not at any time during the five (5)-year period preceding the dispute, performing legal services of any nature for either of the Parties or their
respective Affiliates and which did not, at any time, employ either of the Parties’ chief patent counsels (or persons with similar responsibilities). 

1.78. “Insolvency Event” means the occurrence of any of the following: (a) a case is commenced by or against a Party
under applicable bankruptcy, insolvency or similar laws, and is not dismissed within ninety (90) days, (b) a Party files for or is subject to the institution of bankruptcy, reorganization, liquidation, receivership or similar proceedings,
(c) a Party assigns all or a substantial portion of its assets for the benefit of creditors, (d) a receiver or custodian is appointed for a Party’s business, (e) a substantial portion of a Party’s business is subject to
attachment or similar process, or (f) anything analogous to any of the events described in the foregoing clauses (a) through (e) occurs under the laws of any applicable jurisdiction. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 10 








 1.79. “Joint Patent Right” means any Patent Right comprised in the Joint Program
Technology. 
 1.80. “Joint Program Technology” means any Program Technology the inventors of which are jointly
(a) employees, agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

1.81. “Joint Research Committee” or “JRC” is defined in Section 2.4.1 hereof. 

1.82. “Know-How” means any proprietary invention, discovery, data, information, process, method, technique, material,
technology, result or other know-how, whether or not patentable. 
 1.83. “Liability” is defined in Section 9.2
hereof. 
 1.84. “License Agreement” means the CytomX License Agreement and/or the ImmunoGen License Agreement, as
applicable. 
 1.85. “Licensed Product” has the meaning ascribed to such term in the License Agreement applicable to a
particular Licensed Target. 
 1.86. “Licensed Target” means a CytomX Licensed Target or an ImmunoGen Licensed Target, as
applicable. 
 1.87. “Linker” means any compound or composition that is useful for linking a cytotoxic or cytostatic moiety,
including, without limitation, a Cytotoxic Compound, and a cell-binding moiety, including, without limitation, an Antibody or a Probody, together to form a conjugate of the cytotoxic or cytostatic moiety with the cell-binding moiety. 

1.88. “Mask” means a peptide or polypeptide linked to an Antibody that is capable of inhibiting the specific binding of the
Antibody to its Target. 
 1.89. “Material Breach” is defined in Section 8.2 hereof. 

1.90. “[***] Compound” means [***], and shall include, without limitation, all variants, fragments or derivatives of any of
the foregoing, in each case owned or Controlled by ImmunoGen. 
 1.91. “Non-Disclosing Party” is defined in
Section 6.3.2 hereof. 
 1.92. “Notice of Dispute” is defined in Section 10.9.1 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 11 








 1.93. “Option” means the CytomX Option and/or the ImmunoGen Options, as
applicable. 
 1.94. “Option Exercise Date” means the CytomX Option Exercise Date or the ImmunoGen Option Exercise Date, as
applicable. 
 1.95. “Option Exercise Notice” means the written notice of exercise of an Option delivered by ImmunoGen to
CytomX pursuant to Section 3.1.2 hereof or by CytomX to ImmunoGen pursuant to Section 3.2.2 hereof. 
 1.96.
“Party” and “Parties” is defined in the introduction to this Agreement. 
 1.97. “Patent
Committee” is defined in Section 5.2.4 hereof. 
 1.98. “Patent Rights” means any and all
(a) patents, (b) pending patent applications, including all provisional applications, substitutions, continuations, continuations-in-part, divisions and renewals, and all patents granted thereon, (c) all patents-of-addition, reissues,
reexaminations and extensions or restorations by existing or future extension or restoration mechanisms, including patent term extensions, supplementary protection certificates or the equivalent thereof, (d) inventor’s certificates,
(e) any other form of government-issued right substantially similar to any of the foregoing and (f) all United States and foreign counterparts of any of the foregoing. 

1.99. “Payload” means a therapeutic cytotoxic or cytostatic compound, including, without limitation, a Cytotoxic Compound.

 1.100. “PDC” means a compound that incorporates, is comprised of or is otherwise derived from, a Probody conjugated to a
Payload using a Linker. 
 1.101. “Permitted Third Party Service Providers” is defined in Section 3.1.1 hereof.

 1.102. “Person” means an individual, sole proprietorship, partnership, limited partnership, limited liability
partnership, corporation, limited liability company, business trust, joint stock company, trust, incorporated association, joint venture or similar entity or organization, including a government or political subdivision or department or agency of a
government. 
 1.103. “Probody” means an Antibody linked to a Substrate and a Mask that is claimed or covered by CytomX
Technology. 
 1.104. “Probody Platform Improvements” means any Patent Right, Know-How or other intellectual property right
that is an enhancement, improvement or modification (each, an “Improvement”) to the CytomX Technology invented by either Party or any of its Affiliates (or by a Third Party on behalf of either Party or its Affiliates) that is an


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 12 








 
Improvement to the composition of, or any method of using or method of making or any Tools for developing, any unconjugated Probody, Mask or Substrate (collectively, “Unconjugated Probody
Platform Improvements”). Probody Platform Improvements also include Improvements (a) to any of the analytical methods used for making, releasing and characterizing any Agreement PDCs that are necessary because of the presence of a Mask
and/or Substrate, or (b) consisting of conjugation chemistry or conjugation methods that are necessary because of the presence of a Mask and/or Substrate (collectively, “Conjugation Probody Platform Improvements”). Agreement
PDCs and ImmunoGen Probodies, in and of themselves, will not be considered to be Probody Platform Improvements, although the Parties acknowledge that Probody Platform Improvements may be incorporated into Agreement PDCs and ImmunoGen Probodies. As
used in this definition, Improvements shall be deemed to be “necessary because of the presence of a Mask and/or Substrate” if, and only if, both of the following two (2) elements are present: (i) there is no viable alternative
method of conjugating a Probody to a Payload (other than a Cytotoxic Compound1) that does not vitiate the function of the Mask and/or Substrate; and (ii) the Improvement has no practical
application to ADCs. 
 1.105. “Program Technology” means any and all intellectual property (including Patent Rights and
Know-How) that either Party or any of its Affiliates or Permitted Third Party Service Providers (or any of their respective employees, agents or independent contractors), alone or with others, makes, creates, develops, discovers, conceives or first
actually reduces to practice pursuant to the Research Program, including any Patent Rights related thereto. For purposes of clarity, all Agreement PDCs and ImmunoGen Probodies shall be deemed to be Program Technology. 

1.106. “Proposed Target” means the Target identified in a Proposed Target Notice. 

1.107. “Proposed Target Notice” means the written notice provided by one Party to the other Party pursuant to
Section 2.1.1 or 2.1.3 hereof requesting that a Target be included in the Research Program as a Research Program Target or a Replacement Target. 

1.108. “Proprietary Material” means any CytomX Proprietary Material or ImmunoGen Proprietary Material. 

1.109. “Publishing Party” is defined in Section 6.3.2 hereof. 

 

	1 	For purposes of this definition, the term “Cytotoxic Compound” shall be limited to the cell-killing agents encompassed by one or more of the claims of the issued patents (whether or not expired) listed in
Schedule 1.104 attached hereto, or by one or more of the claims, if any, of any patents issuing from the patent applications listed in Schedule 1.104 or from any divisionals, continuations or foreign counterparts of any of the foregoing.



  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 13 








 1.110. “Receiving Party” is defined in Section 1.14 hereof. 

1.111. “Regulatory Approval” means any technical, medical, scientific or other license, registration, authorization or
approval of any Regulatory Authority (including any approval of a New Drug Application or Biologic License Application) necessary for the development, manufacture or commercialization of a pharmaceutical product in any regulatory jurisdiction. 

1.112. “Regulatory Authority” means the FDA or any counterpart of the FDA outside the United States, or other national,
supra-national, regional, state or local regulatory jurisdiction, any agency, department, bureau, commission, council or other governmental entity with authority over the conduct of the Research Program and the Work Plan Activities. 

1.113. “Replacement Target” is defined in Section 2.1.2 hereof. 

1.114. “Replacement Target Cut-Off Date” is defined in Section 2.1.2 hereof. 

1.115. “Representatives” is defined in Section 1.14 hereof. 

1.116. “Research Program” is defined in Section 2.2 hereof. 

1.117. “Research Program Target” means a CytomX Research Program Target and/or an ImmunoGen Research Program Target, as
applicable. 
 1.118. “Review Period” is defined in Section 6.3.2 hereof. 

1.119. “Sanofi Collaboration Agreement” means that certain Collaboration and License Agreement dated as of July 30, 2003
by and between ImmunoGen and sanofi-aventis U.S. LLC (“Sanofi”), as successor-in-interest to Aventis Pharmaceuticals, Inc., as the same may have been amended prior to the Effective Date. 

1.120. “Substrate” means a moiety that is linked to the Antibody and to the Mask of a Probody and is capable of being cleaved,
reduced or photolysed. 
 1.121. “TAP Platform Improvements” means any Improvement to the ImmunoGen Technology invented by
either Party or any of its Affiliates (or by a Third Party on behalf of either Party or its Affiliates) that is (a) an Improvement to the composition of or methods of making any Cytotoxic Compound, (b) an Improvement to the conjugation
process for making ADCs or PDCs (including, for example, reaction conditions or changes in process that create improvements in the yield of such conjugate), (c) an Improvement to the composition of or methods for making Linkers, (d) an
Improvement to any of the analytical methods used for making, releasing and characterizing any Cytotoxic Compound, Linker, ADCs or PDCs, or (e) an Improvement to the formulation 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 14 








 
of ADCs or PDCs. Agreement PDCs, in and of themselves, will not be deemed to be TAP Platform Improvements, although the Parties acknowledge that TAP Platform Improvements may be incorporated into
Agreement PDCs. 
 1.122. “Target” means a protein described by a unique UniProtKB/Swiss Prot accession number (and all
fragments, mutations and splice variants thereof) that is bound by a cell-binding agent. 
 1.123. “Target,”
“Targeting” or “Targeted” means, when used as a verb to describe the relationship between a molecule and a Target, where the molecule’s primary intended mechanism of action requires that it bind to the Target
(or a portion thereof). 
 1.124. “Term” is defined in Section 8.1 hereof. 

1.125. “Territory” means the entire world. 

1.126. “Third Party” means any Person other than CytomX, ImmunoGen or their respective Affiliates. 

1.127. “Third Party Claims” is defined in Section 9.2 hereof. 

1.128. “Tools” means any Patent Right, Know-How or other intellectual property right covering methods, processes, materials
and tools to the extent generally applicable to the discovery of Masks, or Substrates, or their use in Probodies (but not specifically directed to PDCs), or assays of the activity relating to such discovery, including the cleavage, photolysis or
reduction of Substrates, thereof.  
 1.129. “Unauthorized Use” is defined in Section 2.10.3 hereof. 

1.130. “Unconjugated Probody Platform Improvements” is defined in Section 1.104 hereof. 

1.131. “Work Plan” is defined in Section 2.3.1 hereof. 

1.132. “Work Plan Activities” is defined in Section 2.3.2 hereof. 

1.133. “Work Plan Change” is defined in Section 2.3.3 hereof. 

 

	2.	RESEARCH PROGRAM. 

 2.1. Selection of Research Program Targets. 

2.1.1. Research Project Targets. The Parties’ respective initial Research Program Targets are set forth on Exhibit A. Subject to
Sections 2.1.2 and 2.1.3 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 15 








 
hereof, CytomX is permitted to include one (1) Research Program Target in the Research Program at any given time, and ImmunoGen is permitted to include up to two (2) Research Program
Targets in the Research Program at any given time. In no event will CytomX be required to engage in material activities under a Work Plan for more than one (1) ImmunoGen Research Program Target at a time. 

2.1.2. Target Replacement Right. Each Party shall have the right to replace each of its initial Research Program Targets with another
single Target (a “Replacement Target”), exercisable upon written notice to the other Party, at any time on or prior to the three (3)-year anniversary of the Effective Date (the “Replacement Target Cut-Off Date”),
provided that neither Party may replace an initial Research Program Target with a Replacement Target once the Party has exercised its Option with respect to such initial Research Program Target. For clarity, even though CytomX’s Research
Program Target set forth on Exhibit A consists of two (2) potential Targets due to cross-reactivity, the Probody used to make the Agreement PDC that Targets CytomX’s Replacement Target shall not be a bi-specific Probody or otherwise
cross-react with any Target other than the single Replacement Target. A Replacement Target may not be a Target that is or was previously a Research Program Target of the other Party. 

2.1.3. Availability of Replacement Target. If a Party desires to replace a Research Program Target with a Replacement Target, it
shall provide the other Party with a Proposed Target Notice no later than the Replacement Target Cut-Off Date identifying both the Proposed Target and the existing Research Program Target to be replaced. Within ten (10) Business Days following
the other Party’s receipt of a Proposed Target Notice, such other Party shall notify the Party requesting the Replacement Target in writing whether or not, as of the date of the other’s Party’s receipt of such Proposed Target Notice,
the Proposed Target is a CytomX Excluded Target or an ImmunoGen Excluded Target, as applicable. If the other Party timely notifies the Party requesting the Replacement Target that the Proposed Target is not a CytomX Excluded Target or an ImmunoGen
Excluded Target, as applicable, or if the other Party fails to timely provide any response to the Proposed Target Notice, then such Proposed Target shall thereafter automatically be considered a Research Program Target, the original Target (listed
in Exhibit A) shall thereupon cease to be a Research Program Target for all purposes under this Agreement, and the Parties shall adopt a Work Plan for such new Research Program Target in accordance with Section 2.3.1 hereof. 

2.1.4. Excluded Target Verification. Subject to the other terms of this Section, at the request of the Party submitting a
Proposed Target Notice (which request may not be given more than ten (10) Business Days after the Proposed Target has been identified by the other Party as a CytomX Excluded Target or an 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 16 








 
ImmunoGen Excluded Target, as applicable), at any time during normal business hours within ten (10) Business Days of such other Party’s delivery to the requesting Party of written
acknowledgement of such other Party’s receipt of such request, such other Party shall permit an independent law firm hired by the requesting Party and acceptable to the other Party (which acceptance shall not be unreasonably withheld,
conditioned or delayed) to inspect (during regular business hours) the relevant records upon which the other Party based its determination that the Proposed Target was a CytomX Excluded Target or an ImmunoGen Excluded Target, as applicable, at the
time of the other Party’s receipt of the Proposed Target Notice; provided that such other Party shall have sole discretion in determining which records will be made available to such law firm. Before permitting such law firm to have access to
such records, the other Party may require such law firm to enter into a confidentiality agreement (in form and substance reasonably acceptable to both Parties) as to any confidential information that is to be provided to such law firm while
conducting the verification contemplated hereby. The law firm shall be instructed to provide both Parties with a written report stating its conclusion as to whether the other Party’s determination that a Proposed Target was a CytomX Excluded
Target or an ImmunoGen Excluded Target, as applicable, was correct within ten (10) days after the completion of its inspection. Such law firm may not reveal to the requesting Party any other information learned in the course of such
examination, including, without limitation, the basis for the other Party’s determination. The requesting Party agrees to treat all information disclosed to it in accordance with this Section as the other Party’s Confidential Information,
except to the extent necessary for the requesting Party to enforce its rights under this Agreement. If the law firm’s report concludes that the other Party’s determination was correct, the requesting Party shall be responsible for paying
all fees and expenses invoiced by the law firm. If the law firm’s report concludes that the other Party’s determination was incorrect, (a) the requesting Party shall automatically be deemed to have delivered to the other Party another
Proposed Target Notice for such Target as of the date of such determination, (b) the other Party shall be responsible for paying all reasonable fees and expenses invoiced by the law firm, and (c) if the date of such determination occurs
after the Replacement Target Cut-Off Date set forth in Section 2.1.2 hereof, the Replacement Target Cut-Off Date shall be extended, with respect to such Proposed Target only, to the date of such determination. If the law firm’s
report concludes that, based on the records provided to it by the other Party, it is unable to determine whether the other Party’s determination was correct or incorrect, such determination shall be deemed to be a Dispute, which shall be
resolved in accordance with Section 10.9 hereof. 
 2.1.5. Exclusivity of Research Program Targets. During the Research
Term, for each ImmunoGen Research Program Target, CytomX will not, and will cause 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 17 








 
its Affiliates not to, research, develop or commercialize any PDC Targeted to such ImmunoGen Research Program Target other than pursuant to a Work Plan and will not, and will cause its Affiliates
not to, license CytomX Technology to any Third Party to research, develop or commercialize any PDC Targeted to such ImmunoGen Research Program Target. During the Research Term, ImmunoGen will not, and will cause its Affiliates not to, research,
develop, or commercialize any ADC Targeted to the CytomX Research Program Target and will not, and will cause its Affiliates not to, license ImmunoGen Technology to any Third Party to research, develop or commercialize any product comprising an ADC
Targeted to the CytomX Research Program Target. The foregoing shall not restrict either Party’s or their respective Affiliates’ right to grant Third Parties research licenses under any of their respective Patent Rights and Know-How that
are not Target-specific. 
 2.2. Scope and Conduct of the Research Program. Under the terms and conditions set forth herein, CytomX
and ImmunoGen shall collaborate to conduct discovery and certain pre-clinical development activities to generate and validate Agreement Probodies and generate Agreement PDCs to the Research Program Targets (the “Research Program”).
The Research Program shall be conducted in accordance with the Work Plan for each Research Program Target (as more fully provided in Section 2.3 hereof), and each Party shall use its Commercially Reasonable Efforts to perform all
activities assigned to it and fulfill all of its obligations under each Work Plan. In addition, each Party shall conduct its activities under the Work Plan(s) in accordance with Applicable Law. 

2.3. Work Plans. 
 2.3.1.
Adoption of Work Plans. The Parties shall adopt a work plan (each a “Work Plan”) for each Research Program Target. Each Work Plan shall be approved by the JRC within thirty (30) days of the Effective Date for the initial
CytomX Research Program Target and the first initial ImmunoGen Research Program Target listed on Exhibit A hereof or as determined by the JRC with respect to the second initial ImmunoGen Research Program Target. Each Work Plan will be in
the form of the sample Work Plan attached hereto as Exhibit E. For a Replacement Target that becomes a Research Program Target, a Work Plan shall be approved by the JRC within forty-five (45) days of the date on which such Replacement
Target becomes a Research Program Target. Each Work Plan shall reference this Agreement and shall be subject to all of the provisions of this Agreement, in addition to the specific details set forth in such Work Plan. To the extent any provisions of
a Work Plan conflict or are inconsistent with the provisions of this Agreement, the provisions of this Agreement shall control. If the Parties are unable to agree on a Work Plan within the specified time period, the JRC may specify the Work Plan,
and all Disputes regarding the preparation or modification of any Work Plan (including the approval of any Work Plan Change) shall be resolved in accordance with Section 10.9 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 18 








 2.3.2. Responsibilities. Each Work Plan shall set forth the services and the obligations
and responsibilities assigned to each Party (collectively the “Work Plan Activities”), and shall include the following minimum terms: 

(a) Each Party shall provide Antibodies Targeting the applicable Research Program Target at its own expense, which CytomX will use to generate
a panel of Probodies that Target such Research Program Target. The amount of material to be provided by each Party will be specified in the applicable Work Plan. CytomX will provide the construction, expression and purification of all Agreement
Probodies at its expense. CytomX will only be required to make a panel of Probodies from one (1) Antibody for each ImmunoGen Research Program Target. 

(b) CytomX will investigate and validate each Agreement Probody in accordance with the applicable Work Plan. 

(c) ImmunoGen will conjugate the Agreement Probodies to Linkers and Cytotoxic Compounds using the ImmunoGen Technology to generate a panel of
Agreement PDCs in accordance with the applicable Work Plan. ImmunoGen will only be required to make a panel of Agreement PDCs from one (1) Probody for the CytomX Research Program Target and such other ADCs as are set forth in the applicable
Work Plan. 
 (d) Each Party will perform in vivo modeling and IND-enabling studies with respect to its own Agreement PDCs in
accordance with the applicable Work Plan. 
 (e) Each Party that enters into a License Agreement covering that Party’s Agreement PDC(s)
will develop and commercialize its Agreement PDC(s) as set forth in the applicable License Agreement. 
 (f) If, after completion of the
ImmunoGen Activities under the Work Plan relating to the CytomX Agreement PDCs, CytomX requests that ImmunoGen provide additional services with respect to (i) process development, (ii) analytical method development, or
(iii) manufacturing and/or supply of the CytomX Agreement PDCs for any GLP toxicology studies, then the Parties shall negotiate in good faith the terms of separate written agreements with respect to such activities. 

2.3.3. Changes in Work Plans. Proposed changes to a Work Plan (“Work Plan Changes”) shall be subject to review and
approval by the JRC. Each Work Plan Change shall then be written up in documentation setting forth the agreed changes to the applicable task, protocol, specifications, responsibility, timeline or other matter. As used in this Agreement, a Work Plan
will be deemed to include any Work Plan Changes with respect thereto. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 19 








 2.4. Governance of the Research Program. 

2.4.1. Formation of the Joint Research Committee. CytomX and ImmunoGen hereby establish a “Joint Research Committee”
(or “JRC”) to oversee and coordinate the activities of the Parties under this Agreement in regard to the Research Program. The JRC shall also serve as a forum to facilitate communications between the Parties regarding the Research
Program. The JRC shall be comprised of three (3) representatives from each Party as appointed by such Party, with such representatives possessing appropriate expertise and seniority to carry out the Research Program. The initial members of the
JRC for each Party are set forth in Exhibit F attached hereto. The JRC may change its size from time to time by mutual consent of its members. A Party may replace one or more of its representatives from time to time upon written notice
to the other Party. The JRC shall exist until expiration or earlier termination of the Term, unless the Parties otherwise agree in writing. 

2.4.2. Co-Chairpersons and Secretary of the Joint Research Committee. Each Party shall designate a co-chairperson of the JRC, and a
secretary of the JRC shall be designated by agreement of the members of the JRC. A Party may change the designation of its co-chairperson from time to time upon written notice to the other Party. The co-chairpersons or their designees shall be
responsible for scheduling meetings of the JRC, preparing agendas for meetings and sending to all JRC members notices of all regular meetings and agendas for such meetings at least five (5) Business Days before such meetings. The
co-chairpersons shall solicit input from both Parties regarding matters to be included on the agenda, and any matter either Party desires to have included on the agenda shall be included for discussion. Nothing herein shall be construed to prohibit
the JRC from discussing or acting on matters not included on the applicable agenda. The secretary shall (a) record the minutes of the meeting, (b) circulate copies of meeting minutes to the Parties and each JRC member promptly following
the meeting for review, comment and approval by the JRC members and (c) finalize approved meeting minutes. The co-chairpersons shall be members of the JRC but the secretary need not be a member of the JRC. The initial co-chairpersons are listed
in Exhibit F hereof. 
 2.4.3. Meetings. The JRC shall meet at least three (3) times each Calendar Year (unless the
Parties mutually agree in advance of any scheduled meeting that there is no need for such meeting, in which case the next JRC meeting shall also be scheduled as agreed upon by the Parties) until it has been terminated in accordance with
Section 2.4.1 hereof at dates and times mutually agreed by the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 20 








 
JRC. The initial meeting of the JRC shall be held within thirty (30) days after the Effective Date. Either Party may call a special meeting of the JRC on fifteen (15) days written
notice to the other Party’s members of the JRC (or upon such shorter notice as exigent circumstances may require). Such written notice shall include an agenda for the special meeting. In-person meetings, including special meetings, of the JRC
shall alternate between the offices of the Parties, unless otherwise agreed upon by the members of the JRC. Meetings of the JRC may be held telephonically or by video conference; provided, however, that at least two (2) meetings per year shall
be held in-person. Meetings of the JRC shall be effective only if at least one (1) representative of each Party is in attendance or participating in the meeting. Members of the JRC shall have the right to participate in and vote at meetings
held by telephone or video conference. In addition, the JRC may act on any matter or issue without a meeting if it is documented in a written consent signed by each member of the JRC. 

2.4.4. Responsibilities of the Joint Research Committee. The JRC shall be responsible for (a) planning and overseeing research
under this Agreement, including establishing, reviewing and recommending modifications and updates to the Work Plans; (b) receiving and reviewing relevant data and other information obtained by either Party in connection with the Research
Program and monitoring and reporting to the Parties on activities conducted pursuant to the Work Plans; (c) resolving Disputes between the Parties; and (d) such other functions as expressly specified hereunder or as agreed by the Parties.

 2.4.5. Decisions by Consensus. All decisions of the JRC shall be made by unanimous agreement of both Parties’ representatives,
with each Party having a single vote, irrespective of the number of JRC representatives in attendance at a meeting. If the JRC cannot or does not reach unanimous agreement on a matter within the purview of the JRC, then such Dispute shall be
resolved in accordance with Section 10.9 hereof. 
 2.5. Alliance Managers. In addition to the foregoing governance
provisions, each of the Parties shall appoint a single individual to serve as that Party’s alliance manager (“Alliance Manager”). The role of each Alliance Manager will be to participate and otherwise facilitate the
relationship between the Parties as established by this Agreement. A Party may replace its Alliance Manager from time to time upon written notice to the other Party. 

2.6. Conformance with Law. Each Party shall perform and discharge its obligations under this Agreement and the Research Program in
conformance with (a) professional standards and practices, (b) this Agreement and the Work Plan(s) and (c) all Applicable Laws. Without limiting the generality of the foregoing, each Party shall retain all records relating to its
performance of this Agreement and the Work Plan(s) for the time periods required by Applicable Laws. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 21 








 2.7. Personnel Matters. Each Party acknowledges and agrees that it is solely responsible
for the compensation of its personnel assigned to the Work Plan activities, and shall be responsible for withholding all national, state, local or other applicable taxes and similar items for such personnel. 

2.8. Debarment Certification. Neither Party nor any Person employed or retained to perform services by either Party has been debarred
under Section 306(a) or (b) of the FD&C Act or any comparable provision of foreign law and no debarred Person shall in the future be employed or retained to perform services by either Party in connection with any work to be performed
for or on behalf of the other Party. If, at any time after execution of this Agreement, either Party becomes aware that such Party or any Person employed or retained to perform services by such Party in connection with any work performed for or on
behalf of such Party is, or is in the process of being, debarred, such Party shall so notify the other Party immediately. 
 2.9.
Records. Each Party shall prepare, complete and accurate written records, accounts, notes, reports and data of the Work Plan activities and its performance under this Agreement and the Work Plan(s), in a form and of quality reasonably
acceptable to both Parties. 
 2.10. Transfer and Use of Proprietary Materials. 

2.10.1. Transfer. From time to time, pursuant to a Work Plan, or otherwise, ImmunoGen may provide CytomX with ImmunoGen Proprietary
Materials and Agreement PDCs and CytomX may provide ImmunoGen with CytomX Proprietary Materials and Agreement Probodies. Each Party’s Proprietary Materials, Agreement PDCs and Agreement Probodies are provided by such Party on an
“as-is” basis without representation or warranty of any type, express or implied, including any representation or warranty of merchantability, non-infringement, title or fitness for a particular purpose, each of which is hereby disclaimed
by such providing Party. 
 2.10.2. Use of Proprietary Materials. Each Party shall use the other Party’s Proprietary Materials
(including, without limitation, the other Party’s Proprietary Materials incorporated into Agreement PDCs and Agreement Probodies) solely in connection with conducting the specific activities under this Agreement for which such other
Party’s Proprietary Materials are provided to the receiving Party, including, if applicable, the provisions of any specific Work Plan under which such Proprietary Materials are provided, and for no other purpose. Without limiting the generality
of the foregoing, except as expressly set forth in this 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 22 








 
Agreement or in any applicable Work Plan, neither Party shall make or attempt to make analogues, progeny or derivatives of, or modifications to, the other Party’s Proprietary Materials,
using the other Party’s Confidential Information or the tangible materials provided by the other Party, and each Party shall not use the other Party’s Proprietary Materials for the benefit of any Third Party or of its own internal research
programs outside of the Research Program or as otherwise licensed to the other Party under a Development and Commercialization License. Each Party shall comply with all Applicable Laws regarding the handling and use of the other Party’s
Proprietary Materials. Each Party agrees to retain possession over the other Party’s Proprietary Materials and not to provide the other Party’s Proprietary Materials to any Third Party without the providing Party’s prior written
consent, except as required to perform the Research Program. 
 2.10.3. Unauthorized Use of Confidential Information and Proprietary
Materials. In the event that either Party uses the other Party’s Confidential Information or Proprietary Materials (including, without limitation, the other Party’s Proprietary Materials incorporated into Agreement PDCs and Agreement
Probodies) for any purpose other than the purposes authorized herein (an “Unauthorized Use”), the results of such Unauthorized Use, and any discoveries or inventions that arise from such Unauthorized Use, whether patentable or not,
shall belong solely and exclusively to the Party providing its Confidential Information or Proprietary Materials. If required in order to perfect or enforce a Party’s ownership of such results, discoveries or inventions, each hereby assigns and
agrees to assign to the other Party all of its right, title and interest in and to all such results, discoveries or inventions made through the Unauthorized Use with the other Party’s Confidential Information or Proprietary Materials. Each
Party agrees to cooperate with the other Party, and to execute and deliver any and all documents that the providing Party reasonably deems necessary, to perfect and enforce its rights hereunder. 

 

	3.	OPTION FOR LICENSE AND COMMERCIAL LICENSE GRANTS. 

 3.1. Grants to ImmunoGen. 

3.1.1. Research License and Option Grants. Subject to the terms and conditions of this Agreement, CytomX hereby grants to ImmunoGen
during the Term (a) a non-exclusive, non-sublicensable (except to Affiliates and Permitted Third Party Service Providers), non-transferable (except as expressly permitted by this Agreement), royalty-free license under the CytomX Licensed
Intellectual Property for the sole purpose of conducting the ImmunoGen Work Plan Activities in the Territory, and (b) an exclusive option (each, an “ImmunoGen Option”) to obtain a Development and Commercialization License with
respect to up to two (2) Research Program Targets as set forth in Section 3.1.2. ImmunoGen shall 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 23 








 
have the right to engage one or more Affiliates or Third Parties (the latter being referred to as “Permitted Third Party Service Providers”) as subcontractors to perform some or
all of the ImmunoGen Activities; provided that (i) ImmunoGen shall remain responsible for the conduct of such activities in accordance with the terms and conditions of this Agreement and (ii) ImmunoGen shall cause each such Affiliate or
Third Party Service Provider to assign or license (with a right to sublicense to CytomX to the extent required under this Agreement) to ImmunoGen all intellectual property rights (including, without limitation, Patent Rights) in and to any Probody
Platform Improvements, whether patentable or not, the inventors of which (alone or with others) are employees of, or others obligated to assign inventions to, such Permitted Third Party Service Provider in the performance of services for ImmunoGen.

 3.1.2. Exercise of each ImmunoGen Option. On an ImmunoGen Research Program Target-by-ImmunoGen Research Program Target basis, each
of the ImmunoGen Options may be separately exercised by ImmunoGen at any time during the Term, but in each case no later than one hundred eighty-two (182) days after the first dosing of any animal in the first IND-enabling GLP toxicology study
of the applicable ImmunoGen Agreement PDC (each, the “ImmunoGen Option Exercise Cut-Off Date”), by providing CytomX with an Option Exercise Notice (the date of CytomX’s receipt of any such Option Exercise Notice, the
“ImmunoGen Option Exercise Date”). If ImmunoGen does not provide CytomX with an Option Exercise Notice with respect to any Research Program Target during the Term and prior the ImmunoGen Option Exercise Cut-Off Date, then the
applicable Target shall no longer be considered an ImmunoGen Research Program Target. Notwithstanding the foregoing, the ImmunoGen Option Exercise Cut-Off Date with respect to each of the first two (2) ImmunoGen Research Program Targets shall
be the sixtieth (60th) day after the Replacement Target Cut-Off Date if ImmunoGen has not notified CytomX on or prior to the Replacement Target Cut-Off Date of its intention to replace such
ImmunoGen Research Program Target with a Replacement Target in accordance with Sections 2.1.2 and 2.1.3 hereof. 
 3.1.3.
Development and Commercialization License. Subject to the terms and conditions of this Agreement, on a Research Program Target-by-Research Program Target basis and effective on the ImmunoGen Option Exercise Date for such Research Program
Target, (a) the Licensed Intellectual Property (as defined in the ImmunoGen License Agreement) shall be licensed by CytomX to ImmunoGen with respect to the Research Program Target specified in the Option Exercise Notice (each, an
“ImmunoGen Licensed Target”) on the terms and subject to the conditions set forth in the ImmunoGen License Agreement, and (b) the foregoing Development and Commercialization License shall be effective as of the ImmunoGen Option
Exercise Date. CytomX shall deliver to ImmunoGen, 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 24 








 
within ten (10) Business Days following the ImmunoGen Option Exercise Date, an ImmunoGen License Agreement executed on behalf of CytomX in which CytomX has (i) inserted the name and
unique UniProtKB/Swiss Prot accession number of the applicable ImmunoGen Licensed Target in Schedule A of the ImmunoGen License Agreement, and (ii) inserted the ImmunoGen Option Exercise Date as the effective date of the ImmunoGen License
Agreement. If either Party fails to deliver an executed copy of the ImmunoGen License Agreement as described above, CytomX shall nevertheless be deemed to have granted ImmunoGen the rights with respect to the ImmunoGen Licensed Target consistent
with the ImmunoGen License Agreement. 
 3.1.4. Rescission of Exercise of ImmunoGen Option. Anything contained in this Agreement to
the contrary notwithstanding, if, in connection with ImmunoGen’s exercise of an ImmunoGen Option, CytomX delivers to ImmunoGen a Disclosure Letter within ten (10) Business Days of CytomX’s receipt of the applicable Option Exercise
Notice, then ImmunoGen shall be entitled to rescind the exercise of such ImmunoGen Option by delivering to CytomX written notice of such rescission within twenty (20) Business Days of ImmunoGen’s receipt of the Disclosure Letter. Any
failure by CytomX to deliver a Disclosure Letter to ImmunoGen within the applicable ten (10) Business Day period described above shall be deemed a waiver of CytomX’s right to qualify its representations and warranties in the applicable
ImmunoGen License Agreement by any information CytomX may have intended to include in the Disclosure Letter. If CytomX delivers the Disclosure Letter on a timely basis, then any failure by ImmunoGen to deliver a rescission notice to CytomX within
the applicable twenty (20) Business Day period described above shall be deemed a waiver of ImmunoGen’s right to rescind the exercise of such ImmunoGen Option pursuant to this Section 3.1.4, and CytomX’s representations and
warranties in the applicable ImmunoGen License Agreement shall be qualified by any information contained in such Disclosure Letter. If an ImmunoGen Option is rescinded pursuant to this Section 3.1.4, then such ImmunoGen Option shall
remain outstanding in accordance with its original terms; provided, however, that: 
 (a) if the Replacement Target Cut-Off Date occurs
within the period beginning on the applicable ImmunoGen Option Exercise Date and ending on the sixtieth (60th) day after ImmunoGen’s delivery of the rescission notice to CytomX, then
anything set forth in this Agreement to the contrary notwithstanding, ImmunoGen shall have the right to replace the applicable ImmunoGen Research Program Target with a Replacement Target, subject to the terms and conditions set forth in
Sections 2.1.2 and 2.1.3 hereof; and 
 (b) if the applicable ImmunoGen Option Exercise Cut-Off Date occurs within the period
beginning on the applicable ImmunoGen Option 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 25 








 
Exercise Date and ending on the sixtieth (60th) day after ImmunoGen’s delivery of the rescission notice to CytomX, then anything set
forth in this Agreement to the contrary notwithstanding, ImmunoGen shall have the right to exercise the applicable ImmunoGen Option for the same ImmunoGen Research Program Target or, as contemplated by clause (a) above, a different ImmunoGen
Research Program Target, within ninety (90) days (or such longer period as may be mutually agreed to in writing by the Parties) after ImmunoGen’s delivery of the rescission notice to CytomX. 

3.1.5. License to CytomX TAP Platform Improvements. CytomX, on behalf of itself and its Affiliates, hereby grants to ImmunoGen a
non-exclusive, sublicensable, perpetual, irrevocable, royalty-free worldwide license under CytomX’s interest in any CytomX TAP Platform Improvements, including, without limitation, any Patent Rights claiming such CytomX TAP Platform
Improvements, to exploit such CytomX TAP Platform Improvements (a) for any purpose other than developing, manufacturing, using or commercializing PDCs and (b) for any purpose outside of the Field. Except in connection with the performance
of the CytomX Activities under the Work Plans related to the ImmunoGen Research Program Targets, nothing in this Agreement shall be construed as obligating CytomX to engage in any technology transfer or provision of written documentation to
ImmunoGen (other than as provided in Section 5.2.3 hereof) or any of its Affiliates or any Third Party disclosing, describing or otherwise relating to CytomX TAP Platform Improvements. 

3.2. Grants to CytomX. 

3.2.1. Research License and Option Grant. Subject to the terms and conditions of this Agreement, ImmunoGen hereby grants to CytomX
during the Term (a) a non-exclusive, non-sublicensable (except to Affiliates and Permitted Third Party Service Providers), non-transferable (except as expressly permitted by this Agreement) royalty-free license under the ImmunoGen Licensed
Intellectual Property for the sole purpose of conducting the CytomX Work Plan Activities in the Territory, and (b) an exclusive option (the “CytomX Option”) to obtain a Development and Commercialization License with respect to
one (1) CytomX Research Program Target as set forth in Section 3.3.2. CytomX shall have the right to engage one or more Affiliates or Permitted Third Party Service Providers as subcontractors to perform some or all of the CytomX
Activities; provided that (i) CytomX shall remain responsible for the conduct of such activities in accordance with the terms and conditions of this Agreement and (ii) CytomX shall cause each such Affiliate or Third Party Service Provider
to assign or license (with a right to sublicense to ImmunoGen to the extent required under this Agreement) to CytomX all intellectual property rights (including, without 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 26 








 
limitation, Patent Rights) in and to any TAP Platform Improvements, whether patentable or not, the inventors of which (alone or with others) are employees of, or others obligated to assign
inventions to, such Permitted Third Party Service Provider in the performance of services for CytomX. 
 3.2.2. Exercise of the CytomX
Option. The CytomX Option may be exercised by CytomX at any time during the Term, but in no event later than one hundred eighty-two (182) days after the first dosing of any animal in the first IND-enabling GLP toxicology studies of the
applicable CytomX Agreement PDC (the “CytomX Option Exercise Cut-Off Date”), by providing ImmunoGen with an Option Exercise Notice (the date of ImmunoGen’s receipt of the Option Exercise Notice, the “CytomX Option
Exercise Date”). If CytomX does not provide ImmunoGen with an Option Exercise Notice with respect to its Research Program Target during the Term and prior to the CytomX Option Exercise Cut-Off Date, then the applicable Target shall no
longer be considered a CytomX Research Program Target. Notwithstanding the foregoing, the CytomX Option Exercise Cut-Off Date with respect to the CytomX Research Program Target shall be the sixtieth
(60th) day after the Replacement Target Cut-Off Date if CytomX has not notified ImmunoGen on or prior to the Replacement Target Cut-Off Date of its intention to replace such CytomX Research
Program Target with a Replacement Target in accordance with Sections 2.1.2 and 2.1.3 hereof. 
 3.2.3. Development and
Commercialization License. Subject to the terms and conditions of this Agreement, effective on the CytomX Option Exercise Date for its Research Program Target, (a) the Licensed Intellectual Property (as defined in the CytomX License
Agreement) shall be licensed by ImmunoGen to CytomX with respect to the Research Program Target specified in the Option Exercise Notice (the “CytomX Licensed Target”) on the terms and subject to the conditions set forth in the
CytomX License Agreement, and (b) the foregoing license shall be effective as of the CytomX Option Exercise Date. ImmunoGen shall deliver to CytomX, within ten (10) Business Days following the CytomX Option Exercise Date, a CytomX License
Agreement executed on behalf of ImmunoGen in which ImmunoGen has (i) inserted the name and unique UniProtKB/Swiss Prot accession number of the applicable Licensed Target in Schedule A of the CytomX License Agreement, and (ii) inserted
the CytomX Option Exercise Date as the effective date of the CytomX License Agreement. If either Party fails to deliver an executed copy of the CytomX License Agreement as described above, ImmunoGen shall nevertheless be deemed to have granted
CytomX the rights with respect to the CytomX Licensed Target consistent with the CytomX License Agreement. 
 3.2.4. Rescission of
Exercise of CytomX Option. Anything contained in this Agreement to the contrary notwithstanding, if, in connection with CytomX’s 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 27 








 
exercise of the CytomX Option, ImmunoGen delivers to CytomX a Disclosure Letter within ten (10) Business Days of ImmunoGen’s receipt of the applicable Option Exercise Notice, then
CytomX shall be entitled to rescind the exercise of the CytomX Option by delivering to ImmunoGen written notice of such rescission within twenty (20) Business Days of CytomX’s receipt of the Disclosure Letter. Any failure by ImmunoGen to
deliver a Disclosure Letter to CytomX within the applicable ten (10) Business Day period described above shall be deemed a waiver of ImmunoGen’s right to qualify its representations and warranties in the CytomX License Agreement by any
information ImmunoGen may have intended to include in the Disclosure Letter. If ImmunoGen delivers the Disclosure Letter on a timely basis, then any failure by CytomX to deliver a rescission notice to ImmunoGen within the applicable twenty
(20) Business Day period described above shall be deemed a waiver of CytomX’s right to rescind the exercise of the CytomX Option pursuant to this Section 3.2.4, and ImmunoGen’s representations and warranties in the CytomX
License Agreement shall be qualified by any information contained in such Disclosure Letter. If the CytomX Option is rescinded pursuant to this Section 3.2.4, then the CytomX Option shall remain outstanding in accordance with its
original terms; provided, however, that: 
 (a) if the Replacement Target Cut-Off Date occurs within the period beginning on the CytomX
Option Exercise Date and ending on the sixtieth (60th) day after CytomX’s delivery of the rescission notice to ImmunoGen, then anything set forth in this Agreement to the contrary
notwithstanding, CytomX shall have the right to replace the CytomX Research Program Target with a Replacement Target, subject to the terms and conditions set forth in Sections 2.1.2 and 2.1.3 hereof; and 

(b) if the CytomX Option Exercise Cut-Off Date occurs within the period beginning on the CytomX Option Exercise Date and ending on the
sixtieth (60th) day after CytomX’s delivery of the rescission notice to ImmunoGen, then anything set forth in this Agreement to the contrary notwithstanding, CytomX shall have the right
to exercise the CytomX Option for the same CytomX Research Program Target or, as contemplated by clause (a) above, a different ImmunoGen Research Program Target, within ninety (90) days (or such longer period as may be mutually agreed to
in writing by the Parties) after CytomX’s delivery of the rescission notice to ImmunoGen. 
 3.2.5. License to ImmunoGen Probody
Platform Improvements. ImmunoGen, on behalf of itself and its Affiliates, hereby grants to CytomX a non-exclusive, sublicensable, perpetual, irrevocable, royalty-free worldwide license under ImmunoGen’s interest in any ImmunoGen Probody
Platform Improvements, including, without limitation, any Patent Rights claiming such ImmunoGen Probody Platform Improvements, to exploit such ImmunoGen Probody Platform 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 28 








 
Improvements (a) for any purpose other than developing, manufacturing, using or commercializing PDCs having a Payload that is a Cytotoxic
Compound2 and (b) for any purpose outside of the Field. For the avoidance of doubt, the license granted pursuant to this subsection excludes any rights in and to ImmunoGen Background
Technology or any ImmunoGen Program Technology other than the ImmunoGen Probody Platform Improvements. Except in connection with the performance of the ImmunoGen Activities under the Work Plan(s) related to the CytomX Research Program Target(s),
nothing in this Agreement shall be construed as obligating ImmunoGen to engage in any technology transfer or provision of written documentation to CytomX (other than as provided in Section 5.2.2 hereof) or any of its Affiliates or any Third
Party disclosing, describing or otherwise relating to ImmunoGen Probody Platform Improvements. 
 3.3. Section 365(n) of Bankruptcy
Code. All rights and licenses now or hereinafter granted by either Party to the other Party under or pursuant to any section of this Agreement, including the licensed granted in this Article 3, are rights to “intellectual
property” (as defined in Section 101(35A) of Title 11 of the United States Code, as amended (such Title 11, the “Bankruptcy Code”)). 

3.4. No Implied Rights. Except as expressly provided in this Agreement, neither Party shall be deemed, by estoppel, implication or
otherwise, to have granted the other Party any license or other right with respect to any intellectual property owned or Controlled by such Party. 
  

	4.	EXPENSES. 

 4.1. Expenses. Except as expressly stated herein or in a Work Plan,
each Party hereto shall be responsible for its own costs for all activities conducted pursuant to this Agreement. 
  

	5.	INTELLECTUAL PROPERTY. 

 5.1. Inventions. 

5.1.1. Ownership. All determinations of inventorship under this Agreement shall be made in accordance with the laws of the United
States. Determinations of ownership of intellectual property hereunder will be made in accordance with inventorship. 
 (a) ImmunoGen
Solely Owned Technology. As between the Parties, ImmunoGen shall be the sole owner of all ImmunoGen Licensed Intellectual Property (other than Joint Program Technology included therein and any Joint Patent Rights). 

 

	2 	For purposes of this Section, the term “Cytotoxic Compound” shall be limited to the cell-killing agents encompassed by one or more of the claims of the issued patents (whether or not expired) listed in
Schedule 1.104 attached hereto, or by one or more of the claims, if any, of any patents issuing from the patent applications listed in Schedule 1.104 or from any divisionals, continuations or foreign counterparts of any of the foregoing.



  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 29 








 (b) CytomX Solely Owned Technology. As between the Parties, CytomX shall be the sole
owner of all CytomX Licensed Intellectual Property (other than Joint Program Technology included therein and any Joint Patent Rights). 

(c) Jointly Owned Technology. All Joint Program Technology (including, without limitation, all Joint Patent Rights) shall be jointly
owned by the Parties, with each Party holding an undivided one-half interest therein. Subject to the Parties’ other rights and obligations under this Agreement and any then-outstanding License Agreement(s), each Party shall be free to exploit
and assign, either itself or through the grant of licenses to Third Parties, all Joint Program Technology and Joint Patent Rights throughout the world without restriction, without the need to obtain further consent from or provide notice to the
other Party and without any duty to account or otherwise make any payment of any compensation to the other Party. ImmunoGen’s one-half interest in Joint Program Technology and Joint Patent Rights shall be included in the Licensed Intellectual
Property (as defined in the CytomX License Agreement) under the CytomX License Agreement to the extent it otherwise comes within such definition. CytomX’s one-half interest in Joint Program Technology and Joint Patent Rights shall be included
in the Licensed Intellectual Property (as defined in each ImmunoGen License Agreement) under each ImmunoGen License Agreement to the extent it otherwise comes within such definition. Nothing in this Section 5.1.1(c) shall be construed to grant
(i) CytomX any rights in and to ImmunoGen Background Technology or any ImmunoGen Program Technology in connection with its exploitation of Joint Program Technology and Joint Patent Rights outside the scope of the Research Program hereunder or
the development, manufacture and commercialization of Licensed Products under a Development and Commercialization License, or (ii) ImmunoGen any rights in and to CytomX Background Technology and CytomX Program Technology in connection with its
exploitation of Joint Program Technology and Joint Patent Rights outside the scope of the Research Program hereunder or the development, manufacture and commercialization of Licensed Products under a Development and Commercialization License. 

5.1.2. Disclosure. CytomX shall, no less than thirty (30) days before filing any initial Patent Right disclosing CytomX TAP
Platform Improvements or any Joint Program Technology or any other Patent Right that contains ImmunoGen’s 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 30 








 
Confidential Information, provide a copy of such disclosure to ImmunoGen. ImmunoGen shall, no less than thirty (30) days before filing any initial Patent Right disclosing ImmunoGen Probody
Platform Improvements or Joint Program Technology or any other Patent Right that contains CytomX’s Confidential Information, provide a copy of such disclosure to CytomX. In each case, such disclosures to the other Party shall include all
invention disclosures or other similar documents submitted to such Party by its, or its Affiliates’, employees, agents or independent contractors describing such invention and the proposed inventorship of any new Patent Rights intended to be
filed. The other Party shall promptly raise any issue regarding inventorship of any such Patent Rights, and the Parties agree to use their best efforts to determine in good faith the correct inventorship of any Patent Rights in accordance with
Section 10.10.1 hereof. 
 5.2. Filing, Prosecution and Maintenance of Patent Rights. 

5.2.1. Cooperation. Without limiting any other rights and obligations of the Parties under this Agreement, the Parties shall cooperate
with respect to the timing, scope and filing of patent applications and patent claims relating to any Joint Program Technology to preserve and enhance the patent protection for Agreement PDCs, including the manufacture and use thereof and to allow
the Party owning the technology underlying an Improvement to have reasonable input to preserve and enhance its patent portfolio and patenting strategy. 

5.2.2. ImmunoGen Patent Rights. ImmunoGen, at its own expense, shall have the sole right, but not the obligation, to prepare, file,
prosecute and maintain, throughout the world, all ImmunoGen Patent Rights. With respect to any ImmunoGen Patent Rights disclosing or claiming Program Technology (other than TAP Platform Improvements included in the Program Technology), ImmunoGen
shall keep CytomX reasonably informed of the status of the filing, prosecution and maintenance of such Patent Rights and shall consider in good faith any recommendations made by CytomX in regard to the filing, prosecution or maintenance of any such
Patent Right. ImmunoGen shall consult with CytomX in the filing, prosecution and maintenance of any ImmunoGen Patent Right related to ImmunoGen Probody Platform Improvements and shall not unreasonably refuse to incorporate any recommendations made
by CytomX in regard to such filing, prosecution or maintenance. Communications regarding the filing, prosecution and maintenance of any ImmunoGen Patent Rights related to ImmunoGen Probody Platform Improvements will be made through the Patent
Committee established as set forth in Section 5.2.4 hereof. To the extent ImmunoGen decides not to file, prosecute or maintain any ImmunoGen Patent Right that ImmunoGen reasonably believes covers or may cover the development,
manufacture, commercialization or use of any CytomX Licensed Product (other than any such Patent Right owned or co-owned by a Third Party licensor or the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 31 








 
filing of a new initial patent application or any ImmunoGen Patent Rights related to Conjugation Probody Platform Improvements) and except in the case in which the decision not to file, prosecute
or maintain such Patent Right is made by ImmunoGen in the ordinary course of filing continuation applications or as part of an overall strategy to optimize the scope or other aspects of the ImmunoGen Technology, ImmunoGen shall provide CytomX with
thirty (30) days prior written notice to such effect (i.e., at least thirty (30) days prior to the date on which any such filing is intended or due or on which any other such action is due), in which event CytomX may elect to file
or continue prosecution or maintenance of such Patent Right, at CytomX’s expense, and ImmunoGen, upon CytomX’s written request received within such thirty (30) day period, shall execute such documents and perform such acts, at
CytomX’s expense, as may be reasonably necessary to permit CytomX to file, prosecute and maintain such Patent Right; provided that CytomX (a) shall keep ImmunoGen reasonably informed of the status of the filing, prosecution and maintenance
of such Patent Rights, (b) shall consider in good faith any recommendations made by ImmunoGen in regard to such filing, prosecution and maintenance of such Patent Right, and (c) shall not unreasonably refuse to incorporate any
recommendations made by ImmunoGen in regard to such filing, prosecution or maintenance. Any such Patent Right that is prosecuted or maintained by CytomX pursuant to this Section 5.2.2 (i) will continue to be owned by ImmunoGen, and
(ii) subject to the Parties’ other rights and obligations under this Agreement or any then-outstanding License Agreement, may be licensed by ImmunoGen to one or more Third Parties. For avoidance of doubt, “prosecution” as used in
this Section 5.2 includes oppositions, nullity or revocation actions, post-grant reviews and other patent office proceedings involving the referenced Patent Rights. Nothing contained in this Agreement shall be construed as obligating
ImmunoGen to file any patent application in any country or other jurisdiction relating to ImmunoGen Probody Platform Improvements. 
 5.2.3.
CytomX Patent Rights. CytomX, at its own expense, shall have the sole right, but not the obligation, to prepare, file, prosecute and maintain, throughout the world, all CytomX Patent Rights. With respect to any CytomX Patent Rights disclosing
or claiming Program Technology (other than Unconjugated Probody Platform Improvements included in the Program Technology), CytomX shall keep ImmunoGen reasonably informed of the status of the filing, prosecution and maintenance of such Patent Rights
and shall consider in good faith any recommendations made by ImmunoGen in regard to the filing, prosecution or maintenance of any such Patent Right. CytomX shall consult with ImmunoGen in the filing, prosecution and maintenance of any CytomX Patent
Right related to CytomX TAP Platform Improvements and shall not unreasonably refuse to incorporate any recommendations made by ImmunoGen in regard to such filing, prosecution or maintenance. Communications regarding the filing, prosecution


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 32 








 
and maintenance of any CytomX Patent Rights that are Improvements to ImmunoGen Technology will be made through the Patent Committee established as set forth in Section 5.2.4 hereof.
To the extent CytomX decides not to file, prosecute or maintain any CytomX Patent Right that CytomX reasonably believes covers or may cover the development, manufacture, commercialization or use of any ImmunoGen Licensed Product (other than any such
Patent Right owned or co-owned by a Third Party licensor or the filing of a new initial patent application or any CytomX Patent Right related to CytomX TAP Platform Improvements) and except in the case in which the decision not to file, prosecute or
maintain such Patent Right is made by CytomX in the ordinary course of filing continuation applications or as part of an overall strategy to optimize the scope or other aspects of the CytomX Technology, CytomX shall provide ImmunoGen with thirty
(30) days prior written notice to such effect (i.e., at least thirty (30) days prior to the date on which any such filing is intended or due or on which any other such action is due), in which event ImmunoGen may elect to continue
prosecution or maintenance of such Patent Right, at ImmunoGen’s sole expense, and CytomX, upon ImmunoGen’s written request, shall execute such documents and perform such acts, at ImmunoGen’s expense, as may be reasonably necessary to
permit ImmunoGen to file, prosecute and maintain, at its own discretion, such Patent Right; provided that ImmunoGen (a) shall keep CytomX reasonably informed of the status of the filing, prosecution and maintenance of such Patent Rights,
(b) shall consider in good faith any recommendations made by CytomX in regard to such filing, prosecution and maintenance of such Patent Right, and (c) shall not unreasonably refuse to incorporate any recommendations made by CytomX in
regard to such filing, prosecution or maintenance. Any such Patent Right that is prosecuted or maintained by ImmunoGen pursuant to this Section 5.2.3 (a) will continue to be owned by CytomX, and (b) subject to the Parties’
other rights and obligations under this Agreement or any then-outstanding License Agreement, may be licensed by CytomX to one or more Third Parties. Nothing contained in this Agreement shall be construed as obligating CytomX to file any patent
application in any country or other jurisdiction relating to CytomX TAP Platform Improvements. 
 5.2.4. Joint Patent Rights. Prior to
either Party filing any Patent Right disclosing Joint Program Technology, disclosing an Improvement made by ImmunoGen to CytomX Technology or disclosing an Improvement made by CytomX to the ImmunoGen Technology, the Parties shall establish a patent
committee (the “Patent Committee”) comprised of at least one (1) representative of each Party for the purpose of facilitating communication as described in Sections 5.2.2 and 5.2.3 hereof and the preparation,
filing, prosecution, maintenance and defense of Joint Patent Rights. As agreed upon by the Parties, meetings of the Patent Committee may be face-to-face or may be conducted by teleconferences or videoconferences, from time to time as needed. The
Patent 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 33 








 
Committee will be the forum through which the Parties coordinate their respective obligations to each other described in Sections 5.2.2 and 5.2.3 hereof and in this Section. In
the event the Parties conceive or generate any Joint Program Technology, the Parties shall promptly meet to discuss and determine, based on mutual consent, whether to seek patent protection thereon, which Party will control filing, prosecution and
maintenance of such patents and how to pay for the filing, prosecution and maintenance of such patents. It is presumed that CytomX will control filing, prosecution and maintenance of Joint Patent Rights claiming (a) composition of matter or
methods of use of CytomX Agreement PDCs or CytomX Licensed Products or (b) Unconjugated Probody Platform Improvements, and that ImmunoGen will control filing, prosecution and maintenance of Joint Patent Rights claiming (i) composition of
matter or methods of use of ImmunoGen Probodies, ImmunoGen Agreement PDCs or ImmunoGen Licensed Products, (ii) Conjugation Probody Platform Improvements or (iii) TAP Platform Improvements. Neither Party will file any Joint Patent Right
without the prior written consent of the other Party, which consent shall not be unreasonably withheld, conditioned or delayed. The Party controlling filing and prosecution of any such Joint Patent Right (a) shall keep the other Party informed
regarding each Patent Right, (b) shall consider in good faith any recommendations made by the other Party in regard to the filing, prosecution or maintenance of any such Patent Right and (c) shall not unreasonably refuse to incorporate any
recommendations made by the other Party in regard to such filing, prosecution or maintenance. 
 5.2.5. Restrictions on Disclosures in
Patent Applications. Anything contained in this Agreement to the contrary notwithstanding, unless and until the Parties enter into a License Agreement with respect to a Research Program Target, neither Party may, without the prior written
consent of the other Party, which consent may be withheld by such other Party in its sole discretion, (a) identify or describe Agreement Probodies or Agreement PDCs in any patent application, or (b) disclose any data generated under a Work
Plan in support of any Patent Rights that disclose or claim Probodies or PDCs Targeting such Research Program Target; provided, that the foregoing shall not apply to any CytomX Patent Rights covering Agreement Probodies Targeting the CytomX Research
Program Target. 
 5.2.6. Improper Patent Filings. Each Party agrees that, without the prior written consent of the other Party,
neither it nor any of its Affiliates will claim in any patent application filed by or on behalf of such Party (or its Affiliate) any unpatented, nonpublic invention for which the inventor(s) (alone or with others) are employees of, or other persons
obligated to assign inventions to, the other Party or any Affiliate of the other Party, or disclose any such invention in any such patent application in a manner that would prejudice the other Party’s ability to patent such invention. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 34 








 5.2.7. Liability. Except for breaches of Section 5.2.5 or 5.2.6 hereof,
to the extent that a Party is obtaining, prosecuting or maintaining a Patent Right included in the CytomX Licensed Intellectual Property, the ImmunoGen Licensed Intellectual Property or Joint Patent Rights or otherwise exercising its rights under
this Section 5.2, such Party, and its Affiliates, employees, agents or representatives, shall not be liable to the other Party in respect of any act or omission on the part of any such Party, or its Affiliates, employees, agents or
representatives, in connection with such activities undertaken in good faith. 
 5.2.8. Extensions. The decision to file for a patent
term extension and particulars thereof (including which patent(s) to extend) will be made with the goal of obtaining the optimal patent term and scope of protection for Licensed Products. If a Party wishes to file for a patent term extension based
on Patent Rights owned by the other Party, it will so notify the other Party, and the Parties will meet to discuss and determine whether and how to proceed with such patent term extension. 

5.3. Joint Research Agreement. This Agreement shall be understood to be a joint research agreement under 35 U.S.C.
§ 103(c)(3) entered into for the purpose of researching and identifying Agreement PDCs. 
  

	6.	CONFIDENTIALITY 

 6.1. Confidentiality. Except to the extent expressly authorized
by this Agreement, the Parties agree that, during the Term and for five (5) years thereafter, each Party, in its capacity as the Receiving Party shall: (a) keep the Disclosing Party’s Confidential Information confidential;
(b) not disclose, or permit the disclosure of, the Disclosing Party’s Confidential Information; and (c) not use, or permit to be used, the Disclosing Party’s Confidential Information for any purpose, in each case, except for the
performance of its obligations or exercise of its rights under this Agreement, provided, however, that the foregoing obligations shall not apply, or shall cease to apply, to the extent that such Confidential Information (i) was already known by
the Receiving Party or its Affiliates (other than under an obligation of confidentiality to the Disclosing Party) at the time of disclosure by the Disclosing Party; (ii) was generally available to the public or otherwise part of the public
domain at the time of its disclosure to the Receiving Party; (iii) became generally available to the public or otherwise part of the public domain after its disclosure to the Receiving Party, other than through any act or omission of the
Receiving Party or its Affiliates or any of their respective Representatives in breach of its obligations under this Agreement; (iv) was disclosed to the Receiving Party or its Affiliates, other than under an obligation of confidentiality, by a
Third Party who had no obligation to the Disclosing Party not to disclose such information to the Receiving Party; or (v) was independently discovered or developed by or on behalf of the Receiving Party without the use of any Confidential
Information of the Disclosing Party. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 35 








 6.2. Authorized Disclosure. 

6.2.1. Disclosure to Party Representatives. Notwithstanding the foregoing provisions of Section 6.1 hereof, the Receiving
Party may disclose Confidential Information belonging to the Disclosing Party to the Receiving Party’s Representatives who (a) have a need to know such Confidential Information in connection with the performance of the Receiving
Party’s obligations or the exercise of the Receiving Party’s rights under this Agreement and (b) have agreed in writing to non-disclosure and non-use provisions with respect to such Confidential Information that are at least as
restrictive as those set forth in this Article 6. 
 6.2.2. Disclosure to Third Parties. 

(a) Notwithstanding the foregoing provisions of Section 6.1 hereof, the Parties may disclose Confidential Information belonging to
the other Party: 
 (i) subject to Section 5.2 hereof, to the extent reasonably necessary, in connection with filing or
prosecuting Patent Rights as permitted by this Agreement; 
 (ii) to the extent reasonably necessary, in connection with prosecuting or
defending litigation as permitted by this Agreement; 
 (iii) (A) regarding the existence of this Agreement, this Agreement itself or the
material and financial terms of this Agreement, to its accountants, lawyers, and other advisers, and to actual or potential investors, lenders, licensors, licensees, acquirers, investment bankers, or agents of the foregoing in connection with a
financing, licensing transaction, merger, or acquisition, and (B) to any other third parties in connection with the events in (A) with the consent of the disclosing Party, such consent not to be unreasonably withheld, in each case
(A)-(B) under confidentiality obligations no less restrictive than those set forth in this Agreement; 
 (iv) subject to
Section 6.3.2 hereof, in connection with or included in scientific presentations and publications relating to Licensed Products, including abstracts, posters, journal articles and the like, and posting results of and other information
about clinical trials to clinicaltrials.gov or PhRMA websites; and 
 (v) to the extent necessary in order to enforce its rights under this
Agreement. 
 (b) Subject to the restrictions in Section 5.2.5 hereof, data generated by a Party using that Party’s own
Agreement PDC(s) shall not be considered Confidential Information of the other Party, and, therefore, not subject to this Article 6. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 36 








 6.2.3. SEC Filings and Other Disclosures. Notwithstanding any provision of this Agreement
to the contrary, either Party may disclose the existence or terms of this Agreement to the extent required, in the reasonable opinion of such Party’s legal counsel, to comply with Applicable Law. Notwithstanding the foregoing, before disclosing
this Agreement or any of the terms hereof pursuant to this Section 6.2.3, the Parties will consult with one another on the terms of this Agreement to be redacted in making any such disclosure. Further, if a Party discloses this Agreement
or any of the terms hereof in accordance with this Section 6.2.3, such Party shall, at its own expense, use Commercially Reasonable Efforts to seek such confidential treatment of confidential portions of this Agreement and such other
terms, as may be reasonably requested by the other Party. 
 6.3. Public Announcements; Publications. 

6.3.1. Announcements. Except as may be expressly permitted under Section 6.2.3, neither Party will make any public
announcement regarding the existence or terms of this Agreement without the prior written approval of the other Party. For the sake of clarity, nothing in this Agreement shall prevent either Party from making any public disclosure relating to this
Agreement if the contents of such public disclosure have previously been made public other than through a breach of this Agreement by the issuing Party or its Affiliates. The Parties agree that they will issue a joint press release, substantially in
the form attached as Exhibit B attached hereto, regarding the signing of this Agreement following the Effective Date. The Parties agree that each Party may issue future announcements concerning the other Party’s achievement of any
significant milestones, including the selection of a clinical candidate, under this Agreement, provided that the content of any such announcement has been mutually agreed upon by the Parties but a Party will not unreasonably withhold its agreement
to such an announcement. 
 6.3.2. Publications. The Parties acknowledge that scientific publications and presentations must be
strictly monitored to prevent any adverse effect from premature publication or dissemination of results of the activities hereunder. Each Party (in such capacity the “Publishing Party”) agrees that, except as required by Applicable
Laws, it shall not publish or present, or permit to be published or presented, any results of the Research Program to the extent such results refer to, derive from or otherwise relate to (a) in cases where CytomX is


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 37 








 
the Publishing Party, the ImmunoGen Technology, (b) in cases where ImmunoGen is the Publishing Party, the CytomX Technology, and (c) in cases where either Party is the Publishing Party,
the Joint Program Technology, the Agreement PDCs or the ImmunoGen Probodies (the “Covered Results”), without the prior review by and approval of the other Party (in such capacity, the “Non-Disclosing Party”), which
approval shall not be unreasonably withheld; provided that (i) it shall not be deemed unreasonable for CytomX to withhold its consent to any request by ImmunoGen to publish or disseminate Covered Results relating to CytomX Agreement PDCs prior
to the publication or dissemination of such Covered Results by CytomX, and (ii) it shall not be deemed unreasonable for ImmunoGen to withhold its consent to any request by CytomX to publish or disseminate Covered Results relating to ImmunoGen
Probodies and ImmunoGen Agreement PDCs prior to the publication or dissemination of such Covered Results by ImmunoGen. The Publishing Party shall submit to the Non-Disclosing Party for review and approval any proposed academic, scientific and
medical publication or public presentation which contains Covered Results or otherwise contains the Non-Disclosing Party’s Confidential Information. In both instances, such review and approval will be conducted for the purposes of preserving
the value of the CytomX Technology and ImmunoGen Technology and determining whether any portion of the proposed publication or presentation containing the Non-Disclosing Party’s Confidential Information should be modified or deleted. Written
copies of such proposed publication or presentation required to be submitted hereunder shall be submitted to the Non-Disclosing Party no later than sixty (60) days before submission for publication or presentation (the “Review
Period”). The Non-Disclosing Party shall provide its comments with respect to such publications and presentations within thirty (30) days after its receipt of such written copy, and the Publishing Party shall delete any Confidential
Information of the Non-Disclosing Party upon request. The Review Period may be extended for an additional sixty (60) days in the event the Non-Disclosing Party can, within thirty (30) days of receipt of the written copy, demonstrate
reasonable need for such extension, including for the preparation and filing of patent applications. The Parties will each comply with standard academic practice regarding authorship of scientific publications and recognition of contribution of
other parties in any publication governed by this Section 6.3.2. 
 6.3.3. Integration. As to the subject matter of this
Agreement, this Article 6 supersedes any confidential disclosure agreements between the Parties, including, without limitation, the Confidentiality Agreement. Any confidential information of a Party disclosed under the Confidentiality
Agreement relating to the subject matter of this Agreement shall be treated as Confidential Information of such Party hereunder, subject to the terms of this Article 6. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 38 









	7.	REPRESENTATIONS AND WARRANTIES. 

 7.1. Mutual Representations and Warranties. Each
of CytomX and ImmunoGen hereby represents and warrants to the other that: 
 7.1.1. it is duly organized, validly existing and in good
standing under the laws of the jurisdiction of its organization; 
 7.1.2. the execution, delivery and performance of this Agreement by such
Party has been duly authorized by all requisite action under the provisions of its charter, bylaws and other organizational documents, and does not require any action or approval by any of its shareholders or other holders of its voting securities
or voting interests; 
 7.1.3. it has the power and authority to execute and deliver this Agreement and to perform its obligations hereunder;

 7.1.4. this Agreement has been duly executed and is a legal, valid and Binding Obligation on it, enforceable against it in accordance with
its terms; and 
 7.1.5. the execution, delivery and performance by such Party of this Agreement and its compliance with the terms and
provisions hereof does not and will not conflict with or result in a breach of or default under any Binding Obligation existing as of the Effective Date. 

7.2. Representations and Warranties of CytomX. CytomX hereby represents and warrants to ImmunoGen that as of the Effective Date: 

7.2.1. to its Knowledge: (a) the issued and unexpired patents within the CytomX Licensed Intellectual Property are valid and enforceable
patents and (b) CytomX has received no written notice from a Third Party challenging or threatening to challenge the extent, validity or enforceability of any CytomX Patent Rights within the CytomX Licensed Intellectual Property; 

7.2.2. to its Knowledge, CytomX has received no written notice from a Third Party claiming that the use, practice or application by CytomX or
ImmunoGen of any CytomX Licensed Intellectual Property pursuant to the license granted hereunder will infringe any valid claim of an issued and unexpired patent of any such Third Party (excluding, for clarity, any potential infringement that might
arise solely as a result of the combination of any CytomX Licensed Intellectual Property with any other technology or intellectual property); and 

7.2.3. there is no (a) claim, demand, suit, proceeding, arbitration, inquiry, investigation or other legal action of any nature, civil,
criminal, regulatory or otherwise, pending or, to the Knowledge of CytomX, threatened against CytomX or any of its Affiliates or (b) judgment or settlement against or owed by CytomX 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 39 








 
or any of its Affiliates, in each case in connection with the CytomX Licensed Intellectual Property or relating to the transactions contemplated by this Agreement. 

For purposes of this Section 7.2, “Knowledge” means the actual knowledge (without having conducted, or having any
duty to conduct, any specific inquiry) of its Chief Executive Officer, President, any Vice President or other officer who is in charge of a principal business unit or function or who performs a policy-making function, and its Senior Director, Head
of Intellectual Property (or person with similar responsibilities). 
 7.3. Representations and Warranties of ImmunoGen. ImmunoGen
hereby represents and warrants to CytomX that as of the Effective Date: 
 7.3.1. to its Knowledge: (a) the issued and unexpired patents
within the ImmunoGen Licensed Intellectual Property are valid and enforceable patents and (b) ImmunoGen has received no written notice from a Third Party challenging or threatening to challenge the extent, validity or enforceability of any
ImmunoGen Patent Rights within the ImmunoGen Licensed Intellectual Property; 
 7.3.2. to its Knowledge, ImmunoGen has received no written
notice from a Third Party claiming that the use, practice or application by CytomX or ImmunoGen of any ImmunoGen Licensed Intellectual Property pursuant to the license granted hereunder will infringe any valid claim of an issued and unexpired patent
of any Third Party (excluding, for clarity, any potential infringement that might arise solely as a result of the combination of any ImmunoGen Licensed Intellectual Property with any other technology or intellectual property); and 

7.3.3. there is no (a) claim, demand, suit, proceeding, arbitration, inquiry, investigation or other legal action of any nature, civil,
criminal, regulatory or otherwise, pending or, to its Knowledge, threatened against ImmunoGen or any of its Affiliates or (b) judgment or settlement against or owed by ImmunoGen or any of its Affiliates, in each case in connection with the
ImmunoGen Licensed Intellectual Property or relating to the transactions contemplated by this Agreement. 
 For purposes of this
Section 7.3, “Knowledge” means the actual knowledge (without having conducted, or having any duty to conduct, any specific inquiry) of the following ImmunoGen employees: (i) any “executive officer” (as
defined in Rule 3b-7 promulgated under the Securities Exchange Act of 1934, as amended) and (ii) chief patent counsel (or person with similar responsibilities). 

7.4. Government Approvals. Each of CytomX and ImmunoGen shall cooperate with the other Party and use Commercially Reasonable Efforts to
make all registrations, filings 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 40 








 
and applications, to give all notices and to obtain as soon as practicable all governmental or other consents, transfers, approvals, orders, qualifications authorizations, permits and waivers, if
any, and to do all other things necessary or desirable for the consummation of the transactions as contemplated hereby. 
 7.5. Further
Covenants. In addition to the covenants made elsewhere in this Agreement, each Party hereby covenants to the other Party that, from the Effective Date until expiration or termination of this Agreement, it will not (a) knowingly take any
action that conflicts with the rights under the Licensed Intellectual Property granted to the other Party under this Agreement or (b) knowingly fail to take any action that is reasonably necessary to avoid a conflict with the rights under the
Licensed Intellectual Property granted to the other Party under this Agreement. 
 7.6. Representation by Legal Counsel. Each Party
hereto represents that it has been represented by legal counsel in connection with this Agreement and acknowledges that it has participated in the drafting hereof. In interpreting and applying the terms and provisions of this Agreement, the Parties
agree that no presumption shall exist or be implied against the Party which drafted such terms and provisions. 
 7.7. Warranty
Disclaimers. 
 7.7.1. Except as expressly set forth in Section 7.2 or 7.3 hereof, nothing in this Agreement is or
shall be construed as a warranty or representation by either Party (a) as to the validity or scope of any patent application or patent within such Party’s Patent Rights or (b) that anything made, used, sold or otherwise disposed of
under any license granted under this Agreement is or will be free from infringement of patents, copyrights and other rights of Third Parties. 

7.7.2. EXCEPT AS OTHERWISE EXPRESSLY PROVIDED IN THIS AGREEMENT, NEITHER PARTY MAKES ANY REPRESENTATION OR EXTENDS ANY WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, WITH RESPECT TO ANY TECHNOLOGY, GOODS, SERVICES, RIGHTS OR OTHER SUBJECT MATTER OF THIS AGREEMENT, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. 

 

	8.	TERM AND TERMINATION. 

 8.1. Term. The term of this Agreement (the
“Term”) shall commence on the Effective Date and shall extend until the fourth (4th) anniversary of the Effective Date, unless this Agreement is terminated earlier in
accordance with this Article 8. Notwithstanding the foregoing, this Agreement shall terminate as to each Research Program Target upon the exercise of the Option with respect to such Research Program Target. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 41 








 8.2. Termination by Either Party for Cause. Either Party may terminate this Agreement in
its entirety at any time during the Term by giving written notice to the other Party if the other Party commits a material breach of its obligations under this Agreement (a “Material Breach”), such notice to describe such Material
Breach in reasonable detail, and such Material Breach remains uncured for ninety (90) days, measured from the date written notice of such breach is given to the breaching Party; provided, however, that if the nature of the asserted breach is
such that more than ninety (90) days are reasonably required to cure, then the cure period shall be extended for a period not to exceed an additional sixty (60) days so long as the Party seeking to cure the asserted breach is diligently
pursuing such cure to completion. Notwithstanding the foregoing, a Party shall have the right to terminate this Agreement pursuant to this Section 8.2 only if such Material Breach fundamentally frustrates the objectives of or
transactions contemplated by this Agreement taken as a whole or a Work Plan relating to the non-breaching Party’s Research Program Target(s). 

8.3. Termination on Insolvency. This Agreement may be terminated upon written notice by either Party at any time in the event of an
Insolvency Event of the other Party. 
 8.4. Effects of Expiration or Termination. 

8.4.1. Effect of Termination by ImmunoGen. If ImmunoGen terminates this Agreement pursuant to Section 8.2 or
Section 8.3 hereof, then: 
 (a) the license granted by ImmunoGen to CytomX under Section 3.2.1 hereof and the
CytomX Option shall immediately terminate; 
 (b) without limiting ImmunoGen’s rights set forth in clause (c) below, CytomX
and ImmunoGen and their respective Affiliates shall immediately cease any and all work under any then-outstanding Work Plan; 
 (c) the
license and Options granted to ImmunoGen by CytomX under Section 3.1.1 hereof with respect to the ImmunoGen Research Program Targets shall continue on the terms set forth herein, and such license shall be expanded to permit ImmunoGen and
its Affiliates to perform any and all activities in connection with the Research Program with respect to the ImmunoGen Program Targets that would otherwise have been performed by CytomX; 

(d) each Party shall promptly destroy all CytomX Agreement PDCs; and 

(e) CytomX shall promptly return or destroy all of ImmunoGen’s Confidential Information and Proprietary Material, provided that CytomX
may retain, subject to Article 6 hereof, (i) one (1) copy of ImmunoGen’s Confidential Information in its archives solely for the purpose of establishing the contents thereof and ensuring compliance with its obligations
hereunder, (ii) any Confidential Information of ImmunoGen contained in its laboratory notebooks or databases and (iii) any Confidential Information and Proprietary Material of ImmunoGen to the extent reasonably required to exercise its
rights and perform its obligations under any outstanding License Agreement. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 42 








 The foregoing notwithstanding, and subject to Article 6 hereof, ImmunoGen may retain
and use CytomX’s Confidential Information and Proprietary Material in connection with the exercise of its rights set forth in clause (c) above and to the extent reasonably required to exercise its rights and perform its obligations
under any outstanding License Agreement. 
 8.4.2. Effect of Termination by CytomX. If CytomX terminates this Agreement pursuant to
Section 8.2 or Section 8.3 hereof, then 
 (a) the license granted by CytomX to ImmunoGen under
Section 3.1.1 hereof and the ImmunoGen Options shall immediately terminate; 
 (b) without limiting CytomX’s rights under
clause (c) below, CytomX and ImmunoGen and their respective Affiliates shall immediately cease any and all work under any then-outstanding Work Plan(s); 

(c) the license and Option granted to CytomX by ImmunoGen under Section 3.2.1 hereof with respect to the CytomX Research Program
Target shall continue on the terms set forth herein, and such license shall be expanded to permit CytomX and its Affiliates to perform any and all activities in connection with the Research Program with respect to the CytomX Research Target that
would otherwise have been performed by ImmunoGen; 
 (d) each Party shall promptly destroy all ImmunoGen Agreement PDCs; and 

(e) ImmunoGen shall promptly return or destroy all of CytomX’s Confidential Information and Proprietary Material, provided that ImmunoGen
may retain, subject to Article 6 hereof, (i) one (1) copy of CytomX’s Confidential Information in its archives solely for the purpose of establishing the contents thereof and ensuring compliance with its obligations
hereunder, (ii) any Confidential Information of CytomX contained in its laboratory notebooks or databases and (iii) any 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 43 








 
Confidential Information and Proprietary Material of CytomX to the extent reasonably required to exercise its rights and perform its obligations under any outstanding License Agreement. 

The foregoing notwithstanding, and subject to Article 6 hereof, CytomX may retain and use ImmunoGen’s Confidential Information
and Proprietary Material in connection with the exercise of its rights set forth in clause (c) above and to the extent reasonably required to exercise of its rights and perform its obligations under any outstanding License Agreement.

 8.4.3. Satisfaction of Obligations During Notice Period. During the period from providing a notice of termination through
the termination of the Agreement, the Parties shall continue to perform their obligations under this Agreement. 
 8.4.4. Pending Dispute
Resolution. If a Party gives notice of termination and the other Party disputes whether such notice was proper, then the issue of whether this Agreement has been terminated shall be resolved in accordance with Section 10.9 and this
Agreement shall remain in effect pending the resolution of such dispute. If as a result of such dispute resolution process it is determined that the notice of termination was proper, then such termination shall be effective immediately. If as a
result of such dispute resolution process it is determined that the notice of termination was improper, then no termination shall have occurred and this Agreement shall remain in effect. Anything contained in this Agreement to the contrary
notwithstanding, if the asserted breach is cured or shown to be non-existent within the applicable cure period, the first notice of breach hereunder shall be deemed automatically withdrawn and of no effect. 

8.5. Effect of Expiration of this Agreement. If this Agreement expires in accordance with its terms (other than by reason of termination
under Section 8.2 or 8.3 hereof), then: 
 8.5.1. the licenses granted by each Party to the other Party under
Section 3.1.1 and Section 3.2.1 hereof and all Options shall immediately terminate; 
 8.5.2. CytomX and ImmunoGen
and their respective Affiliates shall immediately cease any and all work under any then-outstanding Work Plans; 
 8.5.3. each Party shall
promptly destroy all ImmunoGen Probodies and Agreement PDCs except those, if any, Targeting a Licensed Target: 
 8.5.4. each Party shall
promptly return or destroy all of the Confidential Information and Proprietary Material of the other Party, provided that each Party may retain, subject to Article 6 hereof, (a) one (1) copy of the other Party’s
Confidential Information in its archives solely for the purpose of establishing the contents thereof and ensuring compliance with its obligations hereunder, (b) any 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 44 








 
Confidential Information of the other Party contained in its laboratory notebooks or databases and (c) any Confidential Information and Proprietary Material of the other Party to the extent
reasonably required to exercise its rights and perform its obligations under any outstanding License Agreement. 
 8.6. Remedies.
Except in the case of either Party’s breach of Section 2.10.3 or Article 6 hereof, the rights of the non-breaching Party set forth in Section 8.4 hereof shall be the exclusive legal remedy to a Party arising from a Material
Breach; provided, however, that (a) in addition to the foregoing legal remedy, the Parties may seek any and all equitable remedies, including, without limitation, declarative and injunctive relief and specific performance in accordance with
applicable law, and (b) nothing in this Section shall limit the Parties’ respective rights and obligations with respect to (i) Unauthorized Use of the other Party’s Confidential Information or Proprietary Materials,
(ii) unauthorized disclosure of the other Party’s Confidential Information or (iii) indemnification as set forth in Article 9 hereof. 

8.7. Survival of Certain Obligations. Expiration or termination of this Agreement shall not relieve the Parties of any obligation that
accrued before such expiration or termination. The following provisions shall survive expiration or termination of this Agreement: Sections 2.6, 2.10, 3.1.5 and 3.2.5, Articles 4, 5 and 6,
Sections 7.7, 8.1, 8.4, 8.5, 8.6 and 8.7, and Articles 9 and 10. For avoidance of doubt, any other Section that explicitly states it survives expiration or termination of this
Agreement shall so survive. 
  

	9.	LIMITATION ON LIABILITY, INDEMNIFICATION AND INSURANCE. 

 9.1. No Consequential
Damages. Except with respect to liability arising from a breach of Article 6 hereof, in no event will either Party, its Affiliates or any of its or its Affiliates’ respective Representatives be liable under this Agreement for any
special, indirect, incidental, consequential or punitive or exemplary damages, whether in contract, warranty, tort, negligence, strict liability or otherwise, (a) including loss of profits or revenue suffered by either Party or any of its
respective Affiliates or Representatives or (b) cost of procurement of substitute goods, technology or services, even if either Party is informed in advance of the possibility of such damages and even if the remedies provided for in this
Agreement fail of their essential purpose. For purposes of clarity, a Party’s monetary liability under a Third Party Claim for such Third Party’s special, indirect, incidental or consequential damages or for any punitive or exemplary
damages payable in connection with such Third Party Claim, shall be deemed to be the direct damages of such Party for purposes of this Article 9. 

9.2. Indemnification by ImmunoGen. ImmunoGen will indemnify, defend and hold harmless CytomX, its Affiliates and each of its and their
respective employees, officers, directors and agents (each, a “CytomX Indemnified Party”) from and against any and all liability, loss, damage, expense (including reasonable attorneys’ fees and expenses)


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 45 








 
and cost (collectively, a “Liability”) as a direct result of any Third Party claims, suits, actions, demands or judgments, including, without limitation, personal injury and
product liability matters (collectively, “Third Party Claims”) arising out of: 
 (a) the conduct of any Work
Plan by ImmunoGen or any of its Affiliates; or 
 (b) a Material Breach of this Agreement by ImmunoGen; 

except, in each case, to the extent any such Third Party Claim or Liability results from a Material Breach of this Agreement by CytomX or the
negligence, recklessness or intentional acts of CytomX or any CytomX Indemnified Party; provided that with respect to any Third Party Claim for which CytomX also has an obligation to indemnify any ImmunoGen Indemnified Party pursuant to
Section 9.3 hereof, ImmunoGen shall indemnify each CytomX Indemnified Party for its Liability to the extent of ImmunoGen’s responsibility, relative to CytomX (or to Persons for whom CytomX is legally responsible), for the facts underlying
the Third Party Claim. 
 9.3. Indemnification by CytomX. CytomX will indemnify, defend and hold harmless ImmunoGen, its Affiliates,
contractors, distributors and each of its and their respective employees, officers, directors and agents (each, a “ImmunoGen Indemnified Party”) from and against any and all Liabilities as a direct result of any Third Party Claims
arising out of: 
 (a) the conduct of any Work Plan by CytomX or any of its Affiliates; or 

(b) a Material Breach of this Agreement by CytomX; 

except to the extent any such Third Party Claim or Liability results from a Material Breach of this Agreement by ImmunoGen or the negligence,
recklessness or intentional acts of ImmunoGen or any ImmunoGen Indemnified Party; provided that with respect to any Third Party Claim for which ImmunoGen also has an obligation to indemnify any CytomX Indemnified Party pursuant to Section 9.2
hereof, CytomX shall indemnify each ImmunoGen Indemnified Party for its Liability to the extent of CytomX’s responsibility, relative to ImmunoGen (or to Persons for whom ImmunoGen is legally responsible), for the facts underlying the Third
Party Claim. 
 9.4. Procedure. 

9.4.1. Notice. Each Party will notify the other Party in writing in the event it becomes aware of a claim for which indemnification may
be sought hereunder. In the event that any Third Party asserts a claim or other proceeding (including any governmental investigation) with respect to any matter for which a Party (the “Indemnified Party”) is entitled to
indemnification hereunder, then the Indemnified Party shall promptly notify the Party obligated to indemnify the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 46 








 
Indemnified Party (the “Indemnifying Party”) thereof; provided, however, that no delay on the part of the Indemnified Party in notifying the Indemnifying Party shall relieve the
Indemnifying Party from any obligation hereunder unless (and then only to the extent that) the Indemnifying Party is prejudiced thereby. 

9.4.2. Control. The Indemnifying Party shall have the right, at its sole cost and expense, exercisable by notice to the Indemnified
Party within ten (10) Business Days after receipt of notice from the Indemnified Party of the commencement of or assertion of any Third Party Claim, to assume direction and control of the defense, litigation, settlement, appeal or other
disposition of the Third Party Claim (including the right to settle the claim solely for monetary consideration) with counsel selected by the Indemnifying Party and reasonably acceptable to the Indemnified Party. The Indemnified Party shall
cooperate, and shall cause its Affiliates and agents to cooperate upon request of the Indemnifying Party, in the defense or prosecution of the Third Party Claim, including by furnishing such records, information and testimony and attending such
conferences, discovery proceedings, hearings, trials or appeals as may reasonably be requested by the Indemnifying Party. The Indemnified Party shall have the right to join in (including the right to conduct discovery, interview and examine
witnesses and participate in all settlement conferences), but not control, at its own expense, the defense of any Third Party Claim that the other Party is defending as provided in this Agreement. 

9.4.3. Settlement. Neither the Indemnifying Party nor the Indemnified Party shall enter into any compromise or settlement of a Third
Party Claim for which the right to indemnification hereunder has been asserted without the Indemnified Party’s prior written consent, which consent shall not be unreasonably withheld, conditioned or delayed; provided that the Indemnifying Party
may, without the Indemnified Party’s prior written consent, agree or consent to any settlement or other resolution of such Third Party Claim which requires solely money damages paid by the Indemnifying Party, and which includes as an
unconditional term thereof the giving by such claimant or plaintiff to the Indemnified Party of a release from all liability in respect of such Third Party Claim. Each of the Indemnifying Party and the Indemnified Party shall not make any admission
of liability in respect of any Third Party Claim without the prior written consent of the other Party, and the Indemnified Party shall use reasonable efforts to mitigate Liabilities arising from such Third Party Claim. 

9.5. Insurance. Each Party shall obtain and maintain, during the Term, commercial general liability insurance, including products
liability insurance, with reputable and financially secure insurance carriers (or pursuant to a program of self-insurance reasonably satisfactory to the other Party) to cover its indemnification obligations under Section 9.2 or
Section 9.3 hereof with respect to bodily injury (including death) and 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 47 








 
damage to property, as applicable, in each case with limits of not less than $3,000,000 per occurrence and in the aggregate. Insurance (other than permitted self-insurance) shall be procured with
carriers having an A.M. Best Rating of A-VII or better. Any indemnification payment hereunder shall be made net of any insurance proceeds which the Indemnified Party is entitled to recover; provided, however, that if, following the payment to
the Indemnified Party of any amount under this Article 9, such Indemnified Party becomes entitled to recover any insurance proceeds in respect of the claim for which such indemnification payment was made, the Indemnified Party shall
promptly pay an amount equal to the amount of such proceeds (but not exceeding the amount of such indemnification payment) to the Indemnifying Party. 
  

	10.	MISCELLANEOUS. 

 10.1. Assignment. Neither Party may assign this Agreement without
the prior written consent of the other Party, which consent will not be unreasonably withheld, conditioned or delayed; provided, however, that such consent shall not be required in connection with any assignment of this Agreement to an Affiliate of
the assigned Party, or to a Third Party in connection with the transfer or sale of the business to which this Agreement relates, or to any successor Person resulting from any merger or consolidation of such Party with or into such Person, provided
that the assignee shall have agreed in writing to assume all of the assignor’s obligations hereunder, and provided, further, that the other Party shall be notified promptly after such assignment has been effected. This Agreement shall be
binding upon the successors and permitted assigns of the Parties and the name of a Party appearing herein shall be deemed to include the names of such Party’s successors and permitted assigns to the extent necessary to carry out the intent of
this Agreement. Any purported assignment not in accordance with this Section 10.1 shall be null and void. 
 10.2. Further
Actions. Each Party agrees to execute, acknowledge and deliver such further instruments, and to do all such other acts, as may be necessary or appropriate in order to carry out the purposes and intent of the Agreement. 

10.3. Force Majeure. Each Party shall be excused from the performance of its obligations under this Agreement to the extent that such
performance is prevented by force majeure (defined below) and the nonperforming Party promptly provides notice of the prevention to the other Party. Such excuse shall be continued so long as the condition constituting force
majeure continues and the nonperforming Party takes Commercially Reasonable Efforts to resume performance. For purposes of this Agreement, “force majeure” shall include conditions beyond the control of the Parties, including an
act of God, voluntary or involuntary compliance with any Applicable Law or order of any government, war, act of terror, civil commotion, labor strike or lock-out, epidemic, failure or default of public utilities or common carriers, or destruction of
production facilities or materials by fire, earthquake, storm or like catastrophe. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 48 








 10.4. Notices. Any notice or notification required or permitted to be provided pursuant to
the terms and conditions of this Agreement (including any notice of force majeure, breach, termination, change of address, etc.) shall be in writing and shall be deemed given upon receipt if delivered personally or by facsimile transmission
(receipt verified), five (5) Business Days after deposited in the mail if mailed by certified mail (return receipt requested) postage prepaid, or on the next Business Day if sent by overnight delivery using a nationally recognized express
courier service and specifying next Business Day delivery (receipt verified), to the Parties at the following addresses or facsimile numbers (or at such other address or facsimile number for a Party as shall be specified by like notice, provided,
however, that notices of a change of address shall be effective only upon receipt thereof): 
 All correspondence to ImmunoGen shall be
addressed as follows: 
 ImmunoGen, Inc. 

830 Winter Street 
 Waltham, MA
02451 
 Attn: Vice President, Business Development 

Fax: [***] 
 All correspondence
to CytomX shall be addressed as follows: 
 CytomX Therapeutics, Inc. 

343 Oyster Point Blvd., Suite 100 

South San Francisco, CA 94080-7014 

Attn: CEO 
 Fax:
(650) 351-0353 
 To help expedite the other Party’s awareness and response, copies of notices may be provided to the other Party
by email but must be supplemented by one of the following methods: (a) personal delivery, (b) first class certified mail with return receipt requested, or (c) next-day delivery by major international courier, with confirmation of
delivery. Electronic copies may be sent via email to [***] at CytomX and to [***] at ImmunoGen so long as such individuals remain employed by CytomX or ImmunoGen, respectively. 

10.5. Amendment. No amendment, modification or supplement of any provision of this Agreement shall be valid or effective unless made in
writing and signed by a duly authorized officer of the Party to be bound. 
 10.6. Waiver. No provision of this Agreement shall be
waived by any act, omission or knowledge of a Party or its agents or employees except by an instrument in writing expressly waiving such provision and signed by a duly authorized officer of the waiving


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 49 








 
Party. The waiver by either of the Parties of any breach of any provision hereof by the other Party shall not be construed to be a waiver of any succeeding breach of such provision or a waiver of
the provision itself. 
 10.7. Severability. If any clause or portion thereof in this Agreement is for any reason held to be invalid,
illegal or unenforceable, the same shall not affect any other portion of this Agreement, as it is the intent of the Parties that this Agreement shall be construed in such fashion as to maintain its existence, validity and enforceability to the
greatest extent possible. In any such event, this Agreement shall be construed as if such clause or portion thereof had never been contained in this Agreement, and there shall be deemed substituted therefor such provision as will most nearly carry
out the intent of the Parties as expressed in this Agreement to the fullest extent permitted by Applicable Law. 
 10.8. Descriptive
Headings. The descriptive headings of this Agreement are for convenience only and shall be of no force or effect in construing or interpreting any of the provisions of this Agreement. 

10.9. Dispute Resolution. The Parties recognize that a bona fide dispute as to certain matters may arise from time to time
during the Term relating to the conduct of the Research Program, Work Plan Activities, either Party’s rights or obligations hereunder or otherwise relating to the validity, enforceability or performance of this Agreement, including disputes
relating to alleged breach or termination of this Agreement but excluding any disputes relating to Article 6 hereof or disputes relating to the determination of the validity, scope, infringement, enforceability, inventorship or ownership
of the Parties’ respective Patent Rights (hereinafter, a “Dispute”). In the event of the occurrence of any Dispute, the Parties shall follow the following procedures in an attempt to resolve the dispute or disagreement: 

10.9.1. The Party claiming that such a Dispute exists shall give notice in writing (a “Notice of Dispute”) to the other Party
of the nature of the Dispute. 
 10.9.2. Within fourteen (14) days of receipt of a Notice of Dispute, the ImmunoGen Alliance Manager and
the CytomX Alliance Manager shall meet in person or by teleconference and exchange written summaries reflecting, in reasonable detail, the nature and extent of the Dispute, and at this meeting they shall use their reasonable endeavors to resolve the
Dispute. 
 10.9.3. If the Alliance Managers are unable to resolve the Dispute during the meeting described in Section 10.9.2
hereof or if for any reason such meeting does not take place within the period specified in Section 10.9.2 hereof, then the Dispute will be referred to the JRC which shall meet no later than forty-five (45) days following the
initial receipt of the Notice of Dispute and use reasonable endeavors to resolve the Dispute. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 50 








 10.9.4. If the JRC is unable to resolve the Dispute during the meeting described in
Section 10.9.3 hereof or if for any reason such meeting does not take place within the period specified in Section 10.9.3 hereof, then the Chief Executive Officer of ImmunoGen and the Chief Executive Officer of CytomX shall
meet at a mutually agreed-upon time and location for the purpose of resolving such Dispute. 
 10.9.5. If, within ninety (90) days of
initial receipt of the Notice of Dispute, the Dispute has not been resolved, or if, for any reason, the meeting described in Section 10.9.4 hereof has not been held within ninety (90) days of initial receipt of the Notice of Dispute, then
the Parties agree that such Dispute shall be finally resolved through binding arbitration to be administered by JAMS pursuant to its Comprehensive Arbitration Rules and Procedures and in accordance with the Expedited Procedures in those Rules, as
specifically modified by the provisions of this Section 10.9.5. 
 (a) Arbitration Panel. The arbitration shall be
conducted by a panel of three (3) arbitrators. Within thirty (30) days after the initiation of the arbitration, each Party will nominate one person to act as arbitrator, and the two arbitrators so named will then jointly appoint the third
arbitrator within thirty (30) days of their appointment, who will serve as chairman of the panel. All three (3) arbitrators must be independent Third Parties having at least ten (10) years of dispute resolution experience (which may
include judicial experience) and/or legal or business experience in the biotech or pharmaceutical industry. If either Party fails to nominate its arbitrator, or if the arbitrators selected by the Parties cannot agree on a person to be named as
chairman within such thirty (30) day period, JAMS will make the necessary appointments for such arbitrator(s) or the chairman. Once appointed by a Party, such Party shall have no ex parte communication with its appointed arbitrator.

 (b) Location and Proceedings. The place of arbitration will be in the Borough of Manhattan, City of New York, NY or such other
venue as the Parties may mutually agree. The arbitration proceedings and all communications with respect thereto shall be in English. Any written evidence originally in another language will be submitted in English translation accompanied by the
original or a true copy thereof. The arbitrators have the power to decide all matters in Dispute, including any questions of whether or not such matters are subject to arbitration hereunder. The arbitration shall be governed by the Federal
Arbitration Act, 9 U.S.C. §§1 et seq., and judgment upon the award rendered by the arbitrators may be entered in any court having competent jurisdiction thereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 51 








 (c) Limitation on Awards. The arbitrators shall have no authority to award any special,
indirect, incidental, consequential, punitive, exemplary or other similar damages. Each Party shall bear its own costs and expenses (including attorneys’ fees and expert or consulting fees) incurred in connection with the arbitration. The
Parties shall equally (50/50) share the arbitrators’ fees and other administrative costs and expenses associated with the arbitration. 

(d) Confidentiality. The existence, content and results of any arbitration proceedings pursuant to this Section 10.9.5
shall be deemed the Confidential Information of both Parties. 
 10.9.6. Notwithstanding any provision of this Agreement to the contrary,
either Party may immediately initiate litigation in any court of competent jurisdiction seeking any remedy at law or in equity, including the issuance of a preliminary, temporary or permanent injunction, to preserve or enforce its rights under this
Agreement. 
 10.10. Patent Disputes and Disputes Relating to Article 6. 

10.10.1. Inventorship. Any dispute, controversy or claim between the Parties involving the inventorship of any Program Technology that
is not resolved by mutual agreement of the Party’s respective chief patent counsels (or persons with similar responsibilities) within thirty (30) days after the date the dispute is raised by one or both of the Parties shall be submitted to
an Independent Patent Counsel for resolution. Such Independent Patent Counsel’s determination of inventorship, absent manifest error, shall be final and binding on the Parties; provided, however, that any such determination with respect to a
patent application shall not preclude either Party from disputing inventorship with respect to any patents issuing from such patent application, which disputes shall be resolved in accordance with this Section. The Parties shall equally
(50/50) share the Independent Patent Counsel fees and expenses related to his determination of inventorship. 
 10.10.2. Other Patent
Disputes. Any dispute, controversy or claim between the Parties that involves the validity, scope, infringement, enforceability or ownership of the Parties’ respective Patent Rights (a) that are pending or issued in the United States
shall be subject to actions before the United States Patent and Trademark Office and/or submitted exclusively to the federal court located in the jurisdiction where the Party whose Patent Rights are the subject to such dispute, controversy or claim
resides (provided that if such Party does not reside in the United States, venue shall be the jurisdiction where such Party’s principal U.S. Affiliate resides) and (b) that are pending or issued in any other country (or region) shall be
brought before an appropriate regulatory or administrative body or court in that country (or region), and the Parties hereby consent to jurisdiction and venue in such courts and bodies. 

10.10.3. Disputes Relating to Article 6. Any dispute, controversy or claim between the Parties that relates to the enforcement of
Article 6 hereof shall be subject to action in any court of competent jurisdiction. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 52 








 10.11. Governing Law. This Agreement, and all claims arising under or in connection
therewith, shall be governed by and interpreted in accordance with the substantive laws of the State of New York, without regard to conflict of law principles thereof. 

10.12. Entire Agreement. This Agreement, including its Exhibits and Schedules, constitutes and contains the complete, final and
exclusive understanding and agreement of the Parties and cancels and supersedes any and all prior negotiations, correspondence, understandings and agreements, whether oral or written, between the Parties respecting the subject matter hereof and
thereof, including the Confidentiality Agreement. 
 10.13. Purpose and Scope. The Parties understand and agree that this Agreement is
limited to the activities, rights and obligations as expressly set forth herein. Nothing herein contained shall be deemed to create an employment, agency, joint venture or partnership relationship between the Parties hereto or any of their agents or
employees, or any other legal arrangement that would impose liability upon one Party for the act or failure to act of the other Party. Neither Party shall have any express or implied power to enter into any contracts or commitments or to incur any
liabilities in the name of, or on behalf of, the other Party, or to bind the other Party in any respect whatsoever. 
 10.14.
Counterparts. This Agreement may be executed in two or more counterparts, each of which shall be an original and both of which shall constitute together the same document. Counterparts may be signed and delivered by facsimile or PDF file,
each of which shall be binding when received by the applicable Party. 
 10.15. No Third Party Rights or Obligations. Except as set
forth in Article 9 hereof, no provision of this Agreement shall be deemed or construed in any way to result in the creation of any rights or obligation in any Person not a Party to this Agreement. However, either Party may decide, in its
sole discretion, to use one or more of its Affiliates to perform its obligations and duties hereunder, provided that such Party shall remain liable hereunder for the performance by any such Affiliates of any such obligations. 

10.16. Interpretation. The Parties hereto acknowledge and agree that: (a) each Party and its counsel reviewed and negotiated the
terms and provisions of this Agreement and have contributed to its revision; (b) the rule of construction to the effect that any ambiguities are resolved against the drafting Party shall not be employed in the interpretation of this Agreement;
and (c) the terms and provisions of this Agreement shall 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 53 








 
be construed fairly as to each Party hereto and not in a favor of or against any Party, regardless of which Party was generally responsible for the preparation of this Agreement. In addition,
unless the context otherwise requires, wherever used in this Agreement: (i) the singular shall include the plural, the plural the singular; (ii) the use of any gender shall be applicable to all genders; (iii) the word “or”
is used in the inclusive sense (and/or); (iv) the words “include” or “including” shall be construed as incorporating, also, “but not limited to” or “without limitation” (irrespective of whether the words
are used in the applicable instance); (v) the words “hereof,” “herein,” “hereby” and derivative or similar words refer to this Agreement as a whole and not to any particular provision of this Agreement; and
(vi) all references to “will” are interchangeable with the word “shall” and shall be understood to be imperative or mandatory in nature. 

[The remainder of this page has been intentionally left blank. The signature page follows.] 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 54 








 IN WITNESS WHEREOF, duly authorized representatives of the Parties have duly executed this
Agreement to be effective as of the Effective Date. 
  

									
	IMMUNOGEN, INC.	 		 	CYTOMX THERAPEUTICS, INC.
					
	By:	 	 /s/ Peter Williams
	 		 	By:	 	 /s/ Sean McCarthy

	Name:	 	Peter Williams	 		 	Name:	 	Sean McCarthy
	Title:	 	Vice President, Business Development	 		 	Title:	 	CEO
	Date:	 	January 8, 2014	 		 	Date:	 	


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT A 

CytomX Research Program Target 

** 
 [***]
UniProtKB/Swiss Prot [***] UniProtKB/Swiss Prot [***] for purposes of this Agreement only to the extent that the Agreement Probody incorporated into the CytomX Agreement PDC [***] 

ImmunoGen Research Program Targets 

[***] UniProtKB/Swiss Prot [***] UniProtKB/Swiss Prot [***] 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT B 

Form of Joint Press Release 

[See Attached 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 



 
  

					
	 Contacts for CytomX:
  

For Investors:
 Monique Allaire

Pure Communications, Inc.
 781-631-0759

Monique@purecommunicationsinc.com
  

For Media:
 Kathryn Cook

Pure Communications, Inc.
 910-509-3976

Kathryn@purecommunicationsinc.com
	 		  	 Contacts for ImmunoGen, Inc.:
  

For Investors:
 Carol Hausner

Executive Director, Investor Relations
 and Corporate
Communications
 ImmunoGen, Inc.
 781-895-0600

info@immunogen.com
  

For Media:
 Barbara Yates

The Yates Network
 781-258-6153


 CytomX Therapeutics and ImmunoGen, Inc. Announce Strategic Collaboration 

to Develop Probody-Drug Conjugates Against Cancer Targets 

– Collaboration enables creation of PDCs using 

CytomX’s Probody Platform and ImmunoGen’s ADC technology – 

SOUTH SAN FRANCISCO, CA, and WALTHAM, MA, January 9, 2014 – CytomX Therapeutics, the ProbodyTM therapeutics company, and
ImmunoGen, Inc. (NASDAQ: IMGN), a biotechnology company that develops targeted anticancer therapies using its validated, industry-leading antibody-drug conjugate (ADC) technology, today announced a multi-year, strategic collaboration to
develop Probody-drug conjugate (PDC) therapies for the treatment of cancer. Probodies are a potentially disruptive class of antibody therapeutics that may further broaden the opportunities for ADCs by localizing therapeutic activity to the
tumor microenvironment. 
 Under the terms of the agreement, the companies will collaborate to develop PDCs against a defined number of targets. This
collaboration brings together CytomX’s proprietary antibody masking technology and tumor-selective protease substrates with ImmunoGen’s highly potent ADC cell-killing agents and engineered linkers. 

Each company retains full development control of PDC compounds resulting from its target selection and is responsible for preclinical and clinical testing,
manufacturing, and commercialization. Each company is entitled to potentially receive clinical and post-approval milestone payments from the other company, as well as royalties on the sales of any marketed products resulting from this collaboration.


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 “This strategic collaboration with ImmunoGen is designed to allow each company to build pipeline value by
capitalizing on the best of both technology platforms,” said Sean McCarthy, D.Phil., chief executive officer of CytomX. “By combining our Probody technology with ImmunoGen’s world class linker-payload capabilities we will accelerate
towards our vision of bringing safer, more effective therapies to patients.” 
 “ImmunoGen is committed to developing better therapies for the
treatment of patients with cancer,” commented John Lambert, PhD, EVP and Chief Scientific Officer. “We believe using our state-of-the-art ADC technology with CytomX’s highly promising Probody Platform will enable us to develop
therapies particularly well-suited for certain challenging cancers.” 
 CytomX’s Probodies are masked monoclonal antibodies that are
designed to remain inert in healthy tissue but be activated specifically in the disease microenvironment. Through precise targeting of the disease microenvironment, Probodies have the potential to address diseases in ways that have not been possible
to-date, enabling a new level of tissue targeting, selectivity and activation. 
 ImmunoGen’s ADC technology is used in Roche’s Kadcyla® and in multiple other ADC compounds now in clinical and preclinical testing. It includes highly potent cancer-cell killing agents developed specifically for targeted delivery to cancer cells
using monoclonal antibodies, and linkers engineered to keep the agent attached to the antibody in the blood steam and control its release and activation inside a cancer cell. 

About CytomX 
 CytomX Therapeutics, the ProbodyTM
therapeutics company, is dedicated to transforming lives with safer, more effective therapies. CytomX’s Probody Platform represents a disruptive approach to discovering and developing the next generation of antibody therapeutics and is enabling
the development of a diversified pipeline in major unmet medical needs including cancer and inflammation. CytomX is led by a seasoned and proven management team and is financed by leading life science investors including Third Rock Ventures, Canaan
Partners and the Roche Venture Fund. For more information, please visit www.cytomx.com. 
 About ImmunoGen, Inc. 

ImmunoGen, Inc. develops targeted anticancer therapeutics. The Company’s ADC technology uses a tumor-targeting engineered antibody to deliver one of
ImmunoGen’s highly potent cancer-cell killing agents specifically to tumor cells; the Company has also developed antibodies with anticancer activity of their own. The most advanced compound with ImmunoGen’s ADC technology is Roche’s
Kadcyla®, which is marketed in the US by Genentech and is also gaining approvals internationally. Additional compounds are in clinical testing by ImmunoGen and through the Company’s
partnerships with Amgen, Bayer HealthCare, Biotest and Sanofi. More information about ImmunoGen can be found at www.immunogen.com. 
 Kadcyla® is a registered trademark of Genentech, Inc., a member of the Roche Group. 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 This press release includes forward-looking statements. For these statements, ImmunoGen claims the protection
of the safe harbor for  forward-looking statements provided by the Private Securities Litigation Reform Act of 1995. It should be noted that there are risks and uncertainties related to the development of novel anticancer products, including
PDCs. A review of these risks can be found in ImmunoGen’s Annual Report on Form 10-K for the fiscal year ended June 30, 2013 and other reports filed with the Securities and Exchange Commission. ### 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT C 

Form of CytomX License Agreement 

[See Attached 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 Exhibit C 

LICENSE AGREEMENT 

BETWEEN 
 CYTOMX
THERAPEUTICS, INC. 
 AND 

IMMUNOGEN, INC. 

            , 201     

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 TABLE OF CONTENTS 

 

									
	 	  	Page	 
			
	 1.
	    	 DEFINITIONS
	  	 	1	  
			
	 2.
	    	 PRODUCT DEVELOPMENT, MANUFACTURING AND COMMERCIALIZATION
	  	 	21	  
				
		    	 2.1.
	    	 General
	  	 	21	  
				
		    	 2.2.
	    	 Development Diligence
	  	 	21	  
				
		    	 2.3.
	    	 Joint Development Committee
	  	 	23	  
				
		    	 2.4.
	    	 Alliance Managers
	  	 	24	  
				
		    	 2.5.
	    	 Updates and Reports; Product Recalls
	  	 	25	  
				
		    	 2.6.
	    	 Transfer and Use of Proprietary Materials
	  	 	26	  
				
		    	 2.7.
	    	 Services
	  	 	27	  
			
	 3.
	    	 LICENSE GRANTS
	  	 	28	  
				
		    	 3.1.
	    	 License Grants
	  	 	28	  
				
		    	 3.2.
	    	 Retained Rights and Covenants
	  	 	29	  
				
		    	 3.3.
	    	 License to CytomX TAP Platform Improvements
	  	 	29	  
				
		    	 3.4.
	    	 Section 365(n) of Bankruptcy Code
	  	 	30	  
				
		    	 3.5.
	    	 No Implied Rights
	  	 	30	  
			
	 4.
	    	 PAYMENTS
	  	 	30	  
				
		    	 4.1.
	    	 Milestone Payments
	  	 	30	  
				
		    	 4.2.
	    	 Royalties
	  	 	32	  
				
		    	 4.3.
	    	 Reports and Payments
	  	 	37	  
				
		    	 4.4.
	    	 Maintenance of Records; Audits
	  	 	39	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 i 









											
	 5.
	    	  
	 INTELLECTUAL PROPERTY
	  	 	40	  
				
		    	 	5.1.	  	    	 Inventions
	  	 	40	  
				
		    	 	5.2.	  	    	 Filing, Prosecution and Maintenance of Patent Rights
	  	 	41	  
				
		    	 	5.3.	  	    	 Joint Research Agreement
	  	 	44	  
				
		    	 	5.4.	  	    	 Enforcement of Patent Rights
	  	 	44	  
				
		    	 	5.5.	  	    	 Response to Biosimilar Applicants
	  	 	48	  
				
		    	 	5.6.	  	    	 Interference, Opposition, Revocation and Declaratory Judgment Actions
	  	 	53	  
				
		    	 	5.7.	  	    	 Infringement of Third Party Patent Rights
	  	 	54	  
			
	 6.
	    	  
	 CONFIDENTIALITY
	  	 	54	  
				
		    	 	6.1.	  	    	 Confidentiality
	  	 	54	  
				
		    	 	6.2.	  	    	 Authorized Disclosure
	  	 	54	  
				
		    	 	6.3.	  	    	 Public Announcements; Publications
	  	 	56	  
			
	 7.
	    	  
	 REPRESENTATIONS AND WARRANTIES
	  	 	58	  
				
		    	 	7.1.	  	    	 Mutual Representations and Warranties
	  	 	58	  
				
		    	 	7.2.	  	    	 Representations and Warranties of ImmunoGen
	  	 	58	  
				
		    	 	7.3.	  	    	 Government Approvals
	  	 	59	  
				
		    	 	7.4.	  	    	 Further Covenants
	  	 	59	  
				
		    	 	7.5.	  	    	 Representation by Legal Counsel
	  	 	60	  
				
		    	 	7.6.	  	    	 Warranty Disclaimers
	  	 	60	  
			
	 8.
	    	  
	 TERM AND TERMINATION
	  	 	60	  
				
		    	 	8.1.	  	    	 Term
	  	 	60	  
				
		    	 	8.2.	  	    	 Voluntary Termination by CytomX
	  	 	60	  
				
		    	 	8.3.	  	    	 Termination by Either Party for Cause
	  	 	61	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 ii 









											
		    	 	8.4.	  	    	 Termination on Insolvency
	  	 	61	  
				
		    	 	8.5.	  	    	 Termination for Material Breach of the Research Collaboration Agreement by CytomX
	  	 	61	  
				
		    	 	8.6.	  	    	 Effects of Expiration or Termination
	  	 	61	  
				
		    	 	8.7.	  	    	 Disposition of Inventories of Products
	  	 	63	  
				
		    	 	8.8.	  	    	 Remedies
	  	 	63	  
				
		    	 	8.9.	  	    	 Survival of Certain Obligations
	  	 	63	  
			
	 9.
	    	  
	 LIMITATION ON LIABILITY, INDEMNIFICATION AND INSURANCE
	  	 	64	  
				
		    	 	9.1.	  	    	 No Consequential Damages
	  	 	64	  
				
		    	 	9.2.	  	    	 Indemnification by ImmunoGen
	  	 	64	  
				
		    	 	9.3.	  	    	 Indemnification by CytomX
	  	 	65	  
				
		    	 	9.4.	  	    	 Procedure
	  	 	65	  
				
		    	 	9.5.	  	    	 Insurance
	  	 	66	  
			
	 10.
	    	  
	 MISCELLANEOUS
	  	 	67	  
				
		    	 	10.1.	  	    	 Assignment
	  	 	67	  
				
		    	 	10.2.	  	    	 Further Actions
	  	 	67	  
				
		    	 	10.3.	  	    	 Force Majeure
	  	 	67	  
				
		    	 	10.4.	  	    	 Notices
	  	 	68	  
				
		    	 	10.5.	  	    	 Amendment
	  	 	68	  
				
		    	 	10.6.	  	    	 Waiver
	  	 	68	  
				
		    	 	10.7.	  	    	 Severability
	  	 	68	  
				
		    	 	10.8.	  	    	 Descriptive Headings
	  	 	69	  
				
		    	 	10.9.	  	    	 Dispute Resolution
	  	 	69	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 iii 









											
		    	 	10.10.	  	    	 Patent Disputes and Disputes Relating to Article 6
	  	 	71	  
				
		    	 	10.11.	  	    	 Governing Law
	  	 	72	  
				
		    	 	10.12.	  	    	 Entire Agreement
	  	 	72	  
				
		    	 	10.13.	  	    	 Purpose and Scope
	  	 	72	  
				
		    	 	10.14.	  	    	 Counterparts
	  	 	72	  
				
		    	 	10.15.	  	    	 No Third Party Rights or Obligations
	  	 	72	  
				
		    	 	10.16.	  	    	 Interpretation
	  	 	72	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 iv 








 EXHIBITS 
 Exhibit
A – Licensed Target 
 Exhibit B – Royalty Rate Reduction Methodology 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 v 








 LICENSE AGREEMENT 

This Research Collaboration and License Agreement (the “Agreement”) is entered into as of
                    1 (the “Effective Date”), by and between CytomX
Therapeutics, Inc., a corporation organized and existing under the laws of Delaware and having a place of business at 343 Oyster Point Blvd., Suite 100, South San Francisco, California, 94080 United States (“CytomX”) and
ImmunoGen, Inc., a corporation organized and existing under the laws of Massachusetts and having a place of business at 830 Winter Street, Waltham, Massachusetts, 02451 (“ImmunoGen”). CytomX and ImmunoGen may each be referred
to herein individually as a “Party” and collectively as the “Parties.” 
 WHEREAS, the
Parties have entered into a Research Collaboration Agreement, pursuant to which, among other things, ImmunoGen granted to CytomX the right to obtain a license to certain Know-How and related Patent Rights owned or Controlled by ImmunoGen with
respect to certain Targets; and 
 WHEREAS, pursuant to the Research Collaboration Agreement, CytomX has exercised the CytomX
Option (as defined in the Research Collaboration Agreement), pursuant to which the Parties have agreed to enter into this Agreement setting forth the terms and conditions of an exclusive license from ImmunoGen to CytomX with respect to the Licensed
Target. 
 NOW THEREFORE, in consideration of the mutual promises and covenants set forth below and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the Parties hereby agree as follows: 
  

	1.	DEFINITIONS. 

 When used in this Agreement, the following capitalized
terms shall have the meanings set forth in this Article 1. 
 1.1. “ADC” means a compound that incorporates, is
comprised of or is otherwise derived from an Antibody conjugated to a Payload using a Linker, other than a PDC. 
 1.2.
“Affiliate” means, with respect to any Person, any other Person that controls, is controlled by or is under common control with such Person. A Person shall be regarded as in control of another entity if it owns or controls at least
fifty percent (50%) of the equity securities of the subject entity entitled to vote in the election of directors (or, in the 
  


	1 	 Insert date of receipt by ImmunoGen of Option Exercise Notice with respect to the Licensed Target.




  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 1 








 
case of an entity that is not a corporation, for the election of the corresponding managing authority), provided, however, that the term “Affiliate” shall not include subsidiaries or
other entities in which a Party or its Affiliates owns a majority of the ordinary voting power necessary to elect a majority of the board of directors or other managing authority, but is restricted from electing such majority by contract or
otherwise, until such time as such restrictions are no longer in effect. A Person shall be deemed an Affiliate only so long as it satisfies the foregoing definition. 

1.3. “Alliance Manager” is defined in Section 2.4 hereof. 

1.4. “Annual Maintenance Fees” is defined in Section 2.2.1 hereof. 

1.5. “Annual Net Sales” means, with respect to any Licensed Product in a Calendar Year during the applicable Royalty Term for
such Licensed Product, the aggregate Net Sales by a Party, its Affiliates and its Sublicensees from the sale of such Licensed Product in the Territory during such Calendar Year. 

1.6. “Antibody” means a molecule which comprises or contains: (a) one or more immunoglobulin variable domains; or
(b) fragments, variants, modifications or derivatives of such immunoglobulin variable domains irrespective of origin or source, including but not limited to antigen binding portions including Fab, Fab’, F(ab’)2, Fv, dAb and CDR
fragments, single chain antibodies (scFv), chimeric antibodies, monospecific antibodies, diabodies and polypeptides (including humanized versions thereof) that contain at least a portion of an immunoglobulin that is sufficient to confer specific
antigen binding to the polypeptide. For clarity, as used in this Agreement, the term “Antibody” shall not include Probodies or PDCs. 

1.7. “Applicable Law” means the laws, statutes, rules, regulations, guidelines, or other requirements that may be in effect
from time to time and apply to a particular activity contemplated hereby, including any such laws, statutes, rules, regulations, guidelines or other requirements of the FDA or the EMA or any applicable securities regulatory authorities or national
securities exchanges or securities listing organizations. 
 1.8. “Applicant” is defined in Section 5.5.2
hereof. 
 1.9. “Applicant Response” is defined in Section 5.5.3(b) hereof. 

1.10. “Bankruptcy Code” is defined in Section 3.4 hereof. 

1.11. “Baseline Net Sales” is defined in Section 1.94 hereof. 

1.12. “Binding Obligation” means, with respect to a Party (a) any oral or written agreement or arrangement that binds or
legally affects such Party’s operations or property, 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 2 








 
including any assignment, license agreement, loan agreement, guaranty, or financing agreement; (b) the provisions of such Party’s charter, bylaws or other organizational documents or
(c) any order, writ, injunction, decree or judgment of any court or Governmental Authority entered against such Party or by which any of such Party’s operations or property are bound. 

1.13. “Biosimilar Application” means an application submitted to the FDA under subsection (k) of the PHSA or a similar
application submitted under a similar regulatory scheme to another Regulatory Authority. 
 1.14. “BLA” means a
Biologics License Application (as that term is used in Title 21 of the United States Code of Federal Regulations) filed with the FDA seeking Regulatory Approval to market and sell any Licensed Product in the United States for a particular
indication. 
 1.15. “BPCIA” means the Biologics Price Competition and Innovation Act of 2009. 

1.16. “Business Day” means a day other than a Saturday, a Sunday or other day on which banking institutions in Boston,
Massachusetts or San Francisco, California are required to be closed or are actually closed with legal authorization. 
 1.17.
“Calendar Quarter” means the respective periods of three (3) consecutive calendar months ending on March 31, June 30, September 30 or December 31, for so long as this Agreement is in effect. 

1.18. “Calendar Year” means each successive period of twelve (12) calendar months commencing on January 1 and ending
on December 31. 
 1.19. “Challenge” means any challenge to the patentability, validity, or enforceability of any of
the Licensed Patent Rights, including without limitation: (a) filing a declaratory judgment action in which any of the Licensed Patent Rights is alleged to be invalid or unenforceable; (b) citing prior art pursuant to 35 U.S.C.
§122 or §301, filing a request for re-examination of any of the Licensed Patent Rights pursuant to 35 U.S.C. §302 or §311, filing a petition to request an inter partes review of the Licensed Patent Rights pursuant to
35 U.S.C. §311, or filing a petition to request a post-grant review of the Licensed Patent Rights pursuant to 35 U.S.C. §321; or (c) filing or commencing any re-examination, opposition, cancellation, nullity or similar
proceeding against any of the Licensed Patent Rights in any country. 
 1.20. “Challenge Jurisdiction” is defined in
Section 4.2.3(d) hereof. 
 1.21. “Challenged Patent Rights” is defined in Section 4.2.3(d) hereof.


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 3 








 1.22. “Challenge-Related Royalty Increase” is defined in Section 4.2.3
(d) hereof. 
 1.23. “Clawback Amount” is defined in Section 4.2.3(d) hereof. 

1.24. “Combination” is defined in Section 1.104 hereof. 

1.25. “Commercialization” or “Commercialize” means activities with respect to a Licensed Product relating to
commercialization in the Field in the Territory, including pre-launch and launch activities, pricing and reimbursement activities, marketing, promoting, detailing, distributing, offering for sale and selling such Licensed Product, importing and
exporting such Licensed Product for sale, conducting post-marketing human clinical trials, reporting of adverse events in patients and interacting with Regulatory Authorities regarding any of the foregoing. Commercialization shall not include any
activities related to Manufacturing or Development. When used as a verb, “Commercialize” means to engage in Commercialization and “Commercialized” has a corresponding meaning. 

1.26. “Commercially Reasonable Efforts” means, with respect to the efforts to be expended by a Party with respect to any
objective, those reasonable, good faith efforts to accomplish such objective as such Party would normally use to accomplish a similar objective under similar circumstances. With respect to any efforts relating to the Development of a Licensed
Product by CytomX, generally or with respect to any particular country in the Territory, CytomX will be deemed to have exercised Commercially Reasonable Efforts if it has exercised those efforts normally used by CytomX, in the relevant country, with
respect to a compound, product or product candidate, as applicable, owned or Controlled by CytomX, or to which CytomX has similar rights, which compound, product or product candidate is of similar market potential in such country, and is at a
similar stage in its development or product life cycle as the Licensed Product, taking into account all relevant factors in effect at the time such efforts are to be expended. It is expressly understood that, so long as this Agreement may be
terminated by CytomX for convenience pursuant to Section 8.2 hereof, ceasing the Development of a Licensed Product shall be deemed to be inconsistent with Commercially Reasonable Efforts. Further, to the extent that the performance of
CytomX’s obligations hereunder is adversely affected by ImmunoGen’s failure to perform its obligations hereunder, the impact of such performance failure will be taken into account in determining whether CytomX has used its Commercially
Reasonable Efforts to perform any such affected obligations. 
 1.27. “Confidential Information” of a Party means
(a) with respect to CytomX, the identity of the Licensed Target, and (b) with respect to each Party, all Know-How or other information, including proprietary information and materials (whether or not patentable) regarding such Party’s
technology, products, business or objectives, that is communicated in any way or form by or on behalf of such Party (in such capacity, the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 4 








 
“Disclosing Party”) to the other Party (in such capacity, the “Receiving Party”) or to any of the Receiving Party’s or its Affiliates’ employees,
consultants or subcontractors (collectively, “Representatives”), either prior to or after the Effective Date of this Agreement (including any information disclosed pursuant to the Confidentiality Agreement), and whether or not such
Know-How or other information is identified as confidential at the time of disclosure. The terms and conditions of this Agreement shall be deemed to be the Confidential Information of each Party. Confidential Information within the CytomX Program
Technology shall be deemed to be the Confidential Information of CytomX. Confidential Information within the ImmunoGen Program Technology shall be deemed to be the Confidential Information of ImmunoGen. Confidential Information within the Joint
Program Technology shall be deemed to be the Confidential Information of each Party. Certain other information is designated as Confidential Information throughout this Agreement and is included in this definition. 

1.28. “Confidentiality Agreement” means that certain Mutual Confidential Disclosure Agreement between the Parties effective as
of March 21, 2013. 
 1.29. “Conjugation Probody Platform Improvements” has the meaning ascribed to such term in the
Research Collaboration Agreement. 
 1.30. “Control” or “Controlled” means, with respect to any
(a) item of information, including Know-How, (b) intellectual property right, or (c) Proprietary Material, the possession (whether by ownership interest or license, other than pursuant to this Agreement) by a Party of the ability to
grant to the other Party access to or a license under such item, right or material, as provided herein, without violating the terms of any agreement or other arrangements with any Third Party. 

1.31. “Covered Results” is defined in Section 6.3.2 hereof. 

1.32. “Cover(s)” is defined in Section 4.2.3(b)(iii) hereof. 

1.33. “CytomX Accounting Standards” means GAAP, as generally and consistently applied throughout CytomX’s organization.
Beginning upon the First Commercial Sale of a Licensed Product and thereafter during the Term as long as CytomX has an obligation to pay royalties under Section 4.2 hereof, CytomX shall promptly notify ImmunoGen in the event it changes
the accounting principles pursuant to which its records are maintained, it being understood and agreed that only internationally recognized accounting principles may be used (e.g., GAAP, IFRS (International Financial Reporting Standards),
etc.). 
 1.34. “CytomX Indemnified Party” is defined in Section 9.2 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 5 








 1.35. “CytomX Program Technology” means any Program Technology (other than Joint
Program Technology) the inventors of which (alone or with others) are employees of, or others obligated to assign inventions to, CytomX or any of its Affiliates, Sublicensees or Permitted Third Party Service Providers. 

1.36. “CytomX Proprietary Materials” means biological materials (including any Probodies, Masks or Substrates) and other
tangible research materials Controlled by CytomX and provided by CytomX to ImmunoGen under this Agreement. 
 1.37. “CytomX
Response” is defined in Section 5.5.3(c) hereof. 
 1.38. “CytomX Standard Exchange Rate Methodology”
means, with respect to amounts invoiced in U.S. Dollars, all such amounts shall be expressed in U.S. Dollars. With respect to amounts invoiced in a currency other than U.S. Dollars, all such amounts shall be expressed both in the
currency in which the amount was invoiced and in the U.S. Dollar equivalent. The U.S. Dollar equivalent shall be calculated using CytomX’s then-current standard exchange rate methodology, which is in accordance with the CytomX
Accounting Standards applied in its external reporting for the conversion of foreign currency sales into U.S. Dollars or, in the case of Sublicensees, such similar methodology, consistently applied. 

1.39. “CytomX TAP Platform Improvements” means any TAP Platform Improvement (other than a Joint TAP Platform Improvements) the
inventors of which (alone or with others) are employees of, or others obligated to assign inventions to, CytomX or any of its Affiliates, Sublicensees or Permitted Third Party Service Providers pursuant to the Development, Manufacture, use and
Commercialization of any Licensed Product. 
 1.40. “CytomX Technology” means any Patent Right, Know-How or other
intellectual property right that is Controlled by CytomX or any Affiliate of CytomX or that comes into the Control of CytomX at any time during the Term of this Agreement and is actually used by CytomX in Developing Licensed Products under this
Agreement or is otherwise necessary for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the composition of, or any method of using or method of making or any Tools for
Developing, any Probody, Mask or Substrate. 
 1.41. “Cytotoxic Compound” means [***] Compounds and [***] Compounds. 

1.42. “Deemed Royalty Portion” is defined in Section 5.4.2(g)(iii) hereof. 

1.43. “Develop” or “Development” means, with respect to a Licensed Product, all pre-clinical, non-clinical
and clinical research and drug development activities with respect to 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 6 








 
such Licensed Product relating to research and development in connection with seeking, obtaining or maintaining any Regulatory Approval for such Licensed Product, including research, toxicology,
pharmacology and other similar efforts, test method development and stability testing, manufacturing process development, formulation development, delivery system development, quality assurance and quality control development, statistical analysis,
clinical studies (including pre- and post-approval studies), development of diagnostic assays in connection with clinical studies, and all activities directed to obtaining any Regulatory Approval, including any marketing, pricing or reimbursement
approval. When used as a verb, “Develop” means to engage in Development and “Developed” has a corresponding meaning. 

1.44. “Development Milestone” is defined in Section 4.1.1 hereof. 

1.45. “Development Milestone Payment” is defined in Section 4.1.1 hereof. 

1.46. “Diligence Obligation” is defined in Section 2.2.2 hereof. 

1.47. “Disclosing Party” is defined in Section 1.27 hereof. 

1.48. “Disclosure Letter” is defined in Section 7.2 hereof. 

1.49. “Dispute” is defined in Section 10.9 hereof. 

1.50. “Effective Date” is defined in the introduction to this Agreement. 

1.51. “EMA” means the European Medicines Agency, or any successor agency thereto. 

1.52. “Field” means all human therapeutic, prophylactic and diagnostic uses. 

1.53. “FD&C Act” means the United States Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 301 et seq.), as
amended, and the rules and regulations promulgated thereunder. 
 1.54. “FDA” means the United States Food and Drug
Administration or any successor agency thereto. 
 1.55. “First Commercial Sale” means, with respect to any Licensed Product
and any country of the world, the first sale of such Licensed Product under this Agreement by CytomX, its Affiliates or its Sublicensees to a Third Party in such country, after such Licensed Product has been granted Regulatory Marketing Approval by
the competent Regulatory Authorities in such country or, if no such Regulatory Marketing Approval or similar approval is required, the date on which such Licensed Product is first commercially launched in such country. The foregoing notwithstanding,
“First Commercial Sale” shall not include: (a) any distribution or other sale solely for so-called treatment investigational new drug sales, named patient sales, compassionate or 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 7 








 
emergency use sales or pre-approval sales, in each case provided that such Licensed Product is distributed without charge or sold at or below cost; (b) intercompany transfers to Affiliates
of CytomX; nor (c) other similar non-commercial uses, provided that in each case under this clause (c) such Licensed Product is distributed without charge or sold at or below cost. 

1.56. “GAAP” means United States generally accepted accounting principles, consistently applied. 

1.57. “Generic Equivalent” means, with respect to any Licensed Product in a given country, any
biopharmaceutical product that is sold by a Third Party that is not a Sublicensee of CytomX or its Affiliates and such Third Party product (a) contains both (i) an Antibody or Probody that specifically binds to the Licensed Target, and
(ii) the same Linker and Cytotoxic Compound as the relevant Licensed Product, or (b) (i) has been licensed as a biosimilar or interchangeable biological product by FDA pursuant to Section 351(k) of the PHSA or any subsequent or
superseding law, statute or regulation, (ii) has been licensed as a similar biological medicinal product by the European Medicines Agency pursuant to Directive 2001/83/EC, as may be amended, or any subsequent or superseding law, statute or
regulation, or (iii) has otherwise achieved analogous regulatory marketing approval in reliance on the prior approval of the Licensed Product from another applicable Regulatory Authority where in the case of each of subclauses (i),
(ii) or (iii) of clause (b) above, the Licensed Product is the reference product for purposes of determining (bio)similarity or interchangeability of the Third Party product. 

1.58. “Governmental Authority” means any court, agency, department, authority or other instrumentality of any national, state,
county, city or other political subdivision. 
 1.59. “[***] Compounds” means [***], including, without limitation, all
analogs, variants, fragments or derivatives of any of the foregoing, in each case owned or Controlled by ImmunoGen. 
 1.60.
“Immediate Patent Infringement Action” means an immediate patent infringement action pursuant to Section 351(1)(6) of the PHSA. 

1.61. [Reserved] 
 1.62.
“ImmunoGen Indemnified Party” is defined in Section 9.3 hereof. 
 1.63. [Reserved] 

1.64. “ImmunoGen Program Technology” means any Program Technology (other than Joint Program Technology) the inventors of which
are employees, agents or 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 8 








 
independent contractors of ImmunoGen or any of its Affiliates. Anything contained in this Agreement to the contrary notwithstanding, any and all ImmunoGen Program Technology that is necessary or
useful for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the composition of, or any method of using or method of making any Licensed Product, Linker or Cytotoxic Compound
comprised in a Licensed Product shall be included in the Licensed Intellectual Property. 
 1.65. “ImmunoGen Proprietary Antibody
Rights” means all Know-How (and associated Patent Rights) owned or Controlled by ImmunoGen during the Term constituting or claiming (a) the composition of matter or method of use of, or method of making, an Antibody that was generated
or in-licensed by ImmunoGen, whether or not patentable (an “ImmunoGen Proprietary Antibody”), or (b) the composition of matter or method of use of, or method of making an ADC where the Antibody is an ImmunoGen
Proprietary Antibody. For purposes of clarity, “ImmunoGen Proprietary Antibody Rights” does not include any Program Technology that relates to Probodies Targeting the Licensed Target or any Patent Rights claiming such Program Technology.

 1.66. “ImmunoGen Proprietary Materials” means any chemical (including any Cytotoxic Compounds), biological (including any
Antibodies) and other tangible research materials Controlled by ImmunoGen and provided by ImmunoGen to CytomX under this Agreement. Subject to the last sentence of this definition, any mutant, derivative, progeny or improvement of ImmunoGen
Proprietary Materials shall be considered to be ImmunoGen Proprietary Materials. Without limiting the generality of the foregoing, any [***] furnished by ImmunoGen to CytomX or any of its Affiliates, Sublicensees or Permitted Third Party Service
Providers, including, without limitation any samples, cultures or cell banks derived directly or indirectly from any [***] derivative, [***] or improvement thereof (collectively, the “[***]”), shall be deemed to be ImmunoGen Proprietary
Materials and included within the Licensed Know-How. Without prejudice to any of ImmunoGen’s intellectual property rights in and to [***] Compounds, any tangible [***] Compounds manufactured by or for CytomX or any of its Affiliates,
Sublicensees or Permitted Third Party Service Providers using the [***] as a precursor in connection with the Development, Manufacture, use and Commercialization of Licensed Products shall not be deemed to be ImmunoGen Proprietary Materials for
purposes of this Agreement. 
 1.67. “ImmunoGen Technology Transfer Materials” means ImmunoGen information (including,
without limitation, technical transfer reports) as consistently provided by ImmunoGen to its other licensees of the Licensed Intellectual Property for the purpose of performing process development, manufacturing and clinical development activities
with respect to ADCs, Cytotoxic Compounds and Linkers, as applicable, for use by CytomX for the purpose of Developing, Manufacturing and Commercializing Licensed Products, 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 9 








 
including: (a) nomenclature, structure and general properties; (b) an example of an ADC manufacturing process, including materials, steps, intermediaries and equipment; (c) an
example test panel for controls and characterization and description of methods; (d) information on reference standards and materials; (e) an example of stability data; (f) technical reports on research data for Licensed Products
developed by ImmunoGen under the Research Collaboration Agreement; and (g) a list of raw materials (Linkers and Cytotoxic Compounds) and protocols for conjugating Licensed Products. 

1.68. [Reserved] 
 1.69.
“Improvement” is defined in Section 1.141 hereof. 
 1.70. “IND” means an Investigational New
Drug Application, as defined in the FD&C Act, that is required to be filed with the FDA before beginning clinical testing of a Licensed Product in human subjects, or an equivalent foreign filing. 

1.71. “Indemnified Party” is defined in Section 9.4.1 hereof. 

1.72. “Indemnifying Party” is defined in Section 9.4.1 hereof. 

1.73. “Independent Patent Counsel” means an outside patent counsel reasonably acceptable to both Parties who (and whose firm)
is not at the time of the dispute, and was not at any time during the five (5)-year period preceding the dispute, performing legal services of any nature for either of the Parties or their respective Affiliates (or, in the case of CytomX, its
Sublicensees) and which did not, at any time, employ either of the Parties’ chief patent counsels (or persons with similar responsibilities). 

1.74. “Infringed Patent List” is defined in Section 5.5.3(e) hereof. 

1.75. “Infringement” is defined in Section 5.4.1 hereof. 

1.76. “Insolvency Event” means the occurrence of any of the following: (a) a case is commenced by or against a Party
under applicable bankruptcy, insolvency or similar laws, and is not dismissed within ninety (90) days, (b) a Party files for or is subject to the institution of bankruptcy, reorganization, liquidation, receivership or similar proceedings,
(c) a Party assigns all or a substantial portion of its assets for the benefit of creditors, (d) a receiver or custodian is appointed for a Party’s business, (e) a substantial portion of a Party’s business is subject to
attachment or similar process, or (f) anything analogous to any of the events described in the foregoing clauses (a) through (e) occurs under the laws of any applicable jurisdiction. 

1.77. “Joint Conjugation Probody Platform Improvements” means Conjugation Probody Platform Improvements the inventors of which
are jointly (a) employees, agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 10 








 1.78. “Joint Development Committee” or “JDC” is defined in
Section 2.3.1 hereof. 
 1.79. “Joint Patent Right” means any Patent Right comprised in the Joint Program
Technology. 
 1.80. [Reserved] 

1.81. “Joint Program Technology” means any Program Technology (other than Joint TAP Platform Improvements) the inventors of
which are jointly (a) employees, agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

1.82. “Joint TAP Platform Improvements” means TAP Platform Improvements the inventors of which are jointly (a) employees,
agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

1.83. “Joint Unconjugated Probody Platform Improvements” means Unconjugated Probody Platform Improvements the inventors of
which are jointly (a) employees, agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

1.84. “Know-How” means any proprietary invention, discovery, data, information, process, method, technique, material,
technology, result or other know-how, whether or not patentable. 
 1.85. “Knowledge” is defined in Section 7.2
hereof. 
 1.86. “Liability” is defined in Section 9.2 hereof. 

1.87. “License Agreement” has the meaning ascribed to such term in the Research Collaboration Agreement. 

1.88. “Licensed Intellectual Property” means any Patent Right, Know-How or other intellectual property right that is owned or
Controlled by ImmunoGen or any Affiliate of ImmunoGen or that becomes owned or Controlled by ImmunoGen or any of its Affiliates at any time during the Term (including ImmunoGen’s one-half interest in Joint Program Technology and Joint TAP
Platform Improvements) that is necessary or useful for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the composition of, or any method of using or method


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 11 








 
of making any Licensed Product, Linker or Cytotoxic Compound comprised in a Licensed Product, provided, however, that Licensed Intellectual Property shall expressly exclude any ImmunoGen
Proprietary Antibody Rights. 
 1.89. “Licensed Know-How” means any Know-How comprised in the Licensed Intellectual
Property. 
 1.90. “Licensed Patent Rights” means any Patent Rights comprised in the Licensed Intellectual Property. 

1.91. “Licensed Product” means any product that incorporates, is comprised of, or is otherwise derived from, a Target-Binding Probody conjugated to a Cytotoxic Compound using a Linker. 
 1.92. “Licensed
Target” means [***] UniProtKB/Swiss Prot [***] UniProtKB/Swiss Prot [***] but only so long as the Target-Binding Antibody [***]; otherwise, the Licensed Target is only [***]2] [the Target
set forth in Exhibit A attached hereto and incorporated herein by reference3]. 

1.93. “Linker” means any compound or composition that is useful for linking a cytotoxic or cytostatic moiety, including,
without limitation, a Cytotoxic Compound, and a cell-binding moiety, including, without limitation, an Antibody or a Probody, together to form a conjugate of the cytotoxic or cytostatic moiety with the cell-binding moiety. 

1.94. “Loss of Market Exclusivity” with respect to any Licensed Product in any country, shall be deemed to have occurred only
if: (a) one or more Generic Equivalent(s) are being marketed by a Third Party (excluding any Sublicensee) in such country; and (b) Net Sales of such Licensed Product in that country during any Calendar Quarter following introduction of the
Generic Equivalent(s) have declined by at least twenty percent (20%) in that country relative to the average quarterly Net Sales of such Licensed Product in such country over the last two (2) Calendar Quarters ending prior to the
introduction of such Generic Equivalent(s) (the “Baseline Net Sales”) and such decline in Net Sales is not primarily attributable to (i) any action of the applicable Regulatory Authority limiting sales of the Licensed Product
in such country, (ii) the inability of CytomX or its Affiliates or Sublicensees to supply sufficient quantities of the Licensed Product in such country to meet demand, or (iii) any voluntary or involuntary recall of the Licensed Product in
such country; provided that such Loss of Market Exclusivity shall be deemed to exist only for so long as material sales of such Generic Equivalent(s) persist in 

 

	2 	Insert this provision if CytomX intends to develop a Licensed Product using a Probody that [***]. 


	3 	Insert this provision if CytomX intends to develop a Licensed Product using any Probody other than one that [***]. 


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 12 








 
such country. Anything contained in this Agreement to the contrary notwithstanding, a “Loss of Market Exclusivity” shall not be deemed to have occurred if the events described in
clauses (a) and (b) of this definition were caused by or result from any act or omission of CytomX (or any of its Affiliates or Sublicensees) determined to have been made negligently or in bad faith in the performance of CytomX’s
obligations under Section 5.5.3 hereof that results in actual prejudice to ImmunoGen’s ability to preserve its rights in the Licensed Patent Rights and eliminate the infringement threatened by Applicant (excluding any acts or omissions
undertaken pursuant to the specific instruction of ImmunoGen). 
 1.95. “Major EU Market Country” means any of France,
Germany, Italy, Spain or the United Kingdom. 
 1.96. “Manufacturing” or “Manufacture” means activities
directed to making, producing, manufacturing, processing, filling, finishing, packaging, labeling, quality assurance testing and release, shipping or storage of a product. 

1.97. “Marginal Royalty Rates” is defined in Section 4.2.1 hereof. 

1.98. “Mask” means a peptide linked to an Antibody that is capable of inhibiting the specific binding of the Antibody to its
Target. 
 1.99. “Material Breach” is defined in Section 8.3 hereof. 

1.100. “[***] Compound” means [***], and shall include, without limitation, all variants, fragments or derivatives of any of
the foregoing, in each case owned or Controlled by ImmunoGen. 
 1.101. “Milestone Payment” means any Development Milestone
Payment or Sales Milestone Payment. 
 1.102. “Monies” is defined in Section 5.4.2(g) hereof. 

1.103. “Negotiation Period” is defined in Section 5.5.3(e) hereof. 

1.104. “Net Sales” means, with respect to a Licensed Product, gross receipts from sales by CytomX and its Affiliates and
Sublicensees of such Licensed Product to Third Parties in the Territory, less in each case (a) bad debts, (b) sales returns and allowances actually paid, granted or accrued, including trade, quantity and cash discounts and any other
adjustments, including those granted on account of price adjustments, billing errors, rejected goods, damaged or defective goods, recalls, returns, rebates, chargeback rebates, reimbursements or similar payments granted or given to wholesalers or
other distributors, buying groups, health care insurance carriers, chain pharmacies, mass merchandisers, 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 13 








 
staff model HMO’s, pharmacy benefit managers or other institutions in respect of the purchase price, (c) adjustments actually paid, granted or accrued arising from consumer discount
programs or other similar programs, (d) customs or excise duties, sales tax, consumption tax, value added tax, and other taxes (except income taxes) or duties relating to sales, (e) any payment made by CytomX, its Affiliates or
Sublicensees in respect of sales to the United States government, any state government or any foreign government, or to any other Governmental Authority, or with respect to any government-subsidized program or managed care organization, and
(f) freight and freight insurance (to the extent that CytomX, its Affiliates or Sublicensees bears the cost of freight and freight insurance for the Licensed Product), in each case in accordance with GAAP, as consistently applied by CytomX with
respect to its overall operations. 
 Net Sales shall not include sales or transfers among CytomX and its Affiliates and
Sublicensees where the Licensed Product is intended for subsequent sale to the end user. All the foregoing elements of Net Sales calculations shall be determined from the books and records of CytomX and its Sublicensees, maintained in accordance
with the CytomX Accounting Standards or, in the case of Sublicensees, such similar accounting principles, consistently applied. 

In the event a Licensed Product is sold as a component of a combination or bundled product that consists of a Licensed Product
together with another therapeutically active product, or screening or diagnostic product, for the same indication (a “Combination”), the Net Sales from the Combination, for the purposes of determining royalty payments hereunder, shall be
determined by multiplying the Net Sales of the Combination (as defined in the standard Net Sales definition above) by the fraction A/(A+B), where A is the weighted average per unit sale price of the Licensed Product when sold separately in finished
form in the country in which the Combination is sold in similar volumes and of the same class, purity, potency and dosage form, and B is the weighted average per unit sale price of the other product(s) included in the Combination when sold
separately in finished form in the country in which the Combination is sold in similar volumes and of the same class, purity, potency and dosage form. 

In the event that the weighted average per unit sale price of the Licensed Product can be determined but the weighted average
per unit sale price of the other product(s) included in the Combination cannot be determined, Net Sales for purposes of determining royalty payments shall be calculated by multiplying the Net Sales of the Combination (as defined in the standard Net
Sales definition above) by the fraction A/C, where A is the weighted average sale price of the Licensed Product when sold separately in finished form in the country in which the Combination is sold in similar volumes and of the same class, purity,
potency and dosage form, and C is the weighted average per unit sale price of the Combination. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 14 








 In the event that the weighted average per unit sale price of the other
product(s) included in the Combination can be determined but the weighted average per unit sale price of the Licensed Product in similar volumes and of the same class purity, potency and dosage form as in the Combination cannot be determined, Net
Sales for purposes of determining royalty payments shall be calculated by multiplying Net Sales of the Combination (as defined in the standard Net Sales definition above) by a fraction determined by the following formula: one (1) minus
(B/C) where B is the weighted average per unit sale price of the other product(s) included in the Combination when sold separately in finished form in the country in which the Combination is sold in similar volumes and of the same class,
purity, potency and dosage form and C is the weighted average per unit sale price of the Combination. 
 In the event that
such average per unit sale price cannot be determined for the Licensed Product, on the one hand, and all other product(s) included in the Combination, on the other, Net Sales for the purposes of determining royalty payments shall be mutually agreed
upon by the Parties based on the relative value contributed by each component, such agreement to be negotiated in good faith. 

The weighted average per unit sale price for both the Licensed Product, on the one hand, and all other product(s) included in
the Combination, on the other, shall be calculated once each Calendar Year and such price shall be used during all applicable royalty reporting periods for the entire following Calendar Year. When determining the weighted average per unit sale price
of a Licensed Product, other product(s), or Combination, the weighted average per unit sale price shall be calculated by dividing sales dollars (translated into U.S. Dollars using the CytomX Standard Exchange Rate Methodology) by the units sold
during the twelve (12) months (or the number of months in which sales occurred in a partial Calendar Year) of the preceding Calendar Year for the respective Licensed Product, other product(s), or Combination. In the initial Calendar Year, a
forecasted weighted average per unit sale price will be used for the Licensed Product, other product(s), or Combination. Any over- or under-payment due to a difference between the forecasted and actual weighted average per unit sale price will be
paid or credited in the first royalty payment of the following Calendar Year. 
 1.105. “Non-Disclosing Party” is defined in
Section 6.3.2 hereof. 
 1.106. “Notice of Dispute” is defined in Section 10.9.1 hereof. 

1.107. “Party” and “Parties” is defined in the introduction to this Agreement. 

1.108. “Patent Committee” is defined in Section 5.2.4 hereof. 

1.109. “Patent Rights” means any and all (a) patents, (b) pending patent applications, including all provisional
applications, substitutions, continuations, continuations-in-part, 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 15 








 
divisions and renewals, and all patents granted thereon, (c) all patents-of-addition, reissues, reexaminations and extensions or restorations by existing or future extension or restoration
mechanisms, including patent term extensions, supplementary protection certificates or the equivalent thereof, (d) inventor’s certificates, (e) any other form of government-issued right substantially similar to any of the foregoing
and (f) all United States and foreign counterparts of any of the foregoing. 
 1.110. “Payload” means a therapeutic
cytotoxic or cytostatic compound, including, without limitation, a Cytotoxic Compound. 
 1.111. “PDC” means a compound that
incorporates, is comprised of or is otherwise derived from, a Probody conjugated to a Payload using a Linker. 
 1.112. “Permitted
Third Party Service Providers” is defined in Section 3.1.1 hereof. 
 1.113. “Person” means an
individual, sole proprietorship, partnership, limited partnership, limited liability partnership, corporation, limited liability company, business trust, joint stock company, trust, incorporated association, joint venture or similar entity or
organization, including a government or political subdivision or department or agency of a government. 
 1.114. “Phase 1 Clinical
Study” means an initial study of a Licensed Product in human subjects or patients with the endpoint of determining initial tolerance, safety, metabolism or pharmacokinetic information and clinical pharmacology of such product as and to the
extent defined for the United States in 21 C.F.R. § 312.21(a), or its successor regulation, or the equivalent regulation in any other country. 

1.115. “Phase 2 Clinical Study” means a study of a Licensed Product in human patients that is intended to obtain information
on the Licensed Product’s activity for an indication at a prescribed (or otherwise limited) dose and administration schedule, as well as additional information on the Licensed Product’s safety and toxicity as and to the extent defined for
the United States in 21 C.F.R. § 312.21(b), or its successor regulation, or the equivalent regulation in any other country. Without limiting the generality of the foregoing, a clinical study shall be deemed to be a “Phase 2 Clinical
Study” hereunder if such study has been designated by the sponsor as a Phase 2 [II] clinical trial on www.clinicaltrials.gov (or any successor website maintained by the U.S. National Institutes of Health (or any successor agency of
the U.S. Government)). 
 1.116. “Phase 3 Clinical Study” means a study of a Licensed Product in human patients with a
defined dose or a set of defined doses of a Licensed Product designed to (a) ascertain efficacy and safety of such Licensed Product for its intended use; (b) define warnings, precautions and adverse reactions that are associated with the
Licensed Product in the dosage range to be prescribed; and (c) support preparing and submitting 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 16 








 
applications for Regulatory Marketing Approval to the competent Regulatory Authorities in a country of the world, as and to the extent defined for the United States in 21 C.F.R.§ 312.21(c),
or its successor regulation, or the equivalent regulation in any other country. “Phase 3 Clinical Study” shall also include any other human clinical trial serving as a pivotal study from which the data are actually submitted to the
applicable Regulatory Authority in connection with a Regulatory Marketing Approval Application, whether or not such trial is called a “Phase 3” study. Without limiting the generality of the foregoing, a clinical study shall be deemed to be
a “Phase 3 Clinical Study” hereunder if such study has been designated by the sponsor as a Phase 3 [III] clinical trial on www.clinicaltrials.gov (or any successor website maintained by the U.S. National Institutes of Health
(or any successor agency of the U.S. Government)). 
 1.117. “PHSA” means the Public Health Services Act, as amended
(42 U.S.C. § 201 et seq.). 
 1.118. “Pre-Market Notice” is defined in Section 5.5.4(b)
hereof. 
 1.119. “Probody” means an Antibody linked to a Substrate and a Mask that is claimed or covered by CytomX
Technology. 
 1.120. [Reserved] 

1.121. “Program Technology” means all Know-How (other than TAP Platform Improvements) that either Party or any of its
Affiliates, Sublicensees or Permitted Third Party Service Providers (or any of their respective employees, agents or independent contractors), alone or with others, makes, creates, develops, discovers, conceives or first actually reduces to practice
pursuant to the Development, Manufacture, use or Commercialization of any Licensed Product, including any Patent Rights related thereto. Program Technology also includes “Program Technology” (as defined in the Research Collaboration
Agreement) that is necessary or useful for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the composition of, or any method of using or method of making any Licensed
Product, Linker or Cytotoxic Compound comprised in any Licensed Product. 
 1.122. “Proposed Biosimilar Product” is defined
in Section 5.5.1 hereof. 
 1.123. “Proposed Patent List” is defined in Section 5.5.3(a) hereof.

 1.124. “Publishing Party” is defined in Section 6.3.2 hereof. 

1.125. “Receiving Party” is defined in Section 1.27 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 17 








 1.126. “Regulatory Approval” means any technical, medical, scientific or other
license, registration, authorization or approval of any Regulatory Authority (including any approval of a New Drug Application or Biologic License Application) necessary for the Development, Manufacture, use or Commercialization of a pharmaceutical
product in any regulatory jurisdiction. 
 1.127. “Regulatory Approval Application” means any application submitted to an
appropriate Regulatory Authority seeking any Regulatory Approval. 
 1.128. “Regulatory Authority” means the FDA or any
counterpart of the FDA outside the United States, or other national, supra-national, regional, state or local regulatory jurisdiction, any agency, department, bureau, commission, council or other governmental entity with authority over the
Development, Manufacture, use or Commercialization of a Licensed Product. 
 1.129. “Regulatory Marketing Approval” means,
with respect to any pharmaceutical product and any indication, Regulatory Approval (including any supplement thereto) to sell such pharmaceutical product for such indication, including, in any jurisdiction other than the United States, to the extent
required for any sale in such country, all pricing and reimbursement approvals to be obtained from the Regulatory Authority granting such Regulatory Approval or any affiliated Regulatory Authority. 

1.130. “Representatives” is defined in Section 1.27 hereof. 

1.131. “Research Collaboration Agreement” means that certain Research Collaboration Agreement effective as of January 8,
2014 by and between CytomX and ImmunoGen, as the same may be amended from time to time. 
 1.132. “Research Program” has the
meaning ascribed to such term in the Research Collaboration Agreement. 
 1.133. “Review Period” is defined in
Section 6.3.2 hereof. 
 1.134. “Royalty Term” means, on a Licensed Product-by-Licensed Product and
country-by-country basis, the period of time from the First Commercial Sale of such Licensed Product in such country until the later of (a) the expiration of the last Valid Claim that would, but for the license granted hereunder, be infringed
by the manufacture, use, sale, offer for sale or importation of such Licensed Product in such country or (b) the twelfth (12th) anniversary of the date of the First Commercial Sale of such Licensed Product in such country, but in the case
of (b), in no event later than the twentieth (20th) anniversary of the earlier of the date of the First Commercial Sale of such Licensed Product in the United States or the date of the First
Commercial Sale of such Licensed Product in any Major EU Market Country. Anything contained in this Agreement to the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 18 








 
contrary notwithstanding, if the Licensed Product (or any component or intermediate thereof) was manufactured in a country where such manufacture would, at the time of such manufacture, have
infringed a Valid Claim within the Licensed Patent Rights in the country of manufacture in the absence of the license granted under Section 3.3.1 hereof, then the Royalty Term in the country of sale of such Licensed Product, if otherwise
expired pursuant to the first sentence of this Section, shall be extended or reinstated, as the case may be, but only with respect to sales of Licensed Products so manufactured. In determining infringement of Valid Claims for purposes of this
definition of Royalty Term, (i) any Valid Claim within the Licensed Patent Rights that is jointly owned by CytomX (or any of its Affiliates) with ImmunoGen (or any of its Affiliates) shall be deemed to be owned solely by ImmunoGen or an
Affiliate of ImmunoGen, and (ii) claims contained in patent applications that have not resulted in the issuance of a patent in a country will be disregarded for purposes of determining the expiration of the Royalty Term for a Licensed Product
in such country under this definition. 
 1.135. “Sales Milestone” is defined in Section 4.1.2 hereof. 

1.136. “Sales Milestone Payment” is defined in Section 4.1.2 hereof. 

1.137. “Sales Threshold” is defined in Section 4.1.2 hereof. 

1.138. “Strain” is defined in Section 1.66 hereof. 

1.139. “Sublicensee” means any Third Party to whom CytomX or an Affiliate of CytomX grants or has granted, directly or
indirectly, a sublicense of rights licensed by ImmunoGen under this Agreement, in accordance with the provisions of this Agreement. 
 1.140.
“Substrate” means a moiety that is linked to the Antibody and to the Mask of a Probody and is capable of being cleaved, reduced or photolysed. 

1.141. “TAP Platform Improvements” means any enhancement, improvement or modification (each, an
“Improvement”) to the Licensed Intellectual Property that is (a) an Improvement to the composition of or methods of making any Cytotoxic Compound, (b) an Improvement to the conjugation process for making ADCs or PDCs
(including, for example, reaction conditions or changes in process that create improvements in the yield of such conjugate), (c) an Improvement to the composition of or methods for making Linkers, (d) an Improvement to any of the
analytical methods used for making, releasing and characterizing any Cytotoxic Compound, Linker, ADCs or PDCs, or (e) an Improvement to the formulation of ADCs or PDCs. Licensed Products, in and of themselves, will not be deemed to be TAP
Platform Improvements, although the Parties acknowledge that TAP Platform Improvements may be incorporated into Licensed Products. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 19 








 1.142. “Target” means a protein described by a unique UniProtKB/Swiss Prot
accession number (and all fragments, mutations and splice variants thereof) that is bound by an Antibody or a Probody. 
 1.143.
“Target,” “Targeting” or “Targeted” means, when used as a verb to describe the relationship between a molecule and a Target, where the molecule’s primary intended mechanism of action requires
that it bind to the Target (or a portion thereof). 
 1.144. “Target-Binding Probody” means a Probody that Targets the
Licensed Target. [For purposes of clarity, a “Target-Binding Probody” includes a Probody that Targets [***] does not include bi-specific or multi-specific Probodies (i.e., Probodies that Target more than one Target).4] [For purposes of clarity, “Target-Binding Probody” does not include bi-specific or multi-specific Probodies (i.e., Probodies that Target more than one Target).5] 
 1.145. “Term” is defined in Section 8.1 hereof. 

1.146. “Territory” means the entire world. 

1.147. “Third Party” means any Person other than CytomX, ImmunoGen or their respective Affiliates. 

1.148. “Third Party Claims” is defined in Section 9.2 hereof. 

1.149. “Third Party Payments” is defined in Section 4.2.3(a) hereof. 

1.150. “Unauthorized Use” is defined in Section 2.6.3 hereof. 

1.151. “Unconjugated Probody Platform Improvements” has the meaning ascribed to such term in the Research Collaboration
Agreement. 
 1.152. “Valid Claim” means, with respect to a particular country, (a) a claim of an issued and unexpired
patent right included within the Licensed Patent Rights that (i) has not been held permanently revoked, unenforceable or invalid by a decision of a court or other governmental authority of competent jurisdiction, which decision is unappealed or
unappealable within the time allowed for appeal, and (ii) has not been cancelled, withdrawn, abandoned, disclaimed or admitted to be invalid or unenforceable through reissue, disclaimer or otherwise; or (b) a bona fide claim of
a pending patent application included within the Licensed Patent Rights that has not been (i) cancelled, withdrawn or 
  

	4 	Insert this provision if CytomX intends to develop a Licensed Product using a Probody that [***]. 


	5 	Insert this provision if CytomX intends to develop a Licensed Product using any Probody other than one that [***]. 


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 20 








 
abandoned without being refiled in another application in the applicable jurisdiction or (ii) finally rejected by an administrative agency action from which no appeal can be taken or that
has not been appealed within the time allowed for appeal, provided that any claim in any patent application pending for more than seven (7) years from the earliest date on which such patent application claims priority shall not be considered a
Valid Claim for purposes of the Agreement from and after such seven (7) year date unless and until a patent containing such claim issues from such patent application and solely if such patent issues while another Valid Claim covers the relevant
Licensed Product in the relevant country. Anything contained in this Agreement to the contrary notwithstanding, a claim within an issued and unexpired patent within the Licensed Patent Rights shall remain a Valid Claim for all purposes under this
Agreement, notwithstanding a determination that such claim is unenforceable pursuant to the operation of the BPCIA, if such determination is exclusively caused by or results solely from any act or omission by CytomX (or any of its Affiliates or
Sublicensee) determined to have been made negligently or in bad faith in the performance of CytomX’s obligations under Section 5.5.3 hereof that results in actual prejudice to ImmunoGen’s ability to preserve its rights in the Licensed
Patent Rights and eliminate the infringement threatened by the Applicant (excluding any acts or omissions undertaken pursuant to the specific written instruction of ImmunoGen). 

 

	2.	PRODUCT DEVELOPMENT, MANUFACTURING AND COMMERCIALIZATION. 

 2.1. General. CytomX
shall have sole authority over, responsibility for and control of (notwithstanding the formation of the JDC or its decisions and/or disputes among the membership of the JDC) the Development, Manufacture, use and Commercialization of the Licensed
Products, and shall bear all costs associated with such Development, Manufacture, use and Commercialization. To the extent it has not already done so or is not required to do so under the Research Collaboration Agreement, upon request by CytomX,
ImmunoGen will provide CytomX and/or its designated Permitted Third Party Service Providers with the ImmunoGen Technology Transfer Materials. In addition, upon reasonable request by CytomX, ImmunoGen shall use reasonable efforts to provide CytomX
with technical advice to assist CytomX in its use of the ImmunoGen Technology Transfer Materials in connection with the Development and Manufacture of Licensed Products hereunder. 

2.2. Development Diligence. 

2.2.1. CytomX Diligence. CytomX will use Commercially Reasonable Efforts to Develop Licensed Products and to undertake investigations
and actions required to obtain Regulatory Marketing Approval in the Territory; provided that the obligations set forth in this Section shall cease upon the achievement of the first Regulatory Marketing Approval for any Licensed Product in any
country or 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 21 








 
other jurisdiction in the Territory. For avoidance of doubt, any actions taken by CytomX’s Affiliates or Sublicensees under this Agreement shall be treated as actions taken by CytomX in
regard to satisfaction of the requirements of this Section 2.2.1. Beginning on the sixth (6th) anniversary of the Effective Date and thereafter, CytomX will make non-refundable
and non-creditable maintenance payments in the amounts set forth below (the “Annual Maintenance Fees”) until the earlier of (a) the first filing of an IND in the U.S. or in any European Union country for any Licensed
Product or (b) the termination of this Agreement in accordance with its terms. The amounts of the Annual Maintenance Fee accruing as of each anniversary of the Effective Date, beginning with the sixth (6th) anniversary are as follows: 
  

			
	 Anniversary of the Effective Date
	  	 Maintenance Fee

		
	 Sixth (6th) anniversary
	  	$[***]
		
	 Seventh (7th) anniversary
	  	$[***]
		
	 Eighth (8th) anniversary and each anniversary thereafter
	  	The amount payable with respect to the previous anniversary, plus $[***]

 CytomX will pay the applicable Annual Maintenance Fee in accordance with Section 4.3 hereof within
sixty (60) days after the applicable anniversary of the Effective Date. Payment of Annual Maintenance Fees by CytomX shall not establish that CytomX has satisfied its due diligence obligations under this Section 2.2, and such
payments shall be given no consideration or weight in determining whether CytomX has satisfied such due diligence obligations. Anything contained in this Agreement to the contrary notwithstanding, CytomX shall have no obligation to pay Annual
Maintenance Fees hereunder if the first filing of an IND in the U.S. or in any European Union country for any Licensed Product has occurred prior to the sixth (6th) anniversary of the
Effective Date. 
 2.2.2. Exceptions to Diligence Obligations. Notwithstanding any provision of this Agreement to the contrary, CytomX
will be relieved from and will have no obligation to undertake any efforts with respect to any diligence obligation under Section 3.2.1 with respect to a given Licensed Product (each, a “Diligence Obligation”) in the
event that ImmunoGen materially breaches any of its Development or other obligations under this Agreement related to such Licensed Product upon which performance of the applicable Diligence Obligation is dependent. 

2.2.3. Remedies for Breach of Diligence Obligations. A material breach of any Diligence Obligation by CytomX shall be deemed to be a
Material Breach by CytomX hereunder. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 22 








 2.3. Joint Development Committee. 

2.3.1. Formation of the Joint Development Committee. As soon as practicable after the Effective Date, CytomX and ImmunoGen shall
establish a “Joint Development Committee” (or “JDC”) to coordinate the sharing of safety data and minutes of meetings with Regulatory Authorities with regard to Licensed Products. The JDC shall also serve as a forum
to facilitate communications between the Parties regarding this Agreement. The JDC shall be comprised of two (2) representatives from each Party as appointed by such Party, with such representatives possessing appropriate expertise and
seniority. The JDC may change its size from time to time by mutual consent of its members. A Party may replace one or more of its representatives from time to time upon written notice to the other Party. The JDC shall exist until the expiration of
the Term or earlier termination of the Agreement, unless the Parties otherwise agree in writing, provided that CytomX may dissolve the JDC upon the achievement of the first Regulatory Marketing Approval for any Licensed Product in any country or
other jurisdiction in the Territory. 
 2.3.2. Chairperson and Secretary of the Joint Development Committee. CytomX shall designate a
chairperson of the JDC, and a secretary of the JDC shall be designated by agreement of the members of the JDC. CytomX may change the designation of the chairperson from time to time upon written notice to ImmunoGen. The chairperson or his or her
designee shall be responsible for scheduling meetings of the JDC, preparing agendas for meetings and sending to all JDC members notices of all regular meetings and agendas for such meetings at least five (5) Business Days before such meetings.
The chairperson shall solicit input from both Parties regarding matters to be included on the agenda, and any matter either Party desires to have included on the agenda shall be included for discussion. Nothing herein shall be construed to prohibit
the JDC from discussing or acting on matters not included on the applicable agenda. The secretary shall (a) record the minutes of the meeting, (b) circulate copies of meeting minutes to the Parties and each JDC member promptly following
the meeting for review, comment and approval by the JDC members and (c) finalize approved meeting minutes. The chairperson shall be a member of the JDC but the secretary need not be a member of the JDC. 

2.3.3. Meetings. The JDC shall meet at least three (3) times each Calendar Year (unless the Parties mutually agree in advance of
any scheduled meeting that there is no need for such meeting, in which case the next JDC meeting shall also be 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 23 








 
scheduled as agreed upon by the Parties) until it has been terminated in accordance with Section 2.3.1 hereof at dates and times mutually agreed by the JDC. The initial meeting of the
JDC shall be held within sixty (60) days after the Effective Date. Either Party may call a special meeting of the JDC on fifteen (15) days written notice to the other Party’s members of the JDC (or upon such shorter notice as exigent
circumstances may require). Such written notice shall include an agenda for the special meeting. In-person meetings, including special meetings, of the JDC shall alternate between the offices of the Parties, unless otherwise agreed upon by the
members of the JDC. Meetings of the JDC may be held telephonically or by video conference; provided, however, that at least two (2) meetings per year shall be held in-person. Meetings of the JDC shall be effective only if at least one
(1) representative of each Party is in attendance or participating in the meeting. Members of the JDC shall have the right to participate in at meetings held by telephone or video conference. In addition, the JDC may act on any matter or issue
without a meeting if it is documented in a written consent signed by each member of the JDC. 
 2.3.4. Responsibilities of the Joint
Development Committee. The JDC shall be responsible for (a) receiving and reviewing all safety data, relevant regulatory information and other related information obtained by either Party in connection with the Development, Manufacture, use
and Commercialization of Licensed Products; (b) facilitating communication between the Parties, (c) resolving Disputes between the Parties, such as Disputes about interpretation of this Agreement, understanding that CytomX has sole
authority over the Development, Manufacturing, use and Commercialization of Licensed Products; and (d) such other functions as expressly specified hereunder or as agreed by the Parties. At the time that the first Licensed Product enters a
clinical trial, the Parties shall negotiate in good faith the terms of a separate written safety data exchange agreement that, among other things, will govern the exchange of pharmacovigilance information. 

2.3.5. Resolution by Consensus. All resolution of Disputes by the JDC shall be made by unanimous agreement of both Parties’
representatives, with each Party having a single vote, irrespective of the number of JDC representatives in attendance at a meeting. If the JDC cannot or does not reach unanimous agreement on a Dispute, then such Dispute shall be resolved in
accordance with Section 10.9 hereof. 
 2.4. Alliance Managers. In addition to the foregoing governance provisions, each
of the Parties shall appoint a single individual to serve as that Party’s alliance manager (“Alliance Manager”). The role of each Alliance Manager will be to participate and otherwise facilitate the relationship between the
Parties as established by this Agreement. A Party may replace its Alliance Manager from time to time upon written notice to the other Party. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 24 








 2.5. Updates and Reports; Product Recalls. 

2.5.1. Development Updates. Upon the request of ImmunoGen, CytomX shall provide ImmunoGen with brief written reports, which ImmunoGen
may request no more frequently than once per Calendar Year until satisfaction of CytomX’s obligations under Section 2.2.1 hereof, that shall summarize CytomX’s efforts to Develop the Licensed Products in the Field in the
Territory in sufficient detail to establish that CytomX is using Commercially Reasonable Efforts to Develop the Licensed Product, identify the applications for Regulatory Approval that CytomX or its Affiliates or Sublicensees have filed, sought or
attempted to obtain in the prior twelve (12)-month period, and any they reasonably expect to file, seek or attempt to obtain in the following twelve (12)-month period. The Parties agree that the minutes of the JDC meetings may serve as reports
hereunder, to the extent such minutes adequately address the above subject matter. 
 2.5.2. Correspondence for Licensed Products. To
the extent reasonably practicable and subject to any Third Party confidentiality obligations, CytomX shall provide ImmunoGen with copies of any material documents or correspondence pertaining to ImmunoGen’s manufacture or supply of Cytotoxic
Compound or Licensed Product in drug substance form and prepared for submission to any Regulatory Authority and any material documents or other correspondence received from any Regulatory Authority pertaining to ImmunoGen’s manufacture or
supply of Cytotoxic Compound or Licensed Product in drug substance form. ImmunoGen shall complete its review within ten (10) Business Days after receipt of the proposed submission. When requested in writing, ImmunoGen shall use commercially
reasonable efforts to provide assistance to CytomX in obtaining Regulatory Approvals for Licensed Products. Notwithstanding the foregoing, CytomX shall have the sole responsibility for, and ImmunoGen agrees that CytomX shall be the sole owner of,
any Regulatory Approval for the Licensed Products. 
 2.5.3. Product Recalls. In the event any Regulatory Authority issues or requests
a recall or takes similar action with respect to a Licensed Product that CytomX reasonably believes is or may be attributable to or otherwise relates to the Licensed Intellectual Property, or in the event either Party reasonably believes that an
event, incident or circumstance has occurred that may result in the need for such a recall, such Party shall promptly notify the other Party thereof by telephone, facsimile or email. Following such notification, CytomX shall decide and have control
of whether to conduct a recall or market withdrawal (except in the event of a recall or market withdrawal mandated by a Regulatory Authority, in 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 25 








 
which case it shall be required) or take such other corrective action in any country and the manner in which any such recall, market withdrawal or corrective action shall be conducted, provided
that CytomX shall keep ImmunoGen informed regarding any such recall, market withdrawal or corrective action as ImmunoGen from time to time may reasonably request, but only to the extent CytomX is legally permitted to do so. CytomX shall bear all
expenses of any such recall, market withdrawal or corrective action, including, without limitation, expenses of notification, destruction and return of the affected Licensed Product and any refund to customers of the amounts paid for such Licensed
Product. 
 2.5.4. Confidential Information. All reports, updates, product complaints and other information provided by the Disclosing
Party to the Receiving Party under this Agreement (including under this Section 2.5), shall be considered Confidential Information of the Disclosing Party, subject to the terms of Article 7 hereof. 

2.6. Transfer and Use of Proprietary Materials. 

2.6.1. Transfer and Use of ImmunoGen Proprietary Materials. From time to time during the Term, ImmunoGen may provide CytomX with
ImmunoGen Proprietary Materials for use in the Development and Manufacture of Licensed Products under this Agreement. ImmunoGen’s Proprietary Materials are provided by ImmunoGen on an “as-is” basis without representation or warranty
of any type, express or implied, including any representation or warranty of merchantability, non-infringement, title or fitness for a particular purpose, each of which is hereby disclaimed by ImmunoGen. In connection with the foregoing, CytomX
agrees that (a) it shall not use ImmunoGen’s Proprietary Materials provided under this Agreement for any purpose other than exercising its rights and performing its obligations hereunder; (b) it shall not use ImmunoGen Proprietary
Materials provided under this Agreement in any human subject; (c) it shall use ImmunoGen Proprietary Materials in compliance with all Applicable Laws; (d) it does not acquire any right, title or interest in or to ImmunoGen Proprietary
Materials as a result of such provision by ImmunoGen; and (e) upon expiration or termination of this Agreement for any reason, CytomX shall, if and as instructed by ImmunoGen, either destroy or return ImmunoGen Proprietary Materials provided
under this Agreement that are not the subject of a continuing license hereunder. CytomX shall be entitled to transfer ImmunoGen Proprietary Materials to any Affiliate, Sublicensee or Permitted Third Party Service Provider under terms obligating such
Affiliate, Sublicensee or Permitted Third Party Service Provider not to use or transfer such ImmunoGen Proprietary Materials except in compliance with the preceding sentence. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 26 








 2.6.2. Transfer and Use of CytomX Proprietary Materials. From time to time during the
Term, CytomX may provide ImmunoGen with CytomX Proprietary Materials. ImmunoGen shall use the CytomX Proprietary Materials solely in connection with conducting the specific activities for which such CytomX Proprietary Materials are provided to
ImmunoGen, and for no other purpose. Without limiting the generality of the foregoing, except as expressly set forth in this Agreement or in other written authorization by CytomX, ImmunoGen shall not make or attempt to make analogues, progeny or
derivatives of, or modifications to, the CytomX Proprietary Materials, using CytomX’s Confidential Information, and ImmunoGen shall not use the CytomX Proprietary Materials for the benefit of any Third Party or of its own internal research
programs. ImmunoGen shall comply with all Applicable Laws regarding the handling and use of the CytomX Proprietary Materials. ImmunoGen agrees to retain possession over the CytomX Proprietary Materials and not to provide the CytomX Proprietary
Materials to any Third Party without CytomX’s prior written consent. 
 2.6.3. Unauthorized Use of Confidential Information and
Proprietary Materials. In the event that (a) CytomX or any of its Affiliates or Sublicensees use ImmunoGen’s Confidential Information (including, without limitation, any Confidential Information within the Licensed Know-How) or
ImmunoGen Proprietary Materials for any purpose other than in connection with CytomX’s exercise of its rights and performance of its obligations hereunder or the Research Collaboration Agreement (if then in effect) or (b) ImmunoGen or any
of its Affiliates uses CytomX’s Confidential Information or CytomX Proprietary Materials for any purpose other than the purposes authorized herein or in any other License Agreement or the Research Collaboration Agreement (if then in effect) (in
each case, an “Unauthorized Use”), the results of such Unauthorized Use, and any discoveries or inventions that arise from such Unauthorized Use, whether patentable or not, shall belong solely and exclusively to the providing Party.
If required in order to perfect or enforce the providing Party’s ownership of such results, discoveries or inventions, each Party, on behalf of itself and its Affiliates (and in the case of CytomX, its Sublicensees), each hereby assigns and
agrees to assign to the providing Party all of its and their right, title and interest in and to all such results, discoveries or inventions made through such Unauthorized Use. Each Party agrees to cooperate, and to cause its Affiliates (and in the
case of CytomX, its Sublicensees) to cooperate, with the providing Party, and to execute and deliver any and all documents that the providing Party reasonably deems necessary, to perfect and enforce its rights hereunder. 

2.7. Services. If, during the Term, CytomX requests that ImmunoGen provide additional services with respect to (a) process
development, (b) analytical method 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 27 








 
development, or (c) manufacturing and supply of Licensed Product in drug substance form for any GLP toxicology studies, clinical studies, or commercial scale-up, but excluding pivotal
studies and commercial supply, or (d) any other tasks in connection with the Development, Manufacture, use or Commercialization of Licensed Products with respect to which the Parties may mutually agree, then the Parties shall negotiate in good
faith the terms of separate written agreements with respect to such activities. 
  

	3.	LICENSE GRANTS. 

 3.1. License Grants. 

3.1.1. Commercial License. Subject to the terms and conditions of this Agreement, ImmunoGen hereby grants to CytomX and its Affiliates
an exclusive (even as to ImmunoGen), non-transferable (except as expressly permitted in this Agreement), royalty-bearing license, including the right to grant sublicenses as described in Section 3.1.2 hereof, under the Licensed
Intellectual Property, to Develop, make, have made, use, sell, offer for sale, import and otherwise Commercialize Licensed Products in the Field in the Territory. CytomX and its Affiliates shall have the right to engage one or more Affiliates or
Third Parties (the latter being referred to herein as “Permitted Third Party Service Providers”) as subcontractors to perform designated functions in connection with its activities under this Agreement (including transferring
Licensed Know-How and ImmunoGen Proprietary Materials as may be necessary for such Permitted Third Party Service Providers to perform such designated functions); provided that (a) CytomX shall remain responsible for the conduct of such
activities in accordance with the terms and conditions of this Agreement and (b) CytomX shall cause each such Affiliate or Third Party Service Provider to assign or license (with a right to sublicense to ImmunoGen to the extent required under
this Agreement) to CytomX all intellectual property rights (including, without limitation, Patent Rights) in and to any TAP Platform Improvements, whether patentable or not, the inventors of which (alone or with others) are employees of, or others
obligated to assign inventions to, such Permitted Third Party Service Provider in the performance of services for CytomX. 
 3.1.2. Right
to Sublicense. CytomX and its Affiliates shall have the right to grant sublicenses under the rights granted to them under Section 3.1.1 hereof with respect to any Licensed Product to any Sublicensee, provided that (a) each such
sublicense shall be consistent with the terms and conditions of this Agreement, (b) CytomX shall provide the identity of each Sublicensee within twenty (20) Business Days after execution of such sublicense, (c) CytomX and its
Affiliates shall cause each Sublicensee to assign or license (with a right to sublicense to ImmunoGen to the extent required by this Agreement) to CytomX all intellectual property rights (including, without limitation, Patent Rights) in and to any
TAP 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 28 








 
Platform Improvements, whether or not patentable, the inventors of which (alone or with others) are employees of, or others obligated to assign inventions to, such Sublicensee in connection with
its exercise of its rights under the applicable sublicense, (d) CytomX shall be jointly and severally responsible with its Sublicensees to ImmunoGen for failure by its Sublicensees to comply with the terms and conditions of this Agreement and
(e) CytomX shall remain responsible for the payment to ImmunoGen of all Milestone Payments and royalties payable with respect to the activities and Net Sales of any Sublicensee. 

3.2. Retained Rights and Covenants. 

3.2.1. Retained Rights. Subject to the other terms of this Agreement (including, without limitation, Section 3.2.2 and 3.3 hereof),
ImmunoGen retains the right to use the unpatented Licensed Know-How and practice the Licensed Patent Rights (a) to develop, make, have made, use, sell, offer for sale, import or otherwise commercialize any product (excluding, on a
country-by-country basis, while the exclusive license granted under Section 3.1.1 hereof remains in effect in such country, any PDC that Targets the Licensed Target), and to grant licenses to Third Parties to do the same; and (b) for any
and all uses outside of the Field. 
 3.2.2. Covenants. Anything contained in Section 3.2.1 or 3.3 hereof to the contrary
notwithstanding, ImmunoGen hereby agrees that, on a country-by-country basis, during the period that the exclusive license granted under Section 3.3.1 hereof remains in effect in such country, neither it nor any of its Affiliates shall
(a) develop or commercialize any PDC that Targets the Licensed Target, or (b) grant to any Third Party any license or other right under any Patent Rights or Know-How owned or Controlled by ImmunoGen to develop or commercialize any PDC that
Targets the Licensed Target; provided that the foregoing shall not restrict ImmunoGen’s or its Affiliates’ right to grant to Third Parties research licenses under any Patent Rights or Know-How owned or Controlled by ImmunoGen that are not
Target-specific. 
 3.3. License to CytomX TAP Platform Improvements. CytomX, on behalf of itself and its Affiliates, hereby grants to
ImmunoGen a non-exclusive, sublicensable, perpetual, irrevocable, royalty-free worldwide license under CytomX’s interest in any CytomX TAP Platform Improvements, including, without limitation, any Patent Rights claiming such CytomX TAP Platform
Improvements, to exploit such CytomX TAP Platform Improvements (a) for any purpose in the Field other than developing, manufacturing, using or commercializing PDCs and (b) for any purpose outside of the Field. Nothing in this Agreement
shall be construed as obligating CytomX to engage in any technology transfer or provision of written documentation to ImmunoGen (other than as provided in Section 5.2.3 hereof) or any of its Affiliates or any Third Party disclosing, describing
or otherwise relating to CytomX TAP Platform Improvements. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 29 








 3.4. Section 365(n) of Bankruptcy Code. All rights and licenses now or hereinafter
granted by either Party to the other Party under or pursuant to any section of this Agreement, including the licensed granted in this Article 3, are rights to “intellectual property” (as defined in Section 101(35A) of
Title 11 of the United States Code, as amended (such Title 11, the “Bankruptcy Code”)). The Parties hereto acknowledge and agree that the payments provided for under Article 4 hereof, other than royalty
payments pursuant to Section 4.2 hereof, do not constitute royalties within the meaning of Section 365(n) of the Bankruptcy Code or relate to licenses of intellectual property under this Agreement. 

3.5. No Implied Rights. Except as expressly provided in this Agreement, neither Party shall be deemed, by estoppel, implication or
otherwise, to have granted the other Party any license or other right with respect to any intellectual property of such Party. 
  

	4.	PAYMENTS. 

 4.1. Milestone Payments. 

4.1.1. Development Milestones. Within ten (10) Business Days following the first occurrence of each event (each, a
“Development Milestone”) described below for the first Licensed Product that achieves such milestone, CytomX shall provide written notice to ImmunoGen identifying the Development Milestone achieved, and CytomX shall pay to ImmunoGen
the amount set forth below within forty-five (45) days of receipt of ImmunoGen’s notice with respect to such Development Milestone (each such amount, a “Development Milestone Payment”) to be payable only once regardless of
how many Licensed Products achieve such Development Milestone. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 30 









					
	 Development Milestone
	  	Payment	 
	 Dosing of first patient in a Phase 1 Clinical Study
	  	 	[***	] 
	 Dosing of first patient in a Phase 2 Clinical Study
	  	 	[***	] 
	 Dosing of first patient in a Phase 3 Clinical Study
	  	 	[***	] 
	 Date of filing of BLA
	  	 	[***	] 
	 Date of receipt of Regulatory Approval in the United States
	  	 	[***	] 
	 Date of receipt of Regulatory Marketing Approval in Major EU Market Country
	  	 	[***	] 
	 Date of receipt of Regulatory Marketing Approval in Japan
	  	 	[***	] 

 If a clinical milestone is achieved and any previous clinical milestone has not yet been achieved for any
reason, notwithstanding anything herein to the contrary such previous milestone(s) shall be deemed to have been achieved and the corresponding Development Milestone Payment set forth in the table above shall be payable simultaneously with the
Development Milestone Payment for the achievement of the subsequent Milestone. All Development Milestone Payments shall be non-refundable and noncreditable. 

4.1.2. Sales Milestones. CytomX shall pay to ImmunoGen the following one-time payments (each, a “Sales Milestone
Payment”) when aggregate Annual Net Sales of a Licensed Product in the Territory in a Calendar Year first reach the respective threshold (a “Sales Threshold”) indicated below (each, a “Sales Milestone”):

  

					
	 Total Annual Net Sales
	  	Sales Milestone
Payment	 
	 Total Annual Net Sales at least equal $500,000,000
	  	 	[***	] 
	 Total Annual Net Sales at least equal $750,000,000
	  	 	[***	] 
	 Total Annual Net Sales at least equal $1,000,000,000
	  	 	[***	] 
	 Total Annual Net Sales at least equal $1,500,000,000
	  	 	[***	] 


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 31 








 Any Sales Milestone Payment with respect to any Calendar Year shall be payable within sixty
(60) days of the end of such Calendar Year in the United States. Each Sales Milestone Payment is payable a maximum of one time only, regardless of the number of times a Licensed Product achieves a particular Sales Threshold or the number of
Licensed Products that achieve a particular Sales Threshold. All Sales Milestone Payments shall be nonrefundable and noncreditable. 
 4.2.
Royalties. 
 4.2.1. Royalty Payments. With respect to each Licensed Product and subject to the provisions of
Section 4.2.2 hereof, CytomX shall pay ImmunoGen royalties in the amount of the applicable rates (“Marginal Royalty Rates”) set forth below of Annual Net Sales of such Licensed Product during the Royalty Term: 

 

					
	 Annual Net Sales
	  	Marginal Royalty Rate for
Licensed Products (% of
Annual Net Sales)	 
	 Annual Net Sales of such Licensed Product during a given Calendar Year up to and including $500,000,000
	  	 	[***	]% 
	 Annual Net Sales of such Licensed Product during a given Calendar Year above $500,000,000, up to and including $1,000,000,000
	  	 	[***	]% 
	 Annual Net Sales of such Licensed Product during a given Calendar Year above $1,000,000,000
	  	 	[***	]% 


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 32 








 4.2.2. Marginal Royalty Rate Application. Each Marginal Royalty Rate set forth in the
table above shall apply only to that portion of the Annual Net Sales of a given Licensed Product in the Territory during a given Calendar Year that falls within the indicated range. 

4.2.3. Royalty Adjustments. 

(a) Third Party Royalty Offset. Subject to Section 4.2.3(e) hereof, if, with respect to a Calendar Quarter, CytomX or any
of its Affiliates or Sublicensees actually makes royalty payments to one or more Third Parties in consideration of a license, in the absence of which CytomX could not practice the Licensed Intellectual Property to make, offer for sale, sell or
import the Cytotoxic Compound portion or Linker portion of any Licensed Product included within the Licensed Intellectual Property (excluding any Licensed Intellectual Property jointly owned by ImmunoGen or its Affiliates, on the one hand, and
CytomX or its Affiliates, on the other hand) without infringing an issued patent or patents owned or exclusively licensed by such Third Party in any country (collectively, “Third Party Payments”), as evidenced, to the extent requested by
ImmunoGen, by an opinion of Independent Patent Counsel selected by CytomX and approved by ImmunoGen (which approval shall not be unreasonably withheld), then CytomX shall have the right to reduce the royalties otherwise due to ImmunoGen pursuant to
Section 4.2.1, 4.2.3(c) or 4.2.3(d) hereof (but not the royalties otherwise due to ImmunoGen pursuant to Section 4.2.3(b) hereof) with respect to Net Sales in such country of such Licensed Products in such Calendar Quarter by an amount
equal to fifty percent (50%) of the amount of such Third Party Payments. For purposes of clarity, the term “Third Party Payments” includes only prospective running royalties payable on the same basis as required by this
Section 4.2, and does not include any lump-sum license fees, milestone payments, minimum royalties in excess of accrued royalties, any amounts paid for past infringement of any Third Party’s rights or any amount paid for rights not
required to permit CytomX to practice the Licensed Intellectual Property to make, use, offer for sale, sell or import the Cytotoxic Compound portion or Linker portion of any Licensed Product included in the Licensed Intellectual Property in any
country. For the avoidance of doubt, the Parties agree and acknowledge that this Section 4.2.3(a) shall not apply with respect to royalties payable by a Party to any Third Party under any agreement in existence as of the Effective Date.


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 33 








 (b) Valid Claim Coverage. 

(i) No Patent Coverage. Subject to Section 4.2.3(e) hereof, the royalty rates set forth in Sections 4.2.1,
4.2.3(c) and 4.2.3(d) hereof shall apply, on a country-by-country basis and Licensed Product-by-Licensed Product basis, to Net Sales of Licensed Products only where (A) such Licensed Product (or its manufacture, use, sale, offer
for sale or importation) in such country is Covered by a Valid Claim within the Licensed Patent Rights or (B) such Licensed Product (or any component or intermediate thereof) was manufactured in a country where the manufacture of such Licensed
Product (or such component or intermediate), was, at the time of its manufacture, Covered by a Valid Claim within the Licensed Patent Rights, regardless of the country in which such Licensed Product is sold. Subject to the other terms of this
Agreement (except for Section 4.2.3(a) hereof, which shall not apply), on a country-by-country and Licensed Product-by-Licensed Product basis where and as of and when the royalty rates under Sections 4.2.1, 4.2.3(c) and
4.2.3(d) hereof do not apply as a result of this Section 4.2.3(b)(i), the royalties payable with respect to Net Sales of such Licensed Product sold by CytomX, its Affiliates and its Sublicensees in such country shall be reduced by
fifty percent (50%) of the royalties otherwise owed to ImmunoGen pursuant to Section 4.2.1 or 4.2.3(d) hereof, as applicable, without giving effect to any royalty reduction provided in Section 4.2.3(c) hereof,
using the methodology outlined in Exhibit B attached hereto. The Parties hereby acknowledge and agree that such royalties shall be in consideration of the commercial advantage, know-how and background information gained from the
unpatented Licensed Know-How, including, without limitation, ImmunoGen’s Confidential Information and ImmunoGen Proprietary Materials. 

(ii) Applicability of Royalty Rates. For purposes of clarity, (A) if a Licensed Product (or its manufacture, use, sale, offer for
sale or importation) is Covered by a Valid Claim in a country within the Territory such that royalties are paid by CytomX pursuant to Section 4.2.1, 4.2.3(c) or 4.2.3(d) hereof and, prior to the expiration of the Royalty
Term for such Licensed Product in such country, the Licensed Product (and its manufacture, use, sale, offer for sale or importation) is no longer Covered by a Valid Claim in such country, CytomX shall pay ImmunoGen a royalty at the rate set forth in
Section 4.2.1(b)(i) hereof for the portion of the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 34 








 
Royalty Term during which no such Valid Claim Covers such Licensed Product (or its manufacture, use, sale, offer for sale or importation) in such country; and (B) if a Licensed Product (or
its manufacture, use, sale, offer for sale or importation) is not Covered by a Valid Claim in a country within the Territory such that royalties are paid by CytomX pursuant to Section 4.2.1(b)(i) hereof and, prior to the expiration of
the Royalty Term for such Licensed Product in such country, the Licensed Product (or its manufacture, use, sale, offer for sale or importation) becomes Covered by a Valid Claim within the Licensed Patent Rights in such country, CytomX shall pay
ImmunoGen a royalty at the rates set forth in Section 4.2.1, 4.2.3(c) or 4.2.3(d) hereof, as applicable, for that portion of the Royalty Term during which such Valid Claim Covers such Licensed Product (or its manufacture,
use, sale, offer for sale or importation) in such country. 
 (iii) Definition of “Cover”. A Valid Claim within the
Licensed Patent Rights “Covers” the Licensed Product (or its manufacture, use, sale, offer for sale or importation) in a country if, but for the license granted under Section 3.1.1 hereof, the manufacture, use, sale,
offer for sale or importation of the Licensed Product by CytomX or any of its Affiliates or Sublicensees in such country would infringe such Valid Claim; provided, however, that in determining whether a Valid Claim within such Licensed Patent Rights
“Covers” (as defined above) the Licensed Product (or its manufacture, use, sale, offer for sale or importation), (A) any Valid Claim within the Licensed Patent Rights that is jointly owned by CytomX (or any of its Affiliates)
with ImmunoGen (or any of its Affiliates) shall be deemed to be owned solely by ImmunoGen or an Affiliate of ImmunoGen and (B) any Valid Claim contained in an unissued patent application within the Licensed Patent Rights that has not been
(1) canceled, withdrawn or abandoned or (2) pending for more than seven (7) years from its earliest priority date shall be deemed to have been issued. 

(c) Loss of Market Exclusivity. Subject to Section 4.2.3(e) hereof, if, with respect to a Calendar Quarter, CytomX or any
of its Affiliates or Sublicensees experiences a Loss of Market Exclusivity for a Licensed Product in any country, then CytomX shall have the right to reduce the royalties otherwise due to ImmunoGen pursuant to Section 4.2.1 or
4.2.3(d) hereof (but not the royalties otherwise due to ImmunoGen under Section 4.2.3(b) hereof) with respect to Net Sales in such country of such Licensed Products in such Calendar Quarter as described below, in each case using


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 35 








 
a methodology similar to that outlined in Exhibit B attached hereto. In calculating royalty reductions pursuant to this Section 4.2.3(c), the applicable WARR (as defined in
Exhibit B) shall be multiplied by a percentage which is equal to a fraction, the numerator of which is the actual Net Sales of the Licensed Product in the country for the applicable Calendar Quarter during the period of Loss of Market Exclusivity,
and the denominator of which is the Baseline Net Sales of the Licensed Product in such country; provided, however, that (i) if the percentage referred to above is greater than eighty percent (80%), no reductions shall be made pursuant to this
Section 4.2.3(c) with respect to Net Sales of the Licensed Product in such country for such Calendar Quarter; and (ii) such percentage shall never be less than fifty percent (50%), regardless of whether Net Sales of such Licensed Product
in such country for such Calendar Quarter are less than fifty percent (50%) of the applicable Baseline Net Sales. 
 (d) Effect of
Challenge. In further consideration of the grant by ImmunoGen of the license hereunder and except to the extent the following is unenforceable under the Applicable Laws of a particular jurisdiction where a patent application within the Licensed
Patent Rights is pending or a patent within the Licensed Patent Rights is issued, if CytomX, its Affiliates or Sublicensees initiates a Challenge or induces or assists a Third Party in initiating or prosecuting a Challenge (the Licensed Patent
Rights subject to such Challenge being referred to herein as the “Challenged Patent Rights”), then during the period that such Challenge is pending, the royalty rates set forth in Section 4.2.1 hereof shall be increased by an
additional two percent (2%) of annual Net Sales (the “Challenge-Related Royalty Increase”) in the country(ies) in which the Challenged Patent Rights were pending or issued (each, a “Challenge Jurisdiction”)
commencing on the date of such initiation or the date CytomX, its Affiliates or Sublicensees first induces or provides assistance to such Third Party, as applicable, but only with respect to Net Sales of Licensed Products in the applicable Challenge
Jurisdiction(s). If, following the final, unappealable conclusion of a Challenge in a Challenge Jurisdiction, there remains one or more Valid Claims within the Challenged Patent Rights that would be infringed by the manufacture, use, sale, offer for
sale or importation then (i) the royalty rates set forth in Section 4.2.1 hereof shall be increased by an additional three percent (3%) of annual Net Sales (which shall be in addition to the Challenge-Related Royalty Increase) in the
applicable Challenge Jurisdiction, commencing upon the final, unappealable conclusion of such Challenge and continuing for the remainder of the Royalty Term in the applicable Challenge Jurisdiction, and (ii) CytomX shall reimburse ImmunoGen for
its costs 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 36 








 
and expenses (including, without limitation, reasonable attorneys’ and experts’ fees and expenses of litigation) incurred in responding to the Challenge. CytomX shall be required to pay
such reimbursement within sixty (60) days of receiving an invoice therefor from ImmunoGen, which shall set forth in reasonable detail the basis for the charges for which ImmunoGen is seeking reimbursement. If, following the final, unappealable
conclusion of a Challenge in a Challenge Jurisdiction, there remain no Valid Claims within the Challenged Patent Rights that would be infringed by the manufacture, use, sale, offer for sale or importation of Licensed Products by CytomX or any of its
Affiliates or Sublicensees in such Challenge Jurisdiction in the absence of the license granted under Section 3.1.1 hereof, then ImmunoGen shall reimburse CytomX for all amounts with respect to the Challenge-Related Royalty Increase actually
paid by CytomX to ImmunoGen with respect to the Challenge Jurisdiction (the “Clawback Amount”) as follows: (A) CytomX shall be entitled to credit one hundred percent (100%) of each royalty payment due under
Section 4.2 hereof as they become due from and after the final, unappealable conclusion of such Challenge in such Challenge Jurisdiction against the Clawback Amount until reimbursed in full; and (B) any unreimbursed portion of the Clawback
Amount outstanding at the conclusion of the Royalty Term in all countries and jurisdictions in the Territory shall be paid to CytomX within sixty (60) days after receipt by ImmunoGen of an invoice from CytomX therefor. 

(e) Minimum Royalty Rate. Anything contained in this Agreement to the contrary notwithstanding, none of the reductions to royalties
provided in Sections 4.2.3(a), 4.2.3(b) and 4.2.3(c) hereof, shall, individually or in the aggregate, reduce the royalties payable with respect to Net Sales of any Licensed Product sold by CytomX, its Affiliates and its
Sublicensees in any country during the Royalty Term by more than fifty percent (50%) of the royalties otherwise owed to ImmunoGen pursuant to Section 4.2.1 or 4.2.3(d), as applicable, without giving effect to any royalty
reduction provided in Section 4.2.3(a), 4.2.3(b) or 4.2.3(c) hereof. 
 4.3. Reports and Payments. 

4.3.1. Cumulative Royalties. The obligation to pay royalties under Section 4.2 shall be imposed only once with respect to a
single unit of a Licensed Product regardless of how many Valid Claims in Patent Rights included within the Licensed Intellectual Property would, but for this Agreement, be infringed by the use or sale of such Licensed Product in the country in which
such Licensed Product is used or sold. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 37 








 4.3.2. Royalty Statements and Payments. Within sixty (60) days after the end of each
Calendar Quarter, CytomX shall deliver to ImmunoGen a report setting forth for such Calendar Quarter the following information, on a Licensed Product-by-Licensed Product basis: (a) the gross sales (if available) and the Net Sales of each
Licensed Product (specifying in reasonable detail the deductions to gross sales used to calculate Net Sales, (b) the basis for any adjustments to the royalty payable for the sale of each Licensed Product, (c) the applicable exchange rate
to convert each country’s currency to U.S. Dollars under Section 4.3.4 hereof and (d) the royalties due hereunder for the sale of each Licensed Product. No such reports shall be due for any Licensed Product before the
First Commercial Sale of such Licensed Product in the Territory. The total royalty due for the sale of Licensed Products during such Calendar Quarter shall be remitted at the time such report is delivered. 

4.3.3. No Set-Off; Taxes and Withholding. All payments made by CytomX to ImmunoGen hereunder shall be made without set-off or
counterclaim and free and clear of any taxes, duties, levies, fees or charges, except withholding taxes, if any. In the event any of the payments made pursuant to this Agreement become subject to withholding taxes under the Applicable Law of any
jurisdiction, CytomX shall deduct and withhold the amount of such taxes for the account of ImmunoGen, to the extent required by Applicable Law, such amounts payable to ImmunoGen shall be reduced by the amount of taxes deducted and withheld, and
CytomX shall pay the amounts of such taxes to the proper Governmental Authority in a timely manner and promptly transmit to ImmunoGen an official tax certificate or other evidence of such tax obligations together with proof of payment from the
relevant Governmental Authority of all amounts deducted and withheld sufficient to enable ImmunoGen to claim such payment of taxes. Any such withholding taxes required under Applicable Law to be paid or withheld shall be an expense of, and borne
solely by, ImmunoGen. CytomX will provide ImmunoGen with reasonable assistance to enable ImmunoGen to recover such taxes as permitted by Applicable Law. 

4.3.4. Currency. All amounts payable and calculations hereunder shall be in United States dollars, and all payments due under this
Agreement shall be made by wire transfer in immediately available funds to an account designated by the Party owed such payment. As applicable, Net Sales and any royalty deductions shall be converted into United States dollars in accordance with the
CytomX Standard Exchange Rate Methodology. 
 4.3.5. Overdue Payments. Subject to the other terms of this Agreement, any payments
hereunder not paid within the applicable time period set forth herein shall bear interest from the due date until paid in full, at a rate per annum equal to 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 38 








 
the lesser of (a) one and one-half percent (1-1/2%) per month, compounded monthly, or (b) the maximum interest rate permitted by applicable law in regard to such payments,
calculated in each case from the date such payment was due through to the date on which payment is actually made; provided, however, that with respect to any disputed payments, no interest shall be due until such dispute is resolved and the interest
that shall be payable thereon shall be based on the finally-resolved amount of such payment, calculated from the original date on which the disputed payment was due through the date on which payment is actually made. Such payments when made shall be
accompanied by all interest so accrued. Such interest and the payment and acceptance thereof shall not negate or waive the right of ImmunoGen to any other remedy, legal or equitable, to which it may be entitled because of the delinquency of the
payment. 
 4.4. Maintenance of Records; Audits. 

4.4.1. Record Keeping. CytomX shall keep, and cause its Affiliates and Sublicensees to keep, accurate books of account and records in
connection with the sale of Licensed Products, in sufficient detail to permit accurate determination of all figures necessary for verification of royalties to be paid hereunder. CytomX shall maintain, and cause its Affiliates and Sublicensees to
maintain, such records for a period of at least three (3) years after the end of the Calendar Year in which they were generated. 

4.4.2. Audits. Upon thirty (30) days prior written notice from ImmunoGen, CytomX shall permit an independent certified public
accounting firm of internationally recognized standing selected by ImmunoGen and reasonably acceptable to CytomX to examine, at ImmunoGen’s sole expense, the relevant books and records of CytomX, its Affiliates and Sublicensees during the
period covered by such examination, as may be reasonably necessary to verify the accuracy of the reports submitted by CytomX in accordance with Section 4.3 hereof and the payment of royalties hereunder. An examination by ImmunoGen under
this Section 4.4.2 shall occur not more than once in any Calendar Year and shall be limited to the pertinent books and records for any Calendar Year ending not more than three (3) years before the date of the request. The accounting
firm shall be provided access to such books and records at the facilities where such books and records are kept and such examination shall be conducted during normal business hours. CytomX may require the accounting firm to sign a reasonable and
customary non-disclosure agreement before providing the accounting firm access to CytomX’s facilities or records. Upon completion of the audit, the accounting firm shall provide both ImmunoGen and CytomX a written report disclosing whether the
reports submitted by CytomX are correct or incorrect, whether the royalties paid are correct or incorrect and, in each case, the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 39 








 
specific details concerning any discrepancies. CytomX and ImmunoGen shall each have the right to request a further determination by such accounting firm as to matters which such Party disputes
within thirty (30) days following receipt of such report. The Party initiating a dispute will provide the other Party and the accounting firm with a reasonably detailed statement of the grounds upon which it disputes any findings in the written
report and the accounting firm shall undertake to complete such further determination within thirty (30) days after the dispute notice is provided, which determination shall be limited to the disputed matters and provided to both Parties. The
Parties shall use reasonable efforts, through the participation of finance representatives of both Parties, to resolve any dispute arising in relation to the audit by good faith discussion. The results of any such audit, reflecting the accounting
firm’s determination of any disputed matters, shall be binding on both Parties. 
 4.4.3. Underpayments/Overpayments. If such
accounting firm concludes that additional royalties were due to ImmunoGen, CytomX shall pay the additional royalties (plus interest thereon at the rate provided in Section 4.3.5 hereof) within forty-five (45) days of the date CytomX
receives such accountant’s written report so concluding. If such underpayment exceeds five percent (5%) of the royalties that were to be paid and is also greater than Fifty Thousand U.S. Dollars ($50,000), CytomX also shall reimburse
ImmunoGen for all reasonable charges of such accountants for conducting the audit. If such accounting firm concludes that CytomX overpaid royalties, ImmunoGen shall repay such amount in full within forty-five (45) days of the receipt of such
accountant’s report, or, at CytomX’s option, it shall be entitled to offset all such overpayments against any outstanding or future amounts payable to ImmunoGen hereunder until CytomX has received full credit for such overpayments. 

4.4.4. Confidentiality. All financial information that is subject to review under this Section 4.4 shall be deemed to be the
Confidential Information of the audited Party subject to the provisions of Article 6 hereof. 
  

	5.	INTELLECTUAL PROPERTY. 

 5.1. Inventions. 

5.1.1. Ownership. All determinations of inventorship under this Agreement shall be made in accordance with the laws of the United
States. Determinations of ownership of intellectual property hereunder will be made in accordance with inventorship. 
 (a) ImmunoGen
Solely Owned Technology. As between the Parties, ImmunoGen shall be the sole owner of all Licensed Intellectual Property (other than Joint Program Technology and Joint TAP Platform Improvements included therein and any Joint Patent Rights). 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 40 








 (b) CytomX Solely Owned Technology. As between the Parties, CytomX shall be the sole
owner of all CytomX Program Technology and CytomX TAP Platform Improvements and any Patent Rights claiming such CytomX Program Technology and CytomX TAP Platform Improvements. 

(c) Jointly Owned Technology. All Joint Program Technology and Joint TAP Platform Improvements (including, without limitation, all
Joint Patent Rights) shall be jointly owned by the Parties, with each Party holding an undivided one-half interest therein. Subject to the Parties’ other rights and obligations under this Agreement and any then-outstanding License Agreement,
each Party shall be free to exploit and assign, either itself or through the grant of licenses to Third Parties, all Joint Program Technology, Joint TAP Platform Technology Improvements and Joint Patent Rights throughout the world without
restriction, without the need to obtain further consent from or provide notice to the other Party and without any duty to account or otherwise make any payment of any compensation to the other Party. 

5.1.2. Disclosure. CytomX shall, no less than thirty (30) days before filing any initial Patent Right disclosing CytomX TAP
Platform Improvements or any Joint Program Technology or Joint TAP Platform Improvements or any other Patent Right that contains ImmunoGen’s Confidential Information, provide a copy of such disclosure to ImmunoGen. ImmunoGen shall, no less than
thirty (30) days before filing any initial Patent Right disclosing Joint Program Technology or Joint TAP Platform Improvements or any other Patent Right that contains CytomX’s Confidential Information, provide a copy of such disclosure to
CytomX. In each case, such disclosures to the other Party shall include all invention disclosures or other similar documents submitted to such Party by its, or its Affiliates’, employees, agents or independent contractors describing such
invention and the proposed inventorship of any new Patent Rights intended to be filed. The other Party shall promptly raise any issue regarding inventorship of any such Patent Rights, and the Parties agree to determine the correct inventorship of
any Patent Rights in accordance with Section 10.10.1 hereof. 
 5.2. Filing, Prosecution and Maintenance of Patent Rights.

 5.2.1. Cooperation. Without limiting any other rights and obligations of the Parties under this Agreement, the Parties shall
cooperate with respect to the timing, scope and filing of patent applications and patent claims relating to any Joint Program Technology to preserve and enhance the patent protection for 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 41 








 
Licensed Products, including the manufacture and use thereof and to allow the Party owning the technology underlying an Improvement to have reasonable input to preserve and enhance its patent
portfolio and patenting strategy. 
 5.2.2. ImmunoGen Patent Rights. ImmunoGen, at its own expense, shall have the sole right, but not
the obligation, to prepare, file, prosecute and maintain, throughout the world, all Licensed Patent Rights (other than Licensed Patent Rights claiming Joint Program Technology or Joint TAP Platform Improvements). With respect to any Licensed Patent
Rights disclosing or claiming Program Technology (other than TAP Platform Improvements included in the Program Technology), ImmunoGen shall keep CytomX reasonably informed of the status of the filing, prosecution and maintenance of such Patent
Rights and shall consider in good faith any recommendations made by CytomX in regard to the filing, prosecution or maintenance of any such Patent Right. ImmunoGen shall consult with CytomX in the filing, prosecution and maintenance of any ImmunoGen
Patent Right related to Improvements to CytomX Technology and shall not unreasonably refuse to incorporate any recommendations made by CytomX in regard to such filing, prosecution or maintenance. To the extent ImmunoGen decides not to file,
prosecute or maintain any Licensed Patent Right that ImmunoGen reasonably believes covers or may cover the Development, Manufacture, Commercialization or use of any Licensed Product (other than any such Patent Right owned or co-owned by a Third
Party licensor or the filing of a new initial patent application) and except in the case in which the decision not to file, prosecute or maintain such Patent Right is made by ImmunoGen in the ordinary course of filing continuation applications or as
part of an overall strategy to optimize the scope or other aspects of the Licensed Intellectual Property, ImmunoGen shall provide CytomX with thirty (30) days prior written notice to such effect (i.e., at least thirty (30) days
prior to the date on which any such filing is intended or due or on which any other such action is due), in which event CytomX may elect to file or continue prosecution or maintenance of such Patent Right, at CytomX’s expense, and ImmunoGen,
upon CytomX’s written request received within such thirty (30) day period, shall execute such documents and perform such acts, at CytomX’s expense, as may be reasonably necessary to permit CytomX to file, prosecute and maintain such
Patent Right; provided that CytomX (a) shall keep ImmunoGen reasonably informed of the status of the filing, prosecution and maintenance of such Patent Rights, (b) shall consider in good faith any recommendations made by ImmunoGen in
regard to such filing, prosecution and maintenance of such Patent Right, and (c) shall not unreasonably refuse to incorporate any recommendations made by ImmunoGen in regard to such filing, prosecution or maintenance. Any such Patent Right that
is prosecuted or maintained by CytomX pursuant to this Section 5.2.2 (a) will continue to be owned by ImmunoGen, and (b) subject to the Parties’ other rights and obligations


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 42 








 
under this Agreement, may be licensed by ImmunoGen to one or more Third Parties. For avoidance of doubt, “prosecution” as used in this Section 5.2 includes oppositions,
nullity or revocation actions, post-grant reviews and other patent office proceedings involving the referenced Patent Rights. 
 5.2.3.
CytomX Patent Rights. CytomX, at its own expense, shall have the sole right, but not the obligation, to prepare, file, prosecute and maintain, throughout the world, any Patent Rights comprised in the CytomX TAP Platform Improvements. CytomX
shall consult with ImmunoGen in the filing, prosecution and maintenance of any Patent Right related to CytomX TAP Platform Improvements (including, without limitation, keeping ImmunoGen reasonably informed of the status thereof), shall consider in
good faith any recommendations made by ImmunoGen in regard to such filing, prosecution or maintenance, and shall not unreasonably refuse to incorporate any recommendations made by ImmunoGen in regard to such filing, prosecution or maintenance.
Nothing contained in this Agreement shall be construed as obligating CytomX to file any patent application in any country or other jurisdiction relating to CytomX TAP Platform Improvements. 

5.2.4. Joint Patent Rights. If not already established under the Research Collaboration Agreement, prior to either Party filing any
Patent Right disclosing Joint Program Technology or Joint TAP Platform Improvements, the Parties shall establish a patent committee (the “Patent Committee”) comprised of at least one (1) representative of each Party for the
purpose of facilitating the preparation, filing, prosecution, maintenance and defense of Joint Patent Rights. As agreed upon by the Parties, meetings of the Patent Committee may be face-to-face or may be conducted by teleconferences or
videoconferences, from time to time as needed. The Patent Committee will be the forum through which the Parties coordinate their respective obligations to each other described in Sections 5.2.2 and 5.2.3 hereof and in this
Section. In the event the Parties conceive or generate any Joint Program Technology or Joint TAP Platform Improvements, the Parties shall promptly meet to discuss and determine, based on mutual consent, whether to seek patent protection thereon,
which Party will control filing, prosecution and maintenance of such patents and how to pay for the filing, prosecution and maintenance of such patents. It is presumed that CytomX will control filing, prosecution and maintenance of Joint Patent
Rights claiming Joint Program Technology or Joint Unconjugated Probody Platform Improvements, and that ImmunoGen will control filing, prosecution and maintenance of Joint Patent Rights claiming Joint TAP Platform Improvements or Joint Conjugation
Probody Platform Improvements. Neither Party will file any Joint Patent Right without the prior written consent of the other Party, which consent shall not be unreasonably withheld, conditioned or delayed. The Party controlling filing and
prosecution of 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 43 








 
any such Joint Patent Right (a) shall keep the other Party informed regarding each Patent Right, (b) shall consider in good faith any recommendations made by the other Party in regard
to the filing, prosecution or maintenance of any such Patent Right and (c) shall not unreasonably refuse to incorporate any recommendations made by the other Party in regard to such filing, prosecution or maintenance. 

5.2.5. Improper Patent Filings. Each Party agrees that, without the prior written consent of the other Party, neither it nor any of its
Affiliates will claim in any patent application filed by or on behalf of such Party (or its Affiliate) any unpatented, nonpublic invention for which the inventor(s) (alone or with others) are employees of, or other persons obligated to assign
inventions to, the other Party or any Affiliate of the other Party, or disclose any such invention in any such patent application in a manner that would prejudice the other Party’s ability to patent such invention. 

5.2.6. Liability. Except for breaches of Section 5.2.5 hereof, to the extent that a Party is obtaining, prosecuting or
maintaining a Patent Right included in the Licensed Intellectual Property or Joint Patent Rights or otherwise exercising its rights under this Section 5.2, such Party, and its Affiliates, employees, agents or representatives, shall not
be liable to the other Party in respect of any act or omission on the part of any such Party, or its Affiliates, employees, agents or representatives, in connection with such activities undertaken in good faith. 

5.2.7. Extensions. The decision to file for a patent term extension and particulars thereof (including which patent(s) to extend) will
be made with the goal of obtaining the optimal patent term and scope of protection for Licensed Products. If a Party wishes to file for a patent term extension based on Patent Rights owned by the other Party, it will so notify the other Party, and
the Parties will meet to discuss and determine whether and how to proceed with such patent term extension. 
 5.3. Joint Research
Agreement. This Agreement shall be understood to be a joint research agreement under 35 U.S.C. § 103(c)(3) entered into for the purpose of Developing Licensed Products. 

5.4. Enforcement of Patent Rights. 

5.4.1. Notice. If either ImmunoGen or CytomX becomes aware of any infringement anywhere in the world of any issued Patent Right within
the Licensed Intellectual Property or Joint Patent Rights by any Third Party (an “Infringement”), such Party shall promptly notify the other Party in writing to that effect. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 44 








 5.4.2. Infringement of Certain Patent Rights. 

(a) In the event of any Infringement of a Patent Right included in the Licensed Intellectual Property (including, without limitation, Joint
Patent Rights included in the Joint TAP Platform Improvements and Joint Conjugation Probody Platform Improvements but excluding Joint Patent Rights included in the Joint Program Technology (other than Joint Conjugation Probody Platform
Improvements)), ImmunoGen shall have the first right to take action to obtain a discontinuance of Infringement or bring suit against a Third Party infringer of such Patent Right within six (6) months from the date of notice. 

(b) ImmunoGen shall bear all the expenses of any suit brought by it claiming infringement of any such Patent Right. CytomX shall reasonably
cooperate with ImmunoGen in any such suit and shall have the right to consult with ImmunoGen and to participate in and be represented by independent counsel in such litigation at its own expense. ImmunoGen shall incur no liability to CytomX as a
consequence of such litigation or any unfavorable decision resulting therefrom, including any decision holding any such Patent Right invalid or unenforceable, and ImmunoGen shall not, without CytomX’s prior written consent (which consent shall
not be unreasonably withheld, conditioned or delayed), enter into any settlement or consent decree that admits the invalidity or unenforceability or limits the scope of any such Patent Right. 

(c) If ImmunoGen has not obtained a discontinuance of such Infringement by, or filed suit against, any such Third Party infringer within the
six (6) month period set forth in subsection (a) above, then CytomX shall have the right, but not the obligation, to bring suit against such Third Party infringer, at CytomX’s sole expense, under any Licensed Intellectual Property.
ImmunoGen shall reasonably cooperate with CytomX in any such litigation, including being joined as a party, at CytomX’s expense, provided that ImmunoGen may, at its sole discretion, elect to be represented by independent counsel in such
litigation at its own expense. CytomX shall incur no liability to ImmunoGen as a consequence of such litigation or any unfavorable decision resulting therefrom, including any decision holding any such ImmunoGen Patent Right invalid or unenforceable;
and CytomX shall not, without ImmunoGen’s prior written consent (which ImmunoGen may withhold in its sole discretion), enter into any settlement or consent decree that requires any payment by or admits or imparts any other liability to
ImmunoGen or admits the invalidity or unenforceability or limits the scope of any such Patent Right. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 45 








 (d) In the event of any Infringement of a Joint Patent Right included in the Joint Program
Technology (other than Joint Conjugation Probody Platform Improvements), CytomX shall have the first right to take action to obtain a discontinuance of Infringement or bring suit against a Third Party infringer of such Patent Right within six
(6) months from the date of notice. 
 (e) CytomX shall bear all the expenses of any suit brought by it claiming infringement of any
such Patent Right. ImmunoGen shall reasonably cooperate with CytomX in any such suit and shall have the right to consult with CytomX and to participate in and be represented by independent counsel in such litigation at its own expense. CytomX shall
incur no liability to ImmunoGen as a consequence of such litigation or any unfavorable decision resulting therefrom, including any decision holding any such Patent Right invalid or unenforceable, and CytomX shall not, without ImmunoGen’s prior
written consent, enter into any settlement or consent decree that admits the invalidity or unenforceability or limits the scope of any such Patent Right. 

(f) If CytomX has not obtained a discontinuance of such Infringement by, or filed suit against, any such Third Party infringer within the six
(6) month period set forth in subsection (d) above, then ImmunoGen shall have the right, but not the obligation, to bring suit against such Third Party infringer, at ImmunoGen’s sole expense, under any CytomX TAP Platform
Improvements. CytomX shall reasonably cooperate with ImmunoGen in any such litigation, including being joined as a party, at ImmunoGen’s expense, provided that CytomX may, at its sole discretion, elect to be represented by independent counsel
in such litigation at its own expense. ImmunoGen shall incur no liability to CytomX as a consequence of such litigation or any unfavorable decision resulting therefrom, including any decision holding any such CytomX Patent Right invalid or
unenforceable; and ImmunoGen shall not, without CytomX’s prior written consent (which CytomX may withhold in its sole discretion), enter into any settlement or consent decree that requires any payment by or admits or imparts any other liability
to CytomX or admits the invalidity or unenforceability or limits the scope of any such Patent Right 
 (g) The enforcing Party shall keep
the other Party reasonably informed of all material developments in connection with any such suit. Any recoveries obtained by either Party as a result of any proceeding against such a Third Party infringer (“Monies”) shall be
allocated as follows: 
 (i) the Monies will be distributed first to the controlling Party for its out-of-pocket litigation costs and
expenses incurred in connection with such litigation; then 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 46 








 (ii) the Monies will then be distributed to the other Party for its out-of-pocket litigation
costs and expenses incurred in connection with such litigation; then 
 (iii) to the extent the remaining Monies recovered represent such
Third Party’s infringing sales with respect to Licensed Products, (A) ImmunoGen will receive an amount out of such remaining Monies equal to the royalties that would have been due upon sales of the infringing product as if such infringing
sales had been incremental Net Sales of a Licensed Product sold by CytomX (the “Deemed Royalty Portion”), and (B) CytomX will receive the amount of such remaining Monies representing such Third Party’s infringing sales with
respect to Licensed Products, minus the Deemed Royalty Portion; or 
 (iv) to the extent the remaining Monies recovered represent
CytomX’s lost profits with respect to Licensed Products, the amount of such Monies shall be grossed up to an amount equivalent to what would have been Net Sales (taking into account CytomX’s costs of manufacture and sale relative to such
Third Party’s costs of manufacture and sale) and (A) ImmunoGen will receive the Deemed Royalty Portion of such calculated Net Sales, and (B) CytomX will receive the amount of such remaining Monies representing CytomX’s lost
profits with respect to Licensed Products, minus the Deemed Royalty Portion; or 
 (v) to the extent the remaining Monies recovered
represent royalties from sales of a product that infringes (A) any Licensed Patent Rights alone or (B) any Licensed Patent Rights and any other Patent Rights owned by or licensed to CytomX or one of its Affiliates or Sublicensees,
and the applicable decision-making authority in the action, suit or proceeding has not allocated the Monies between ImmunoGen and the owner of such other Patent Rights, then the Parties shall agree, in good faith, to an allocation of such Monies
based on the relevant contributions of the Licensed Patent Rights and such other Patent Rights to the Licensed Product; provided that if the Parties are unable to agree in good faith as to the allocation of such Monies on such basis, then the
Parties shall submit such matter for determination to an Independent Patent Counsel; provided that the determination of such independent patent counsel shall be final and binding upon the Parties; then 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 47 








 (vi) if CytomX is the controlling Party, then CytomX will retain all Monies remaining after the
distributions described in subsections (i) through (v) above, including, without limitation, those for any multiple damages, punitive damages or other non-compensatory damages, which are applicable to the Licensed Products; or 

(vii) if ImmunoGen is the controlling Party, then ImmunoGen will retain all Monies remaining after the distributions described in
subsections (i) through (v) above, including, without limitation, those for any multiple damages, punitive damages or other non-compensatory damages. 

(h) Other Infringement. For any infringement of Patent Rights owned by CytomX or licensed by CytomX from Third Parties, CytomX retains
the sole right (as between the Parties), but not the obligation, to enforce such Patent Rights. 
 (i) Infringement of Joint Patent
Rights. With respect to any notice of a Third Party infringer of any Joint Patent Right other than a Patent Right included in the Joint Program Technology or Joint TAP Platform Improvements, the Parties shall meet as soon as reasonably
practicable to discuss such infringement and determine an appropriate course of action and the Parties’ respective rights and responsibilities with respect to any enforcement thereof. 

5.5. Response to Biosimilar Applicants. 

5.5.1. Notice. In the event that CytomX (a) receives a copy of a Biosimilar Application, whether or not such copy is provided under
any Applicable Laws (including the BPCIA, the United States Patient Protection and Affordable Care Act, implementing FDA regulations and guidance or similar foreign laws or regulations) applicable to the approval or manufacture of any biosimilar or
interchangeable biological product (a “Proposed Biosimilar Product”) for which a Licensed Product is a “reference product,” as such term is used in the BPCIA, or (b) otherwise becomes aware that such a Biosimilar
Application has been filed (such as in an instance described in Section 351(l)(9)(C) of the PHSA), then CytomX shall promptly provide ImmunoGen with written notice. 

5.5.2. Access to Confidential Information. Upon written request from ImmunoGen and to the extent permitted by Applicable Laws, CytomX
shall provide ImmunoGen with confidential access to those portions of the Biosimilar 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 48 








 
Application and such other information provided to CytomX by the Third Party that submitted the Biosimilar Application (the “Applicant”) that describe the Linker and Payload of
the Proposed Biosimilar Product or the method(s) of conjugating the cell-binding moiety of the Proposed Biosimilar Product to its Payload; provided, however, that prior to receiving the Biosimilar Application and such confidential information,
ImmunoGen shall provide notice to CytomX and the Applicant confirming its agreement to be subject to the confidentiality provisions in Section 351(l)(1)(B)(iii) of the PHSA. For purposes of clarity, the Parties acknowledge and agree that
ImmunoGen has retained a right to assert any patent within the Licensed Patent Rights and participate in litigation concerning any such patent. 

5.5.3. Proposed Patent List. 

(a) Preparation of Proposed Patent List. Not later than twenty (20) days from the date of receipt by CytomX of a copy of a
Biosimilar Application and related manufacturing information, CytomX, with cooperation from ImmunoGen, shall prepare and provide ImmunoGen with a list (the “Proposed Patent List”) of (i) those patents within the Licensed Patent
Rights that CytomX reasonably believes would be infringed by the manufacture and/or sale of the Proposed Biosimilar Product and (ii) those patents within the Licensed Patent Rights, if any, that CytomX would be willing to sublicense to such
Applicant in accordance with the terms of this Agreement. As soon as practicable following the date of receipt by ImmunoGen of the Proposed Patent List, ImmunoGen and CytomX shall discuss in good faith the patents within the Licensed Patent Rights
to be included on the Proposed Patent List and CytomX shall consider in good faith ImmunoGen’s proposals for changes to the Proposed Patent List with respect to the patents within the Licensed Patent Rights. Not later than the end of the period
specified by Applicable Laws, CytomX shall provide the Applicant with a copy of the Proposed Patent List; provided, however, that CytomX shall incorporate certain ImmunoGen requests in accordance with Section 5.5.3(d) hereof.
Notwithstanding the enforcement rights with respect to the Licensed Patent Rights set forth in Section 5.2.2 hereof, CytomX shall have the right to include any of the patents within the Licensed Patent Rights on the Proposed Patent List
to the extent that CytomX reasonably believes that a claim of patent infringement for such patent could be asserted by either ImmunoGen or CytomX; provided, however, that the right to control any suit or proceeding in which such a claim is asserted
shall be as set forth in Section 5.5.4 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 49 








 (b) Disclosure of Applicant’s Response. Provided that ImmunoGen has agreed to comply
with the confidentiality provisions in Section 351(l)(1)(B)(iii) of the PHSA and to the extent permitted by Applicable Laws, CytomX shall provide to ImmunoGen the portion of the Applicant Response (as defined below) pertaining to the Licensed
Patent Rights no later than ten (10) days from the date of receipt by CytomX of a response from the Applicant with regard to any patent within the Licensed Patent Rights included on the Proposed Patent List, including any response required by
the BPCIA (the “Applicant Response”). 
 (c) Preparation of CytomX Response. Not later than thirty (30) days
from the date of receipt by CytomX of the Applicant Response, CytomX, with cooperation and assistance from ImmunoGen, shall prepare and provide ImmunoGen with a proposed response with respect to the Licensed Patent Rights (the “CytomX
Response”) that (i) describes on a claim-by-claim basis, how each patent within the Licensed Patent Rights on the Proposed Patent List would be infringed by the commercial marketing of the Proposed Biosimilar Product, and
(ii) responds to Applicant’s claims, if any, that the patents within the Licensed Patent Rights on the Proposed Patent List are invalid or unenforceable. The CytomX Response shall include only the foregoing and shall not be construed to
include any proposed response to the Applicant relating to any patents other than the Licensed Patent Rights; further, any actual response to the Applicant under the BPCIA and all decisions relating to subsequent procedures under the BPCIA with
regard to any patent other than those included within the Licensed Patent Rights shall be within the sole discretion of CytomX. As soon as practicable following the date of receipt by ImmunoGen of the proposed CytomX Response, the Parties shall
discuss in good faith the statements in the proposed CytomX Response and CytomX shall consider in good faith ImmunoGen’s proposals for changes to the CytomX Response. Not later than the end of the period specified by Applicable Laws, CytomX
shall provide the Applicant with a copy of the CytomX Response; provided, however, that CytomX shall incorporate certain ImmunoGen requests in accordance with Section 5.5.3(d) hereof. 

(d) Inclusion of Licensed Patent Rights or Responsive Information. Provided that CytomX is legally able under Applicable Law to provide
ImmunoGen with a copy of the Biosimilar Application (and related manufacturing agreement) and ImmunoGen has provided notice to CytomX and Applicant confirming its agreement to be subject to the confidentiality provisions of
Section 351(l)(1)(B)(iii) of the PHSA, if ImmunoGen requests in writing to either (i) include a patent in the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 50 








 
Proposed Patent List that was not included in CytomX’s initial Proposed Patent List provided to ImmunoGen by CytomX pursuant to Section 5.5.3(a) hereof or (ii) include
responsive information with respect to any patent within the Licensed Patent Rights in the CytomX Response that was not included in CytomX’s initial CytomX Response provided to ImmunoGen pursuant to Section 5.5.3(c) hereof, then, absent
manifest error, CytomX shall include such patent in the Proposed Patent List and such responsive information in the CytomX Response provided to Applicant, as applicable; provided, however, that ImmunoGen shall indemnify CytomX in accordance with
Section 9.2 hereof to the extent any submissions requested by ImmunoGen are determined to have been made negligently or in bad faith. 

(e) Negotiation; ImmunoGen Rights. As soon as possible following the date on which CytomX provides the CytomX Response to the
Applicant, CytomX shall commence good faith negotiations with Applicant for a period of not more than fifteen (15) days (the “Negotiation Period”) in an effort to reach agreement on the patents on the Proposed Patent List (the
“Infringed Patent List”) that will be the subject to an Immediate Patent Infringement Action; provided, however, that if the Proposed Patent List includes both patents within the Licensed Patent Rights and patents that are not
within the Licensed Patent Rights, then CytomX shall not agree to the inclusion in the Infringed Patent List of any patents within the Licensed Patent Rights without the prior written consent of ImmunoGen, which consent shall not be unreasonably
withheld, conditioned or delayed. If CytomX and Applicant fail to reach agreement under Section 351(l)(4)(A) of the PHSA on the Infringed Patent List, CytomX shall have the sole right to determine under Section 351(l)(5)(B) of the PHSA
which patents of those on the Proposed Patent List should be the subject of an Immediate Patent Infringement Action; provided, however, that if the Proposed Patent List includes both patents within the Licensed Patent Rights and patents that are not
within the Licensed Patent Rights, then CytomX shall not include in the list of patents to be provided by CytomX to Applicant pursuant to Sections 351(l)(5)(B)(i)(II) of the PHSA any patents within the Licensed Patent Rights without the prior
written consent of ImmunoGen, which consent shall not be unreasonably withheld, conditioned or delayed. Within ten (10) days following the exchange of such lists by CytomX and the Applicant, CytomX shall, to the extent legally permissible,
provide ImmunoGen with a copy of the portion of the combined Infringed Patent List containing patents within the Licensed Patent Rights that will be the subject of an Immediate Patent Infringement Action. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 51 








 (f) Supplements to Proposed Patent List. ImmunoGen shall provide CytomX with a copy of
any U.S. patent within the Licensed Patent Rights that is issued after CytomX has provided the Proposed Patent List to the Applicant within ten (10) day after such issuance. As soon as practicable following the date of receipt by CytomX of
any such patent, ImmunoGen and CytomX shall discuss in good faith whether such patent would be infringed by the manufacture and/or sale of the Proposed Biosimilar Product. CytomX shall provide the Applicant with a supplement to the Proposed Patent
List to include such patent not later than thirty (30) days after the issuance of such patent if CytomX reasonably believes that a claim of patent infringement for such patent could be asserted by either ImmunoGen or CytomX or if ImmunoGen,
absent manifest error, requests that CytomX supplement the Proposed Patent List to include such patent provided, however, that ImmunoGen shall indemnify CytomX in accordance with Section 9.2 hereof to the extent any supplement
submissions requested by ImmunoGen are determined to have been made negligently or in bad faith. 
 5.5.4. Claims, Suits and
Proceedings. 
 (a) Immediate Patent Infringement Action. With respect to any patents within the Licensed Patent Rights or any
Patent Rights claiming CytomX TAP Platform Improvements, Joint Program Technology or Joint TAP Platform Improvements that are to be the subject of an Immediate Patent Infringement Action, the Parties’ respective rights and obligations with
respect to the litigation of such patents (including rights to initiate, step in, participate in, settle and share amounts recovered pursuant to such Immediate Patent Infringement Action, and obligations to pay legal costs and expenses with respect
to such Immediate Patent Infringement Action) shall be as set forth in Section 5.4.2 hereof, except that the Party having the first right to file a claim for Infringement against the Applicant with respect to any such patent subject to
an Immediate Patent Infringement Action shall file such claim within fifteen (15) days after agreement is reached as to the Infringed Patent List under Section 351(l)(4) or the exchange of the lists under Section 351(l)(5)(B) of the
PHSA, as applicable. 
 (b) Pre-Marketing Litigation. Either Party shall, within ten (10) days of receiving any notice of
commercial marketing provided by the Applicant pursuant to Section 351(l)(8)(A) of the PHSA (the “Premarket Notice”), notify the other Party. Thereafter, the Parties’ respective rights and obligations with respect to any
litigation pursuant to Section 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 52 








 
351(l)(8)(B) of the PHSA (including rights to initiate, step in, participate in, settle and share amounts recovered pursuant to such action, and obligations to pay legal costs and expenses with
respect to such action) shall be as set forth in Section 5.4.2 hereof. 
 (c) Cooperation; Standing. If a Party with the
right to initiate legal proceedings under this Section 5.5.4 lacks standing to do so (or lacks the right under the BPCIA to do so) and the other Party has standing (or the sole right under the BPCIA) to initiate such legal proceedings,
such Party with standing shall initiate such legal proceedings at the request and expense of the other Party. 
 5.5.5. Invalidity or
Unenforceability Defenses or Actions. In the event that the Applicant asserts, as a defense or as a counterclaim in any infringement action under Section 5.5.4 hereof, that any of the Licensed Patent Rights or any Patent Rights
claiming CytomX TAP Platform Improvements, Joint Program Technology or Joint TAP Platform Improvements is invalid or unenforceable, then the Parties’ respective rights and obligations with respect to the response to such defense or the defense
against such counterclaim, as applicable, (including rights to initiate, step in, participate in, settle and share amounts recovered pursuant to such action, and obligations to pay legal costs and expenses with respect to such action) shall be as
set forth in Section 5.4.2 hereof; provided that for these purposes any such defense or counterclaim shall be deemed to be an Infringement. In all other cases, including any declaratory judgment action or similar action or claim filed by
an Applicant asserting that any of the Licensed Patent Rights or any Patent Rights claiming CytomX TAP Platform Improvements, Joint Program Technology or Joint TAP Platform Improvements is invalid or unenforceable (as in a declaratory judgment
action brought by the Applicant following the Premarket Notice), then the Parties’ respective rights and obligations with respect to such action (including rights to initiate, step in, participate in, settle and share amounts recovered pursuant
to such action, and obligations to pay legal costs and expenses with respect to such action) shall be as set forth in Section 5.4.2 hereof; provided that for these purposes any such case shall be deemed to be an Infringement. 

5.5.6. Changes in Applicable Law. The Parties have agreed to the provisions of this Section 5.5 on the basis of the BPCIA
and other applicable laws and regulations in effect as of the Effective Date. If there are any material changes to the BPCIA or other Applicable Laws that would affect these provisions, the Parties will discuss amendments to this
Section 5.5 in good faith. 
 5.6. Interference, Opposition, Revocation and Declaratory Judgment Actions. If the Parties
mutually determine that, based upon the review of a Third Party’s patent or 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 53 








 
patent application or other intellectual property rights, it may be desirable in connection with any Licensed Product to provoke or institute an interference, opposition, revocation, post-grant
review or other patent office proceedings or declaratory judgment action with respect thereto, then the Parties shall consult with one another and shall reasonably cooperate in connection with such an action. Each Party shall retain all rights to
control any actions initiated prior to the Effective Date. 
 5.7. Infringement of Third Party Patent Rights. If the Development,
Manufacture, use or Commercialization of any Licensed Product is alleged by a Third Party to infringe a Third Party’s patent or other intellectual property rights, the Party becoming aware of such allegation shall promptly notify the other
Party. CytomX shall have the right to take such action as it deems appropriate in response to such allegation, and shall be solely responsible for all damages, costs and expenses in connection therewith, subject to Article 9 hereof. 

 

	6.	CONFIDENTIALITY 

 6.1. Confidentiality. Except to the extent expressly authorized
by this Agreement, the Parties agree that, during the Term and for ten (10) years thereafter, each Party, in its capacity as the Receiving Party shall: (a) keep the Disclosing Party’s Confidential Information confidential;
(b) not disclose, or permit the disclosure of, the Disclosing Party’s Confidential Information; and (c) not use, or permit to be used, the Disclosing Party’s Confidential Information for any purpose, in each case, except for the
performance of its obligations or exercise of its rights under this Agreement, provided, however, that the foregoing obligations shall not apply, or shall cease to apply, to the extent that such Confidential Information (i) was already known by
the Receiving Party or its Affiliates (other than under an obligation of confidentiality to the Disclosing Party) at the time of disclosure by the Disclosing Party; (ii) was generally available to the public or otherwise part of the public
domain at the time of its disclosure to the Receiving Party; (iii) became generally available to the public or otherwise part of the public domain after its disclosure to the Receiving Party, other than through any act or omission of the
Receiving Party or its Affiliates or any of their respective Representatives in breach of its obligations under this Agreement; (iv) was disclosed to the Receiving Party or its Affiliates, other than under an obligation of confidentiality, by a
Third Party who had no obligation to the Disclosing Party not to disclose such information to the Receiving Party ; or (v) was independently discovered or developed by or on behalf of the Receiving Party without the use of any Confidential
Information of the Disclosing Party. 
 6.2. Authorized Disclosure. 

6.2.1. Disclosure to Party Representatives. Notwithstanding the foregoing provisions of Section 6.1 hereof, the Receiving
Party may disclose Confidential Information belonging to the Disclosing Party to the Receiving Party’s 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 54 








 
Representatives who (a) have a need to know such Confidential Information in connection with the performance of the Receiving Party’s obligations or the exercise of the Receiving
Party’s rights under this Agreement and (b) have agreed in writing to non-disclosure and non-use provisions with respect to such Confidential Information that are at least as restrictive as those set forth in this Article 6.

 6.2.2. Disclosure to Third Parties. 

(a) Notwithstanding the foregoing provisions of Section 6.1 hereof, the Parties may disclose Confidential Information belonging to
the other Party: 
 (i) to Governmental Authorities to the extent reasonably necessary to obtain or maintain INDs or Regulatory Approvals
for any Licensed Product and in order to respond to inquiries, requests, investigations, orders or subpoenas of Governmental Authorities relating to this Agreement; 

(ii) to outside consultants, contractors, advisory boards, managed care organizations, and non-clinical and clinical investigators, in each
case to the extent reasonably necessary to Develop, Manufacture, use or Commercialize any Licensed Product under reasonable obligations of confidentiality; 

(iii) subject to Section 5.2 hereof, to the extent reasonably necessary, in connection with filing or prosecuting Patent Rights as
permitted by this Agreement; 
 (iv) to the extent reasonably necessary, in connection with prosecuting or defending litigation as permitted
by this Agreement; 
 (v) regarding the existence of this Agreement, this Agreement itself or the material and financial terms of this
Agreement, (A) to its accountants, lawyers, and other advisers, and (B) to actual or potential investors, lenders, licensors, licensees, acquirers, investment bankers, or agents of the foregoing in connection with a financing, licensing
transaction, merger, or acquisition, in each case (A)-(B) under confidentiality obligations no less restrictive than those set forth in this Agreement, provided that ImmunoGen shall not disclose the identity of the Licensed Target under clause
(B) without the prior written consent of CytomX; 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 55 








 (vi) subject to Section 6.3.2 hereof, in connection with or included in scientific
presentations and publications relating to Licensed Products, including abstracts, posters, journal articles and the like, and posting results of and other information about clinical trials to clinicaltrials.gov or PhRMA websites; and 

(vii) to the extent necessary in order to enforce its rights under this Agreement. 

(b) In the event a Party deems it reasonably necessary to disclose Confidential Information belonging to the other Party pursuant to
Section 6.2.2(a)(i) hereof, the Disclosing Party shall to the extent possible give reasonable advance written notice of such disclosure to the other Party and take all reasonable measures to ensure confidential treatment of such
information. 
 (c) Data generated by CytomX using Licensed Products shall not be considered Confidential Information of ImmunoGen, and,
therefore, not subject to this Article 6. 
 6.2.3. SEC Filings and Other Disclosures. Notwithstanding any provision of
this Agreement to the contrary, either Party may disclose the existence or terms of this Agreement to the extent required, in the reasonable opinion of such Party’s legal counsel, to comply with Applicable Law. Notwithstanding the foregoing,
before disclosing this Agreement or any of the terms hereof pursuant to this Section 6.2.3, the Parties will consult with one another on the terms of this Agreement to be redacted in making any such disclosure. Further, if a Party
discloses this Agreement or any of the terms hereof in accordance with this Section 6.2.3, such Party shall, at its own expense, use Commercially Reasonable Efforts to seek such confidential treatment of confidential portions of this
Agreement and such other terms, as may be reasonably requested by the other Party. 
 6.3. Public Announcements; Publications. 

6.3.1. Announcements. Except as may be expressly permitted under Section 6.2.3, neither Party will make any public
announcement regarding the existence or terms of this Agreement without the prior written approval of the other Party. For the sake of clarity, nothing in this Agreement shall prevent either Party from making any public disclosure relating to this
Agreement if the contents of such public disclosure have previously been made public other than through a breach of this Agreement by the issuing Party or its Affiliates. The Parties shall mutually agree to one or more press releases regarding the
signing of this 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 56 








 
Agreement following the Effective Date. The Parties agree that each Party may issue future announcements concerning CytomX’s achievement of any significant milestones, including the
selection of a clinical candidate, under this Agreement, provided that the content of any such announcement has been mutually agreed upon by the Parties. 

6.3.2. Publications. The Parties acknowledge that scientific publications and presentations must be strictly monitored to prevent any
adverse effect from premature publication or dissemination of results of the activities hereunder. Each Party (in such capacity the “Publishing Party”) agrees that, except as required by Applicable Laws, it shall not publish or
present, or permit to be published or presented, any results of the Development, Manufacture, use or Commercialization of a Licensed Product to the extent such results refer to, derive from or otherwise relate to the Licensed Intellectual Property
(the “Covered Results”), without the prior review by and approval of the other Party (in such capacity, the “Non-Disclosing Party”), which approval shall not be unreasonably withheld; provided that it shall not be
deemed unreasonable for CytomX to withhold its consent to any request by ImmunoGen to publish or disseminate Covered Results prior to the publication or dissemination of such Covered Results by CytomX. The Publishing Party shall submit to the
Non-Disclosing Party for review and approval any proposed academic, scientific and medical publication or public presentation which contains Covered Results or otherwise contains the Non-Disclosing Party’s Confidential Information; provided
that the foregoing requirement shall apply to CytomX only to the extent any such proposed publication or presentation would refer to, describe or otherwise disclose Confidential Information of ImmunoGen (including, without limitation, any non-public
Licensed Intellectual Property). In addition, each Party shall submit to the other Party for review and approval any proposed publication or public presentation relating to data generated under the Research Program. In both instances, such review
and approval will be conducted for the purposes of preserving the value of the Licensed Intellectual Property and determining whether any portion of the proposed publication or presentation containing the Non-Disclosing Party’s Confidential
Information should be modified or deleted. Written copies of such proposed publication or presentation required to be submitted hereunder shall be submitted to the Non-Disclosing Party no later than thirty (30) days before submission for
publication or presentation (the “Review Period”). The Non-Disclosing Party shall provide its comments with respect to such publications and presentations within fifteen (15) days after its receipt of such written copy, and the
Publishing Party shall delete any Confidential Information of the Non-Disclosing Party upon request. The Review Period may be extended for an additional sixty (60) days in the event the Non-Disclosing Party can, within fifteen (15) days of
receipt of the written copy, demonstrate 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 57 








 
reasonable need for such extension, including for the preparation and filing of patent applications. The Parties will each comply with standard academic practice regarding authorship of
scientific publications and recognition of contribution of other parties in any publication governed by this Section 6.3.2. 

6.3.3. Integration. As to the subject matter of this Agreement, this Article 6 supersedes any confidential disclosure
agreements between the Parties, including, without limitation, the Confidentiality Agreement and the confidentiality provisions of the Research Collaboration Agreement. Any confidential information of a Party disclosed under the Confidentiality
Agreement or the Research Collaboration Agreement relating to the subject matter of this Agreement shall be treated as Confidential Information of such Party hereunder, subject to the terms of this Article 6. 

 

	7.	REPRESENTATIONS AND WARRANTIES. 

 7.1. Mutual Representations and Warranties. Each
of CytomX and ImmunoGen hereby represents and warrants to the other that: 
 7.1.1. it is duly organized, validly existing and in good
standing under the laws of the jurisdiction of its organization; 
 7.1.2. the execution, delivery and performance of this Agreement by such
Party has been duly authorized by all requisite action under the provisions of its charter, bylaws and other organizational documents, and does not require any action or approval by any of its shareholders or other holders of its voting securities
or voting interests; 
 7.1.3. it has the power and authority to execute and deliver this Agreement and to perform its obligations hereunder;

 7.1.4. this Agreement has been duly executed and is a legal, valid and Binding Obligation on it, enforceable against it in accordance with
its terms; and 
 7.1.5. the execution, delivery and performance by such Party of this Agreement and its compliance with the terms and
provisions hereof does not and will not conflict with or result in a breach of or default under any Binding Obligation existing as of the Effective Date. 

7.2. Representations and Warranties of ImmunoGen. Except as set forth in a written disclosure letter (the “Disclosure
Letter”) delivered by ImmunoGen to CytomX within fifteen (15) days after the Effective Date (which shall be deemed Confidential Information of ImmunoGen), ImmunoGen hereby represents and warrants to CytomX that as of the Effective
Date: 
 7.2.1. to its Knowledge, (a) the issued and unexpired patents within the Licensed Intellectual Property are valid and
enforceable patents and (b) ImmunoGen has received no written notice from a Third Party challenging or threatening to challenge the extent, validity or enforceability of any Licensed Patent Rights; 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 58 








 7.2.2. to its Knowledge, ImmunoGen has received no written notice from a Third Party claiming
that the use, practice or application of the Licensed Intellectual Property pursuant to the license granted hereunder to CytomX will infringe the issued patents of any such Third Party (excluding, for clarity, any potential infringement that might
arise solely as a result of the combination of any Licensed Intellectual Property with any other technology or intellectual property); and 

7.2.3. there is no (a) claim, demand, suit, proceeding, arbitration, inquiry, investigation or other legal action of any nature, civil,
criminal, regulatory or otherwise, pending or, to its Knowledge, threatened against ImmunoGen or any of its Affiliates or (b) judgment or settlement against or owed by ImmunoGen or any of its Affiliates, in each case in connection with the
Licensed Intellectual Property or relating to the transactions contemplated by this Agreement 
 For purposes of this Section 7.2,
“Knowledge” means the actual knowledge (without having conducted, or having any duty to conduct, any specific inquiry) of the following ImmunoGen employees: (i) any “executive officer” (as defined in Rule 3b-7
promulgated under the Securities Exchange Act of 1934, as amended) and (ii) chief patent counsel (or person with similar responsibilities). 

7.3. Government Approvals. Each of CytomX and ImmunoGen shall cooperate with the other Party and use Commercially Reasonable Efforts to
make all registrations, filings and applications, to give all notices and to obtain as soon as practicable all governmental or other consents, transfers, approvals, orders, qualifications authorizations, permits and waivers, if any, and to do all
other things necessary or desirable for the consummation of the transactions as contemplated hereby. 
 7.4. Further Covenants. In
addition to the covenants made elsewhere in this Agreement, ImmunoGen hereby covenants to CytomX that, from the Effective Date until expiration or termination of this Agreement, it will not (a) knowingly take any action that conflicts with the
rights under the Licensed Intellectual Property granted to CytomX under this Agreement or (b) knowingly fail to take any action that is reasonably necessary to avoid a conflict with the rights under the Licensed Intellectual Property granted to
CytomX under this Agreement. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 59 








 7.5. Representation by Legal Counsel. Each Party hereto represents that it has been
represented by legal counsel in connection with this Agreement and acknowledges that it has participated in the drafting hereof. In interpreting and applying the terms and provisions of this Agreement, the Parties agree that no presumption shall
exist or be implied against the Party which drafted such terms and provisions. 
 7.6. Warranty Disclaimers. 

7.6.1. Except as expressly set forth in Section 7.1 or 7.2 hereof, nothing in this Agreement is or shall be construed as a
warranty or representation by ImmunoGen (a) as to the validity or scope of any patent application or patent within the Licensed Patent Rights or (b) that anything made, used, sold or otherwise disposed of under any license granted under
this Agreement is or will be free from infringement of patents, copyrights and other rights of Third Parties. 
 7.6.2. EXCEPT AS OTHERWISE
EXPRESSLY PROVIDED IN THIS AGREEMENT, NEITHER PARTY MAKES ANY REPRESENTATION OR EXTENDS ANY WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH RESPECT TO ANY TECHNOLOGY, GOODS, SERVICES, RIGHTS OR OTHER SUBJECT MATTER OF THIS AGREEMENT, INCLUDING,
WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. 
  

	8.	TERM AND TERMINATION. 

 8.1. Term. The term of this Agreement (the
“Term”) shall commence on the Effective Date and shall extend, unless this Agreement is terminated earlier in accordance with this Article 8, on a Licensed Product-by-Licensed Product and country-by-country basis, until
such time as the Royalty Term with respect to the sale of such Licensed Product in such country expires. Provided this Agreement has not been terminated prior thereto by ImmunoGen under Section 8.3, 8.4 or 8.5 hereof or by
CytomX under Section 8.2 or 8.4 hereof, following the expiration of the Royalty Term applicable to a Licensed Product in a country in accordance with Section 1.134 hereof, CytomX and its Affiliates shall have a fully
paid-up, irrevocable, freely transferable and sublicensable license under the relevant Licensed Intellectual Property, to make, have made, use, sell, offer for sale and import such Licensed Products in such country. 

8.2. Voluntary Termination by CytomX. CytomX shall have the right to terminate this Agreement at any time prior to the achievement of
the first Regulatory Marketing Approval for any Licensed Product in any country or other jurisdiction in the Territory, upon not less than ninety (90) days’ prior written notice to ImmunoGen. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 60 








 8.3. Termination by Either Party for Cause. Either Party may terminate this Agreement in
its entirety at any time during the Term by giving written notice to the other Party if the other Party commits a material breach of its obligations under this Agreement (a “Material Breach”), such notice to describe such Material
Breach in reasonable detail, and such Material Breach remains uncured for ninety (90) days, measured from the date written notice of such breach is given to the breaching Party; provided, however, that if the nature of the asserted breach is
such that more than ninety (90) days are reasonably required to cure, then the cure period shall be extended for a period not to exceed an additional sixty (60) days so long as the Party seeking to cure the asserted breach is diligently
pursuing such cure to completion. 
 8.4. Termination on Insolvency. This Agreement may be terminated upon written notice by either
Party at any time in the event of an Insolvency Event of the other Party. 
 8.5. Termination for Material Breach of the Research
Collaboration Agreement by CytomX. ImmunoGen shall have the right to terminate this Agreement, effective upon thirty (30) days’ prior written notice to CytomX, in the event ImmunoGen has terminated the Research Collaboration Agreement
due to the occurrence of a Material Breach (as defined in the Research Collaboration Agreement) thereunder by CytomX which remains uncured as of the termination date of the Research Collaboration Agreement. 

8.6. Effects of Expiration or Termination. 

8.6.1. Effect of Termination by ImmunoGen under Section 8.3, 8.4 or 8.5 or by CytomX under Section 8.2. If ImmunoGen
terminates this Agreement pursuant to Section 8.3, 8.4 or 8.5 hereof, or CytomX terminates this Agreement pursuant to Section 8.2 hereof, then: 

(a) the license granted by ImmunoGen to CytomX and its Affiliates under Section 3.1.1 hereof shall immediately terminate, and
CytomX and its Affiliates shall discontinue the use of any Licensed Intellectual Property except, with respect to the Licensed Patent Rights, as otherwise permitted under 35 U.S.C. § 271(e)(1) with respect to activities performed in
the United States; 
 (b) CytomX and its Affiliates and Sublicensees shall cease any Development and Commercialization of Licensed Products
in the Territory, subject to Section 8.6.3 hereof; and 
 (c) each Party shall promptly return or destroy all of the other
Party’s Confidential Information, provided that each Party may retain, subject to Article 6 hereof, (i) one (1) copy of the other Party’s Confidential 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 61 








 
Information in its archives solely for the purpose of establishing the contents thereof and ensuring compliance with its obligations hereunder, (ii) any Confidential Information of the other
Party contained in its laboratory notebooks or databases, and (iii) any Confidential Information of the other Party to the extent reasonably required to exercise its rights and perform its obligations under any other then-outstanding License
Agreement. 
 8.6.2. Effect of Termination by CytomX under Section 8.3 or 8.4. If CytomX terminates this Agreement pursuant to
Section 8.3 or 8.4 hereof, then 
 (a) the license granted to CytomX by ImmunoGen pursuant to Section 3.1.1
hereof shall continue on the terms set forth herein, subject to CytomX’s continued payment of all milestone and royalty payments in accordance with this Agreement, and on a country-by-country and Licensed Product-by-Licensed Product basis, upon
the expiration of the Royalty Term applicable to a Licensed Product in country in accordance with Section 1.134 hereof and provided CytomX shall have paid to ImmunoGen all royalty amounts due to ImmunoGen with respect to Net Sales in
such country, CytomX and its Affiliates shall thereafter have a fully paid-up, irrevocable, freely transferable ad sublicensable license under the relevant Licensed Intellectual Property, to make, have made, use, sell, offer for sale and import such
Licensed Product in such country; 
 (b) ImmunoGen shall remain entitled to receive payments that accrued before the effective date of such
termination; and 
 (c) each Party shall promptly return or destroy all of the other Party’s Confidential Information, provided that
each Party may retain, subject to Article 6 hereof, (i) one (1) copy of the other Party’s Confidential Information in its archives solely for the purpose of establishing the contents thereof and ensuring compliance with
its obligations hereunder, (ii) any Confidential Information of the other Party contained in its laboratory notebooks or databases and (iii) any Confidential Information of the other Party to the extent reasonably required to exercise its
rights and perform its obligations under any then-outstanding License Agreement. The foregoing notwithstanding, and subject to Article 6 hereof, CytomX may retain and use ImmunoGen’s Confidential Information with respect to the
exercise of its rights set forth in clause (a) above or necessary or useful to exercise any other of its rights under this Agreement that survive such termination. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 62 








 8.6.3. Treatment of Sublicensees on Termination. Notwithstanding the foregoing, ImmunoGen
shall permit a Sublicensee of CytomX to become its direct Sublicensee upon notification to ImmunoGen. 
 8.6.4. Satisfaction of
Obligations During Notice Period. During the period from providing a notice of termination through the termination of the Agreement, the Parties shall continue to perform their obligations under this Agreement. 

8.6.5. Pending Dispute Resolution. If a Party gives notice of termination and the other Party disputes whether such notice was proper,
then the issue of whether this Agreement has been terminated shall be resolved in accordance with Section 10.9 or 10.10 hereof, as applicable, and this Agreement shall remain in effect pending the resolution of such dispute. If as
a result of such dispute resolution process it is determined that the notice of termination was proper, then such termination shall be effective immediately. If as a result of such dispute resolution process it is determined that the notice of
termination was improper, then no termination shall have occurred and this Agreement shall remain in effect. Anything contained in this Agreement to the contrary notwithstanding, if the asserted breach is cured or shown to be non-existent within the
applicable cure period, the first notice of breach hereunder shall be deemed automatically withdrawn and of no effect. 
 8.7. Disposition
of Inventories of Products. Following termination of this Agreement by ImmunoGen pursuant to Section 8.3 or 8.4, CytomX and its Affiliates and Sublicensees shall have the right to continue to sell their existing inventories of
Licensed Product(s) that have received Regulatory Marketing Approval prior to such termination for a period not to exceed six (6) months after the effective date of such termination or expiration and CytomX shall pay any milestones and
royalties payable in connection with such sales in accordance with Article 4 hereof. 
 8.8. Remedies. Except in the case
of either Party’s breach of Section 2.6 or Article 6 hereof, the rights of the non-breaching Party set forth in Section 8.6 hereof shall be the exclusive legal remedy to a Party arising from a Material Breach; provided,
however, that (a) in addition to the foregoing legal remedy, the Parties may seek any and all equitable remedies, including, without limitation, declarative and injunctive relief and specific performance in accordance with applicable law, and
(b) nothing in this Section shall limit the Parties’ respective rights and obligations with respect to (i) Unauthorized Use of the other Party’s Confidential Information or Proprietary Materials, (ii) unauthorized disclosure
of the other Party’s Confidential Information or (iii) indemnification as set forth in Article 9 hereof. 
 8.9.
Survival of Certain Obligations. Expiration or termination of this Agreement shall not relieve the Parties of any obligation that accrued before such expiration or 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 63 








 
termination. The following provisions shall survive expiration or termination of this Agreement: Sections 2.5.2, 2.5.3, 2.5.4, 2.6 and 3.3,
Articles 4, 5 and 6, Sections 7.6, 8.1, 8.6, 8.7 (for the period set forth therein), 8.8 and 8.9, and Articles 9 and 10. For avoidance of doubt, any other
Section that explicitly states it survives expiration or termination of this Agreement shall so survive. 
  

	9.	LIMITATION ON LIABILITY, INDEMNIFICATION AND INSURANCE. 

 9.1. No Consequential
Damages. Except with respect to liability arising from a breach of Article 6 hereof, in no event will either Party, its Affiliates or any of its or its Affiliates’ respective Representatives be liable under this Agreement for any
special, indirect, incidental, consequential or punitive or exemplary damages, whether in contract, warranty, tort, negligence, strict liability or otherwise, (a) including loss of profits or revenue suffered by either Party or any of its
respective Affiliates or Representatives or (b) cost of procurement of substitute goods, technology or services, even if either Party is informed in advance of the possibility of such damages and even if the remedies provided for in this
Agreement fail of their essential purpose. For purposes of clarity, a Party’s monetary liability under a Third Party Claim for such Third Party’s special, indirect, incidental or consequential damages or for any punitive or exemplary
damages payable in connection with such Third Party Claim, shall be deemed to be the direct damages of such Party for purposes of this Article 9. 

9.2. Indemnification by ImmunoGen. ImmunoGen will indemnify, defend and hold harmless CytomX, its Affiliates and each of its and their
respective employees, officers, directors and agents (each, a “CytomX Indemnified Party”) from and against any and all liability, loss, damage, expense (including reasonable attorneys’ fees and expenses) and cost (collectively,
a “Liability”) as a direct result of any Third Party claims, suits, actions, demands or judgments, including, without limitation, personal injury and product liability matters (collectively, “Third Party Claims”)
arising out of a Material Breach of this Agreement by ImmunoGen, except, in each case, to the extent any such Third Party Claim or Liability results from a Material Breach of this Agreement by CytomX, the Development, Manufacture, Commercialization
or use (including, without limitation, the production, manufacture, promotion, import, sale or use by any Person) of any Licensed Product by, on behalf of, or under the authority of, CytomX or any of its Affiliates, Sublicensees, subcontractors,
distributors or agents (other than an ImmunoGen Indemnified Party), or the negligence, recklessness or intentional acts of CytomX or any of its Affiliates, Sublicensees, subcontractors, distributors or agents; provided that with respect to any Third
Party Claim for which CytomX also has an obligation to indemnify any ImmunoGen Indemnified Party pursuant to Section 9.3 hereof, ImmunoGen shall indemnify each CytomX Indemnified Party for its Liability to the extent of ImmunoGen’s
responsibility, relative to CytomX (or to Persons for whom CytomX is legally responsible), for the facts underlying the Third Party Claim. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 64 








 9.3. Indemnification by CytomX. CytomX will indemnify, defend and hold harmless ImmunoGen,
its Affiliates, contractors, distributors and each of its and their respective employees, officers, directors and agents (each, a “ImmunoGen Indemnified Party”) from and against any and all Liabilities as a direct result of any
Third Party Claims arising out of: 
 (a) the Development, Manufacture, Commercialization or use (including, without limitation, the
production, manufacture, promotion, import, sale or use by any Person) of any Licensed Product by, on behalf of, or under the authority of, CytomX or any of its Affiliates, Sublicensees, subcontractors, distributors or agents (other than by any
ImmunoGen Indemnified Party); or 
 (b) a Material Breach of this Agreement by CytomX; 

except to the extent any such Third Party Claim or Liability results from a Material Breach of this Agreement by ImmunoGen or the negligence,
recklessness or intentional acts of ImmunoGen or any ImmunoGen Indemnified Party; provided that with respect to any Third Party Claim for which ImmunoGen also has an obligation to indemnify any CytomX Indemnified Party pursuant to Section 9.2
hereof, CytomX shall indemnify each ImmunoGen Indemnified Party for its Liability to the extent of CytomX’s responsibility, relative to ImmunoGen (or to Persons for whom ImmunoGen is legally responsible), for the facts underlying the Third
Party Claim. 
 9.4. Procedure. 

9.4.1. Notice. Each Party will notify the other Party in writing in the event it becomes aware of a claim for which indemnification may
be sought hereunder. In the event that any Third Party asserts a claim or other proceeding (including any governmental investigation) with respect to any matter for which a Party (the “Indemnified Party”) is entitled to
indemnification hereunder, then the Indemnified Party shall promptly notify the Party obligated to indemnify the Indemnified Party (the “Indemnifying Party”) thereof; provided, however, that no delay on the part of the Indemnified
Party in notifying the Indemnifying Party shall relieve the Indemnifying Party from any obligation hereunder unless (and then only to the extent that) the Indemnifying Party is prejudiced thereby. 

9.4.2. Control. The Indemnifying Party shall have the right, at its sole cost and expense, exercisable by notice to the Indemnified
Party within ten (10) Business Days after receipt of notice from the Indemnified Party of the commencement of or assertion of any Third Party Claim, to assume direction and control of the defense, litigation, settlement, appeal or other
disposition of the Third Party Claim (including the right to settle the claim solely for monetary consideration) with counsel selected by the Indemnifying Party and reasonably acceptable to the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 65 








 
Indemnified Party. The Indemnified Party shall cooperate, and shall cause its Affiliates and agents to cooperate upon request of the Indemnifying Party, in the defense or prosecution of the Third
Party Claim, including by furnishing such records, information and testimony and attending such conferences, discovery proceedings, hearings, trials or appeals as may reasonably be requested by the Indemnifying Party. The Indemnified Party shall
have the right to join in (including the right to conduct discovery, interview and examine witnesses and participate in all settlement conferences), but not control, at its own expense, the defense of any Third Party Claim that the other Party is
defending as provided in this Agreement. 
 9.4.3. Settlement. Neither the Indemnifying Party nor the Indemnified Party shall enter
into any compromise or settlement of a Third Party Claim for which the right to indemnification hereunder has been asserted without the Indemnified Party’s prior written consent, which consent shall not be unreasonably withheld, conditioned or
delayed; provided that the Indemnifying Party may, without the Indemnified Party’s prior written consent, agree or consent to any settlement or other resolution of such Third Party Claim which requires solely money damages paid by the
Indemnifying Party, and which includes as an unconditional term thereof the giving by such claimant or plaintiff to the Indemnified Party of a release from all liability in respect of such Third Party Claim. Each of the Indemnifying Party and the
Indemnified Party shall not make any admission of liability in respect of any Third Party Claim without the prior written consent of the other Party, and the Indemnified Party shall use reasonable efforts to mitigate Liabilities arising from such
Third Party Claim. 
 9.5. Insurance. Each Party shall obtain and maintain, during the Term, commercial general liability insurance,
including products liability insurance, with reputable and financially secure insurance carriers (or pursuant to a program of self-insurance reasonably satisfactory to the other Party) to cover its indemnification obligations under
Section 9.2 or 9.3 hereof with respect to bodily injury (including death) and damage to property, as applicable, in each case with limits of not less than $3,000,000 per occurrence and in the aggregate. Insurance (other than
permitted self-insurance) shall be procured with carriers having an A.M. Best Rating of A-VII or better. Any indemnification payment hereunder shall be made net of any insurance proceeds which the Indemnified Party is entitled to recover;
provided, however, that if, following the payment to the Indemnified Party of any amount under this Article 9, such Indemnified Party becomes entitled to recover any insurance proceeds in respect of the claim for which such
indemnification payment was made, the Indemnified Party shall promptly pay an amount equal to the amount of such proceeds (but not exceeding the amount of such indemnification payment) to the Indemnifying Party. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 66 









	10.	MISCELLANEOUS. 

 10.1. Assignment. Neither Party may assign this Agreement without
the prior written consent of the other Party, which consent will not be unreasonably withheld, conditioned or delayed; provided, however, that such consent shall not be required in connection with any assignment of this Agreement to an Affiliate of
the assigned Party, or to a Third Party in connection with the transfer or sale of the business to which this Agreement relates, or to any successor Person resulting from any merger or consolidation of such Party with or into such Person, provided
that the assignee shall have agreed in writing to assume all of the assignor’s obligations hereunder, and provided, further, that the other Party shall be notified promptly after such assignment has been effected. This Agreement shall be
binding upon the successors and permitted assigns of the Parties and the name of a Party appearing herein shall be deemed to include the names of such Party’s successors and permitted assigns to the extent necessary to carry out the intent of
this Agreement. Any purported assignment not in accordance with this Section 10.1 shall be null and void. 
 10.2. Further
Actions. Each Party agrees to execute, acknowledge and deliver such further instruments, and to do all such other acts, as may be necessary or appropriate in order to carry out the purposes and intent of the Agreement. 

10.3. Force Majeure. Each Party shall be excused from the performance of its obligations under this Agreement to the extent that such
performance is prevented by force majeure (defined below) and the nonperforming Party promptly provides notice of the prevention to the other Party. Such excuse shall be continued so long as the condition constituting force majeure
continues and the nonperforming Party takes Commercially Reasonable Efforts to resume performance. For purposes of this Agreement, “force majeure” shall include conditions beyond the control of the Parties, including an act of God,
voluntary or involuntary compliance with any Applicable Law or order of any government, war, act of terror, civil commotion, labor strike or lock-out, epidemic, failure or default of public utilities or common carriers, or destruction of production
facilities or materials by fire, earthquake, storm or like catastrophe; provided that financial inability to pay in and of itself shall not be considered to be a force majeure event. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 67 








 10.4. Notices. Any notice or notification required or permitted to be provided pursuant to
the terms and conditions of this Agreement (including any notice of force majeure, breach, termination, change of address, etc.) shall be in writing and shall be deemed given upon receipt if delivered personally or by facsimile transmission
(receipt verified), five (5) Business Days after deposited in the mail if mailed by certified mail (return receipt requested) postage prepaid, or on the next Business Day if sent by overnight delivery using a nationally recognized express
courier service and specifying next Business Day delivery (receipt verified), to the Parties at the following addresses or facsimile numbers (or at such other address or facsimile number for a Party as shall be specified by like notice, provided,
however, that notices of a change of address shall be effective only upon receipt thereof): 
 All correspondence to ImmunoGen shall be
addressed as follows: 
 ImmunoGen, Inc. 

830 Winter Street 
 Waltham, MA
02451 
 Attn: Vice President, Business Development 

Fax: [***] 
 All correspondence
to CytomX shall be addressed as follows: 
 CytomX Therapeutics, Inc. 

343 Oyster Point Blvd., Suite 100 

South San Francisco, CA 94080-7014 

Attn: CEO 
 Fax: 1-650-351-0353

 To help expedite the other Party’s awareness and response, copies of notices may be provided to the other Party by email but must be
supplemented by one of the following methods: (a) personal delivery, (b) first class certified mail with return receipt requested, or (c) next-day delivery by major international courier, with confirmation of delivery. Electronic
copies may be sent via email to [***] at CytomX and to [***] at ImmunoGen so long as such individuals remain employed by CytomX or ImmunoGen, respectively. 

10.5. Amendment. No amendment, modification or supplement of any provision of this Agreement shall be valid or effective unless made in
writing and signed by a duly authorized officer of the Party to be bound. 
 10.6. Waiver. No provision of this Agreement shall be
waived by any act, omission or knowledge of a Party or its agents or employees except by an instrument in writing expressly waiving such provision and signed by a duly authorized officer of the waiving Party. The waiver by either of the Parties of
any breach of any provision hereof by the other Party shall not be construed to be a waiver of any succeeding breach of such provision or a waiver of the provision itself. 

10.7. Severability. If any clause or portion thereof in this Agreement is for any reason held to be invalid, illegal or unenforceable,
the same shall not affect any other portion of this Agreement, as it is the intent of the Parties that this Agreement shall be construed in such fashion as to maintain its existence, validity and enforceability to the greatest extent 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 68 








 
possible. In any such event, this Agreement shall be construed as if such clause or portion thereof had never been contained in this Agreement, and there shall be deemed substituted therefor such
provision as will most nearly carry out the intent of the Parties as expressed in this Agreement to the fullest extent permitted by Applicable Law. 

10.8. Descriptive Headings. The descriptive headings of this Agreement are for convenience only and shall be of no force or effect in
construing or interpreting any of the provisions of this Agreement. 
 10.9. Dispute Resolution. The Parties recognize that a
bona fide dispute as to certain matters may arise from time to time during the Term relating to either Party’s rights or obligations hereunder or otherwise relating to the validity, enforceability or performance of this Agreement,
including disputes relating to alleged breach or termination of this Agreement but excluding any disputes relating to Article 6 hereof or disputes relating to the determination of the validity, scope, infringement, enforceability,
inventorship or ownership of the Parties’ respective Patent Rights (hereinafter, a “Dispute”). In the event of the occurrence of any Dispute, the Parties shall follow the following procedures in an attempt to resolve the
dispute or disagreement: 
 10.9.1. The Party claiming that such a Dispute exists shall give notice in writing (a “Notice of
Dispute”) to the other Party of the nature of the Dispute. 
 10.9.2. Within fourteen (14) days of receipt of a Notice of
Dispute, the ImmunoGen Alliance Manager and the CytomX Alliance Manager shall meet in person or by teleconference and exchange written summaries reflecting, in reasonable detail, the nature and extent of the Dispute, and at this meeting they shall
use their reasonable endeavors to resolve the Dispute. 
 10.9.3. If the Alliance Managers are unable to resolve the Dispute during the
meeting described in Section 10.9.2 hereof or if for any reason such meeting does not take place within the period specified in Section 10.9.2 hereof, then the Dispute will be referred to the JDC which shall meet no later
than forty-five (45) days following the initial receipt of the Notice of Dispute and use reasonable endeavors to resolve the Dispute. 

10.9.4. If the JDC is unable to resolve the Dispute during the meeting described in Section 10.9.3 hereof or if for any reason such
meeting does not take place within the period specified in Section 10.9.3 hereof, then the Chief Executive Officer of ImmunoGen and the Chief Executive Officer of CytomX shall meet at a mutually agreed-upon time and location for the
purpose of resolving such Dispute. 
 10.9.5. If, within ninety (90) days of initial receipt of the Notice of Dispute, the Dispute has
not been resolved, or if, for any reason, the meeting described in 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 69 








 
Section 10.9.4 hereof has not been held within ninety (90) days of initial receipt of the Notice of Dispute, then the Parties agree that such Dispute shall be finally resolved through
binding arbitration to be administered by JAMS pursuant to its Comprehensive Arbitration Rules and Procedures and in accordance with the Expedited Procedures in those Rules, as specifically modified by the provisions of this
Section 10.9.5. 
 (a) Arbitration Panel. The arbitration shall be conducted by a panel of three (3) arbitrators.
Within thirty (30) days after the initiation of the arbitration, each Party will nominate one person to act as arbitrator, and the two arbitrators so named will then jointly appoint the third arbitrator within thirty (30) days of their
appointment, who will serve as chairman of the panel. All three (3) arbitrators must be independent Third Parties having at least ten (10) years of dispute resolution experience (which may include judicial experience) and/or legal or
business experience in the biotech or pharmaceutical industry. If either Party fails to nominate its arbitrator, or if the arbitrators selected by the Parties cannot agree on a person to be named as chairman within such thirty (30) day period,
JAMS will make the necessary appointments for such arbitrator(s) or the chairman. Once appointed by a Party, such Party shall have no ex parte communication with its appointed arbitrator. 

(b) Location and Proceedings. The place of arbitration will be in the Borough of Manhattan, City of New York, NY or such other venue as
the Parties may mutually agree. The arbitration proceedings and all communications with respect thereto shall be in English. Any written evidence originally in another language will be submitted in English translation accompanied by the original or
a true copy thereof. The arbitrators have the power to decide all matters in Dispute, including any questions of whether or not such matters are subject to arbitration hereunder. The arbitration shall be governed by the Federal Arbitration Act,
9 U.S.C. §§1 et seq., and judgment upon the award rendered by the arbitrators may be entered in any court having competent jurisdiction thereof. 

(c) Limitation on Awards. Except for breaches of Article 6 hereof, the arbitrators shall have no authority to award any
special, indirect, incidental, consequential, punitive, exemplary or other similar damages. Each Party shall bear its own costs and expenses (including attorneys’ fees and expert or consulting fees) incurred in connection with the arbitration.
The Parties shall equally (50/50) share the arbitrators’ fees and other administrative costs and expenses associated with the arbitration. 

(d) Confidentiality. The existence, content and results of any arbitration proceedings pursuant to this Section 10.9.5
shall be deemed the Confidential Information of both Parties. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 70 








 10.9.6. Notwithstanding any provision of this Agreement to the contrary, either Party may
immediately initiate litigation in any court of competent jurisdiction seeking any remedy at law or in equity, including the issuance of a preliminary, temporary or permanent injunction, to preserve or enforce its rights under this Agreement. 

10.10. Patent Disputes and Disputes Relating to Article 6. 

10.10.1. Inventorship. Any dispute, controversy or claim between the Parties involving the inventorship of any Program Technology that
is not resolved by mutual agreement of the Party’s respective chief patent counsels (or persons 
 with similar responsibilities) within
thirty (30) days after the date the dispute is raised by one or both of the Parties shall be submitted to an Independent Patent Counsel for resolution. Such Independent Patent Counsel’s determination of inventorship, absent manifest error,
shall be final and binding on the Parties; provided, however, that any such determination with respect to a patent application shall not preclude either Party from disputing inventorship with respect to any patents issuing from such patent
application, which disputes shall be resolved in accordance with this Section. The Parties shall equally (50/50) share the Independent Patent Counsel fees and expenses related to his determination of inventorship. 

10.10.2. Other Patent Disputes. Any dispute, controversy or claim between the Parties that involves the validity, scope, infringement,
enforceability or ownership of the Parties’ respective Patent Rights (a) that are pending or issued in the United States shall be subject to actions before the United States Patent and Trademark Office and/or submitted exclusively to the
federal court located in the jurisdiction where the Party whose Patent Rights are the subject to such dispute, controversy or claim resides (provided that if such Party does not reside in the United States, venue shall be the jurisdiction where such
Party’s principal U.S. Affiliate resides) and (b) that are pending or issued in any other country (or region) shall be brought before an appropriate regulatory or administrative body or court in that country (or region), and the Parties
hereby consent to jurisdiction and venue in such courts and bodies. 
 10.10.3. Disputes Relating to Article 6. Any dispute,
controversy or claim between the Parties that relates to the enforcement of Article 6 hereof shall be subject to action in any court of competent jurisdiction. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 71 








 10.11. Governing Law. This Agreement, and all claims arising under or in connection
therewith, shall be governed by and interpreted in accordance with the substantive laws of the State of New York, without regard to conflict of law principles thereof. 

10.12. Entire Agreement. This Agreement, including its Exhibits and Schedules, constitutes and contains the complete, final and
exclusive understanding and agreement of the Parties and cancels and supersedes any and all prior negotiations, correspondence, understandings and agreements, whether oral or written, between the Parties respecting the subject matter hereof and
thereof, including the Confidentiality Agreement. 
 10.13. Purpose and Scope. The Parties understand and agree that this Agreement is
limited to the activities, rights and obligations as expressly set forth herein. Nothing herein contained shall be deemed to create an employment, agency, joint venture or partnership relationship between the Parties hereto or any of their agents or
employees, or any other legal arrangement that would impose liability upon one Party for the act or failure to act of the other Party. Neither Party shall have any express or implied power to enter into any contracts or commitments or to incur any
liabilities in the name of, or on behalf of, the other Party, or to bind the other Party in any respect whatsoever. 
 10.14.
Counterparts. This Agreement may be executed in two or more counterparts, each of which shall be an original and both of which shall constitute together the same document. Counterparts may be signed and delivered by facsimile or PDF file,
each of which shall be binding when received by the applicable Party. 
 10.15. No Third Party Rights or Obligations. Except as set
forth in Article 9 hereof, no provision of this Agreement shall be deemed or construed in any way to result in the creation of any rights or obligation in any Person not a Party to this Agreement. However, either Party may decide, in its
sole discretion, to use one or more of its Affiliates to perform its obligations and duties hereunder, provided that such Party shall remain liable hereunder for the performance by any such Affiliates of any such obligations. 

10.16. Interpretation. The Parties hereto acknowledge and agree that: (a) each Party and its counsel reviewed and negotiated the
terms and provisions of this Agreement and have contributed to its revision; (b) the rule of construction to the effect that any ambiguities are resolved against the drafting Party shall not be employed in the interpretation of this Agreement;
and (c) the terms and provisions of this Agreement shall be construed fairly as to each Party hereto and not in a favor of or against any Party, regardless of which Party was generally responsible for the preparation of this Agreement. In
addition, unless the context otherwise requires, wherever used in this Agreement: (i) the singular shall include the plural, the plural the singular; (ii) the use of any gender shall be applicable to all genders; (iii) the word
“or” is used in the inclusive sense (and/or); (iv) the words “include” or “including” shall be construed as incorporating, also, “but not limited to” or “without limitation” (irrespective of
whether the words are used in 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 72 








 
the applicable instance); (v) the words “hereof,” “herein,” “hereby” and derivative or similar words refer to this Agreement as a whole and not to any
particular provision of this Agreement; and (vi) all references to “will” are interchangeable with the word “shall” and shall be understood to be imperative or mandatory in nature. 

[The remainder of this page has been intentionally left blank. The signature page follows.] 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 73 








 IN WITNESS WHEREOF, duly authorized representatives of the Parties have duly
executed this Agreement to be effective as of the Effective Date. 
  

									
	IMMUNOGEN, INC.	 		 	CYTOMX THERAPEUTICS, INC.
					
	By:	 	  
	 		 	By:	 	  

					
	Name:	 		 		 	Name:	 	
					
	Title:	 		 		 	Title:	 	
					
	Date:	 		 		 	Date:	 	



  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT A 

Licensed Target 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT B 

Royalty Rate Reduction Methodology 
 Step
1 – Calculate the Weighted Average Royalty Rate (WARR) for the Calendar Quarter 
  

	•	 	This is the weighted average rate calculated based on the worldwide Net Sales of the Licensed Product for a Calendar Quarter, based upon the rates detailed in Section 4.2 of this Agreement and assuming that there
are not any countries where the royalty rate is to be reduced per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. (M = Million) 

  

	•	 	For instance, if the worldwide Net Sales for Calendar Quarter 1 of 2020 is $1,000M, then the WARR for that period is ($500M*[***]% + $500M*[***]%) / $1,000M = [***]% 


 

	•	 	WARR is the basis for the royalty reduction; it is not the effective royalty rate for a certain country or for the Licensed Product on a worldwide basis. 


Step 2 – Determine the reduced royalty due to ImmunoGen for those countries in the world for which a reduced royalty rate is to be applied per
Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. 
  

	•	 	The reduced royalty rate is the WARR * 50% 

  

	•	 	Continuing with the example in Step 1, 

  

	•	 	If Country X is the one (and only) country in the world for which a reduced royalty rate is to be applied per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement, and 


 

	•	 	sales in Country X for the Calendar Quarter are $50M (out of the $1,000M of worldwide sales), 

  

	•	 	then the reduced royalty due to ImmunoGen for Country X is: 

 [***]% * 50% * $50M = $[***] 

 

	•	 	This calculation should be repeated for each country for which a reduced royalty rate is to be applied per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. 


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 Step 3 – Apply the WARR from Step 1 to Net Sales for the Calendar Quarter in all countries of the world in
which the royalty rate is not to be reduced per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. 
  

	•	 	Continuing with the example in Step 1, 

  

	•	 	Net Sales for the Calendar Quarter excluding Country X are $950M (out of the $1,000M of worldwide sales) 

  

	•	 	Then the royalties due to ImmunoGen for all countries of the world excluding Country X are: 

 $500M*[***]% +
$450M*[***]% = $[***] 
 Step 4 – Sum the amounts calculated in Steps 2 and 3 above to arrive at the total royalties due to ImmunoGen for the Calendar
Quarter. 
  

	•	 	Continuing with the example in Step 1, 

 $[***] + $[***] = $[***] 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT D 

Form of ImmunoGen License Agreement 

[See Attached 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 Exhibit D 

LICENSE AGREEMENT 

BETWEEN 
 IMMUNOGEN,
INC. 
 AND 

CYTOMX THERAPEUTICS, INC. 

            , 201     

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 TABLE OF CONTENTS 

 

									
	 	 	 	 	 	  	Page	 
			
	1.	 	 DEFINITIONS
	  	 	1	  
			
	2.	 	 PRODUCT DEVELOPMENT, MANUFACTURING AND COMMERCIALIZATION
	  	 	20	  
				
		 	2.1.	 	 General
	  	 	20	  
				
		 	2.2.	 	 Development Diligence
	  	 	21	  
				
		 	2.3.	 	 Joint Development Committee
	  	 	22	  
				
		 	2.4.	 	 Alliance Managers
	  	 	24	  
				
		 	2.5.	 	 Updates and Reports; Product Recalls
	  	 	24	  
				
		 	2.6.	 	 Transfer and Use of Proprietary Materials
	  	 	25	  
				
		 	2.7.	 	 Services
	  	 	26	  
			
	3.	 	 LICENSE GRANTS
	  	 	27	  
				
		 	3.1.	 	 License Grants
	  	 	27	  
				
		 	3.2.	 	 Retained Rights and Covenants
	  	 	28	  
				
		 	3.3.	 	 License to ImmunoGen Probody Platform Improvements
	  	 	28	  
				
		 	3.4.	 	 Section 365(n) of Bankruptcy Code
	  	 	29	  
				
		 	3.5.	 	 No Implied Rights
	  	 	29	  
			
	4.	 	 PAYMENTS
	  	 	29	  
				
		 	4.1.	 	 Milestone Payments
	  	 	29	  
				
		 	4.2.	 	 Royalties
	  	 	31	  
				
		 	4.3.	 	 Reports and Payments
	  	 	36	  
				
		 	4.4.	 	 Maintenance of Records; Audits
	  	 	38	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 i 









									
			
	5.	 	 INTELLECTUAL PROPERTY
	  	 	39	  
				
		 	5.1.	 	 Inventions
	  	 	39	  
				
		 	5.2.	 	 Filing, Prosecution and Maintenance of Patent Rights
	  	 	41	  
				
		 	5.3.	 	 Joint Research Agreement
	  	 	43	  
				
		 	5.4.	 	 Enforcement of Patent Rights
	  	 	44	  
				
		 	5.5.	 	 Response to Biosimilar Applicants
	  	 	47	  
				
		 	5.6.	 	 Interference, Opposition, Revocation and Declaratory Judgment Actions
	  	 	53	  
				
		 	5.7.	 	 Infringement of Third Party Patent Rights
	  	 	53	  
			
	6.	 	 CONFIDENTIALITY
	  	 	53	  
				
		 	6.1.	 	 Confidentiality
	  	 	53	  
				
		 	6.2.	 	 Authorized Disclosure
	  	 	54	  
				
		 	6.3.	 	 Public Announcements; Publications
	  	 	56	  
			
	7.	 	 REPRESENTATIONS AND WARRANTIES
	  	 	57	  
				
		 	7.1.	 	 Mutual Representations and Warranties
	  	 	57	  
				
		 	7.2.	 	 Representations and Warranties of CytomX
	  	 	58	  
				
		 	7.3.	 	 Government Approvals
	  	 	59	  
				
		 	7.4.	 	 Further Covenants
	  	 	59	  
				
		 	7.5.	 	 Representation by Legal Counsel
	  	 	59	  
				
		 	7.6.	 	 Warranty Disclaimers
	  	 	59	  
			
	8.	 	 TERM AND TERMINATION
	  	 	59	  
				
		 	8.1.	 	 Term
	  	 	59	  
				
		 	8.2.	 	 Voluntary Termination by ImmunoGen
	  	 	60	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 ii 









									
				
		 	8.3.	 	 Termination by Either Party for Cause
	  	 	60	  
				
		 	8.4.	 	 Termination on Insolvency
	  	 	60	  
				
		 	8.5.	 	 Termination for Material Breach of the Research Collaboration Agreement by ImmunoGen
	  	 	60	  
				
		 	8.6.	 	 Effects of Expiration or Termination
	  	 	60	  
				
		 	8.7.	 	 Disposition of Inventories of Products
	  	 	62	  
				
		 	8.8.	 	 Remedies
	  	 	63	  
				
		 	8.9.	 	 Survival of Certain Obligations
	  	 	63	  
			
	9.	 	 LIMITATION ON LIABILITY, INDEMNIFICATION AND INSURANCE
	  	 	63	  
				
		 	9.1.	 	 No Consequential Damages
	  	 	63	  
				
		 	9.2.	 	 Indemnification by CytomX
	  	 	63	  
				
		 	9.3.	 	 Indemnification by ImmunoGen
	  	 	64	  
				
		 	9.4.	 	 Procedure
	  	 	64	  
				
		 	9.5.	 	 Insurance
	  	 	65	  
			
	10.	 	 MISCELLANEOUS
	  	 	66	  
				
		 	10.1.	 	 Assignment
	  	 	66	  
				
		 	10.2.	 	 Further Actions
	  	 	66	  
				
		 	10.3.	 	 Force Majeure
	  	 	66	  
				
		 	10.4.	 	 Notices
	  	 	67	  
				
		 	10.5.	 	 Amendment
	  	 	68	  
				
		 	10.6.	 	 Waiver
	  	 	68	  
				
		 	10.7.	 	 Severability
	  	 	68	  
				
		 	10.8.	 	 Descriptive Headings
	  	 	68	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 iii 









									
				
		 	10.9.	 	 Dispute Resolution
	  	 	68	  
				
		 	10.10.	 	 Patent Disputes and Disputes Relating to Article 6
	  	 	70	  
				
		 	10.11.	 	 Governing Law
	  	 	71	  
				
		 	10.12.	 	 Entire Agreement
	  	 	71	  
				
		 	10.13.	 	 Purpose and Scope
	  	 	71	  
				
		 	10.14.	 	 Counterparts
	  	 	71	  
				
		 	10.15.	 	 No Third Party Rights or Obligations
	  	 	71	  
				
		 	10.16.	 	 Interpretation
	  	 	72	  


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 iv 








 EXHIBITS 

Exhibit A – Licensed Target 
 Exhibit B –
Royalty Rate Reduction Methodology 
 Schedule 1.120 – List of Cytotoxic Compound Patent Rights 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 v 








 LICENSE AGREEMENT 

This Research Collaboration and License Agreement (the “Agreement”) is entered into as of
                    1 (the “Effective Date”), by and between CytomX
Therapeutics, Inc., a corporation organized and existing under the laws of Delaware and having a place of business at 343 Oyster Point Blvd., Suite 100, South San Francisco, California, 94080 United States (“CytomX”) and
ImmunoGen, Inc., a corporation organized and existing under the laws of Massachusetts and having a place of business at 830 Winter Street, Waltham, Massachusetts, 02451 (“ImmunoGen”). CytomX and ImmunoGen may each be referred
to herein individually as a “Party” and collectively as the “Parties.” 
 WHEREAS, the
Parties have entered into a Research Collaboration Agreement, pursuant to which, among other things, CytomX granted to ImmunoGen the right to obtain a license to certain Know-How and related Patent Rights owned or Controlled by CytomX with respect
to certain Targets; and 
 WHEREAS, pursuant to the Research Collaboration Agreement, ImmunoGen has exercised an ImmunoGen
Option (as defined in the Research Collaboration Agreement), pursuant to which the Parties have agreed to enter into this Agreement setting forth the terms and conditions of an exclusive license from CytomX to ImmunoGen with respect to the Licensed
Target. 
 NOW THEREFORE, in consideration of the mutual promises and covenants set forth below and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the Parties hereby agree as follows: 
  

	1.	DEFINITIONS. 

 When used in this Agreement, the following capitalized
terms shall have the meanings set forth in this Article 1. 
 1.1. “ADC” means a compound that incorporates, is
comprised of or is otherwise derived from an Antibody (or other cell-binding moiety) conjugated to a Payload using a Linker, other than a PDC. 

1.2. “Affiliate” means, with respect to any Person, any other Person that controls, is controlled by or is under common
control with such Person. A Person shall be regarded as in control of another entity if it owns or controls at least fifty percent (50%) of the equity securities of the subject entity entitled to vote in the election of directors (or, in the

  

	1 	Insert date of receipt by ImmunoGen of Option Exercise Notice with respect to the Licensed Target. 


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 1 








 case of an entity that is not a corporation, for the election of the corresponding managing
authority), provided, however, that the term “Affiliate” shall not include subsidiaries or other entities in which a Party or its Affiliates owns a majority of the ordinary voting power necessary to elect a majority of the board of
directors or other managing authority, but is restricted from electing such majority by contract or otherwise, until such time as such restrictions are no longer in effect. A Person shall be deemed an Affiliate only so long as it satisfies the
foregoing definition. 
 1.3. “Alliance Manager” is defined in Section 2.4 hereof. 

1.4. “Annual Maintenance Fees” is defined in Section 2.2.1 hereof. 

1.5. “Annual Net Sales” means, with respect to any Licensed Product in a Calendar Year during the applicable Royalty Term for
such Licensed Product, the aggregate Net Sales by a Party, its Affiliates and its Sublicensees from the sale of such Licensed Product in the Territory during such Calendar Year. 

1.6. “Antibody” means a molecule which comprises or contains: (a) one or more immunoglobulin variable domains; or
(b) fragments, variants, modifications or derivatives of such immunoglobulin variable domains irrespective of origin or source, including but not limited to antigen binding portions including Fab, Fab’, F(ab’)2, Fv, dAb and CDR
fragments, single chain antibodies (scFv), chimeric antibodies, monospecific antibodies, diabodies and polypeptides (including humanized versions thereof) that contain at least a portion of an immunoglobulin that is sufficient to confer specific
antigen binding to the polypeptide. For clarity, as used in this Agreement, the term “Antibody” shall not include Probodies or PDCs. 

1.7. “Applicable Law” means the laws, statutes, rules, regulations, guidelines, or other requirements that may be in effect
from time to time and apply to a particular activity contemplated hereby, including any such laws, statutes, rules, regulations, guidelines or other requirements of the FDA or the EMA or any applicable securities regulatory authorities or national
securities exchanges or securities listing organizations. 
 1.8. “Applicant” is defined in Section 5.5.2
hereof. 
 1.9. “Applicant Response” is defined in Section 5.5.3(b) hereof. 

1.10. “Bankruptcy Code” is defined in Section 3.4 hereof. 

1.11. “Baseline Net Sales” is defined in Section 1.94 hereof. 

1.12. “Binding Obligation” means, with respect to a Party (a) any oral or written agreement or arrangement that binds or
legally affects such Party’s operations or property, 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 2 








 
including any assignment, license agreement, loan agreement, guaranty, or financing agreement; (b) the provisions of such Party’s charter, bylaws or other organizational documents or
(c) any order, writ, injunction, decree or judgment of any court or Governmental Authority entered against such Party or by which any of such Party’s operations or property are bound. 

1.13. “Biosimilar Application” means an application submitted to the FDA under subsection (k) of the PHSA or a similar
application submitted under a similar regulatory scheme to another Regulatory Authority. 
 1.14. “BLA” means a Biologics
License Application (as that term is used in Title 21 of the United States Code of Federal Regulations) filed with the FDA seeking Regulatory Approval to market and sell any Licensed Product in the United States for a particular indication.

 1.15. “BPCIA” means the Biologics Price Competition and Innovation Act of 2009. 

1.16. “Business Day” means a day other than a Saturday, a Sunday or other day on which banking institutions in Boston,
Massachusetts or San Francisco, California are required to be closed or are actually closed with legal authorization. 
 1.17.
“Calendar Quarter” means the respective periods of three (3) consecutive calendar months ending on March 31, June 30, September 30 or December 31, for so long as this Agreement is in effect. 

1.18. “Calendar Year” means each successive period of twelve (12) calendar months commencing on January 1 and ending
on December 31. 
 1.19. “Challenge” means any challenge to the patentability, validity, or enforceability of any of
the Licensed Patent Rights, including without limitation: (a) filing a declaratory judgment action in which any of the Licensed Patent Rights is alleged to be invalid or unenforceable; (b) citing prior art pursuant to 35 U.S.C.
§122 or §301, filing a request for re-examination of any of the Licensed Patent Rights pursuant to 35 U.S.C. §302 or §311, filing a petition to request an inter partes review of the Licensed Patent Rights pursuant to
35 U.S.C. §311, or filing a petition to request a post-grant review of the Licensed Patent Rights pursuant to 35 U.S.C. §321; or (c) filing or commencing any re-examination, opposition, cancellation, nullity or similar
proceeding against any of the Licensed Patent Rights in any country. 
 1.20. “Challenge Jurisdiction” is defined in
Section 4.2.3(d) hereof. 
 1.21. “Challenged Patent Rights” is defined in Section 4.2.3(d) hereof.


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 3 








 1.22. “Challenge-Related Royalty Increase” is defined in Section 4.2.3
(d) hereof. 
 1.23. “Clawback Amount” is defined in Section 4.2.3(d) hereof. 

1.24. “Combination” is defined in Section 1.104 hereof. 

1.25. “Commercialization” or “Commercialize” means activities with respect to a Licensed Product relating to
commercialization in the Field in the Territory, including pre-launch and launch activities, pricing and reimbursement activities, marketing, promoting, detailing, distributing, offering for sale and selling such Licensed Product, importing and
exporting such Licensed Product for sale, conducting post-marketing human clinical trials, reporting of adverse events in patients and interacting with Regulatory Authorities regarding any of the foregoing. Commercialization shall not include any
activities related to Manufacturing or Development. When used as a verb, “Commercialize” means to engage in Commercialization and “Commercialized” has a corresponding meaning. 

1.26. “Commercially Reasonable Efforts” means, with respect to the efforts to be expended by a Party with respect to any
objective, those reasonable, good faith efforts to accomplish such objective as such Party would normally use to accomplish a similar objective under similar circumstances. With respect to any efforts relating to the Development of a Licensed
Product by ImmunoGen, generally or with respect to any particular country in the Territory, ImmunoGen will be deemed to have exercised Commercially Reasonable Efforts if it has exercised those efforts normally used by ImmunoGen, in the relevant
country, with respect to a compound, product or product candidate, as applicable, owned or Controlled by ImmunoGen, or to which ImmunoGen has similar rights, which compound, product or product candidate is of similar market potential in such
country, and is at a similar stage in its development or product life cycle as the Licensed Product, taking into account all relevant factors in effect at the time such efforts are to be expended. It is expressly understood that, so long as this
Agreement may be terminated by ImmunoGen for convenience pursuant to Section 8.2 hereof, ceasing the Development of a Licensed Product shall be deemed to be inconsistent with Commercially Reasonable Efforts. Further, to the extent that the
performance of ImmunoGen’s obligations hereunder is adversely affected by CytomX’s failure to perform its obligations hereunder, the impact of such performance failure will be taken into account in determining whether ImmunoGen has used
its Commercially Reasonable Efforts to perform any such affected obligations. 
 1.27. “Confidential Information” of a Party
means (a) with respect to ImmunoGen, the identity of the Licensed Target, and (b) with respect to each Party, all Know-How or other information, including proprietary information and materials (whether or not patentable) regarding such
Party’s technology, products, business or objectives, that is 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 4 








 
communicated in any way or form by or on behalf of such Party (in such capacity, the “Disclosing Party”) to the other Party (in such capacity, the “Receiving
Party”) or to any of the Receiving Party’s or its Affiliates’ employees, consultants or subcontractors (collectively, “Representatives”), either prior to or after the Effective Date of this Agreement (including
any information disclosed pursuant to the Confidentiality Agreement), and whether or not such Know-How or other information is identified as confidential at the time of disclosure. The terms and conditions of this Agreement shall be deemed to be the
Confidential Information of each Party. Confidential Information within the CytomX Program Technology shall be deemed to be the Confidential Information of CytomX. Confidential Information within the ImmunoGen Program Technology shall be deemed to
be the Confidential Information of ImmunoGen. Confidential Information within the Joint Program Technology shall be deemed to be the Confidential Information of each Party. Certain other information is designated as Confidential Information
throughout this Agreement and is included in this definition. 
 1.28. “Confidentiality Agreement” means that certain Mutual
Confidential Disclosure Agreement between the Parties effective as of March 21, 2013. 
 1.29. “Conjugation Probody Platform
Improvements” is defined in Section 1.120 hereof. 
 1.30. “Control” or “Controlled”
means, with respect to any (a) item of information, including Know-How, (b) intellectual property right, or (c) Proprietary Material, the possession (whether by ownership interest or license, other than pursuant to this Agreement) by
a Party of the ability to grant to the other Party access to or a license under such item, right or material, as provided herein, without violating the terms of any agreement or other arrangements with any Third Party. 

1.31. “Covered Results” is defined in Section 6.3.2 hereof. 

1.32. “Cover(s)” is defined in Section 4.2.3(b)(iii) hereof. 

1.33. [Reserved] 
 1.34.
“CytomX Indemnified Party” is defined in Section 9.3 hereof. 
 1.35. “CytomX Program
Technology” means any Program Technology (other than Joint Program Technology) the inventors of which are employees, agents or independent contractors of CytomX or any of its Affiliates. Anything contained in this Agreement to the contrary
notwithstanding, any and all CytomX Program Technology that is necessary or useful for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the composition of, or any method of
using or method of making any Licensed Product or Probody comprised in a Licensed Product shall be included in the Licensed Intellectual Property. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 5 








 1.36. “CytomX Proprietary Materials” means biological materials (including any
Probodies, Masks or Substrates) and other tangible research materials Controlled by CytomX and provided by CytomX to ImmunoGen under this Agreement. Without prejudice to any intellectual property rights in and to Probodies, any tangible Probodies
produced by or for ImmunoGen or any of its Affiliates, Sublicensees or Permitted Third Party Service Providers using any hybridoma or genetic sequencing information provided by CytomX in connection with the Development, Manufacture, use and
Commercialization of Licensed Products shall not be deemed to be CytomX Proprietary Materials for purposes of this Agreement. 
 1.37.
[Reserved] 
 1.38. [Reserved] 

1.39. [Reserved] 
 1.40.
“CytomX Technology” means any Patent Right, Know-How or other intellectual property right that is Controlled by CytomX or any Affiliate of CytomX or that comes into the Control of CytomX at any time during the Term of this Agreement
and is actually used by CytomX in Developing Licensed Products under this Agreement or is otherwise necessary for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the
composition of, or any method of using or method of making or any Tools for Developing, any Probody, Mask or Substrate. 
 1.41.
“Cytotoxic Compound” means [***] Compounds and [***] Compounds. 
 1.42. “Deemed Royalty Portion” is
defined in Section 5.4.2(g)(iii) hereof. 
 1.43. “Develop” or “Development” means, with
respect to a Licensed Product, all pre-clinical, non-clinical and clinical research and drug development activities with respect to such Licensed Product relating to research and development in connection with seeking, obtaining or maintaining any
Regulatory Approval for such Licensed Product, including research, toxicology, pharmacology and other similar efforts, test method development and stability testing, manufacturing process development, formulation development, delivery system
development, quality assurance and quality control development, statistical analysis, clinical studies (including pre- and post-approval studies), development of diagnostic assays in connection with clinical studies, and all activities directed to
obtaining any Regulatory Approval, including any marketing, pricing or reimbursement approval. When used as a verb, “Develop” means to engage in Development and “Developed” has a corresponding meaning. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 6 








 1.44. “Development Milestone” is defined in Section 4.1.1 hereof.

 1.45. “Development Milestone Payment” is defined in Section 4.1.1 hereof. 

1.46. “Diligence Obligation” is defined in Section 2.2.2 hereof. 

1.47. “Disclosing Party” is defined in Section 1.27 hereof. 

1.48. “Disclosure Letter” is defined in Section 7.2 hereof. 

1.49. “Dispute” is defined in Section 10.9 hereof. 

1.50. “Effective Date” is defined in the introduction to this Agreement. 

1.51. “EMA” means the European Medicines Agency, or any successor agency thereto. 

1.52. “Field” means all human therapeutic, prophylactic and diagnostic uses. 

1.53. “FD&C Act” means the United States Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 301 et seq.), as
amended, and the rules and regulations promulgated thereunder. 
 1.54. “FDA” means the United States Food and Drug
Administration or any successor agency thereto. 
 1.55. “First Commercial Sale” means, with respect to any Licensed Product
and any country of the world, the first sale of such Licensed Product under this Agreement by ImmunoGen, its Affiliates or its Sublicensees to a Third Party in such country, after such Licensed Product has been granted Regulatory Marketing Approval
by the competent Regulatory Authorities in such country or, if no such Regulatory Marketing Approval or similar approval is required, the date on which such Licensed Product is first commercially launched in such country. The foregoing
notwithstanding, “First Commercial Sale” shall not include: (a) any distribution or other sale solely for so-called treatment investigational new drug sales, named patient sales, compassionate or emergency use sales or pre-approval
sales, in each case provided that such Licensed Product is distributed without charge or sold at or below cost; (b) intercompany transfers to Affiliates of ImmunoGen; nor (c) other similar non-commercial uses, provided that in each case
under this clause (c) such Licensed Product is distributed without charge or sold at or below cost. 
 1.56. “GAAP”
means United States generally accepted accounting principles, consistently applied. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 7 








 1.57. “Generic Equivalent” means, with respect to any Licensed Product in a
given country, any biopharmaceutical product that is sold by a Third Party that is not a Sublicensee of ImmunoGen or its Affiliates and such Third Party product (a) contains both (i) an Antibody or Probody that specifically binds to the
Licensed Target, and (ii) the same Linker and Cytotoxic Compound as the relevant Licensed Product, or (b) (i) has been licensed as a biosimilar or interchangeable biological product by FDA pursuant to Section 351(k) of the PHSA
or any subsequent or superseding law, statute or regulation, (ii) has been licensed as a similar biological medicinal product by the European Medicines Agency pursuant to Directive 2001/83/EC, as may be amended, or any subsequent or superseding
law, statute or regulation, or (iii) has otherwise achieved analogous regulatory marketing approval in reliance on the prior approval of the Licensed Product from another applicable Regulatory Authority where in the case of each of
subclauses (i), (ii) or (iii) of clause (b) above, the Licensed Product is the reference product for purposes of determining (bio)similarity or interchangeability of the Third Party product. 

1.58. “Governmental Authority” means any court, agency, department, authority or other instrumentality of any national, state,
county, city or other political subdivision. 
 1.59. “[***] Compounds” means [***], including, without limitation, all
analogs, variants, fragments or derivatives of any of the foregoing, in each case owned or Controlled by ImmunoGen. 
 1.60.
“Immediate Patent Infringement Action” means an immediate patent infringement action pursuant to Section 351(1)(6) of the PHSA. 

1.61. “ImmunoGen Accounting Standards” means GAAP, as generally and consistently applied throughout ImmunoGen’s
organization. Beginning upon the First Commercial Sale of a Licensed Product and thereafter during the Term as long as ImmunoGen has an obligation to pay royalties under Section 4.2 hereof, ImmunoGen shall promptly notify CytomX in the
event it changes the accounting principles pursuant to which its records are maintained, it being understood and agreed that only internationally recognized accounting principles may be used (e.g., GAAP, IFRS (International Financial
Reporting Standards), etc.). 
 1.62. “ImmunoGen Indemnified Party” is defined in Section 9.2 hereof. 

1.63. “ImmunoGen Probody Platform Improvements” means any Probody Platform Improvement (other than a Joint Probody Platform
Improvements) the inventors of which (alone or with others) are employees of, or others obligated to assign inventions to, ImmunoGen or any of its Affiliates, Sublicensees or Permitted Third Party Service Providers pursuant to the Development,
Manufacture, use and Commercialization of any Licensed Product. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 8 








 1.64. “ImmunoGen Program Technology” means any Program Technology (other than
Joint Program Technology) the inventors of which (alone or with others) are employees of, or others obligated to assign inventions to, ImmunoGen or any of its Affiliates, Sublicensees or Permitted Third Party Service Providers. 

1.65. [Reserved] 
 1.66.
“ImmunoGen Proprietary Materials” means any chemical (including any Cytotoxic Compounds), biological (including any Antibodies) and other tangible research materials Controlled by ImmunoGen and provided by ImmunoGen to CytomX under
this Agreement. Subject to the last sentence of this definition, any mutant, derivative, progeny or improvement of ImmunoGen Proprietary Materials shall be considered to be ImmunoGen Proprietary Materials. 

1.67. “ImmunoGen Response” is defined in Section 5.5.3(c) hereof. 

1.68. “ImmunoGen Standard Exchange Rate Methodology” means, with respect to amounts invoiced in U.S. Dollars, all such
amounts shall be expressed in U.S. Dollars. With respect to amounts invoiced in a currency other than U.S. Dollars, all such amounts shall be expressed both in the currency in which the amount was invoiced and in the U.S. Dollar
equivalent. The U.S. Dollar equivalent shall be calculated using ImmunoGen’s then-current standard exchange rate methodology, which is in accordance with the ImmunoGen Accounting Standards applied in its external reporting for the
conversion of foreign currency sales into U.S. Dollars or, in the case of Sublicensees, such similar methodology, consistently applied. 

1.69. “Improvement” is defined in Section 1.120 hereof. 

1.70. “IND” means an Investigational New Drug Application, as defined in the FD&C Act, that is required to be filed with
the FDA before beginning clinical testing of a Licensed Product in human subjects, or an equivalent foreign filing. 
 1.71.
“Indemnified Party” is defined in Section 9.4.1 hereof. 
 1.72. “Indemnifying Party” is
defined in Section 9.4.1 hereof. 
 1.73. “Independent Patent Counsel” means an outside patent counsel
reasonably acceptable to both Parties who (and whose firm) is not at the time of the dispute, and was not at any time during the five (5)-year period preceding the dispute, performing legal services of any nature for either of the Parties or their
respective Affiliates (or, in the case of ImmunoGen, its Sublicensees) and which did not, at any time, employ either of the Parties’ chief patent counsels (or persons with similar responsibilities). 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 9 








 1.74. “Infringed Patent List” is defined in Section 5.5.3(e) hereof.

 1.75. “Infringement” is defined in Section 5.4.1 hereof. 

1.76. “Insolvency Event” means the occurrence of any of the following: (a) a case is commenced by or against a Party
under applicable bankruptcy, insolvency or similar laws, and is not dismissed within ninety (90) days, (b) a Party files for or is subject to the institution of bankruptcy, reorganization, liquidation, receivership or similar proceedings,
(c) a Party assigns all or a substantial portion of its assets for the benefit of creditors, (d) a receiver or custodian is appointed for a Party’s business, (e) a substantial portion of a Party’s business is subject to
attachment or similar process, or (f) anything analogous to any of the events described in the foregoing clauses (a) through (e) occurs under the laws of any applicable jurisdiction. 

1.77. “Joint Conjugation Probody Platform Improvements” means Conjugation Probody Platform Improvements the inventors of which
are jointly (a) employees, agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

1.78. “Joint Development Committee” or “JDC” is defined in Section 2.3.1 hereof. 

1.79. “Joint Patent Right” means any Patent Right comprised in the Joint Program Technology. 

1.80. “Joint Probody Platform Improvements” means Probody Platform Improvements the inventors of which are jointly
(a) employees, agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

1.81. “Joint Program Technology” means any Program Technology (other than Joint Probody Platform Improvements) the inventors
of which are jointly (a) employees, agents or independent contractors of CytomX or any of its Affiliates and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

1.82. [Reserved] 
 1.83.
“Joint Unconjugated Probody Platform Improvements” means Unconjugated Probody Platform Improvements the inventors of which are jointly (a) employees, agents or independent contractors of CytomX or any of its Affiliates
and (b) employees, agents or independent contractors of ImmunoGen or any of its Affiliates. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 10 








 1.84. “Know-How” means any proprietary invention, discovery, data, information,
process, method, technique, material, technology, result or other know-how, whether or not patentable. 
 1.85. “Knowledge”
is defined in Section 7.2 hereof. 
 1.86. “Liability” is defined in Section 9.2 hereof. 

1.87. “License Agreement” has the meaning ascribed to such term in the Research Collaboration Agreement. 

1.88. “Licensed Intellectual Property” means any Patent Right, Know-How or other intellectual property right that is owned or
Controlled by CytomX or any Affiliate of CytomX or that becomes owned or Controlled by CytomX or any of its Affiliates at any time during the Term (including CytomX’s one-half interest in Joint Program Technology and Joint Probody Platform
Improvements) that is necessary or useful for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the composition of, or any method of using or method of making any Licensed
Product or Probody comprised in a Licensed Product. 
 1.89. “Licensed Know-How” means any Know-How comprised in the
Licensed Intellectual Property. 
 1.90. “Licensed Patent Rights” means any Patent Rights comprised in the Licensed
Intellectual Property. 
 1.91. “Licensed Product” means any product that incorporates, is comprised of, or is otherwise
derived from, a Target-Binding Probody conjugated to a Cytotoxic Compound using a Linker. 
 1.92. “Licensed Target” means
the Target set forth in Exhibit A attached hereto and incorporated herein by reference. 
 1.93. “Linker” means
any compound or composition that is useful for linking a cytotoxic or cytostatic moiety, including, without limitation, a Cytotoxic Compound, and a cell-binding moiety, including, without limitation, an Antibody or a Probody, together to form a
conjugate of the cytotoxic or cytostatic moiety with the cell-binding moiety. 
 1.94. “Loss of Market Exclusivity” with
respect to any Licensed Product in any country, shall be deemed to have occurred only if: (a) one or more Generic Equivalent(s) are being marketed by a Third Party (excluding any Sublicensee) in such country; and (b) Net Sales of such
Licensed Product in that country during any Calendar Quarter following introduction of the Generic Equivalent(s) have declined by at least twenty 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 11 








 
percent (20%) in that country relative to the average quarterly Net Sales of such Licensed Product in such country over the last two (2) Calendar Quarters ending prior to the
introduction of such Generic Equivalent(s) (the “Baseline Net Sales”) and such decline in Net Sales is not primarily attributable to (i) any action of the applicable Regulatory Authority limiting sales of the Licensed Product in such
country, (ii) the inability of ImmunoGen or its Affiliates or Sublicensees to supply sufficient quantities of the Licensed Product in such country to meet demand, or (iii) any voluntary or involuntary recall of the Licensed Product in such
country; provided that such Loss of Market Exclusivity shall be deemed to exist only for so long as material sales of such Generic Equivalent(s) persist in such country. Anything contained in this Agreement to the contrary notwithstanding, a
“Loss of Market Exclusivity” shall not be deemed to have occurred if the events described in clauses (a) and (b) of this definition were caused by or result from any act or omission of ImmunoGen (or any of its Affiliates or
Sublicensees) determined to have been made negligently or in bad faith in the performance of ImmunoGen’s obligations under Section 5.5.3 hereof that results in actual prejudice to CytomX’s ability to preserve its rights in the
Licensed Patent Rights and eliminate the infringement threatened by Applicant (excluding any acts or omissions undertaken pursuant to the specific instruction of CytomX). 

1.95. “Major EU Market Country” means any of France, Germany, Italy, Spain or the United Kingdom. 

1.96. “Manufacturing” or “Manufacture” means activities directed to making, producing, manufacturing,
processing, filling, finishing, packaging, labeling, quality assurance testing and release, shipping or storage of a product. 
 1.97.
“Marginal Royalty Rates” is defined in Section 4.2.1 hereof. 
 1.98. “Mask” means a peptide
linked to an Antibody that is capable of inhibiting the specific binding of the Antibody to its Target. 
 1.99. “Material
Breach” is defined in Section 8.3 hereof. 
 1.100. “[***] Compound” means [***], and shall include,
without limitation, all variants, fragments or derivatives of any of the foregoing, in each case owned or Controlled by ImmunoGen. 
 1.101.
“Milestone Payment” means any Development Milestone Payment or Sales Milestone Payment. 
 1.102. “Monies”
is defined in Section 5.4.2(g) hereof. 
 1.103. “Negotiation Period” is defined in Section 5.5.3(e)
hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 12 








 1.104. “Net Sales” means, with respect to a Licensed Product, gross receipts
from sales by ImmunoGen and its Affiliates and Sublicensees of such Licensed Product to Third Parties in the Territory, less in each case (a) bad debts, (b) sales returns and allowances actually paid, granted or accrued, including trade,
quantity and cash discounts and any other adjustments, including those granted on account of price adjustments, billing errors, rejected goods, damaged or defective goods, recalls, returns, rebates, chargeback rebates, reimbursements or similar
payments granted or given to wholesalers or other distributors, buying groups, health care insurance carriers, chain pharmacies, mass merchandisers, staff model HMO’s, pharmacy benefit managers or other institutions in respect of the purchase
price, (c) adjustments actually paid, granted or accrued arising from consumer discount programs or other similar programs, (d) customs or excise duties, sales tax, consumption tax, value added tax, and other taxes (except income taxes) or
duties relating to sales, (e) any payment made by ImmunoGen, its Affiliates or Sublicensees in respect of sales to the United States government, any state government or any foreign government, or to any other Governmental Authority, or with
respect to any government-subsidized program or managed care organization, and (f) freight and freight insurance (to the extent that ImmunoGen, its Affiliates or Sublicensees bears the cost of freight and freight insurance for the Licensed
Product), in each case in accordance with GAAP, as consistently applied by ImmunoGen with respect to its overall operations. 

Net Sales shall not include sales or transfers among ImmunoGen and its Affiliates and Sublicensees where the Licensed Product
is intended for subsequent sale to the end user. All the foregoing elements of Net Sales calculations shall be determined from the books and records of ImmunoGen and its Sublicensees, maintained in accordance with the ImmunoGen Accounting Standards
or, in the case of Sublicensees, such similar accounting principles, consistently applied. 
 In the event a Licensed Product
is sold as a component of a combination or bundled product that consists of a Licensed Product together with another therapeutically active product, or screening or diagnostic product, for the same indication (a “Combination”), the Net
Sales from the Combination, for the purposes of determining royalty payments hereunder, shall be determined by multiplying the Net Sales of the Combination (as defined in the standard Net Sales definition above) by the fraction A/(A+B), where A is
the weighted average per unit sale price of the Licensed Product when sold separately in finished form in the country in which the Combination is sold in similar volumes and of the same class, purity, potency and dosage form, and B is the weighted
average per unit sale price of the other product(s) included in the Combination when sold separately in finished form in the country in which the Combination is sold in similar volumes and of the same class, purity, potency and dosage form. 

In the event that the weighted average per unit sale price of the Licensed Product can be determined but the weighted average
per unit sale price of the other product(s) 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 13 








 
included in the Combination cannot be determined, Net Sales for purposes of determining royalty payments shall be calculated by multiplying the Net Sales of the Combination (as defined in the
standard Net Sales definition above) by the fraction A/C, where A is the weighted average sale price of the Licensed Product when sold separately in finished form in the country in which the Combination is sold in similar volumes and of the same
class, purity, potency and dosage form, and C is the weighted average per unit sale price of the Combination. 
 In the event
that the weighted average per unit sale price of the other product(s) included in the Combination can be determined but the weighted average per unit sale price of the Licensed Product in similar volumes and of the same class purity, potency and
dosage form as in the Combination cannot be determined, Net Sales for purposes of determining royalty payments shall be calculated by multiplying Net Sales of the Combination (as defined in the standard Net Sales definition above) by a fraction
determined by the following formula: one (1) minus (B/C) where B is the weighted average per unit sale price of the other product(s) included in the Combination when sold separately in finished form in the country in which the Combination
is sold in similar volumes and of the same class, purity, potency and dosage form and C is the weighted average per unit sale price of the Combination. 

In the event that such average per unit sale price cannot be determined for the Licensed Product, on the one hand, and all
other product(s) included in the Combination, on the other, Net Sales for the purposes of determining royalty payments shall be mutually agreed upon by the Parties based on the relative value contributed by each component, such agreement to be
negotiated in good faith. 
 The weighted average per unit sale price for both the Licensed Product, on the one hand, and all
other product(s) included in the Combination, on the other, shall be calculated once each Calendar Year and such price shall be used during all applicable royalty reporting periods for the entire following Calendar Year. When determining the
weighted average per unit sale price of a Licensed Product, other product(s), or Combination, the weighted average per unit sale price shall be calculated by dividing sales dollars (translated into U.S. Dollars using the ImmunoGen Standard
Exchange Rate Methodology) by the units sold during the twelve (12) months (or the number of months in which sales occurred in a partial Calendar Year) of the preceding Calendar Year for the respective Licensed Product, other product(s), or
Combination. In the initial Calendar Year, a forecasted weighted average per unit sale price will be used for the Licensed Product, other product(s), or Combination. Any over- or under-payment due to a difference between the forecasted and actual
weighted average per unit sale price will be paid or credited in the first royalty payment of the following Calendar Year. 
 1.105.
“Non-Disclosing Party” is defined in Section 6.3.2 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 14 








 1.106. “Notice of Dispute” is defined in Section 10.9.1 hereof. 

1.107. “Party” and “Parties” is defined in the introduction to this Agreement. 

1.108. “Patent Committee” is defined in Section 5.2.4 hereof. 

1.109. “Patent Rights” means any and all (a) patents, (b) pending patent applications, including all provisional
applications, substitutions, continuations, continuations-in-part, divisions and renewals, and all patents granted thereon, (c) all patents-of-addition, reissues, reexaminations and extensions or restorations by existing or future extension or
restoration mechanisms, including patent term extensions, supplementary protection certificates or the equivalent thereof, (d) inventor’s certificates, (e) any other form of government-issued right substantially similar to any of the
foregoing and (f) all United States and foreign counterparts of any of the foregoing. 
 1.110. “Payload” means a
therapeutic cytotoxic or cytostatic compound, including, without limitation, a Cytotoxic Compound. 
 1.111. “PDC” means a
compound that incorporates, is comprised of or is otherwise derived from, a Probody conjugated to a Payload using a Linker. 
 1.112.
“Permitted Third Party Service Providers” is defined in Section 3.1.1 hereof. 
 1.113.
“Person” means an individual, sole proprietorship, partnership, limited partnership, limited liability partnership, corporation, limited liability company, business trust, joint stock company, trust, incorporated association, joint
venture or similar entity or organization, including a government or political subdivision or department or agency of a government. 
 1.114.
“Phase 1 Clinical Study” means an initial study of a Licensed Product in human subjects or patients with the endpoint of determining initial tolerance, safety, metabolism or pharmacokinetic information and clinical pharmacology of
such product as and to the extent defined for the United States in 21 C.F.R. § 312.21(a), or its successor regulation, or the equivalent regulation in any other country. 

1.115. “Phase 2 Clinical Study” means a study of a Licensed Product in human patients that is intended to obtain information
on the Licensed Product’s activity for an indication at a prescribed (or otherwise limited) dose and administration schedule, as well as additional information on the Licensed Product’s safety and toxicity as and to the extent defined for
the United States in 21 C.F.R. § 312.21(b), or its successor regulation, or the equivalent regulation in any other country. Without limiting the generality of the foregoing, a clinical study shall be deemed to be a “Phase 2 Clinical
Study” hereunder if such study has been designated by the sponsor as a Phase 2 [II] clinical trial on www.clinicaltrials.gov (or any successor website maintained by the U.S. National Institutes of Health (or any successor agency of
the U.S. Government)). 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 15 








 1.116. “Phase 3 Clinical Study” means a study of a Licensed Product in human
patients with a defined dose or a set of defined doses of a Licensed Product designed to (a) ascertain efficacy and safety of such Licensed Product for its intended use; (b) define warnings, precautions and adverse reactions that are
associated with the Licensed Product in the dosage range to be prescribed; and (c) support preparing and submitting applications for Regulatory Marketing Approval to the competent Regulatory Authorities in a country of the world, as and to the
extent defined for the United States in 21 C.F.R.§ 312.21(c), or its successor regulation, or the equivalent regulation in any other country. “Phase 3 Clinical Study” shall also include any other human clinical trial serving as a
pivotal study from which the data are actually submitted to the applicable Regulatory Authority in connection with a Regulatory Marketing Approval Application, whether or not such trial is called a “Phase 3” study. Without limiting the
generality of the foregoing, a clinical study shall be deemed to be a “Phase 3 Clinical Study” hereunder if such study has been designated by the sponsor as a Phase 3 [III] clinical trial on www.clinicaltrials.gov (or any successor
website maintained by the U.S. National Institutes of Health (or any successor agency of the U.S. Government)). 
 1.117.
“PHSA” means the Public Health Services Act, as amended (42 U.S.C. § 201 et seq.). 
 1.118.
“Pre-Market Notice” is defined in Section 5.5.4(b) hereof. 
 1.119. “Probody” means an
Antibody linked to a Substrate and a Mask that is claimed or covered by CytomX Technology. 
 1.120. “Probody Platform
Improvements” means any Patent Right, Know-How or other intellectual property right that is an enhancement, improvement or modification (each, an “Improvement”) to the CytomX Technology invented by either Party or any of
its Affiliates (or by a Third Party on behalf of either Party or its Affiliates) that is an Improvement to the composition of, or any method of using or method of making or any Tools for developing, any unconjugated Probody, Mask or Substrate
(collectively, “Unconjugated Probody Platform Improvements”). Probody Platform Improvements also include Improvements (a) to any of the analytical methods used for making, releasing and characterizing any Agreement PDCs that
are necessary because of the presence of a Mask and/or Substrate, or (b) consisting of conjugation chemistry or conjugation methods that are necessary because of the presence of a Mask and/or Substrate (collectively, “Conjugation
Probody Platform Improvements”). Licensed Products and ImmunoGen Probodies, in and of themselves, will not be considered to be Probody Platform Improvements, although the Parties acknowledge that Probody


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 16 








 
Platform Improvements may be incorporated into Licensed Products and ImmunoGen Probodies. As used in this definition, Improvements shall be deemed to be “necessary because of the presence of
a Mask and/or Substrate” if, and only if, both of the following two (2) elements are present: (i) there is no viable alternative method of conjugating a Probody to a Payload (other than a Cytotoxic Compound2) that does not vitiate the function of the Mask and/or Substrate; and (ii) the Improvement has no practical application to ADCs. 

1.121. “Program Technology” means all Know-How (other than Probody Platform Improvements) that either Party or any of its
Affiliates, Sublicensees or Permitted Third Party Service Providers (or any of their respective employees, agents or independent contractors), alone or with others, makes, creates, develops, discovers, conceives or first actually reduces to practice
pursuant to the Development, Manufacture, use or Commercialization of any Licensed Product, including any Patent Rights related thereto. Program Technology also includes “Program Technology” (as defined in the Research Collaboration
Agreement) that is necessary or useful for Developing, Manufacturing, using or Commercializing Licensed Products and that claims, covers or is specifically directed to the composition of, or any method of using or method of making any Target-Binding
Antibody, Licensed Product, Linker or Cytotoxic Compound comprised in any Licensed Product. 
 1.122. “Proposed Biosimilar
Product” is defined in Section 5.5.1 hereof. 
 1.123. “Proposed Patent List” is defined in
Section 5.5.3(a) hereof. 
 1.124. “Publishing Party” is defined in Section 6.3.2 hereof. 

1.125. “Receiving Party” is defined in Section 1.27 hereof. 

1.126. “Regulatory Approval” means any technical, medical, scientific or other license, registration, authorization or
approval of any Regulatory Authority (including any approval of a New Drug Application or Biologic License Application) necessary for the Development, Manufacture, use or Commercialization of a pharmaceutical product in any regulatory jurisdiction.

  

	2 	For purposes of this definition, the term “Cytotoxic Compound” shall be limited to the cell-killing agents encompassed by one or more of the claims of the issued patents (whether or not expired) listed in
Schedule 1.120 attached hereto, or by one or more of the claims, if any, of any patents issuing from the patent applications listed in Schedule 1.120 or from any divisionals, continuations or foreign counterparts of any of the foregoing.



  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 17 








 1.127. “Regulatory Approval Application” means any application submitted to an
appropriate Regulatory Authority seeking any Regulatory Approval. 
 1.128. “Regulatory Authority” means the FDA or any
counterpart of the FDA outside the United States, or other national, supra-national, regional, state or local regulatory jurisdiction, any agency, department, bureau, commission, council or other governmental entity with authority over the
Development, Manufacture, use or Commercialization of a Licensed Product. 
 1.129. “Regulatory Marketing Approval” means,
with respect to any pharmaceutical product and any indication, Regulatory Approval (including any supplement thereto) to sell such pharmaceutical product for such indication, including, in any jurisdiction other than the United States, to the extent
required for any sale in such country, all pricing and reimbursement approvals to be obtained from the Regulatory Authority granting such Regulatory Approval or any affiliated Regulatory Authority. 

1.130. “Representatives” is defined in Section 1.27 hereof. 

1.131. “Research Collaboration Agreement” means that certain Research Collaboration Agreement effective as of January 8,
2014 by and between CytomX and ImmunoGen, as the same may be amended from time to time. 
 1.132. “Research Program” has the
meaning ascribed to such term in the Research Collaboration Agreement. 
 1.133. “Review Period” is defined in
Section 6.3.2 hereof. 
 1.134. “Royalty Term” means, on a Licensed Product-by-Licensed Product and
country-by-country basis, the period of time from the First Commercial Sale of such Licensed Product in such country until the later of (a) the expiration of the last Valid Claim that would, but for the license granted hereunder, be infringed
by the manufacture, use, sale, offer for sale or importation of such Licensed Product in such country or (b) the twelfth (12th) anniversary of the date of the First Commercial Sale of
such Licensed Product in such country, but in the case of (b), in no event later than the twentieth (20th) anniversary of the earlier of the date of the First Commercial Sale of such Licensed
Product in the United States or the date of the First Commercial Sale of such Licensed Product in any Major EU Market Country. Anything contained in this Agreement to the contrary notwithstanding, if the Licensed Product (or any component or
intermediate thereof) was manufactured in a country where such manufacture would, at the time of such manufacture, have infringed a Valid Claim within the Licensed Patent Rights in the country of manufacture in the absence of the license granted
under Section 3.3.1 hereof, then the Royalty Term in the country of sale of such Licensed Product, if otherwise expired pursuant to the first sentence of this Section, shall be extended or reinstated, as


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 18 








 
the case may be, but only with respect to sales of Licensed Products so manufactured. In determining infringement of Valid Claims for purposes of this definition of Royalty Term, (i) any
Valid Claim within the Licensed Patent Rights that is jointly owned by CytomX (or any of its Affiliates) with CytomX (or any of its Affiliates) shall be deemed to be owned solely by CytomX or an Affiliate of CytomX, and (ii) claims contained in
patent applications that have not resulted in the issuance of a patent in a country will be disregarded for purposes of determining the expiration of the Royalty Term for a Licensed Product in such country under this definition. 

1.135. “Sales Milestone” is defined in Section 4.1.2 hereof. 

1.136. “Sales Milestone Payment” is defined in Section 4.1.2 hereof. 

1.137. “Sales Threshold” is defined in Section 4.1.2 hereof. 

1.138. [Reserved] 
 1.139.
“Sublicensee” means any Third Party to whom ImmunoGen or an Affiliate of ImmunoGen grants or has granted, directly or indirectly, a sublicense of rights licensed by CytomX under this Agreement, in accordance with the provisions of
this Agreement. 
 1.140. “Substrate” means a moiety that is linked to the Antibody and to the Mask of a Probody and is
capable of being cleaved, reduced or photolysed. 
 1.141. [Reserved] 

1.142. “Target” means a protein described by a unique UniProtKB/Swiss Prot accession number (and all fragments, mutations and
splice variants thereof) that is bound by an Antibody or a Probody. 
 1.143. “Target,” “Targeting” or
“Targeted” means, when used as a verb to describe the relationship between a molecule and a Target, where the molecule’s primary intended mechanism of action requires that it bind to the Target (or a portion thereof). 

1.144. “Target-Binding Probody” means a Probody that Targets the Licensed Target. For purposes of clarity,
“Target-Binding Probody” does not include bi-specific or multi-specific Probodies (i.e., Probodies that Target more than one Target). 

1.145. “Term” is defined in Section 8.1 hereof. 

1.146. “Territory” means the entire world. 

1.147. “Third Party” means any Person other than CytomX, ImmunoGen or their respective Affiliates. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 19 








 1.148. “Third Party Claims” is defined in Section 9.2 hereof. 

1.149. “Third Party Payments” is defined in Section 4.2.3(a) hereof. 

1.150. “Unauthorized Use” is defined in Section 2.6.3 hereof. 

1.151. “Unconjugated Probody Platform Improvements” is defined in Section 1.120 hereof. 

1.152. “Valid Claim” means, with respect to a particular country, (a) a claim of an issued and unexpired patent right
included within the Licensed Patent Rights that (i) has not been held permanently revoked, unenforceable or invalid by a decision of a court or other governmental authority of competent jurisdiction, which decision is unappealed or unappealable
within the time allowed for appeal, and (ii) has not been cancelled, withdrawn, abandoned, disclaimed or admitted to be invalid or unenforceable through reissue, disclaimer or otherwise; or (b) a bona fide claim of a pending
patent application included within the Licensed Patent Rights that has not been (i) cancelled, withdrawn or abandoned without being refiled in another application in the applicable jurisdiction or (ii) finally rejected by an administrative
agency action from which no appeal can be taken or that has not been appealed within the time allowed for appeal, provided that any claim in any patent application pending for more than seven (7) years from the earliest date on which such
patent application claims priority shall not be considered a Valid Claim for purposes of the Agreement from and after such seven (7) year date unless and until a patent containing such claim issues from such patent application and solely if
such patent issues while another Valid Claim covers the relevant Licensed Product in the relevant country. Anything contained in this Agreement to the contrary notwithstanding, a claim within an issued and unexpired patent within the Licensed Patent
Rights shall remain a Valid Claim for all purposes under this Agreement, notwithstanding a determination that such claim is unenforceable pursuant to the operation of the BPCIA, if such determination is exclusively caused by or results solely from
any act or omission by ImmunoGen (or any of its Affiliates or Sublicensee) determined to have been made negligently or in bad faith in the performance of ImmunoGen’s obligations under Section 5.5.3 hereof that results in actual prejudice
to CytomX’s ability to preserve its rights in the Licensed Patent Rights and eliminate the infringement threatened by the Applicant (excluding any acts or omissions undertaken pursuant to the specific written instruction of CytomX). 

 

	2.	PRODUCT DEVELOPMENT, MANUFACTURING AND COMMERCIALIZATION. 

 2.1. General.
ImmunoGen shall have sole authority over, responsibility for and control of (notwithstanding the formation of the JDC or its decisions and/or disputes among the membership of the JDC) the Development, Manufacture, use and Commercialization of the
Licensed Products, and shall bear all costs associated with such Development, Manufacture, use and Commercialization. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 20 








 2.2. Development Diligence. 

2.2.1. ImmunoGen Diligence. ImmunoGen will use Commercially Reasonable Efforts to Develop Licensed Products and to undertake
investigations and actions required to obtain Regulatory Marketing Approval in the Territory; provided that the obligations set forth in this Section shall cease upon the achievement of the first Regulatory Marketing Approval for any Licensed
Product in any country or other jurisdiction in the Territory. For avoidance of doubt, any actions taken by ImmunoGen’s Affiliates or Sublicensees under this Agreement shall be treated as actions taken by ImmunoGen in regard to satisfaction of
the requirements of this Section 2.2.1. Beginning on the sixth (6th) anniversary of the Effective Date and thereafter, ImmunoGen will make non-refundable and non-creditable
maintenance payments in the amounts set forth below (the “Annual Maintenance Fees”) until the earlier of (a) the first filing of an IND in the U.S. or in any European Union country for any Licensed Product or (b) the
termination of this Agreement in accordance with its terms. The amounts of the Annual Maintenance Fee accruing as of each anniversary of the Effective Date, beginning with the sixth
(6th) anniversary are as follows: 
  

			
	 Anniversary of the Effective Date
	  	 Maintenance Fee

		
	Sixth (6th) anniversary	  	[***]
		
	Seventh (7th) anniversary	  	[***]
		
	Eighth (8th) anniversary and each anniversary thereafter	  	The amount payable with respect to the previous anniversary, plus $[***]

 ImmunoGen will pay the applicable Annual Maintenance Fee in accordance with Section 4.3 hereof
within sixty (60) days after the applicable anniversary of the Effective Date. Payment of Annual Maintenance Fees by ImmunoGen shall not establish that ImmunoGen has satisfied its due diligence obligations under this Section 2.2,
and such payments shall be given no consideration or weight in determining whether ImmunoGen has satisfied such due diligence obligations. Anything contained in this Agreement to the contrary notwithstanding, ImmunoGen shall have no obligation to
pay Annual Maintenance Fees hereunder if the first filing of an IND in the U.S. or in any European Union country for any Licensed Product has occurred prior to the sixth
(6th) anniversary of the Effective Date. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 21 








 2.2.2. Exceptions to Diligence Obligations. Notwithstanding any provision of this
Agreement to the contrary, ImmunoGen will be relieved from and will have no obligation to undertake any efforts with respect to any diligence obligation under Section 3.2.1 with respect to a given Licensed Product (each, a
“Diligence Obligation”) in the event that CytomX materially breaches any of its Development or other obligations under this Agreement related to such Licensed Product upon which performance of the applicable Diligence Obligation is
dependent. 
 2.2.3. Remedies for Breach of Diligence Obligations. A material breach of any Diligence Obligation by ImmunoGen shall be
deemed to be a Material Breach by ImmunoGen hereunder. 
 2.3. Joint Development Committee. 

2.3.1. Formation of the Joint Development Committee. As soon as practicable after the Effective Date, CytomX and ImmunoGen shall
establish a “Joint Development Committee” (or “JDC”) to coordinate the sharing of safety data and minutes of meetings with Regulatory Authorities with regard to Licensed Products. The JDC shall also serve as a forum
to facilitate communications between the Parties regarding this Agreement. The JDC shall be comprised of two (2) representatives from each Party as appointed by such Party, with such representatives possessing appropriate expertise and
seniority. The JDC may change its size from time to time by mutual consent of its members. A Party may replace one or more of its representatives from time to time upon written notice to the other Party. The JDC shall exist until the expiration of
the Term or earlier termination of the Agreement, unless the Parties otherwise agree in writing, provided that ImmunoGen may dissolve the JDC upon the achievement of the first Regulatory Marketing Approval for any Licensed Product in any country or
other jurisdiction in the Territory. 
 2.3.2. Chairperson and Secretary of the Joint Development Committee. ImmunoGen shall designate
a chairperson of the JDC, and a secretary of the JDC shall be designated by agreement of the members of the JDC. ImmunoGen may change the designation of the chairperson from time to time upon written notice to CytomX. The chairperson or his or her
designee shall be responsible for scheduling meetings of the JDC, preparing agendas for meetings and sending to all JDC members notices of all regular meetings and agendas for such meetings at least five (5) Business Days before such meetings.
The chairperson shall solicit input from both Parties regarding matters to be included on the agenda, and any 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 22 








 
matter either Party desires to have included on the agenda shall be included for discussion. Nothing herein shall be construed to prohibit the JDC from discussing or acting on matters not
included on the applicable agenda. The secretary shall (a) record the minutes of the meeting, (b) circulate copies of meeting minutes to the Parties and each JDC member promptly following the meeting for review, comment and approval by the
JDC members and (c) finalize approved meeting minutes. The chairperson shall be a member of the JDC but the secretary need not be a member of the JDC. 

2.3.3. Meetings. The JDC shall meet at least three (3) times each Calendar Year (unless the Parties mutually agree in advance of
any scheduled meeting that there is no need for such meeting, in which case the next JDC meeting shall also be scheduled as agreed upon by the Parties) until it has been terminated in accordance with Section 2.3.1 hereof at dates and
times mutually agreed by the JDC. The initial meeting of the JDC shall be held within sixty (60) days after the Effective Date. Either Party may call a special meeting of the JDC on fifteen (15) days written notice to the other
Party’s members of the JDC (or upon such shorter notice as exigent circumstances may require). Such written notice shall include an agenda for the special meeting. In-person meetings, including special meetings, of the JDC shall alternate
between the offices of the Parties, unless otherwise agreed upon by the members of the JDC. Meetings of the JDC may be held telephonically or by video conference; provided, however, that at least two (2) meetings per year shall be held
in-person. Meetings of the JDC shall be effective only if at least one (1) representative of each Party is in attendance or participating in the meeting. Members of the JDC shall have the right to participate in at meetings held by telephone or
video conference. In addition, the JDC may act on any matter or issue without a meeting if it is documented in a written consent signed by each member of the JDC. 

2.3.4. Responsibilities of the Joint Development Committee. The JDC shall be responsible for (a) receiving and reviewing all safety
data, relevant regulatory information and other related information obtained by either Party in connection with the Development, Manufacture, use and Commercialization of Licensed Products; (b) facilitating communication between the Parties,
(c) resolving Disputes between the Parties, such as Disputes about interpretation of this Agreement, understanding that ImmunoGen has sole authority over the Development, Manufacturing, use and Commercialization of Licensed Products; and
(d) such other functions as expressly specified hereunder or as agreed by the Parties. At the time that the first Licensed Product enters a clinical trial, the Parties shall negotiate in good faith the terms of a separate written safety data
exchange agreement that, among other things, will govern the exchange of pharmacovigilance information. 
 2.3.5. Resolution by
Consensus. All resolution of Disputes by the JDC shall be made by unanimous agreement of both Parties’ representatives, with each Party having a single vote, irrespective of the number of JDC representatives in attendance at a meeting. If
the JDC cannot or does not reach unanimous agreement on a Dispute, then such Dispute shall be resolved in accordance with Section 10.9 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 23 








 2.4. Alliance Managers. In addition to the foregoing governance provisions, each of the
Parties shall appoint a single individual to serve as that Party’s alliance manager (“Alliance Manager”). The role of each Alliance Manager will be to participate and otherwise facilitate the relationship between the Parties as
established by this Agreement. A Party may replace its Alliance Manager from time to time upon written notice to the other Party. 
 2.5.
Updates and Reports; Product Recalls. 
 2.5.1. Development Updates. Upon the request of CytomX, ImmunoGen shall provide CytomX
with brief written reports, which CytomX may request no more frequently than once per Calendar Year until satisfaction of ImmunoGen’s obligations under Section 2.2.1 hereof, that shall summarize ImmunoGen’s efforts to Develop the
Licensed Products in the Field in the Territory in sufficient detail to establish that ImmunoGen is using Commercially Reasonable Efforts to Develop the Licensed Product, identify the applications for Regulatory Approval that ImmunoGen or its
Affiliates or Sublicensees have filed, sought or attempted to obtain in the prior twelve (12)-month period, and any they reasonably expect to file, seek or attempt to obtain in the following twelve (12)-month period. The Parties agree that the
minutes of the JDC meetings may serve as reports hereunder, to the extent such minutes adequately address the above subject matter. 
 2.5.2.
[Reserved] 
 2.5.3. Product Recalls. In the event any Regulatory Authority issues or requests a recall or takes similar action
with respect to a Licensed Product that ImmunoGen reasonably believes is or may be attributable to or otherwise relates to the Licensed Intellectual Property, or in the event either Party reasonably believes that an event, incident or circumstance
has occurred that may result in the need for such a recall, such Party shall promptly notify the other Party thereof by telephone, facsimile or email. Following such notification, ImmunoGen shall decide and have control of whether to conduct a
recall or market withdrawal (except in the event of a recall or market withdrawal mandated by a Regulatory Authority, in which case it shall be required) or take such other corrective action in any country and the manner in which any such recall,
market withdrawal or 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 24 








 
corrective action shall be conducted, provided that ImmunoGen shall keep CytomX informed regarding any such recall, market withdrawal or corrective action as CytomX from time to time may
reasonably request, but only to the extent ImmunoGen is legally permitted to do so. ImmunoGen shall bear all expenses of any such recall, market withdrawal or corrective action, including, without limitation, expenses of notification, destruction
and return of the affected Licensed Product and any refund to customers of the amounts paid for such Licensed Product. 
 2.5.4.
Confidential Information. All reports, updates, product complaints and other information provided by the Disclosing Party to the Receiving Party under this Agreement (including under this Section 2.5), shall be considered
Confidential Information of the Disclosing Party, subject to the terms of Article 7 hereof. 
 2.6. Transfer and Use of
Proprietary Materials. 
 2.6.1. Transfer and Use of CytomX Proprietary Materials. From time to time during the Term, CytomX may
provide ImmunoGen with CytomX Proprietary Materials for use in the Development and Manufacture of Licensed Products under this Agreement. CytomX’s Proprietary Materials are provided by CytomX on an “as-is” basis without representation
or warranty of any type, express or implied, including any representation or warranty of merchantability, non-infringement, title or fitness for a particular purpose, each of which is hereby disclaimed by CytomX. In connection with the foregoing,
ImmunoGen agrees that (a) it shall not use CytomX’s Proprietary Materials provided under this Agreement for any purpose other than exercising its rights and performing its obligations hereunder; (b) it shall not use CytomX Proprietary
Materials provided under this Agreement in any human subject; (c) it shall use CytomX Proprietary Materials in compliance with all Applicable Laws; (d) it does not acquire any right, title or interest in or to CytomX Proprietary Materials
as a result of such provision by CytomX; and (e) upon expiration or termination of this Agreement for any reason, ImmunoGen shall, if and as instructed by CytomX, either destroy or return CytomX Proprietary Materials provided under this
Agreement that are not the subject of a continuing license hereunder. ImmunoGen shall be entitled to transfer CytomX Proprietary Materials to any Affiliate, Sublicensee or Permitted Third Party Service Provider under terms obligating such Affiliate,
Sublicensee or Permitted Third Party Service Provider not to use or transfer such CytomX Proprietary Materials except in compliance with the preceding sentence. 

2.6.2. Transfer and Use of ImmunoGen Proprietary Materials. From time to time during the Term, ImmunoGen may provide CytomX with
ImmunoGen 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 25 








 
Proprietary Materials. CytomX shall use the ImmunoGen Proprietary Materials solely in connection with conducting the specific activities for which such ImmunoGen Proprietary Materials are
provided to CytomX, and for no other purpose. Without limiting the generality of the foregoing, except as expressly set forth in this Agreement or in other written authorization by ImmunoGen, CytomX shall not make or attempt to make analogues,
progeny or derivatives of, or modifications to, the ImmunoGen Proprietary Materials, using ImmunoGen’s Confidential Information, and CytomX shall not use the ImmunoGen Proprietary Materials for the benefit of any Third Party or of its own
internal research programs. CytomX shall comply with all Applicable Laws regarding the handling and use of the ImmunoGen Proprietary Materials. CytomX agrees to retain possession over the ImmunoGen Proprietary Materials and not to provide the
ImmunoGen Proprietary Materials to any Third Party without ImmunoGen’s prior written consent. 
 2.6.3. Unauthorized Use of
Confidential Information and Proprietary Materials. In the event that (a) ImmunoGen or any of its Affiliates or Sublicensees use CytomX’s Confidential Information (including, without limitation, any Confidential Information within the
Licensed Know-How) or CytomX Proprietary Materials for any purpose other than in connection with ImmunoGen’s exercise of its rights and performance of its obligations hereunder or the Research Collaboration Agreement (if then in effect) or
(b) CytomX or any of its Affiliates uses ImmunoGen’s Confidential Information or ImmunoGen Proprietary Materials for any purpose other than the purposes authorized herein or in any other License Agreement or the Research Collaboration
Agreement (if then in effect) (in each case, an “Unauthorized Use”), the results of such Unauthorized Use, and any discoveries or inventions that arise from such Unauthorized Use, whether patentable or not, shall belong solely and
exclusively to the providing Party. If required in order to perfect or enforce the providing Party’s ownership of such results, discoveries or inventions, each Party, on behalf of itself and its Affiliates (and in the case of ImmunoGen, its
Sublicensees), each hereby assigns and agrees to assign to the providing Party all of its and their right, title and interest in and to all such results, discoveries or inventions made through such Unauthorized Use. Each Party agrees to cooperate,
and to cause its Affiliates (and in the case of ImmunoGen, its Sublicensees) to cooperate, with the providing Party, and to execute and deliver any and all documents that the providing Party reasonably deems necessary, to perfect and enforce its
rights hereunder. 
 2.7. Services. If, during the Term, ImmunoGen requests that CytomX provide additional services with respect to
(a) the creation of new Probodies Targeting the Licensed Target or (b) any other tasks in connection with the Development, Manufacture, 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 26 








 
use or Commercialization of Licensed Products with respect to which the Parties may mutually agree, then the Parties shall negotiate in good faith the terms of separate written agreements with
respect to such activities. 
  

	3.	LICENSE GRANTS. 

 3.1. License Grants. 

3.1.1. Commercial License. Subject to the terms and conditions of this Agreement, CytomX hereby grants to ImmunoGen and its Affiliates
an exclusive (even as to CytomX), non-transferable (except as expressly permitted in this Agreement), royalty-bearing license, including the right to grant sublicenses as described in Section 3.1.2 hereof, under the Licensed Intellectual
Property, to Develop, make, have made, use, sell, offer for sale, import and otherwise Commercialize Licensed Products in the Field in the Territory. ImmunoGen and its Affiliates shall have the right to engage one or more Affiliates or Third Parties
(the latter being referred to herein as “Permitted Third Party Service Providers”) as subcontractors to perform designated functions in connection with its activities under this Agreement (including transferring Licensed Know-How
and CytomX Proprietary Materials as may be necessary for such Permitted Third Party Service Providers to perform such designated functions); provided that (a) ImmunoGen shall remain responsible for the conduct of such activities in accordance
with the terms and conditions of this Agreement and (b) ImmunoGen shall cause each such Affiliate or Third Party Service Provider to assign or license (with a right to sublicense to CytomX to the extent required under this Agreement) to
ImmunoGen all intellectual property rights (including, without limitation, Patent Rights) in and to any Probody Platform Improvements, whether patentable or not, the inventors of which (alone or with others) are employees of, or others obligated to
assign inventions to, such Permitted Third Party Service Provider in the performance of services for ImmunoGen. 
 3.1.2. Right to
Sublicense. ImmunoGen and its Affiliates shall have the right to grant sublicenses under the rights granted to them under Section 3.1.1 hereof with respect to any Licensed Product to any Sublicensee, provided that (a) each such
sublicense shall be consistent with the terms and conditions of this Agreement, (b) ImmunoGen shall provide the identity of each Sublicensee within twenty (20) Business Days after execution of such sublicense, (c) ImmunoGen and its
Affiliates shall cause each Sublicensee to assign or license (with a right to sublicense to CytomX to the extent required by this Agreement) to ImmunoGen all intellectual property rights (including, without limitation, Patent Rights) in and to any
Probody Platform Improvements, whether or not patentable, the inventors of which (alone or with others) are employees of, or others obligated to assign 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 27 








 
inventions to, such Sublicensee in connection with its exercise of its rights under the applicable sublicense, (d) ImmunoGen shall be jointly and severally responsible with its Sublicensees
to CytomX for failure by its Sublicensees to comply with the terms and conditions of this Agreement and (e) ImmunoGen shall remain responsible for the payment to CytomX of all Milestone Payments and royalties payable with respect to the
activities and Net Sales of any Sublicensee. 
 3.2. Retained Rights and Covenants. 

3.2.1. Retained Rights. Subject to the other terms of this Agreement (including, without limitation, Section 3.2.2 and 3.3 hereof),
CytomX retains the right to use the unpatented Licensed Know-How and practice the Licensed Patent Rights (a) to develop, make, have made, use, sell, offer for sale, import or otherwise commercialize any product (excluding, on a
country-by-country basis, while the exclusive license granted under Section 3.1.1 hereof remains in effect in such country, any PDC having a Payload that is a Cytotoxic Compound that Targets the Licensed Target), and to grant licenses to Third
Parties to do the same; and (b) for any and all uses outside of the Field. 
 3.2.2. Covenants. Anything contained in
Section 3.2.1 or 3.3 hereof to the contrary notwithstanding, CytomX hereby agrees that, on a country-by-country basis, during the period that the exclusive license granted under Section 3.3.1 hereof remains in effect in such country,
neither it nor any of its Affiliates shall (a) develop or commercialize any PDC having a Payload that is a Cytotoxic Compound that Targets the Licensed Target, or (b) grant to any Third Party any license or other right under any Patent
Rights or Know-How owned or Controlled by CytomX to develop or commercialize any PDC having a Payload that is a Cytotoxic Compound that Targets the Licensed Target; provided that the foregoing shall not restrict CytomX’s or its Affiliates’
right to grant to Third Parties research licenses under any Patent Rights or Know-How owned or Controlled by CytomX that are not Target-specific. 

3.3. License to ImmunoGen Probody Platform Improvements. ImmunoGen, on behalf of itself and its Affiliates, hereby grants to CytomX a
non-exclusive, sublicensable, perpetual, irrevocable, royalty-free worldwide license under ImmunoGen’s interest in any ImmunoGen Probody Platform Improvements, including, without limitation, any Patent Rights claiming such ImmunoGen Probody
Platform Improvements, to exploit such ImmunoGen Probody Platform Improvements (a) for any purpose in the Field other than developing, manufacturing, using or commercializing PDCs having a Payload that is a


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 28 








 
Cytotoxic Compound3 and (b) for any purpose outside of the Field. Nothing in this Agreement shall be construed as obligating ImmunoGen to
engage in any technology transfer or provision of written documentation to CytomX (other than as provided in Section 5.2.3 hereof) or any of its Affiliates or any Third Party disclosing, describing or otherwise relating to ImmunoGen Probody
Platform Improvements. 
 3.4. Section 365(n) of Bankruptcy Code. All rights and licenses now or hereinafter granted by either
Party to the other Party under or pursuant to any section of this Agreement, including the licensed granted in this Article 3, are rights to “intellectual property” (as defined in Section 101(35A) of Title 11 of the
United States Code, as amended (such Title 11, the “Bankruptcy Code”)). The Parties hereto acknowledge and agree that the payments provided for under Article 4 hereof, other than royalty payments pursuant to
Section 4.2 hereof, do not constitute royalties within the meaning of Section 365(n) of the Bankruptcy Code or relate to licenses of intellectual property under this Agreement. 

3.5. No Implied Rights. Except as expressly provided in this Agreement, neither Party shall be deemed, by estoppel, implication or
otherwise, to have granted the other Party any license or other right with respect to any intellectual property of such Party. 
  

	4.	PAYMENTS. 

 4.1. Milestone Payments. 

4.1.1. Development Milestones. Within ten (10) Business Days following the first occurrence of each event (each, a
“Development Milestone”) described below for the first Licensed Product that achieves such milestone, ImmunoGen shall provide written notice to CytomX identifying the Development Milestone achieved, and ImmunoGen shall pay to CytomX
the amount set forth below within forty-five (45) days of receipt of CytomX’s notice with respect to such Development Milestone (each such amount, a “Development Milestone Payment”) to be payable only once regardless of
how many Licensed Products achieve such Development Milestone. 
  

	3 	For purposes of this Section, the term “Cytotoxic Compound” shall be limited to the cell-killing agents encompassed by one or more of the claims of the issued patents (whether or not expired) listed in
Schedule 1.120 attached hereto, or by one or more of the claims, if any, of any patents issuing from the patent applications listed in Schedule 1.120 or from any divisionals, continuations or foreign counterparts of any of the foregoing.



  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 29 









					
	 Development Milestone
	  	Payment	 
	 Dosing of first patient in a Phase 1 Clinical Study
	  	 	[***	] 
	 Dosing of first patient in a Phase 2 Clinical Study*
	  	 	[***	] 
	 Dosing of first patient in a Phase 3 Clinical Study
	  	 	[***	] 
	 Date of filing of BLA
	  	 	[***	] 
	 Date of receipt of Regulatory Approval in the United States
	  	 	[***	] 
	 Date of receipt of Regulatory Marketing Approval in Major EU Market Country
	  	 	[***	] 
	 Date of receipt of Regulatory Marketing Approval in Japan
	  	 	[***	] 

 If a clinical milestone is achieved and any previous clinical milestone has not yet been achieved for any
reason, notwithstanding anything herein to the contrary such previous milestone(s) shall be deemed to have been achieved and the corresponding Development Milestone Payment set forth in the table above shall be payable simultaneously with the
Development Milestone Payment for the achievement of the subsequent Milestone. All Development Milestone Payments shall be non-refundable and noncreditable. 

4.1.2. Sales Milestones. ImmunoGen shall pay to CytomX the following one-time payments (each, a “Sales Milestone
Payment”) when aggregate Annual Net Sales of a Licensed Product in the Territory in a Calendar Year first reach the respective threshold (a “Sales Threshold”) indicated below (each, a “Sales Milestone”):

  

					
	 Total Annual Net Sales
	  	Sales Milestone
Payment	 
	 Total Annual Net Sales at least equal $500,000,000
	  	 	[***	] 
	 Total Annual Net Sales at least equal $750,000,000
	  	 	[***	] 
	 Total Annual Net Sales at least equal $1,000,000,000
	  	 	[***	] 
	 Total Annual Net Sales at least equal $1,500,000,000
	  	 	[***	] 


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 30 








 Any Sales Milestone Payment with respect to any Calendar Year shall be payable within sixty
(60) days of the end of such Calendar Year in the United States. Each Sales Milestone Payment is payable a maximum of one time only, regardless of the number of times a Licensed Product achieves a particular Sales Threshold or the number of
Licensed Products that achieve a particular Sales Threshold. All Sales Milestone Payments shall be nonrefundable and noncreditable. 
 4.2.
Royalties. 
 4.2.1. Royalty Payments. With respect to each Licensed Product and subject to the provisions of
Section 4.2.2 hereof, ImmunoGen shall pay CytomX royalties in the amount of the applicable rates (“Marginal Royalty Rates”) set forth below of Annual Net Sales of such Licensed Product during the Royalty Term: 

 

					
	 Annual Net Sales
	  	Marginal Royalty Rate for
Licensed Products (% of
Annual Net Sales)	 
	 Annual Net Sales of such Licensed Product during a given Calendar Year up to and including $500,000,000
	  	 	[***	]% 
	 Annual Net Sales of such Licensed Product during a given Calendar Year above $500,000,000, up to and including $1,000,000,000
	  	 	[***	]% 
	 Annual Net Sales of such Licensed Product during a given Calendar Year above $1,000,000,000
	  	 	[***	]% 


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 31 








 4.2.2. Marginal Royalty Rate Application. Each Marginal Royalty Rate set forth in the
table above shall apply only to that portion of the Annual Net Sales of a given Licensed Product in the Territory during a given Calendar Year that falls within the indicated range. 

4.2.3. Royalty Adjustments. 

(a) Third Party Royalty Offset. Subject to Section 4.2.3(e) hereof, if, with respect to a Calendar Quarter, ImmunoGen or
any of its Affiliates or Sublicensees actually makes royalty payments to one or more Third Parties in consideration of a license, in the absence of which ImmunoGen could not practice the Licensed Intellectual Property to make, offer for sale, sell
or import the Mask or Substrate portion of the Probody portion of any Licensed Product included within the Licensed Intellectual Property (excluding any Licensed Intellectual Property jointly owned by CytomX or its Affiliates, on the one hand, and
ImmunoGen or its Affiliates, on the other hand) without infringing an issued patent or patents owned or exclusively licensed by such Third Party in any country (collectively, “Third Party Payments”), as evidenced, to the extent requested
by CytomX, by an opinion of Independent Patent Counsel selected by ImmunoGen and approved by CytomX (which approval shall not be unreasonably withheld), then ImmunoGen shall have the right to reduce the royalties otherwise due to CytomX pursuant to
Section 4.2.1, 4.2.3(c) or 4.2.3(d) hereof (but not the royalties otherwise due to CytomX pursuant to Section 4.2.3(b) hereof) with respect to Net Sales in such country of such Licensed Products in such Calendar Quarter by an amount equal
to fifty percent (50%) of the amount of such Third Party Payments. For purposes of clarity, the term “Third Party Payments” includes only prospective running royalties payable on the same basis as required by this Section 4.2,
and does not include any lump-sum license fees, milestone payments, minimum royalties in excess of accrued royalties, any amounts paid for past infringement of any Third Party’s rights or any amount paid for rights not required to permit
ImmunoGen to practice the Licensed Intellectual Property to make, use, offer for sale, sell or import the Mark or Substarte portion of the Probody portion of any Licensed Product included in the Licensed Intellectual Property in any country.
For the avoidance of doubt, the Parties agree and acknowledge that this Section 4.2.3(a) shall not apply with respect to royalties payable by a Party to any Third Party under any agreement in existence as of the Effective Date. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 32 








 (b) Valid Claim Coverage. 

(i) No Patent Coverage. Subject to Section 4.2.3(e) hereof, the royalty rates set forth in Sections 4.2.1,
4.2.3(c) and 4.2.3(d) hereof shall apply, on a country-by-country basis and Licensed Product-by-Licensed Product basis, to Net Sales of Licensed Products only where (A) such Licensed Product (or its manufacture, use, sale, offer
for sale or importation) in such country is Covered by a Valid Claim within the Licensed Patent Rights or (B) such Licensed Product (or any component or intermediate thereof) was manufactured in a country where the manufacture of such Licensed
Product (or such component or intermediate), was, at the time of its manufacture, Covered by a Valid Claim within the Licensed Patent Rights, regardless of the country in which such Licensed Product is sold. Subject to the other terms of this
Agreement (except for Section 4.2.3(a) hereof, which shall not apply), on a country-by-country and Licensed Product-by-Licensed Product basis where and as of and when the royalty rates under Sections 4.2.1, 4.2.3(c) and
4.2.3(d) hereof do not apply as a result of this Section 4.2.3(b)(i), the royalties payable with respect to Net Sales of such Licensed Product sold by ImmunoGen, its Affiliates and its Sublicensees in such country shall be reduced
by fifty percent (50%) of the royalties otherwise owed to CytomX pursuant to Section 4.2.1 or 4.2.3(d) hereof, as applicable, without giving effect to any royalty reduction provided in Section 4.2.3(c) hereof,
using the methodology outlined in Exhibit B attached hereto. The Parties hereby acknowledge and agree that such royalties shall be in consideration of the commercial advantage, know-how and background information gained from the
unpatented Licensed Know-How, including, without limitation, CytomX’s Confidential Information and CytomX Proprietary Materials. 

(ii) Applicability of Royalty Rates. For purposes of clarity, (A) if a Licensed Product (or its manufacture, use, sale, offer for
sale or importation) is Covered by a Valid Claim in a country within the Territory such that royalties are paid by ImmunoGen pursuant to Section 4.2.1, 4.2.3(c) or 4.2.3(d) hereof and, prior to the expiration of the Royalty
Term for such Licensed Product in such country, the Licensed Product (and its manufacture, use, sale, offer for sale or importation) is no longer Covered by a Valid Claim in such country, ImmunoGen shall pay CytomX a royalty at the rate set forth in
Section 4.2.1(b)(i) hereof for the portion of the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 33 








 
Royalty Term during which no such Valid Claim Covers such Licensed Product (or its manufacture, use, sale, offer for sale or importation) in such country; and (B) if a Licensed Product (or
its manufacture, use, sale, offer for sale or importation) is not Covered by a Valid Claim in a country within the Territory such that royalties are paid by ImmunoGen pursuant to Section 4.2.1(b)(i) hereof and, prior to the expiration of
the Royalty Term for such Licensed Product in such country, the Licensed Product (or its manufacture, use, sale, offer for sale or importation) becomes Covered by a Valid Claim within the Licensed Patent Rights in such country, ImmunoGen shall pay
CytomX a royalty at the rates set forth in Section 4.2.1, 4.2.3(c) or 4.2.3(d) hereof, as applicable, for that portion of the Royalty Term during which such Valid Claim Covers such Licensed Product (or its manufacture, use,
sale, offer for sale or importation) in such country. 
 (iii) Definition of “Cover”. A Valid Claim within the Licensed
Patent Rights “Covers” the Licensed Product (or its manufacture, use, sale, offer for sale or importation) in a country if, but for the license granted under Section 3.1.1 hereof, the manufacture, use, sale, offer for
sale or importation of the Licensed Product by ImmunoGen or any of its Affiliates or Sublicensees in such country would infringe such Valid Claim; provided, however, that in determining whether a Valid Claim within such Licensed Patent Rights
“Covers” (as defined above) the Licensed Product (or its manufacture, use, sale, offer for sale or importation), (A) any Valid Claim within the Licensed Patent Rights that is jointly owned by ImmunoGen (or any of its
Affiliates) with CytomX (or any of its Affiliates) shall be deemed to be owned solely by CytomX or an Affiliate of CytomX and (B) any Valid Claim contained in an unissued patent application within the Licensed Patent Rights that has not been
(1) canceled, withdrawn or abandoned or (2) pending for more than seven (7) years from its earliest priority date shall be deemed to have been issued. 

(c) Loss of Market Exclusivity. Subject to Section 4.2.3(e) hereof, if, with respect to a Calendar Quarter, ImmunoGen or
any of its Affiliates or Sublicensees experiences a Loss of Market Exclusivity for a Licensed Product in any country, then ImmunoGen shall have the right to reduce the royalties otherwise due to CytomX pursuant to Section 4.2.1 or
4.2.3(d) hereof (but not the royalties otherwise due to CytomX under Section 4.2.3(b) hereof) with respect to Net Sales in such country of such Licensed 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 34 








 
Products in such Calendar Quarter as described below, in each case using a methodology similar to that outlined in Exhibit B attached hereto. In calculating royalty reductions
pursuant to this Section 4.2.3(c), the applicable WARR (as defined in Exhibit B) shall be multiplied by a percentage which is equal to a fraction, the numerator of which is the actual Net Sales of the Licensed Product in the country for the
applicable Calendar Quarter during the period of Loss of Market Exclusivity, and the denominator of which is the Baseline Net Sales of the Licensed Product in such country; provided, however, that (i) if the percentage referred to above is
greater than eighty percent (80%), no reductions shall be made pursuant to this Section 4.2.3(c) with respect to Net Sales of the Licensed Product in such country for such Calendar Quarter; and (ii) such percentage shall never be less than
fifty percent (50%), regardless of whether Net Sales of such Licensed Product in such country for such Calendar Quarter are less than fifty percent (50%) of the applicable Baseline Net Sales. 

(d) Effect of Challenge. In further consideration of the grant by CytomX of the license hereunder and except to the extent the
following is unenforceable under the Applicable Laws of a particular jurisdiction where a patent application within the Licensed Patent Rights is pending or a patent within the Licensed Patent Rights is issued, if CytomX, its Affiliates or
Sublicensees initiates a Challenge or induces or assists a Third Party in initiating or prosecuting a Challenge (the Licensed Patent Rights subject to such Challenge being referred to herein as the “Challenged Patent Rights”), then
during the period that such Challenge is pending, the royalty rates set forth in Section 4.2.1 hereof shall be increased by an additional two percent (2%) of annual Net Sales (the “Challenge-Related Royalty
Increase”) in the country(ies) in which the Challenged Patent Rights were pending or issued (each, a “Challenge Jurisdiction”) commencing on the date of such initiation or the date ImmunoGen, its Affiliates or Sublicensees
first induces or provides assistance to such Third Party, as applicable, but only with respect to Net Sales of Licensed Products in the applicable Challenge Jurisdiction(s). If, following the final, unappealable conclusion of a Challenge in a
Challenge Jurisdiction, there remains one or more Valid Claims within the Challenged Patent Rights that would be infringed by the manufacture, use, sale, offer for sale or importation then (i) the royalty rates set forth in
Section 4.2.1 hereof shall be increased by an additional three percent (3%) of annual Net Sales (which shall be in addition to the Challenge-Related Royalty Increase) in the applicable Challenge Jurisdiction, commencing upon the
final, unappealable conclusion of such Challenge and continuing 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 35 








 
for the remainder of the Royalty Term in the applicable Challenge Jurisdiction, and (ii) ImmunoGen shall reimburse CytomX for its costs and expenses (including, without limitation,
reasonable attorneys’ and experts’ fees and expenses of litigation) incurred in responding to the Challenge. ImmunoGen shall be required to pay such reimbursement within sixty (60) days of receiving an invoice therefor from CytomX,
which shall set forth in reasonable detail the basis for the charges for which CytomX is seeking reimbursement. If, following the final, unappealable conclusion of a Challenge in a Challenge Jurisdiction, there remain no Valid Claims within the
Challenged Patent Rights that would be infringed by the manufacture, use, sale, offer for sale or importation of Licensed Products by ImmunoGen or any of its Affiliates or Sublicensees in such Challenge Jurisdiction in the absence of the license
granted under Section 3.1.1 hereof, then CytomX shall reimburse ImmunoGen for all amounts with respect to the Challenge-Related Royalty Increase actually paid by ImmunoGen to CytomX with respect to the Challenge Jurisdiction (the
“Clawback Amount”) as follows: (A) ImmunoGen shall be entitled to credit one hundred percent (100%) of each royalty payment due under Section 4.2 hereof as they become due from and after the final, unappealable
conclusion of such Challenge in such Challenge Jurisdiction against the Clawback Amount until reimbursed in full; and (B) any unreimbursed portion of the Clawback Amount outstanding at the conclusion of the Royalty Term in all countries and
jurisdictions in the Territory shall be paid to ImmunoGen within sixty (60) days after receipt by CytomX of an invoice from ImmunoGen therefor. 

(e) Minimum Royalty Rate. Anything contained in this Agreement to the contrary notwithstanding, none of the reductions to royalties
provided in Sections 4.2.3(a), 4.2.3(b) and 4.2.3(c) hereof, shall, individually or in the aggregate, reduce the royalties payable with respect to Net Sales of any Licensed Product sold by ImmunoGen, its Affiliates and its
Sublicensees in any country during the Royalty Term by more than fifty percent (50%) of the royalties otherwise owed to CytomX pursuant to Section 4.2.1 or 4.2.3(d), as applicable, without giving effect to any royalty
reduction provided in Section 4.2.3(a), 4.2.3(b) or 4.2.3(c) hereof. 
 4.3. Reports and Payments. 

4.3.1. Cumulative Royalties. The obligation to pay royalties under Section 4.2 shall be imposed only once with respect to a
single unit of a Licensed Product regardless of how many Valid Claims in Patent Rights included within the Licensed Intellectual Property would, but for this Agreement, be infringed by the use or sale of such Licensed Product in the country in which
such Licensed Product is used or sold. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 36 








 4.3.2. Royalty Statements and Payments. Within sixty (60) days after the end of each
Calendar Quarter, ImmunoGen shall deliver to CytomX a report setting forth for such Calendar Quarter the following information, on a Licensed Product-by-Licensed Product basis: (a) the gross sales (if available) and the Net Sales of each
Licensed Product (specifying in reasonable detail the deductions to gross sales used to calculate Net Sales, (b) the basis for any adjustments to the royalty payable for the sale of each Licensed Product, (c) the applicable exchange rate
to convert each country’s currency to U.S. Dollars under Section 4.3.4 hereof and (d) the royalties due hereunder for the sale of each Licensed Product. No such reports shall be due for any Licensed Product before the
First Commercial Sale of such Licensed Product in the Territory. The total royalty due for the sale of Licensed Products during such Calendar Quarter shall be remitted at the time such report is delivered. 

4.3.3. No Set-Off; Taxes and Withholding. All payments made by ImmunoGen to CytomX hereunder shall be made without set-off or
counterclaim and free and clear of any taxes, duties, levies, fees or charges, except withholding taxes, if any. In the event any of the payments made pursuant to this Agreement become subject to withholding taxes under the Applicable Law of any
jurisdiction, ImmunoGen shall deduct and withhold the amount of such taxes for the account of CytomX, to the extent required by Applicable Law, such amounts payable to CytomX shall be reduced by the amount of taxes deducted and withheld, and
ImmunoGen shall pay the amounts of such taxes to the proper Governmental Authority in a timely manner and promptly transmit to CytomX an official tax certificate or other evidence of such tax obligations together with proof of payment from the
relevant Governmental Authority of all amounts deducted and withheld sufficient to enable CytomX to claim such payment of taxes. Any such withholding taxes required under Applicable Law to be paid or withheld shall be an expense of, and borne solely
by, CytomX. ImmunoGen will provide CytomX with reasonable assistance to enable CytomX to recover such taxes as permitted by Applicable Law. 

4.3.4. Currency. All amounts payable and calculations hereunder shall be in United States dollars, and all payments due under this
Agreement shall be made by wire transfer in immediately available funds to an account designated by the Party owed such payment. As applicable, Net Sales and any royalty deductions shall be converted into United States dollars in accordance with the
ImmunoGen Standard Exchange Rate Methodology. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 37 








 4.3.5. Overdue Payments. Subject to the other terms of this Agreement, any payments
hereunder not paid within the applicable time period set forth herein shall bear interest from the due date until paid in full, at a rate per annum equal to the lesser of (a) one and one-half percent (1-1/2%) per month, compounded monthly,
or (b) the maximum interest rate permitted by applicable law in regard to such payments, calculated in each case from the date such payment was due through to the date on which payment is actually made; provided, however, that with respect to
any disputed payments, no interest shall be due until such dispute is resolved and the interest that shall be payable thereon shall be based on the finally-resolved amount of such payment, calculated from the original date on which the disputed
payment was due through the date on which payment is actually made. Such payments when made shall be accompanied by all interest so accrued. Such interest and the payment and acceptance thereof shall not negate or waive the right of CytomX to any
other remedy, legal or equitable, to which it may be entitled because of the delinquency of the payment. 
 4.4. Maintenance of Records;
Audits. 
 4.4.1. Record Keeping. ImmunoGen shall keep, and cause its Affiliates and Sublicensees to keep, accurate books of
account and records in connection with the sale of Licensed Products, in sufficient detail to permit accurate determination of all figures necessary for verification of royalties to be paid hereunder. ImmunoGen shall maintain, and cause its
Affiliates and Sublicensees to maintain, such records for a period of at least three (3) years after the end of the Calendar Year in which they were generated. 

4.4.2. Audits. Upon thirty (30) days prior written notice from CytomX, ImmunoGen shall permit an independent certified public
accounting firm of internationally recognized standing selected by CytomX and reasonably acceptable to ImmunoGen to examine, at CytomX’s sole expense, the relevant books and records of ImmunoGen, its Affiliates and Sublicensees during the
period covered by such examination, as may be reasonably necessary to verify the accuracy of the reports submitted by ImmunoGen in accordance with Section 4.3 hereof and the payment of royalties hereunder. An examination by CytomX under
this Section 4.4.2 shall occur not more than once in any Calendar Year and shall be limited to the pertinent books and records for any Calendar Year ending not more than three (3) years before the date of the request. The accounting
firm shall be provided access to such books and records at the facilities where such books and records are kept and such examination shall be conducted during normal business hours. ImmunoGen may require the accounting firm to sign a reasonable and
customary non-disclosure agreement before providing the accounting firm access to ImmunoGen’s facilities or records. Upon completion of the audit, the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 38 








 
accounting firm shall provide both CytomX and ImmunoGen a written report disclosing whether the reports submitted by ImmunoGen are correct or incorrect, whether the royalties paid are correct or
incorrect and, in each case, the specific details concerning any discrepancies. ImmunoGen and CytomX shall each have the right to request a further determination by such accounting firm as to matters which such Party disputes within thirty
(30) days following receipt of such report. The Party initiating a dispute will provide the other Party and the accounting firm with a reasonably detailed statement of the grounds upon which it disputes any findings in the written report and
the accounting firm shall undertake to complete such further determination within thirty (30) days after the dispute notice is provided, which determination shall be limited to the disputed matters and provided to both Parties. The Parties
shall use reasonable efforts, through the participation of finance representatives of both Parties, to resolve any dispute arising in relation to the audit by good faith discussion. The results of any such audit, reflecting the accounting
firm’s determination of any disputed matters, shall be binding on both Parties. 
 4.4.3. Underpayments/Overpayments. If such
accounting firm concludes that additional royalties were due to CytomX, ImmunoGen shall pay the additional royalties (plus interest thereon at the rate provided in Section 4.3.5 hereof) within forty-five (45) days of the date ImmunoGen
receives such accountant’s written report so concluding. If such underpayment exceeds five percent (5%) of the royalties that were to be paid and is also greater than Fifty Thousand U.S. Dollars ($50,000), ImmunoGen also shall
reimburse CytomX for all reasonable charges of such accountants for conducting the audit. If such accounting firm concludes that ImmunoGen overpaid royalties, CytomX shall repay such amount in full within forty-five (45) days of the receipt of
such accountant’s report, or, at ImmunoGen’s option, it shall be entitled to offset all such overpayments against any outstanding or future amounts payable to CytomX hereunder until ImmunoGen has received full credit for such overpayments.

 4.4.4. Confidentiality. All financial information that is subject to review under this Section 4.4 shall be deemed to
be the Confidential Information of the audited Party subject to the provisions of Article 6 hereof. 
  

	5.	INTELLECTUAL PROPERTY. 

 5.1. Inventions. 

5.1.1. Ownership. All determinations of inventorship under this Agreement shall be made in accordance with the laws of the United
States. Determinations of ownership of intellectual property hereunder will be made in accordance with inventorship. 
 (a) CytomX Solely
Owned Technology. As between the Parties, CytomX shall be the sole owner of all Licensed Intellectual Property (other than Joint Program Technology and Joint Probody Platform Improvements included therein and any Joint Patent Rights). 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 39 








 (b) ImmunoGen Solely Owned Technology. As between the Parties, ImmunoGen shall be the
sole owner of all ImmunoGen Program Technology and ImmunoGen Probody Platform Improvements and any Patent Rights claiming such ImmunoGen Program Technology and ImmunoGen Probody Platform Improvements. 

(c) Jointly Owned Technology. All Joint Program Technology and Joint Probody Platform Improvements (including, without limitation, all
Joint Patent Rights) shall be jointly owned by the Parties, with each Party holding an undivided one-half interest therein. Subject to the Parties’ other rights and obligations under this Agreement and any then-outstanding License Agreement,
each Party shall be free to exploit and assign, either itself or through the grant of licenses to Third Parties, all Joint Program Technology, Joint Probody Platform Technology Improvements and Joint Patent Rights throughout the world without
restriction, without the need to obtain further consent from or provide notice to the other Party and without any duty to account or otherwise make any payment of any compensation to the other Party. 

5.1.2. Disclosure. ImmunoGen shall, no less than thirty (30) days before filing any initial Patent Right disclosing ImmunoGen
Probody Platform Improvements or any Joint Program Technology or Joint Probody Platform Improvements or any other Patent Right that contains CytomX’s Confidential Information, provide a copy of such disclosure to CytomX. CytomX shall, no less
than thirty (30) days before filing any initial Patent Right disclosing Joint Program Technology or Joint Probody Platform Improvements or any other Patent Right that contains ImmunoGen’s Confidential Information, provide a copy of such
disclosure to ImmunoGen. In each case, such disclosures to the other Party shall include all invention disclosures or other similar documents submitted to such Party by its, or its Affiliates’, employees, agents or independent contractors
describing such invention and the proposed inventorship of any new Patent Rights intended to be filed. The other Party shall promptly raise any issue regarding inventorship of any such Patent Rights, and the Parties agree to determine the correct
inventorship of any Patent Rights in accordance with Section 10.10.1 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 40 








 5.2. Filing, Prosecution and Maintenance of Patent Rights. 

5.2.1. Cooperation. Without limiting any other rights and obligations of the Parties under this Agreement, the Parties shall cooperate
with respect to the timing, scope and filing of patent applications and patent claims relating to any Joint Program Technology to preserve and enhance the patent protection for Licensed Products, including the manufacture and use thereof and to
allow the Party owning the technology underlying an Improvement to have reasonable input to preserve and enhance its patent portfolio and patenting strategy. 

5.2.2. CytomX Patent Rights. CytomX, at its own expense, shall have the sole right, but not the obligation, to prepare, file, prosecute
and maintain, throughout the world, all Licensed Patent Rights (other than Licensed Patent Rights claiming Joint Program Technology or Joint Probody Platform Improvements). With respect to any Licensed Patent Rights disclosing or claiming Program
Technology (other than Probody Platform Improvements included in the Program Technology), CytomX shall keep ImmunoGen reasonably informed of the status of the filing, prosecution and maintenance of such Patent Rights and shall consider in good faith
any recommendations made by ImmunoGen in regard to the filing, prosecution or maintenance of any such Patent Right. CytomX shall consult with ImmunoGen in the filing, prosecution and maintenance of any CytomX Patent Right related to Improvements to
ImmunoGen Technology and shall not unreasonably refuse to incorporate any recommendations made by ImmunoGen in regard to such filing, prosecution or maintenance. To the extent CytomX decides not to file, prosecute or maintain any Licensed Patent
Right that CytomX reasonably believes covers or may cover the Development, Manufacture, Commercialization or use of any Licensed Product (other than any such Patent Right owned or co-owned by a Third Party licensor or the filing of a new initial
patent application) and except in the case in which the decision not to file, prosecute or maintain such Patent Right is made by CytomX in the ordinary course of filing continuation applications or as part of an overall strategy to optimize the
scope or other aspects of the Licensed Intellectual Property, CytomX shall provide ImmunoGen with thirty (30) days prior written notice to such effect (i.e., at least thirty (30) days prior to the date on which any such filing is
intended or due or on which any other such action is due), in which event ImmunoGen may elect to file or continue prosecution or maintenance of such Patent Right, at ImmunoGen’s expense, and CytomX, upon ImmunoGen’s written request
received within such thirty (30) day period, shall execute such documents and perform such acts, at ImmunoGen’s expense, as may be reasonably necessary to permit ImmunoGen to file, prosecute and maintain such Patent Right; provided that
ImmunoGen (a) shall keep CytomX reasonably informed of the status of the filing, prosecution and maintenance of such Patent Rights, (b) shall consider in 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 41 








 
good faith any recommendations made by CytomX in regard to such filing, prosecution and maintenance of such Patent Right, and (c) shall not unreasonably refuse to incorporate any
recommendations made by CytomX in regard to such filing, prosecution or maintenance. Any such Patent Right that is prosecuted or maintained by ImmunoGen pursuant to this Section 5.2.2 (a) will continue to be owned by CytomX, and
(b) subject to the Parties’ other rights and obligations under this Agreement, may be licensed by CytomX to one or more Third Parties. For avoidance of doubt, “prosecution” as used in this Section 5.2 includes
oppositions, nullity or revocation actions, post-grant reviews and other patent office proceedings involving the referenced Patent Rights. 

5.2.3. ImmunoGen Patent Rights. ImmunoGen, at its own expense, shall have the sole right, but not the obligation, to prepare, file,
prosecute and maintain, throughout the world, any Patent Rights comprised in the ImmunoGen Probody Platform Improvements. ImmunoGen shall consult with CytomX in the filing, prosecution and maintenance of any Patent Right related to ImmunoGen Probody
Platform Improvements (including, without limitation, keeping CytomX reasonably informed of the status thereof), shall consider in good faith any recommendations made by CytomX in regard to such filing, prosecution or maintenance, and shall not
unreasonably refuse to incorporate any recommendations made by CytomX in regard to such filing, prosecution or maintenance. Nothing contained in this Agreement shall be construed as obligating ImmunoGen to file any patent application in any country
or other jurisdiction relating to ImmunoGen Probody Platform Improvements. 
 5.2.4. Joint Patent Rights. If not already established
under the Research Collaboration Agreement, prior to either Party filing any Patent Right disclosing Joint Program Technology or Joint Probody Platform Improvements, the Parties shall establish a patent committee (the “Patent
Committee”) comprised of at least one (1) representative of each Party for the purpose of facilitating the preparation, filing, prosecution, maintenance and defense of Joint Patent Rights. As agreed upon by the Parties, meetings of the
Patent Committee may be face-to-face or may be conducted by teleconferences or videoconferences, from time to time as needed. The Patent Committee will be the forum through which the Parties coordinate their respective obligations to each other
described in Sections 5.2.2 and 5.2.3 hereof and in this Section. In the event the Parties conceive or generate any Joint Program Technology or Joint Probody Platform Improvements, the Parties shall promptly meet to discuss and
determine, based on mutual consent, whether to seek patent protection thereon, which Party will control filing, prosecution and maintenance of such patents and how to pay for the filing, prosecution and maintenance of such patents. It is presumed
that ImmunoGen will control filing, prosecution and maintenance of Joint Patent Rights claiming 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 42 








 
Joint Program Technology or Joint Conjugation Probody Platform Improvements, and that CytomX will control filing, prosecution and maintenance of Joint Patent Rights claiming Joint Unconjugated
Probody Platform Improvements. Neither Party will file any Joint Patent Right without the prior written consent of the other Party, which consent shall not be unreasonably withheld, conditioned or delayed. The Party controlling filing and
prosecution of any such Joint Patent Right (a) shall keep the other Party informed regarding each Patent Right, (b) shall consider in good faith any recommendations made by the other Party in regard to the filing, prosecution or
maintenance of any such Patent Right and (c) shall not unreasonably refuse to incorporate any recommendations made by the other Party in regard to such filing, prosecution or maintenance. 

5.2.5. Improper Patent Filings. Each Party agrees that, without the prior written consent of the other Party, neither it nor any of its
Affiliates will claim in any patent application filed by or on behalf of such Party (or its Affiliate) any unpatented, nonpublic invention for which the inventor(s) (alone or with others) are employees of, or other persons obligated to assign
inventions to, the other Party or any Affiliate of the other Party, or disclose any such invention in any such patent application in a manner that would prejudice the other Party’s ability to patent such invention. 

5.2.6. Liability. Except for breaches of Section 5.2.5 hereof, to the extent that a Party is obtaining, prosecuting or
maintaining a Patent Right included in the Licensed Intellectual Property or Joint Patent Rights or otherwise exercising its rights under this Section 5.2, such Party, and its Affiliates, employees, agents or representatives, shall not
be liable to the other Party in respect of any act or omission on the part of any such Party, or its Affiliates, employees, agents or representatives, in connection with such activities undertaken in good faith. 

5.2.7. Extensions. The decision to file for a patent term extension and particulars thereof (including which patent(s) to extend) will
be made with the goal of obtaining the optimal patent term and scope of protection for Licensed Products. If a Party wishes to file for a patent term extension based on Patent Rights owned by the other Party, it will so notify the other Party, and
the Parties will meet to discuss and determine whether and how to proceed with such patent term extension. 
 5.3. Joint Research
Agreement. This Agreement shall be understood to be a joint research agreement under 35 U.S.C. § 103(c)(3) entered into for the purpose of Developing Licensed Products. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 43 








 5.4. Enforcement of Patent Rights. 

5.4.1. Notice. If either CytomX or ImmunoGen becomes aware of any infringement anywhere in the world of any issued Patent Right within
the Licensed Intellectual Property or Joint Patent Rights by any Third Party (an “Infringement”), such Party shall promptly notify the other Party in writing to that effect. 

5.4.2. Infringement of Certain Patent Rights. 

(a) In the event of any Infringement of a Patent Right included in the Licensed Intellectual Property (including, without limitation, Joint
Patent Rights included in the Joint Unconjugated Probody Platform Improvements but excluding Joint Patent Rights included in the Joint Program Technology (other than Joint Unconjugated Probody Platform Improvements)), CytomX shall have the first
right to take action to obtain a discontinuance of Infringement or bring suit against a Third Party infringer of such Patent Right within six (6) months from the date of notice. 

(b) CytomX shall bear all the expenses of any suit brought by it claiming infringement of any such Patent Right. ImmunoGen shall reasonably
cooperate with CytomX in any such suit and shall have the right to consult with CytomX and to participate in and be represented by independent counsel in such litigation at its own expense. CytomX shall incur no liability to ImmunoGen as a
consequence of such litigation or any unfavorable decision resulting therefrom, including any decision holding any such Patent Right invalid or unenforceable, and CytomX shall not, without ImmunoGen’s prior written consent (which consent shall
not be unreasonably withheld, conditioned or delayed), enter into any settlement or consent decree that admits the invalidity or unenforceability or limits the scope of any such Patent Right. 

(c) If CytomX has not obtained a discontinuance of such Infringement by, or filed suit against, any such Third Party infringer within the six
(6) month period set forth in subsection (a) above, then ImmunoGen shall have the right, but not the obligation, to bring suit against such Third Party infringer, at ImmunoGen’s sole expense, under any Licensed Intellectual Property.
CytomX shall reasonably cooperate with ImmunoGen in any such litigation, including being joined as a party, at ImmunoGen’s expense, provided that CytomX may, at its sole discretion, elect to be represented by independent counsel in such
litigation at its own expense. ImmunoGen shall incur no liability to CytomX as a consequence of such litigation or any unfavorable decision resulting therefrom, including any decision 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 44 








 
holding any such CytomX Patent Right invalid or unenforceable; and ImmunoGen shall not, without CytomX’s prior written consent (which CytomX may withhold in its sole discretion), enter into
any settlement or consent decree that requires any payment by or admits or imparts any other liability to CytomX or admits the invalidity or unenforceability or limits the scope of any such Patent Right. 

(d) In the event of any Infringement of a Joint Patent Right included in the Joint Program Technology (other than Joint Unconjugated Probody
Platform Improvements), ImmunoGen shall have the first right to take action to obtain a discontinuance of Infringement or bring suit against a Third Party infringer of such Patent Right within six (6) months from the date of notice. 

(e) ImmunoGen shall bear all the expenses of any suit brought by it claiming infringement of any such Patent Right. CytomX shall reasonably
cooperate with ImmunoGen in any such suit and shall have the right to consult with ImmunoGen and to participate in and be represented by independent counsel in such litigation at its own expense. ImmunoGen shall incur no liability to CytomX as a
consequence of such litigation or any unfavorable decision resulting therefrom, including any decision holding any such Patent Right invalid or unenforceable, and ImmunoGen shall not, without CytomX’s prior written consent, enter into any
settlement or consent decree that admits the invalidity or unenforceability or limits the scope of any such Patent Right. 
 (f) If
ImmunoGen has not obtained a discontinuance of such Infringement by, or filed suit against, any such Third Party infringer within the six (6) month period set forth in subsection (d) above, then CytomX shall have the right, but not the
obligation, to bring suit against such Third Party infringer, at CytomX’s sole expense, under any ImmunoGen Probody Platform Improvements. ImmunoGen shall reasonably cooperate with CytomX in any such litigation, including being joined as a
party, at CytomX’s expense, provided that ImmunoGen may, at its sole discretion, elect to be represented by independent counsel in such litigation at its own expense. CytomX shall incur no liability to ImmunoGen as a consequence of such
litigation or any unfavorable decision resulting therefrom, including any decision holding any such ImmunoGen Patent Right invalid or unenforceable; and CytomX shall not, without ImmunoGen’s prior written consent (which ImmunoGen may withhold
in its sole discretion), enter into any settlement or consent decree that requires any payment by or admits or imparts any other liability to ImmunoGen or admits the invalidity or unenforceability or limits the scope of any such Patent Right 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 45 








 (g) The enforcing Party shall keep the other Party reasonably informed of all material
developments in connection with any such suit. Any recoveries obtained by either Party as a result of any proceeding against such a Third Party infringer (“Monies”) shall be allocated as follows: 

(i) the Monies will be distributed first to the controlling Party for its out-of-pocket litigation costs and expenses incurred in connection
with such litigation; then 
 (ii) the Monies will then be distributed to the other Party for its out-of-pocket litigation costs and
expenses incurred in connection with such litigation; then 
 (iii) to the extent the remaining Monies recovered represent such Third
Party’s infringing sales with respect to Licensed Products, (A) CytomX will receive an amount out of such remaining Monies equal to the royalties that would have been due upon sales of the infringing product as if such infringing sales had
been incremental Net Sales of a Licensed Product sold by ImmunoGen (the “Deemed Royalty Portion”), and (B) ImmunoGen will receive the amount of such remaining Monies representing such Third Party’s infringing sales with respect
to Licensed Products, minus the Deemed Royalty Portion; or 
 (iv) to the extent the remaining Monies recovered represent ImmunoGen’s
lost profits with respect to Licensed Products, the amount of such Monies shall be grossed up to an amount equivalent to what would have been Net Sales (taking into account ImmunoGen’s costs of manufacture and sale relative to such Third
Party’s costs of manufacture and sale) and (A) CytomX will receive the Deemed Royalty Portion of such calculated Net Sales, and (B) ImmunoGen will receive the amount of such remaining Monies representing ImmunoGen’s lost profits
with respect to Licensed Products, minus the Deemed Royalty Portion; or 
 (v) to the extent the remaining Monies recovered represent
royalties from sales of a product that infringes (A) any Licensed Patent Rights alone or (B) any Licensed Patent Rights and any other Patent Rights owned by or licensed to ImmunoGen or one of its Affiliates or Sublicensees, and
the applicable decision-making 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 46 








 
authority in the action, suit or proceeding has not allocated the Monies between CytomX and the owner of such other Patent Rights, then the Parties shall agree, in good faith, to an allocation
of such Monies based on the relevant contributions of the Licensed Patent Rights and such other Patent Rights to the Licensed Product; provided that if the Parties are unable to agree in good faith as to the allocation of such Monies on such
basis, then the Parties shall submit such matter for determination to an Independent Patent Counsel; provided that the determination of such independent patent counsel shall be final and binding upon the Parties; then 

(vi) if ImmunoGen is the controlling Party, then ImmunoGen will retain all Monies remaining after the distributions described in
subsections (i) through (v) above, including, without limitation, those for any multiple damages, punitive damages or other non-compensatory damages, which are applicable to the Licensed Products; or 

(vii) if CytomX is the controlling Party, then CytomX will retain all Monies remaining after the distributions described in
subsections (i) through (v) above, including, without limitation, those for any multiple damages, punitive damages or other non-compensatory damages. 

(h) Other Infringement. For any infringement of Patent Rights owned by ImmunoGen or licensed by ImmunoGen from Third Parties, ImmunoGen
retains the sole right (as between the Parties), but not the obligation, to enforce such Patent Rights. 
 (i) Infringement of Joint
Patent Rights. With respect to any notice of a Third Party infringer of any Joint Patent Right other than a Patent Right included in the Joint Program Technology or Joint Probody Platform Improvements, the Parties shall meet as soon as
reasonably practicable to discuss such infringement and determine an appropriate course of action and the Parties’ respective rights and responsibilities with respect to any enforcement thereof. 

5.5. Response to Biosimilar Applicants. 

5.5.1. Notice. In the event that ImmunoGen (a) receives a copy of a Biosimilar Application, whether or not such copy is provided
under any Applicable Laws (including the BPCIA, the United States Patient Protection and Affordable Care Act, implementing FDA regulations and guidance or similar foreign laws or 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 47 








 
regulations) applicable to the approval or manufacture of any biosimilar or interchangeable biological product (a “Proposed Biosimilar Product”) for which a Licensed Product is a
“reference product,” as such term is used in the BPCIA, or (b) otherwise becomes aware that such a Biosimilar Application has been filed (such as in an instance described in Section 351(l)(9)(C) of the PHSA), then ImmunoGen shall
promptly provide CytomX with written notice. 
 5.5.2. Access to Confidential Information. Upon written request from CytomX and to the
extent permitted by Applicable Laws, ImmunoGen shall provide CytomX with confidential access to those portions of the Biosimilar Application and such other information provided to ImmunoGen by the Third Party that submitted the Biosimilar
Application (the “Applicant”) that describe the Linker and Payload of the Proposed Biosimilar Product or the method(s) of conjugating the cell-binding moiety of the Proposed Biosimilar Product to its Payload; provided, however, that
prior to receiving the Biosimilar Application and such confidential information, CytomX shall provide notice to ImmunoGen and the Applicant confirming its agreement to be subject to the confidentiality provisions in Section 351(l)(1)(B)(iii) of
the PHSA. For purposes of clarity, the Parties acknowledge and agree that CytomX has retained a right to assert any patent within the Licensed Patent Rights and participate in litigation concerning any such patent. 

5.5.3. Proposed Patent List. 

(a) Preparation of Proposed Patent List. Not later than twenty (20) days from the date of receipt by ImmunoGen of a copy of a
Biosimilar Application and related manufacturing information, ImmunoGen, with cooperation from CytomX, shall prepare and provide CytomX with a list (the “Proposed Patent List”) of (i) those patents within the Licensed Patent
Rights that ImmunoGen reasonably believes would be infringed by the manufacture and/or sale of the Proposed Biosimilar Product and (ii) those patents within the Licensed Patent Rights, if any, that ImmunoGen would be willing to sublicense to
such Applicant in accordance with the terms of this Agreement. As soon as practicable following the date of receipt by CytomX of the Proposed Patent List, CytomX and ImmunoGen shall discuss in good faith the patents within the Licensed Patent Rights
to be included on the Proposed Patent List and ImmunoGen shall consider in good faith CytomX’s proposals for changes to the Proposed Patent List with respect to the patents within the Licensed Patent Rights. Not later than the end of the period
specified by Applicable Laws, ImmunoGen shall provide the Applicant with a copy of the Proposed Patent List; provided, however, that ImmunoGen shall incorporate certain CytomX 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 48 








 
requests in accordance with Section 5.5.3(d) hereof. Notwithstanding the enforcement rights with respect to the Licensed Patent Rights set forth in Section 5.2.2 hereof,
ImmunoGen shall have the right to include any of the patents within the Licensed Patent Rights on the Proposed Patent List to the extent that ImmunoGen reasonably believes that a claim of patent infringement for such patent could be asserted by
either CytomX or ImmunoGen; provided, however, that the right to control any suit or proceeding in which such a claim is asserted shall be as set forth in Section 5.5.4 hereof. 

(b) Disclosure of Applicant’s Response. Provided that CytomX has agreed to comply with the confidentiality provisions in
Section 351(l)(1)(B)(iii) of the PHSA and to the extent permitted by Applicable Laws, ImmunoGen shall provide to CytomX the portion of the Applicant Response (as defined below) pertaining to the Licensed Patent Rights no later than ten
(10) days from the date of receipt by ImmunoGen of a response from the Applicant with regard to any patent within the Licensed Patent Rights included on the Proposed Patent List, including any response required by the BPCIA (the
“Applicant Response”). 
 (c) Preparation of ImmunoGen Response. Not later than thirty (30) days from the date
of receipt by ImmunoGen of the Applicant Response, ImmunoGen, with cooperation and assistance from CytomX, shall prepare and provide CytomX with a proposed response with respect to the Licensed Patent Rights (the “ImmunoGen
Response”) that (i) describes on a claim-by-claim basis, how each patent within the Licensed Patent Rights on the Proposed Patent List would be infringed by the commercial marketing of the Proposed Biosimilar Product, and
(ii) responds to Applicant’s claims, if any, that the patents within the Licensed Patent Rights on the Proposed Patent List are invalid or unenforceable. The ImmunoGen Response shall include only the foregoing and shall not be construed to
include any proposed response to the Applicant relating to any patents other than the Licensed Patent Rights; further, any actual response to the Applicant under the BPCIA and all decisions relating to subsequent procedures under the BPCIA with
regard to any patent other than those included within the Licensed Patent Rights shall be within the sole discretion of ImmunoGen. As soon as practicable following the date of receipt by CytomX of the proposed ImmunoGen Response, the Parties shall
discuss in good faith the statements in the proposed ImmunoGen Response and ImmunoGen shall consider in good faith CytomX’s proposals for changes to the ImmunoGen Response. Not later than the end of the period specified by Applicable Laws,
ImmunoGen shall provide 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 49 








 
the Applicant with a copy of the ImmunoGen Response; provided, however, that ImmunoGen shall incorporate certain CytomX requests in accordance with Section 5.5.3(d) hereof. 

(d) Inclusion of Licensed Patent Rights or Responsive Information. Provided that ImmunoGen is legally able under Applicable Law to
provide CytomX with a copy of the Biosimilar Application (and related manufacturing agreement) and CytomX has provided notice to ImmunoGen and Applicant confirming its agreement to be subject to the confidentiality provisions of
Section 351(l)(1)(B)(iii) of the PHSA, if CytomX requests in writing to either (i) include a patent in the Proposed Patent List that was not included in ImmunoGen’s initial Proposed Patent List provided to CytomX by ImmunoGen pursuant
to Section 5.5.3(a) hereof or (ii) include responsive information with respect to any patent within the Licensed Patent Rights in the ImmunoGen Response that was not included in ImmunoGen’s initial ImmunoGen Response provided
to CytomX pursuant to Section5.5.3(c) hereof, then, absent manifest error, ImmunoGen shall include such patent in the Proposed Patent List and such responsive information in the ImmunoGen Response provided to Applicant, as applicable;
provided, however, that CytomX shall indemnify ImmunoGen in accordance with Section 9.2 hereof to the extent any submissions requested by CytomX are determined to have been made negligently or in bad faith. 

(e) Negotiation; CytomX Rights. As soon as possible following the date on which ImmunoGen provides the ImmunoGen Response to the
Applicant, ImmunoGen shall commence good faith negotiations with Applicant for a period of not more than fifteen (15) days (the “Negotiation Period”) in an effort to reach agreement on the patents on the Proposed Patent List
(the “Infringed Patent List”) that will be the subject to an Immediate Patent Infringement Action; provided, however, that if the Proposed Patent List includes both patents within the Licensed Patent Rights and patents that are not
within the Licensed Patent Rights, then ImmunoGen shall not agree to the inclusion in the Infringed Patent List of any patents within the Licensed Patent Rights without the prior written consent of CytomX, which consent shall not be unreasonably
withheld, conditioned or delayed. If ImmunoGen and Applicant fail to reach agreement under Section 351(l)(4)(A) of the PHSA on the Infringed Patent List, ImmunoGen shall have the sole right to determine under Section 351(l)(5)(B) of the
PHSA which patents of those on the Proposed Patent List should be the subject of an Immediate Patent Infringement Action; provided, however, that if the Proposed Patent List includes both 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 50 








 
patents within the Licensed Patent Rights and patents that are not within the Licensed Patent Rights, then ImmunoGen shall not include in the list of patents to be provided by ImmunoGen to
Applicant pursuant to Sections 351(l)(5)(B)(i)(II) of the PHSA any patents within the Licensed Patent Rights without the prior written consent of CytomX, which consent shall not be unreasonably withheld, conditioned or delayed. Within ten
(10) days following the exchange of such lists by ImmunoGen and the Applicant, ImmunoGen shall, to the extent legally permissible, provide CytomX with a copy of the portion of the combined Infringed Patent List containing patents within the
Licensed Patent Rights that will be the subject of an Immediate Patent Infringement Action. 
 (f) Supplements to Proposed Patent
List. CytomX shall provide ImmunoGen with a copy of any U.S. patent within the Licensed Patent Rights that is issued after ImmunoGen has provided the Proposed Patent List to the Applicant within ten (10) day after such issuance. As
soon as practicable following the date of receipt by ImmunoGen of any such patent, CytomX and ImmunoGen shall discuss in good faith whether such patent would be infringed by the manufacture and/or sale of the Proposed Biosimilar Product. ImmunoGen
shall provide the Applicant with a supplement to the Proposed Patent List to include such patent not later than thirty (30) days after the issuance of such patent if ImmunoGen reasonably believes that a claim of patent infringement for such
patent could be asserted by either CytomX or ImmunoGen or if CytomX, absent manifest error, requests that ImmunoGen supplement the Proposed Patent List to include such patent provided, however, that CytomX shall indemnify ImmunoGen in accordance
with Section 9.2 hereof to the extent any supplement submissions requested by CytomX are determined to have been made negligently or in bad faith. 

5.5.4. Claims, Suits and Proceedings. 

(a) Immediate Patent Infringement Action. With respect to any patents within the Licensed Patent Rights or any Patent Rights claiming
ImmunoGen Probody Platform Improvements, Joint Program Technology or Joint Probody Platform Improvements that are to be the subject of an Immediate Patent Infringement Action, the Parties’ respective rights and obligations with respect to the
litigation of such patents (including rights to initiate, step in, participate in, settle and share amounts recovered pursuant to such Immediate Patent Infringement Action, and obligations to pay legal costs and expenses with respect to such
Immediate Patent Infringement Action) shall be as set forth in Section 5.4.2 hereof, except 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 51 








 
that the Party having the first right to file a claim for Infringement against the Applicant with respect to any such patent subject to an Immediate Patent Infringement Action shall file such
claim within fifteen (15) days after agreement is reached as to the Infringed Patent List under Section 351(l)(4) or the exchange of the lists under Section 351(l)(5)(B) of the PHSA, as applicable. 

(b) Pre-Marketing Litigation. Either Party shall, within ten (10) days of receiving any notice of commercial marketing provided by
the Applicant pursuant to Section 351(l)(8)(A) of the PHSA (the “Premarket Notice”), notify the other Party. Thereafter, the Parties’ respective rights and obligations with respect to any litigation pursuant to
Section 351(l)(8)(B) of the PHSA (including rights to initiate, step in, participate in, settle and share amounts recovered pursuant to such action, and obligations to pay legal costs and expenses with respect to such action) shall be as set
forth in Section 5.4.2 hereof. 
 (c) Cooperation; Standing. If a Party with the right to initiate legal proceedings
under this Section 5.5.4 lacks standing to do so (or lacks the right under the BPCIA to do so) and the other Party has standing (or the sole right under the BPCIA) to initiate such legal proceedings, such Party with standing shall
initiate such legal proceedings at the request and expense of the other Party. 
 5.5.5. Invalidity or Unenforceability Defenses or
Actions. In the event that the Applicant asserts, as a defense or as a counterclaim in any infringement action under Section 5.5.4 hereof, that any of the Licensed Patent Rights or any Patent Rights claiming ImmunoGen Probody
Platform Improvements, Joint Program Technology or Joint Probody Platform Improvements is invalid or unenforceable, then the Parties’ respective rights and obligations with respect to the response to such defense or the defense against such
counterclaim, as applicable, (including rights to initiate, step in, participate in, settle and share amounts recovered pursuant to such action, and obligations to pay legal costs and expenses with respect to such action) shall be as set forth in
Section 5.4.2 hereof; provided that for these purposes any such defense or counterclaim shall be deemed to be an Infringement. In all other cases, including any declaratory judgment action or similar action or claim filed by an Applicant
asserting that any of the Licensed Patent Rights or any Patent Rights claiming ImmunoGen Probody Platform Improvements, Joint Program Technology or Joint Probody Platform Improvements is invalid or unenforceable (as in a declaratory judgment action
brought by the Applicant following the Premarket Notice), then the Parties’ respective rights and obligations with respect to such action (including rights to 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 52 








 
initiate, step in, participate in, settle and share amounts recovered pursuant to such action, and obligations to pay legal costs and expenses with respect to such action) shall be as set forth
in Section 5.4.2 hereof; provided that for these purposes any such case shall be deemed to be an Infringement. 
 5.5.6.
Changes in Applicable Law. The Parties have agreed to the provisions of this Section 5.5 on the basis of the BPCIA and other applicable laws and regulations in effect as of the Effective Date. If there are any material changes to
the BPCIA or other Applicable Laws that would affect these provisions, the Parties will discuss amendments to this Section 5.5 in good faith. 

5.6. Interference, Opposition, Revocation and Declaratory Judgment Actions. If the Parties mutually determine that, based upon
the review of a Third Party’s patent or patent application or other intellectual property rights, it may be desirable in connection with any Licensed Product to provoke or institute an interference, opposition, revocation, post-grant review or
other patent office proceedings or declaratory judgment action with respect thereto, then the Parties shall consult with one another and shall reasonably cooperate in connection with such an action. Each Party shall retain all rights to control any
actions initiated prior to the Effective Date. 
 5.7. Infringement of Third Party Patent Rights. If the Development,
Manufacture, use or Commercialization of any Licensed Product is alleged by a Third Party to infringe a Third Party’s patent or other intellectual property rights, the Party becoming aware of such allegation shall promptly notify the other
Party. ImmunoGen shall have the right to take such action as it deems appropriate in response to such allegation, and shall be solely responsible for all damages, costs and expenses in connection therewith, subject to Article 9 hereof.

  

	6.	CONFIDENTIALITY 

 6.1. Confidentiality. Except to the extent expressly authorized
by this Agreement, the Parties agree that, during the Term and for ten (10) years thereafter, each Party, in its capacity as the Receiving Party shall: (a) keep the Disclosing Party’s Confidential Information confidential;
(b) not disclose, or permit the disclosure of, the Disclosing Party’s Confidential Information; and (c) not use, or permit to be used, the Disclosing Party’s Confidential Information for any purpose, in each case, except for the
performance of its obligations or exercise of its rights under this Agreement, provided, however, that the foregoing obligations shall not apply, or shall cease to apply, to the extent that such Confidential Information (i) was already known by
the Receiving Party or its Affiliates (other than under an obligation of confidentiality to the Disclosing Party) at the time of disclosure by the Disclosing Party; (ii) was generally available to the public or otherwise part of the public
domain at the time of its disclosure to the Receiving Party; 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 53 








 
(iii) became generally available to the public or otherwise part of the public domain after its disclosure to the Receiving Party, other than through any act or omission of the Receiving
Party or its Affiliates or any of their respective Representatives in breach of its obligations under this Agreement; (iv) was disclosed to the Receiving Party or its Affiliates, other than under an obligation of confidentiality, by a Third
Party who had no obligation to the Disclosing Party not to disclose such information to the Receiving Party ; or (v) was independently discovered or developed by or on behalf of the Receiving Party without the use of any Confidential
Information of the Disclosing Party. 
 6.2. Authorized Disclosure. 

6.2.1. Disclosure to Party Representatives. Notwithstanding the foregoing provisions of Section 6.1 hereof, the Receiving
Party may disclose Confidential Information belonging to the Disclosing Party to the Receiving Party’s Representatives who (a) have a need to know such Confidential Information in connection with the performance of the Receiving
Party’s obligations or the exercise of the Receiving Party’s rights under this Agreement and (b) have agreed in writing to non-disclosure and non-use provisions with respect to such Confidential Information that are at least as
restrictive as those set forth in this Article 6. 
 6.2.2. Disclosure to Third Parties. 

(a) Notwithstanding the foregoing provisions of Section 6.1 hereof, the Parties may disclose Confidential Information belonging to
the other Party: 
 (i) to Governmental Authorities to the extent reasonably necessary to obtain or maintain INDs or Regulatory Approvals
for any Licensed Product and in order to respond to inquiries, requests, investigations, orders or subpoenas of Governmental Authorities relating to this Agreement; 

(ii) to outside consultants, contractors, advisory boards, managed care organizations, and non-clinical and clinical investigators, in each
case to the extent reasonably necessary to Develop, Manufacture, use or Commercialize any Licensed Product under reasonable obligations of confidentiality; 

(iii) subject to Section 5.2 hereof, to the extent reasonably necessary, in connection with filing or prosecuting Patent Rights as
permitted by this Agreement; 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 54 








 (iv) to the extent reasonably necessary, in connection with prosecuting or defending litigation
as permitted by this Agreement; 
 (v) regarding the existence of this Agreement, this Agreement itself or the material and financial terms
of this Agreement, (A) to its accountants, lawyers, and other advisers, and (B) to actual or potential investors, lenders, licensors, licensees, acquirers, investment bankers, or agents of the foregoing in connection with a financing,
licensing transaction, merger, or acquisition, in each case (A)-(B) under confidentiality obligations no less restrictive than those set forth in this Agreement, provided that CytomX shall not disclose the identity of the Licensed Target under
clause (B) without the prior written consent of ImmunoGen; 
 (vi) subject to Section 6.3.2 hereof, in connection with or
included in scientific presentations and publications relating to Licensed Products, including abstracts, posters, journal articles and the like, and posting results of and other information about clinical trials to clinicaltrials.gov or PhRMA
websites; and 
 (vii) to the extent necessary in order to enforce its rights under this Agreement. 

(b) In the event a Party deems it reasonably necessary to disclose Confidential Information belonging to the other Party pursuant to
Section 6.2.2(a)(i) hereof, the Disclosing Party shall to the extent possible give reasonable advance written notice of such disclosure to the other Party and take all reasonable measures to ensure confidential treatment of such
information. 
 (c) Data generated by ImmunoGen using Licensed Products shall not be considered Confidential Information of CytomX, and,
therefore, not subject to this Article 6. 
 6.2.3. SEC Filings and Other Disclosures. Notwithstanding any provision of
this Agreement to the contrary, either Party may disclose the existence or terms of this Agreement to the extent required, in the reasonable opinion of such Party’s legal counsel, to comply with Applicable Law. Notwithstanding the foregoing,
before disclosing this Agreement or any of the terms hereof pursuant to this Section 6.2.3, the Parties will consult with one another on the terms of this Agreement to be redacted in making any such disclosure. Further, if a Party
discloses this Agreement or any of the terms hereof in accordance with this Section 6.2.3, such Party shall, at its own expense, use Commercially Reasonable 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 55 








 
Efforts to seek such confidential treatment of confidential portions of this Agreement and such other terms, as may be reasonably requested by the other Party. 

6.3. Public Announcements; Publications. 

6.3.1. Announcements. Except as may be expressly permitted under Section 6.2.3, neither Party will make any public
announcement regarding the existence or terms of this Agreement without the prior written approval of the other Party. For the sake of clarity, nothing in this Agreement shall prevent either Party from making any public disclosure relating to this
Agreement if the contents of such public disclosure have previously been made public other than through a breach of this Agreement by the issuing Party or its Affiliates. The Parties shall mutually agree to one or more press releases regarding the
signing of this Agreement following the Effective Date. The Parties agree that each Party may issue future announcements concerning ImmunoGen’s achievement of any significant milestones, including the selection of a clinical candidate, under
this Agreement, provided that the content of any such announcement has been mutually agreed upon by the Parties. 
 6.3.2.
Publications. The Parties acknowledge that scientific publications and presentations must be strictly monitored to prevent any adverse effect from premature publication or dissemination of results of the activities hereunder. Each Party (in
such capacity the “Publishing Party”) agrees that, except as required by Applicable Laws, it shall not publish or present, or permit to be published or presented, any results of the Development, Manufacture, use or Commercialization
of a Licensed Product to the extent such results refer to, derive from or otherwise relate to the Licensed Intellectual Property (the “Covered Results”), without the prior review by and approval of the other Party (in such capacity,
the “Non-Disclosing Party”), which approval shall not be unreasonably withheld; provided that it shall not be deemed unreasonable for ImmunoGen to withhold its consent to any request by CytomX
to publish or disseminate Covered Results prior to the publication or dissemination of such Covered Results by ImmunoGen. The Publishing Party shall submit to the Non-Disclosing Party for review and approval
any proposed academic, scientific and medical publication or public presentation which contains Covered Results or otherwise contains the Non-Disclosing Party’s Confidential Information; provided that the foregoing requirement shall apply to
ImmunoGen only to the extent any such proposed publication or presentation would refer to, describe or otherwise disclose Confidential Information of CytomX (including, without limitation, any non-public
Licensed Intellectual Property). In addition, each Party shall submit to the other Party for review and approval any proposed publication or public 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 56 








 
presentation relating to data generated under the Research Program. In both instances, such review and approval will be conducted for the purposes of preserving the value of the Licensed
Intellectual Property and determining whether any portion of the proposed publication or presentation containing the Non-Disclosing Party’s Confidential Information should be modified or deleted. Written copies of such proposed publication or
presentation required to be submitted hereunder shall be submitted to the Non-Disclosing Party no later than thirty (30) days before submission for publication or presentation (the “Review Period”). The Non-Disclosing Party
shall provide its comments with respect to such publications and presentations within fifteen (15) days after its receipt of such written copy, and the Publishing Party shall delete any Confidential Information of the Non-Disclosing Party upon
request. The Review Period may be extended for an additional sixty (60) days in the event the Non-Disclosing Party can, within fifteen (15) days of receipt of the written copy, demonstrate reasonable need for such extension, including for
the preparation and filing of patent applications. The Parties will each comply with standard academic practice regarding authorship of scientific publications and recognition of contribution of other parties in any publication governed by this
Section 6.3.2. 
 6.3.3. Integration. As to the subject matter of this Agreement, this Article 6 supersedes
any confidential disclosure agreements between the Parties, including, without limitation, the Confidentiality Agreement and the confidentiality provisions of the Research Collaboration Agreement. Any confidential information of a Party disclosed
under the Confidentiality Agreement or the Research Collaboration Agreement relating to the subject matter of this Agreement shall be treated as Confidential Information of such Party hereunder, subject to the terms of this Article 6.

  

	7.	REPRESENTATIONS AND WARRANTIES. 

 7.1. Mutual Representations and Warranties. Each
of CytomX and ImmunoGen hereby represents and warrants to the other that: 
 7.1.1. it is duly organized, validly existing and in good
standing under the laws of the jurisdiction of its organization; 
 7.1.2. the execution, delivery and performance of this Agreement by such
Party has been duly authorized by all requisite action under the provisions of its charter, bylaws and other organizational documents, and does not require any action or approval by any of its shareholders or other holders of its voting securities
or voting interests; 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 57 








 7.1.3. it has the power and authority to execute and deliver this Agreement and to perform its
obligations hereunder; 
 7.1.4. this Agreement has been duly executed and is a legal, valid and Binding Obligation on it, enforceable
against it in accordance with its terms; and 
 7.1.5. the execution, delivery and performance by such Party of this Agreement and its
compliance with the terms and provisions hereof does not and will not conflict with or result in a breach of or default under any Binding Obligation existing as of the Effective Date. 

7.2. Representations and Warranties of CytomX. Except as set forth in a written disclosure letter (the “Disclosure
Letter”) delivered by CytomX to ImmunoGen within fifteen (15) days after the Effective Date (which shall be deemed Confidential Information of CytomX), CytomX hereby represents and warrants to ImmunoGen that as of the Effective Date:

 7.2.1. to its Knowledge, (a) the issued and unexpired patents within the Licensed Intellectual Property are valid and enforceable
patents and (b) CytomX has received no written notice from a Third Party challenging or threatening to challenge the extent, validity or enforceability of any Licensed Patent Rights; 

7.2.2. to its Knowledge, CytomX has received no written notice from a Third Party claiming that the use, practice or application of the
Licensed Intellectual Property pursuant to the license granted hereunder to ImmunoGen will infringe the issued patents of any such Third Party (excluding, for clarity, any potential infringement that might arise solely as a result of the combination
of any Licensed Intellectual Property with any other technology or intellectual property); and 
 7.2.3. there is no (a) claim, demand,
suit, proceeding, arbitration, inquiry, investigation or other legal action of any nature, civil, criminal, regulatory or otherwise, pending or, to its Knowledge, threatened against CytomX or any of its Affiliates or (b) judgment or settlement
against or owed by CytomX or any of its Affiliates, in each case in connection with the Licensed Intellectual Property or relating to the transactions contemplated by this Agreement 

For purposes of this Section 7.2, “Knowledge” means the actual knowledge (without having conducted, or having any
duty to conduct, any specific inquiry) of its Chief Executive Officer, President, any Vice President or other officer who is in charge of a principal business unit or function or who performs a policy-making function, and its Senior Director, Head
of Intellectual Property (or person with similar responsibilities). 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 58 








 7.3. Government Approvals. Each of CytomX and ImmunoGen shall cooperate with the other
Party and use Commercially Reasonable Efforts to make all registrations, filings and applications, to give all notices and to obtain as soon as practicable all governmental or other consents, transfers, approvals, orders, qualifications
authorizations, permits and waivers, if any, and to do all other things necessary or desirable for the consummation of the transactions as contemplated hereby. 

7.4. Further Covenants. In addition to the covenants made elsewhere in this Agreement, CytomX hereby covenants to ImmunoGen that, from
the Effective Date until expiration or termination of this Agreement, it will not (a) knowingly take any action that conflicts with the rights under the Licensed Intellectual Property granted to ImmunoGen under this Agreement or
(b) knowingly fail to take any action that is reasonably necessary to avoid a conflict with the rights under the Licensed Intellectual Property granted to ImmunoGen under this Agreement. 

7.5. Representation by Legal Counsel. Each Party hereto represents that it has been represented by legal counsel in connection with this
Agreement and acknowledges that it has participated in the drafting hereof. In interpreting and applying the terms and provisions of this Agreement, the Parties agree that no presumption shall exist or be implied against the Party which drafted such
terms and provisions. 
 7.6. Warranty Disclaimers. 

7.6.1. Except as expressly set forth in Section 7.1 or 7.2 hereof, nothing in this Agreement is or shall be construed as a
warranty or representation by CytomX (a) as to the validity or scope of any patent application or patent within the Licensed Patent Rights or (b) that anything made, used, sold or otherwise disposed of under any license granted under this
Agreement is or will be free from infringement of patents, copyrights and other rights of Third Parties. 
 7.6.2. EXCEPT AS OTHERWISE
EXPRESSLY PROVIDED IN THIS AGREEMENT, NEITHER PARTY MAKES ANY REPRESENTATION OR EXTENDS ANY WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH RESPECT TO ANY TECHNOLOGY, GOODS, SERVICES, RIGHTS OR OTHER SUBJECT MATTER OF THIS AGREEMENT, INCLUDING,
WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. 
  

	8.	TERM AND TERMINATION. 

 8.1. Term. The term of this Agreement (the
“Term”) shall commence on the Effective Date and shall extend, unless this Agreement is terminated earlier in accordance with this Article 8, on a Licensed Product-by-Licensed Product and
country-by-country 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 59 








 
basis, until such time as the Royalty Term with respect to the sale of such Licensed Product in such country expires. Provided this Agreement has not been terminated prior thereto by CytomX under
Section 8.3, 8.4 or 8.5 hereof or by ImmunoGen under Section 8.2 or 8.4 hereof, following the expiration of the Royalty Term applicable to a Licensed Product in a country in accordance with
Section 1.134 hereof, ImmunoGen and its Affiliates shall have a fully paid-up, irrevocable, freely transferable and sublicensable license under the relevant Licensed Intellectual Property, to make, have made, use, sell, offer for sale
and import such Licensed Products in such country. 
 8.2. Voluntary Termination by ImmunoGen. ImmunoGen shall have the right to
terminate this Agreement at any time prior to the achievement of the first Regulatory Marketing Approval for any Licensed Product in any country or other jurisdiction in the Territory, upon not less than ninety (90) days’ prior written
notice to CytomX. 
 8.3. Termination by Either Party for Cause. Either Party may terminate this Agreement in its entirety at any time
during the Term by giving written notice to the other Party if the other Party commits a material breach of its obligations under this Agreement (a “Material Breach”), such notice to describe such Material Breach in reasonable
detail, and such Material Breach remains uncured for ninety (90) days, measured from the date written notice of such breach is given to the breaching Party; provided, however, that if the nature of the asserted breach is such that more than
ninety (90) days are reasonably required to cure, then the cure period shall be extended for a period not to exceed an additional sixty (60) days so long as the Party seeking to cure the asserted breach is diligently pursuing such cure to
completion. 
 8.4. Termination on Insolvency. This Agreement may be terminated upon written notice by either Party at any time in the
event of an Insolvency Event of the other Party. 
 8.5. Termination for Material Breach of the Research Collaboration Agreement by
ImmunoGen. CytomX shall have the right to terminate this Agreement, effective upon thirty (30) days’ prior written notice to ImmunoGen, in the event CytomX has terminated the Research Collaboration Agreement due to the occurrence of a
Material Breach (as defined in the Research Collaboration Agreement) thereunder by ImmunoGen which remains uncured as of the termination date of the Research Collaboration Agreement. 

8.6. Effects of Expiration or Termination. 

8.6.1. Effect of Termination by CytomX under Section 8.3, 8.4 or 8.5 or by ImmunoGen under Section 8.2. If CytomX terminates
this Agreement pursuant to Section 8.3, 8.4 or 8.5 hereof, or ImmunoGen terminates this Agreement pursuant to Section 8.2 hereof, then: 

(a) the license granted by CytomX to ImmunoGen and its Affiliates under Section 3.1.1 hereof shall immediately terminate, and
ImmunoGen and its Affiliates shall discontinue the use of any Licensed Intellectual Property except, with respect to the Licensed Patent Rights, as otherwise permitted under 35 U.S.C. § 271(e)(1) with respect to activities performed
in the United States; 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 60 








 (b) ImmunoGen and its Affiliates and Sublicensees shall cease any Development and
Commercialization of Licensed Products in the Territory, subject to Section 8.6.3 hereof; and 
 (c) each Party shall promptly
return or destroy all of the other Party’s Confidential Information, provided that each Party may retain, subject to Article 6 hereof, (i) one (1) copy of the other Party’s Confidential Information in its archives
solely for the purpose of establishing the contents thereof and ensuring compliance with its obligations hereunder, (ii) any Confidential Information of the other Party contained in its laboratory notebooks or databases, and (iii) any
Confidential Information of the other Party to the extent reasonably required to exercise its rights and perform its obligations under any other then-outstanding License Agreement. 

8.6.2. Effect of Termination by ImmunoGen under Section 8.3 or 8.4. If ImmunoGen terminates this Agreement pursuant to
Section 8.3 or 8.4 hereof, then 
 (a) the license granted to ImmunoGen by CytomX pursuant to Section 3.1.1
hereof shall continue on the terms set forth herein, subject to ImmunoGen’s continued payment of all milestone and royalty payments in accordance with this Agreement, and on a country-by-country and Licensed Product-by-Licensed Product basis,
upon the expiration of the Royalty Term applicable to a Licensed Product in country in accordance with Section 1.134 hereof and provided ImmunoGen shall have paid to CytomX all royalty amounts due to CytomX with respect to Net Sales in
such country, ImmunoGen and its Affiliates shall thereafter have a fully paid-up, irrevocable, freely transferable ad sublicensable license under the relevant Licensed Intellectual Property, to make, have made, use, sell, offer for sale and import
such Licensed Product in such country; 
 (b) CytomX shall remain entitled to receive payments that accrued before the effective date of
such termination; and 
 (c) each Party shall promptly return or destroy all of the other Party’s Confidential Information, provided
that each Party may retain, subject to 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 61 








 
Article 6 hereof, (i) one (1) copy of the other Party’s Confidential Information in its archives solely for the purpose of establishing the contents thereof and
ensuring compliance with its obligations hereunder, (ii) any Confidential Information of the other Party contained in its laboratory notebooks or databases and (iii) any Confidential Information of the other Party to the extent reasonably
required to exercise its rights and perform its obligations under any then-outstanding License Agreement. The foregoing notwithstanding, and subject to Article 6 hereof, ImmunoGen may retain and use CytomX’s Confidential Information
with respect to the exercise of its rights set forth in clause (a) above or necessary or useful to exercise any other of its rights under this Agreement that survive such termination. 

8.6.3. Treatment of Sublicensees on Termination. Notwithstanding the foregoing, CytomX shall permit a Sublicensee of ImmunoGen to become
its direct Sublicensee upon notification to CytomX. 
 8.6.4. Satisfaction of Obligations During Notice Period. During the period from
providing a notice of termination through the termination of the Agreement, the Parties shall continue to perform their obligations under this Agreement. 

8.6.5. Pending Dispute Resolution. If a Party gives notice of termination and the other Party disputes whether such notice was proper,
then the issue of whether this Agreement has been terminated shall be resolved in accordance with Section 10.9 or 10.10 hereof, as applicable, and this Agreement shall remain in effect pending the resolution of such dispute. If as
a result of such dispute resolution process it is determined that the notice of termination was proper, then such termination shall be effective immediately. If as a result of such dispute resolution process it is determined that the notice of
termination was improper, then no termination shall have occurred and this Agreement shall remain in effect. Anything contained in this Agreement to the contrary notwithstanding, if the asserted breach is cured or shown to be non-existent within the
applicable cure period, the first notice of breach hereunder shall be deemed automatically withdrawn and of no effect. 
 8.7. Disposition
of Inventories of Products. Following termination of this Agreement by CytomX pursuant to Section 8.3 or 8.4, ImmunoGen and its Affiliates and Sublicensees shall have the right to continue to sell their existing inventories of
Licensed Product(s) that have received Regulatory Marketing Approval prior to such termination for a period not to exceed six (6) months after the effective date of such termination or expiration and ImmunoGen shall pay any
milestones and royalties payable in connection with such sales in accordance with Article 4 hereof. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 62 








 8.8. Remedies. Except in the case of either Party’s breach of Section 2.6 or
Article 6 hereof, the rights of the non-breaching Party set forth in Section 8.6 hereof shall be the exclusive legal remedy to a Party arising from a Material Breach; provided, however, that (a) in addition to the foregoing
legal remedy, the Parties may seek any and all equitable remedies, including, without limitation, declarative and injunctive relief and specific performance in accordance with applicable law, and (b) nothing in this Section shall limit the
Parties’ respective rights and obligations with respect to (i) Unauthorized Use of the other Party’s Confidential Information or Proprietary Materials, (ii) unauthorized disclosure of the other Party’s Confidential
Information or (iii) indemnification as set forth in Article 9 hereof. 
 8.9. Survival of Certain Obligations.
Expiration or termination of this Agreement shall not relieve the Parties of any obligation that accrued before such expiration or termination. The following provisions shall survive expiration or termination of this Agreement:
Sections 2.5.2, 2.5.3, 2.5.4, 2.6 and 3.3, Articles 4, 5 and 6, Sections 7.6, 8.1, 8.6, 8.7 (for the period set forth therein), 8.8 and
8.9, and Articles 9 and 10. For avoidance of doubt, any other Section that explicitly states it survives expiration or termination of this Agreement shall so survive. 

 

	9.	LIMITATION ON LIABILITY, INDEMNIFICATION AND INSURANCE. 

 9.1. No Consequential
Damages. Except with respect to liability arising from a breach of Article 6 hereof, in no event will either Party, its Affiliates or any of its or its Affiliates’ respective Representatives be liable under this Agreement for any
special, indirect, incidental, consequential or punitive or exemplary damages, whether in contract, warranty, tort, negligence, strict liability or otherwise, (a) including loss of profits or revenue suffered by either Party or any of its
respective Affiliates or Representatives or (b) cost of procurement of substitute goods, technology or services, even if either Party is informed in advance of the possibility of such damages and even if the remedies provided for in this
Agreement fail of their essential purpose. For purposes of clarity, a Party’s monetary liability under a Third Party Claim for such Third Party’s special, indirect, incidental or consequential damages or for any punitive or exemplary
damages payable in connection with such Third Party Claim, shall be deemed to be the direct damages of such Party for purposes of this Article 9. 

9.2. Indemnification by CytomX. CytomX will indemnify, defend and hold harmless ImmunoGen, its Affiliates and each of its and their
respective employees, officers, directors and agents (each, a “ImmunoGen Indemnified Party”) from and against any and all liability, loss, damage, expense (including reasonable attorneys’ fees and expenses) and cost
(collectively, a “Liability”) as a direct result of any Third Party claims, suits, actions, demands or judgments, including, without limitation, personal injury and product liability matters (collectively, “Third Party
Claims”) arising out of a Material Breach of 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 63 








 
this Agreement by CytomX, except, in each case, to the extent any such Third Party Claim or Liability results from a Material Breach of this Agreement by ImmunoGen, the Development, Manufacture,
Commercialization or use (including, without limitation, the production, manufacture, promotion, import, sale or use by any Person) of any Licensed Product by, on behalf of, or under the authority of, ImmunoGen or any of its Affiliates,
Sublicensees, subcontractors, distributors or agents (other than an CytomX Indemnified Party), or the negligence, recklessness or intentional acts of ImmunoGen or any of its Affiliates, Sublicensees, subcontractors, distributors or agents; provided
that with respect to any Third Party Claim for which ImmunoGen also has an obligation to indemnify any CytomX Indemnified Party pursuant to Section 9.3 hereof, CytomX shall indemnify each ImmunoGen Indemnified Party for its Liability to the
extent of CytomX’s responsibility, relative to ImmunoGen (or to Persons for whom ImmunoGen is legally responsible), for the facts underlying the Third Party Claim. 

9.3. Indemnification by ImmunoGen. ImmunoGen will indemnify, defend and hold harmless CytomX, its Affiliates, contractors, distributors
and each of its and their respective employees, officers, directors and agents (each, a “CytomX Indemnified Party”) from and against any and all Liabilities as a direct result of any Third Party Claims arising out of: 

(a) the Development, Manufacture, Commercialization or use (including, without limitation, the production, manufacture, promotion, import, sale
or use by any Person) of any Licensed Product by, on behalf of, or under the authority of, ImmunoGen or any of its Affiliates, Sublicensees, subcontractors, distributors or agents (other than by any CytomX Indemnified Party); or 

(b) a Material Breach of this Agreement by ImmunoGen; 

except to the extent any such Third Party Claim or Liability results from a Material Breach of this Agreement by CytomX or the negligence,
recklessness or intentional acts of CytomX or any CytomX Indemnified Party; provided that with respect to any Third Party Claim for which CytomX also has an obligation to indemnify any ImmunoGen Indemnified Party pursuant to Section 9.2 hereof,
ImmunoGen shall indemnify each CytomX Indemnified Party for its Liability to the extent of ImmunoGen’s responsibility, relative to CytomX (or to Persons for whom CytomX is legally responsible), for the facts underlying the Third Party Claim.

 9.4. Procedure. 

9.4.1. Notice. Each Party will notify the other Party in writing in the event it becomes aware of a claim for which indemnification may
be sought hereunder. In the event that any Third Party asserts a claim or other proceeding (including any governmental investigation) with respect to any matter for which a Party (the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 64 








 
“Indemnified Party”) is entitled to indemnification hereunder, then the Indemnified Party shall promptly notify the Party obligated to indemnify the Indemnified Party (the
“Indemnifying Party”) thereof; provided, however, that no delay on the part of the Indemnified Party in notifying the Indemnifying Party shall relieve the Indemnifying Party from any obligation hereunder unless (and then only to the
extent that) the Indemnifying Party is prejudiced thereby. 
 9.4.2. Control. The Indemnifying Party shall have the right, at its sole
cost and expense, exercisable by notice to the Indemnified Party within ten (10) Business Days after receipt of notice from the Indemnified Party of the commencement of or assertion of any Third Party Claim, to assume direction and control of
the defense, litigation, settlement, appeal or other disposition of the Third Party Claim (including the right to settle the claim solely for monetary consideration) with counsel selected by the Indemnifying Party and reasonably acceptable to the
Indemnified Party. The Indemnified Party shall cooperate, and shall cause its Affiliates and agents to cooperate upon request of the Indemnifying Party, in the defense or prosecution of the Third Party Claim, including by furnishing such records,
information and testimony and attending such conferences, discovery proceedings, hearings, trials or appeals as may reasonably be requested by the Indemnifying Party. The Indemnified Party shall have the right to join in (including the right to
conduct discovery, interview and examine witnesses and participate in all settlement conferences), but not control, at its own expense, the defense of any Third Party Claim that the other Party is defending as provided in this Agreement. 

9.4.3. Settlement. Neither the Indemnifying Party nor the Indemnified Party shall enter into any compromise or settlement of a Third
Party Claim for which the right to indemnification hereunder has been asserted without the Indemnified Party’s prior written consent, which consent shall not be unreasonably withheld, conditioned or delayed; provided that the Indemnifying Party
may, without the Indemnified Party’s prior written consent, agree or consent to any settlement or other resolution of such Third Party Claim which requires solely money damages paid by the Indemnifying Party, and which includes as an
unconditional term thereof the giving by such claimant or plaintiff to the Indemnified Party of a release from all liability in respect of such Third Party Claim. Each of the Indemnifying Party and the Indemnified Party shall not make any admission
of liability in respect of any Third Party Claim without the prior written consent of the other Party, and the Indemnified Party shall use reasonable efforts to mitigate Liabilities arising from such Third Party Claim. 

9.5. Insurance. Each Party shall obtain and maintain, during the Term, commercial general liability insurance, including products
liability insurance, with reputable and 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 65 








 
financially secure insurance carriers (or pursuant to a program of self-insurance reasonably satisfactory to the other Party) to cover its indemnification obligations under
Section 9.2 or 9.3 hereof with respect to bodily injury (including death) and damage to property, as applicable, in each case with limits of not less than $3,000,000 per occurrence and in the aggregate. Insurance (other than
permitted self-insurance) shall be procured with carriers having an A.M. Best Rating of A-VII or better. Any indemnification payment hereunder shall be made net of any insurance proceeds which the Indemnified Party is entitled to recover;
provided, however, that if, following the payment to the Indemnified Party of any amount under this Article 9, such Indemnified Party becomes entitled to recover any insurance proceeds in respect of the claim for which such
indemnification payment was made, the Indemnified Party shall promptly pay an amount equal to the amount of such proceeds (but not exceeding the amount of such indemnification payment) to the Indemnifying Party. 

 

	10.	MISCELLANEOUS. 

 10.1. Assignment. Neither Party may assign this Agreement without
the prior written consent of the other Party, which consent will not be unreasonably withheld, conditioned or delayed; provided, however, that such consent shall not be required in connection with any assignment of this Agreement to an Affiliate of
the assigned Party, or to a Third Party in connection with the transfer or sale of the business to which this Agreement relates, or to any successor Person resulting from any merger or consolidation of such Party with or into such Person, provided
that the assignee shall have agreed in writing to assume all of the assignor’s obligations hereunder, and provided, further, that the other Party shall be notified promptly after such assignment has been effected. This Agreement shall be
binding upon the successors and permitted assigns of the Parties and the name of a Party appearing herein shall be deemed to include the names of such Party’s successors and permitted assigns to the extent necessary to carry out the intent of
this Agreement. Any purported assignment not in accordance with this Section 10.1 shall be null and void. 
 10.2. Further
Actions. Each Party agrees to execute, acknowledge and deliver such further instruments, and to do all such other acts, as may be necessary or appropriate in order to carry out the purposes and intent of the Agreement. 

10.3. Force Majeure. Each Party shall be excused from the performance of its obligations under this Agreement to the extent that such
performance is prevented by force majeure (defined below) and the nonperforming Party promptly provides notice of the prevention to the other Party. Such excuse shall be continued so long as the condition constituting force majeure
continues and the nonperforming Party takes Commercially Reasonable Efforts to resume performance. For purposes of this Agreement, “force majeure” shall include conditions beyond the control of the Parties, including an act of God,
voluntary or involuntary compliance with any Applicable Law or order of any 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 66 








 
government, war, act of terror, civil commotion, labor strike or lock-out, epidemic, failure or default of public utilities or common carriers, or destruction of production facilities or
materials by fire, earthquake, storm or like catastrophe; provided that financial inability to pay in and of itself shall not be considered to be a force majeure event.  

10.4. Notices. Any notice or notification required or permitted to be provided pursuant to the terms and conditions of this Agreement
(including any notice of force majeure, breach, termination, change of address, etc.) shall be in writing and shall be deemed given upon receipt if delivered personally or by facsimile transmission (receipt verified), five (5) Business
Days after deposited in the mail if mailed by certified mail (return receipt requested) postage prepaid, or on the next Business Day if sent by overnight delivery using a nationally recognized express courier service and specifying next Business Day
delivery (receipt verified), to the Parties at the following addresses or facsimile numbers (or at such other address or facsimile number for a Party as shall be specified by like notice, provided, however, that notices of a change of address shall
be effective only upon receipt thereof): 
 All correspondence to ImmunoGen shall be addressed as follows: 

ImmunoGen, Inc. 
 830 Winter
Street 
 Waltham, MA 02451 

Attn: Vice President, Business Development 

Fax: [***] 
 All correspondence
to CytomX shall be addressed as follows: 
 CytomX Therapeutics, Inc. 

343 Oyster Point Blvd., Suite 100 

South San Francisco, CA 94080-7014 

Attn: CEO 
 Fax: 1-650-351-0353

 To help expedite the other Party’s awareness and response, copies of notices may be provided to the other Party by email but must be
supplemented by one of the following methods: (a) personal delivery, (b) first class certified mail with return receipt requested, or (c) next-day delivery by major international courier, with confirmation of delivery. Electronic
copies may be sent via email to [***] at CytomX and to [***] at ImmunoGen so long as such individuals remain employed by CytomX or ImmunoGen, respectively. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 67 








 10.5. Amendment. No amendment, modification or supplement of any provision of this
Agreement shall be valid or effective unless made in writing and signed by a duly authorized officer of the Party to be bound. 
 10.6.
Waiver. No provision of this Agreement shall be waived by any act, omission or knowledge of a Party or its agents or employees except by an instrument in writing expressly waiving such provision and signed by a duly authorized officer of the
waiving Party. The waiver by either of the Parties of any breach of any provision hereof by the other Party shall not be construed to be a waiver of any succeeding breach of such provision or a waiver of the provision itself. 

10.7. Severability. If any clause or portion thereof in this Agreement is for any reason held to be invalid, illegal or unenforceable,
the same shall not affect any other portion of this Agreement, as it is the intent of the Parties that this Agreement shall be construed in such fashion as to maintain its existence, validity and enforceability to the greatest extent possible. In
any such event, this Agreement shall be construed as if such clause or portion thereof had never been contained in this Agreement, and there shall be deemed substituted therefor such provision as will most nearly carry out the intent of the Parties
as expressed in this Agreement to the fullest extent permitted by Applicable Law. 
 10.8. Descriptive Headings. The descriptive
headings of this Agreement are for convenience only and shall be of no force or effect in construing or interpreting any of the provisions of this Agreement. 

10.9. Dispute Resolution. The Parties recognize that a bona fide dispute as to certain matters may arise from time to time
during the Term relating to either Party’s rights or obligations hereunder or otherwise relating to the validity, enforceability or performance of this Agreement, including disputes relating to alleged breach or termination of this Agreement
but excluding any disputes relating to Article 6 hereof or disputes relating to the determination of the validity, scope, infringement, enforceability, inventorship or ownership of the Parties’ respective Patent Rights (hereinafter,
a “Dispute”). In the event of the occurrence of any Dispute, the Parties shall follow the following procedures in an attempt to resolve the dispute or disagreement: 

10.9.1. The Party claiming that such a Dispute exists shall give notice in writing (a “Notice of Dispute”) to the other Party
of the nature of the Dispute. 
 10.9.2. Within fourteen (14) days of receipt of a Notice of Dispute, the ImmunoGen Alliance Manager and
the CytomX Alliance Manager shall meet in person or by teleconference and exchange written summaries reflecting, in reasonable detail, the nature and extent of the Dispute, and at this meeting they shall use their reasonable endeavors to resolve the
Dispute. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 68 








 10.9.3. If the Alliance Managers are unable to resolve the Dispute during the meeting described
in Section 10.9.2 hereof or if for any reason such meeting does not take place within the period specified in Section 10.9.2 hereof, then the Dispute will be referred to the JDC which shall meet no later than forty-five
(45) days following the initial receipt of the Notice of Dispute and use reasonable endeavors to resolve the Dispute. 
 10.9.4. If the
JDC is unable to resolve the Dispute during the meeting described in Section 10.9.3 hereof or if for any reason such meeting does not take place within the period specified in Section 10.9.3 hereof, then the Chief Executive
Officer of ImmunoGen and the Chief Executive Officer of CytomX shall meet at a mutually agreed-upon time and location for the purpose of resolving such Dispute. 

10.9.5. If, within ninety (90) days of initial receipt of the Notice of Dispute, the Dispute has not been resolved, or if, for any reason,
the meeting described in Section 10.9.4 hereof has not been held within ninety (90) days of initial receipt of the Notice of Dispute, then the Parties agree that such Dispute shall be finally resolved through binding arbitration to
be administered by JAMS pursuant to its Comprehensive Arbitration Rules and Procedures and in accordance with the Expedited Procedures in those Rules, as specifically modified by the provisions of this Section 10.9.5. 

(a) Arbitration Panel. The arbitration shall be conducted by a panel of three (3) arbitrators. Within thirty (30) days after
the initiation of the arbitration, each Party will nominate one person to act as arbitrator, and the two arbitrators so named will then jointly appoint the third arbitrator within thirty (30) days of their appointment, who will serve as
chairman of the panel. All three (3) arbitrators must be independent Third Parties having at least ten (10) years of dispute resolution experience (which may include judicial experience) and/or legal or business experience in the biotech
or pharmaceutical industry. If either Party fails to nominate its arbitrator, or if the arbitrators selected by the Parties cannot agree on a person to be named as chairman within such thirty (30) day period, JAMS will make the necessary
appointments for such arbitrator(s) or the chairman. Once appointed by a Party, such Party shall have no ex parte communication with its appointed arbitrator. 

(b) Location and Proceedings. The place of arbitration will be in the Borough of Manhattan, City of New York, NY or such other venue as
the Parties may mutually agree. The arbitration proceedings and all communications with respect thereto shall be in English. Any written evidence originally in another language will be submitted in English


  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 69 








 
translation accompanied by the original or a true copy thereof. The arbitrators have the power to decide all matters in Dispute, including any questions of whether or not such matters are subject
to arbitration hereunder. The arbitration shall be governed by the Federal Arbitration Act, 9 U.S.C. §§1 et seq., and judgment upon the award rendered by the arbitrators may be entered in any court having competent
jurisdiction thereof. 
 (c) Limitation on Awards. Except for breaches of Article 6 hereof, the arbitrators shall have no
authority to award any special, indirect, incidental, consequential, punitive, exemplary or other similar damages. Each Party shall bear its own costs and expenses (including attorneys’ fees and expert or consulting fees) incurred in connection
with the arbitration. The Parties shall equally (50/50) share the arbitrators’ fees and other administrative costs and expenses associated with the arbitration. 

(d) Confidentiality. The existence, content and results of any arbitration proceedings pursuant to this Section 10.9.5
shall be deemed the Confidential Information of both Parties. 
 10.9.6. Notwithstanding any provision of this Agreement to the contrary,
either Party may immediately initiate litigation in any court of competent jurisdiction seeking any remedy at law or in equity, including the issuance of a preliminary, temporary or permanent injunction, to preserve or enforce its rights under this
Agreement. 
 10.10. Patent Disputes and Disputes Relating to Article 6. 

10.10.1. Inventorship. Any dispute, controversy or claim between the Parties involving the inventorship of any Program Technology that
is not resolved by mutual agreement of the Party’s respective chief patent counsels (or persons with similar responsibilities) within thirty (30) days after the date the dispute is raised by one or both of the Parties shall be submitted to
an Independent Patent Counsel for resolution. Such Independent Patent Counsel’s determination of inventorship, absent manifest error, shall be final and binding on the Parties; provided, however, that any such determination with respect to a
patent application shall not preclude either Party from disputing inventorship with respect to any patents issuing from such patent application, which disputes shall be resolved in accordance with this Section. The Parties shall equally
(50/50) share the Independent Patent Counsel fees and expenses related to his determination of inventorship. 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 70 








 10.10.2. Other Patent Disputes. Any dispute, controversy or claim between the Parties that
involves the validity, scope, infringement, enforceability or ownership of the Parties’ respective Patent Rights (a) that are pending or issued in the United States shall be subject to actions before the United States Patent and Trademark
Office and/or submitted exclusively to the federal court located in the jurisdiction where the Party whose Patent Rights are the subject to such dispute, controversy or claim resides (provided that if such Party does not reside in the United States,
venue shall be the jurisdiction where such Party’s principal U.S. Affiliate resides) and (b) that are pending or issued in any other country (or region) shall be brought before an appropriate regulatory or administrative body or court in
that country (or region), and the Parties hereby consent to jurisdiction and venue in such courts and bodies. 
 10.10.3. Disputes
Relating to Article 6. Any dispute, controversy or claim between the Parties that relates to the enforcement of Article 6 hereof shall be subject to action in any court of competent jurisdiction. 

10.11. Governing Law. This Agreement, and all claims arising under or in connection therewith, shall be governed by and interpreted in
accordance with the substantive laws of the State of New York, without regard to conflict of law principles thereof. 
 10.12. Entire
Agreement. This Agreement, including its Exhibits and Schedules, constitutes and contains the complete, final and exclusive understanding and agreement of the Parties and cancels and supersedes any and all prior negotiations, correspondence,
understandings and agreements, whether oral or written, between the Parties respecting the subject matter hereof and thereof, including the Confidentiality Agreement. 

10.13. Purpose and Scope. The Parties understand and agree that this Agreement is limited to the activities, rights and obligations as
expressly set forth herein. Nothing herein contained shall be deemed to create an employment, agency, joint venture or partnership relationship between the Parties hereto or any of their agents or employees, or any other legal arrangement that would
impose liability upon one Party for the act or failure to act of the other Party. Neither Party shall have any express or implied power to enter into any contracts or commitments or to incur any liabilities in the name of, or on behalf of, the other
Party, or to bind the other Party in any respect whatsoever. 
 10.14. Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall be an original and both of which shall constitute together the same document. Counterparts may be signed and delivered by facsimile or PDF file, each of which shall be binding when received by the applicable Party.

 10.15. No Third Party Rights or Obligations. Except as set forth in Article 9 hereof, no provision of this Agreement
shall be deemed or construed in any way to result in the 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 71 








 
creation of any rights or obligation in any Person not a Party to this Agreement. However, either Party may decide, in its sole discretion, to use one or more of its Affiliates to perform its
obligations and duties hereunder, provided that such Party shall remain liable hereunder for the performance by any such Affiliates of any such obligations. 

10.16. Interpretation. The Parties hereto acknowledge and agree that: (a) each Party and its counsel reviewed and negotiated the
terms and provisions of this Agreement and have contributed to its revision; (b) the rule of construction to the effect that any ambiguities are resolved against the drafting Party shall not be employed in the interpretation of this Agreement;
and (c) the terms and provisions of this Agreement shall be construed fairly as to each Party hereto and not in a favor of or against any Party, regardless of which Party was generally responsible for the preparation of this Agreement. In
addition, unless the context otherwise requires, wherever used in this Agreement: (i) the singular shall include the plural, the plural the singular; (ii) the use of any gender shall be applicable to all genders; (iii) the word
“or” is used in the inclusive sense (and/or); (iv) the words “include” or “including” shall be construed as incorporating, also, “but not limited to” or “without limitation” (irrespective of
whether the words are used in the applicable instance); (v) the words “hereof,” “herein,” “hereby” and derivative or similar words refer to this Agreement as a whole and not to any particular provision of
this Agreement; and (vi) all references to “will” are interchangeable with the word “shall” and shall be understood to be imperative or mandatory in nature. 

[The remainder of this page has been intentionally left blank. The signature page follows.] 

  
 ***Certain information
contained herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 


  
 72 








 IN WITNESS WHEREOF, duly authorized representatives of the Parties have duly executed this
Agreement to be effective as of the Effective Date. 
  

									
	IMMUNOGEN, INC.	 		 	CYTOMX THERAPEUTICS, INC.
					
	By:	 	  
	 		 	By:	 	  

					
	Name:	 		 		 	Name:	 	
					
	Title:	 		 		 	Title:	 	
					
	Date:	 		 		 	Date:	 	


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT A 

Licensed Target 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT B 

Royalty Rate Reduction Methodology 
 Step
1 – Calculate the Weighted Average Royalty Rate (WARR) for the Calendar Quarter 
  

	•	 	This is the weighted average rate calculated based on the worldwide Net Sales of the Licensed Product for a Calendar Quarter, based upon the rates detailed in Section 4.2 of this Agreement and assuming that there
are not any countries where the royalty rate is to be reduced per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. (M = Million) 

  

	•	 	For instance, if the worldwide Net Sales for Calendar Quarter 1 of 2020 is $1,000M, then the WARR for that period is ($500M*[***]% + $500M*[***]%) / $1,000M = [***]% 


 

	•	 	WARR is the basis for the royalty reduction; it is not the effective royalty rate for a certain country or for the Licensed Product on a worldwide basis. 


Step 2 – Determine the reduced royalty due to CytomX for those countries in the world for which a reduced royalty rate is to be applied per
Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. 
  

	•	 	The reduced royalty rate is the WARR * 50% 

  

	•	 	Continuing with the example in Step 1, 

  

	•	 	If Country X is the one (and only) country in the world for which a reduced royalty rate is to be applied per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement, and 


 

	•	 	sales in Country X for the Calendar Quarter are $50M (out of the $1,000M of worldwide sales), 

  

	•	 	then the reduced royalty due to CytomX for Country X is: 

 [***]% * 50% * $50M = $[***] 

 

	•	 	This calculation should be repeated for each country for which a reduced royalty rate is to be applied per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. 


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 Step 3 – Apply the WARR from Step 1 to Net Sales for the Calendar Quarter in all countries of the world in
which the royalty rate is not to be reduced per Section 4.2.3(b)(i) or 4.2.3(c) of this Agreement. 
  

	•	 	Continuing with the example in Step 1, 

  

	•	 	Net Sales for the Calendar Quarter excluding Country X are $950M (out of the $1,000M of worldwide sales) 

  

	•	 	Then the royalties due to CytomX for all countries of the world excluding Country X are: 

 $500M*[***]% +
$450M*[***]% = $[***] 
 Step 4 – Sum the amounts calculated in Steps 2 and 3 above to arrive at the total royalties due to CytomX for the Calendar
Quarter. 
  

	•	 	Continuing with the example in Step 1, 

 $[***] + $[***] = $[***] 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 SCHEDULE 1.120 

List of Cytotoxic Compound Patent Rights 

[See Attached] 
 [***]† 
  

	†	Nine pages of text omitted. 


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT E 

Form of Work Plan 
 [See
Attached 

[***]† 

 

	† 	Five pages of text omitted 


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 EXHIBIT F 

Representatives to the Joint Research Committee 

ImmunoGen Representatives 

[***] 
 CytomX
Representatives 
 [***] 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 SCHEDULE 1.104 

List of Cytotoxic Compound Patent Rights 

[See Attached] 
 [***]† 
  

	† 	Nine pages of text omitted. 


  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 FIRST AMENDMENT TO RESEARCH COLLABORATION AGREEMENT 

This First Amendment to Research Collaboration Agreement (the “First Amendment”) is made effective as of the date of
the last signature below by and between ImmunoGen, Inc., a Massachusetts corporation (“ImmunoGen”), with its principal place of business being 830 Winter Street, Waltham, Massachusetts 02451, USA, and CytomX
Therapeutics, Inc., a Delaware corporation (“CytomX”), with its principal place of business being 343 Oyster Point Blvd., Suite 100, South San Francisco, California 94080. ImmunoGen and CytomX are herein sometimes
referred to as a “Party” and collectively as the “Parties.” 
 WHEREAS, ImmunoGen and CytomX
are parties to that certain Research Collaboration Agreement dated as of January 8, 2014 (the “RCA”); and 

WHEREAS, the Parties desire to amend the RCA to provide CytomX with the abilitiy to evaluate a second Replacement Target, as set forth in this
First Amendment; and 
 NOW, THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Parties agree and covenant as follows. 
 1. Target Replacement Right.
Section 2.1.2 of the RCA is amended by adding the following to the end thereof: 
 “Anything contained in this Agreement to the
contrary notwithstanding, CytomX shall have the right to replace its first Replacement Target with another single Replacement Target, exercisable upon written notice to ImmunoGen and payment to ImmunoGen of a fee in the amount of [***] (the
“Expanded Access Fee”) at any time after CytomX has replaced its initial Research Program Targets with a Replacement Target but on or prior to the Replacement Target Cut-Off Date; provided that CytomX may not replace its first
Replacement Target once it has exercised its Option with respect to such first Replacement Target. Any such second Replacement Target for CytomX may not be a Target that is or was previously a Research Program Target of ImmunoGen, and availability
of any such second Replacement Target shall be subject to Section 2.1.3 hereof. Payment of the Expanded Access Fee by CytomX to ImmunoGen shall be made in U.S. Dollars without set-off or counterclaim and free and clear of any taxes,
duties, levies, fees or charges. The Expansion Fee shall be non-refundable and non-creditable.” 
 2. Miscellaneous.
Capitalized terms used and not otherwise defined herein shall have the respective meanings ascribed to them in the RCA. The RCA remains in full force and effect, as amended by this First Amendment. References in the RCA to “Agreement” mean
the RCA as amended by this First Amendment. 

  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 








 IN WITNESS WHEREOF, the Parties have caused this First Amendment to Research Collaboration
Agreement to be executed by their duly authorized representatives. 
  

									
	IMMUNOGEN, INC.	 		 	CYTOMX THERAPEUTICS, INC.
					
	By:	 	 /s/ Peter Williams
	 		 	By:	 	 /s/ Sean McCarthy

					
	Name:	 	 Peter Williams
	 		 	Name:	 	 Sean McCarthy

					
	Title:	 	 Vice President
	 		 	Title:	 	 CEO

					
	Date:	 	 4/3/15
	 		 	Date:	 	 4/1/15



  
 ***Certain information contained
herein has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions.