[***] Certain information in this document has been excluded pursuant to Regulation S-K, Item 601(b)(10).  Such excluded information is not material and would likely cause competitive harm to the registrant if publicly disclosed.

Exhibit 10.3

AMENDMENT NO. 1

TO THE

COLLABORATION AND LICENSE AGREEMENT

This Amendment No. 1 to the Collaboration Agreement (this “Amendment”) is effective as of the  29^th day of September, 2020 (the “Amendment Effective Date”) by and between Amgen Inc., a Delaware corporation having an address at One Amgen Center Drive, Thousand Oaks, California 91320 (“Amgen”) and CytomX Therapeutics, Inc., a Delaware corporation having an address at 151 Oyster Point Blvd., Suite 400, South San Francisco, California 94080 (“CytomX”).  Amgen and CytomX are each hereafter referred to individually as a “Party” and together as the “Parties”.  

WHEREAS, Amgen and CytomX entered into that certain Collaboration and License Agreement, dated as of September 29, 2017 (the “Agreement”); and

WHEREAS, Amgen and CytomX wish to amend certain terms of the Agreement as further provided herein; and

NOW, THEREFORE, in consideration of the mutual promises and covenants hereinafter set forth, the Parties agree to amend the Agreement as follows.  Capitalized terms used in this Amendment and not otherwise defined herein shall have the meanings ascribed to such terms in the Agreement.

PART 1 - AMENDMENTS TO CERTAIN TERMS

“4.4.1Amgen shall have the right to elect to select (a) one (1) additional Target (the “First Additional Amgen Target”) by nominating such additional Target at any time prior to [***] (the “First Additional Amgen Target Selection Date”) for inclusion under this Agreement, subject to Section 4.4.2 (the “Second Additional Amgen Target” and, together with the First Additional Target, the “Additional Amgen Targets”)  and (b) a second (2^nd) additional Target by nominating such additional Target at any time prior to [***] (the “Second Additional Amgen Target Selection Date” and, together with the First Additional Amgen Target Selection Date, the “Selection Dates”) for inclusion under this Agreement, subject to Section 4.4.2 (collectively, the “Amgen Expansion Option”).  

4.4.2CytomX and the Gatekeeper shall maintain an up-to-date list of Targets that are not Available until the time period for the process of nomination and qualification of proposed Additional Amgen Targets expires pursuant to this Section 4.4.2.  To nominate an Additional Amgen Target, Amgen shall provide

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the Gatekeeper and CytomX a notice of exercise of the Amgen Expansion Option, and in its notice to the Gatekeeper, Amgen shall specify its proposed Additional Amgen Target.  The Gatekeeper shall provide written notice to CytomX and Amgen within [***] days of receipt thereof as to whether such proposed Additional Amgen Target is Available.  If the Gatekeeper determines that a proposed Additional Amgen Target is Available, then CytomX shall so notify Amgen and Amgen shall pay to CytomX the Amgen Expansion Option fee in accordance with Section 7.2.  If any such proposed Additional Amgen Target is determined by the Gatekeeper not to be Available, then Amgen shall have the option to continue to nominate another proposed Additional Amgen Target until an Additional Amgen Target nominated by Amgen is determined to be Available, it being understood that the process of nomination and qualification of proposed Additional Amgen Targets may extend beyond [***] as long as Amgen exercised the Amgen Expansion Option prior to [***]; provided that if the process of selection and qualification of proposed Additional Amgen Target extends beyond [***], and if the Gatekeeper provides written notice to Amgen that a proposed Additional Amgen Target is not Available pursuant to this Section 4.4.2, Amgen must propose another Amgen Additional Target, if any, within [***] days after receiving such notice, and provided, further, that in no event shall Amgen’s right to propose any Additional Amgen Target extend beyond the date that is [***] days after the [***].  The JSC shall within [***] days after the Gatekeeper confirms that the relevant Additional Amgen Target is Available generate a Preclinical Development Plan for such Additional Amgen Target in accordance with Section 2.1.3(b), provided that CytomX’s obligations under such Preclinical Development Plan shall not be materially different in nature than CytomX’s obligations under the Preclinical Development Plan for the initial Amgen Target.  Bi-Specific Products directed against such Additional Amgen Target and [***], having Formats selected pursuant to activities under the Preclinical Development Plan, shall be referred to as “Additional Amgen Products”, and the terms of this Agreement that apply to Amgen Products and the Amgen Target shall also apply to each Additional Amgen Target (and corresponding Additional Amgen Products), mutatis mutandis, on an Additional Amgen Target-by-Additional Amgen Target basis.  For the avoidance of doubt, from and after Amgen’s exercise of the Amgen Expansion Option with respect to an Additional Amgen Target, the definition of “Amgen Target” shall be expanded to include such Additional Amgen Target, and the definition of “Amgen Product” shall be expanded to include all such Additional Amgen Products.”

“3.4.1  During the Term, [***], itself or through its Affiliates, shall not [***] of [***] or [***] or [***] or [***] any [***] to [***] or [***], the [***] (a) [***] or (b) [***].  The foregoing restriction shall [***] on a [***] with respect to [***].  Notwithstanding the foregoing, if, during the Term [***] and [***] is [***] or [***], then [***], and [***] by [***] shall [***] provided, that such [***] with respect to [***] from [***] and [***] and [***] and [***] on the [***] from the [***] of the [***] or any [***] and the [***] with respect to [***].

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PART 2 – REFERENCE TO AND EFFECT ON THE AGREEMENT

PART 3 – MISCELLANEOUS

[Signature page follows]

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IN WITNESS THEREOF, duly authorized representatives of the Parties hereto have executed this Amendment No. 1 as of the date first set forth above.