Amendment No. 1 dated November 17, 2021 to the Option, License and Collaboration Agreement dated May 27, 2020 between Arcus Biosciences, Inc. and Gilead Sciences, Inc

EXHIBIT 10.34

[***] = INFORMATION HAS BEEN OMITTED BECAUSE IT IS BOTH NOT MATERIAL AND IS THE TYPE OF INFORMATION THAT ARCUS BIOSCIENCES, INC. TREATS AS PRIVATE OR CONFIDENTIAL

AMENDMENT NO. 1 TO

OPTION, LICENSE AND COLLABORATION AGREEMENT

This Amendment No. 1 (this “Amendment”) to the Option, License and Collaboration Agreement, dated as of May 27, 2020 (the “Agreement”), is entered into as of November 17, 2021 (the “Amendment Execution Date”), by and between Gilead Sciences, Inc. (“Gilead”), and Arcus Biosciences, Inc. (“Arcus”). Capitalized terms used and not otherwise defined herein shall have the meanings given such terms in the Agreement to the extent defined therein.

Whereas, Gilead and Arcus entered into the Agreement, pursuant to which, among other things, Gilead has an Option to collaborate with and license intellectual property from Arcus with respect to each Arcus Program, including the TIGIT Program, the Adenosine Receptor Program, and the CD73 Program (collectively these three Arcus Programs, the “2021 Optioned Programs”), on the terms and conditions set forth therein;

Whereas, Gilead desires to exercise its Option on the 2021 Optioned Programs prior to their respective Option Exercise Periods, in each case, in accordance with Section 8.3(b)(vi) of the Agreement, on the terms and conditions set forth herein; and

Whereas, the Parties now wish to modify the Agreement in connection with Gilead’s exercise of its Option on the 2021 Optioned Programs as set forth herein.

Now, Therefore, in consideration of the mutual promises and assurances contained in the Agreement and this Amendment, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties hereby agree as follows:

“To the extent permitted by applicable Antitrust Laws, and subject to Section 8.3(c)(iii), if the Antitrust Approvals have been obtained for the United States with respect to a 2021 Optioned Program, then (1) an Option Exercise Closing for such 2021 Optioned Program shall occur for the United States and each other jurisdiction in the Territory as to which Antitrust Approval is not required or has

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been obtained (such Option Exercise Closing, the “Amended Initial Option Closing”) and (2) subject to Section 8.3(e), each country for which an Antitrust Approval is still required as of the Amended Initial Option Closing shall not be included in the Gilead Royalty Territory unless and until the applicable required Antitrust Approval has been obtained for such country, as applicable.”

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“Amendment No. 1” means the Amendment No. 1 to this Agreement, dated as of November 17, 2021, between the Parties.

“2021 Optioned Programs” mean each of the TIGIT Program (which, for the avoidance of doubt, includes both AB154 and AB308), the CD73 Program and the Adenosine Receptor Program, in each case, from and after the occurrence, if any, of the Option Exercise Closing (or, if there is more than one closing for the applicable Option, the Amended Initial Option Closing) with respect to each of the respective Arcus Programs contemplated by Amendment No. 1.

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“Subject to Section 4.7(d), with respect to each Optioned Program other than the PD-1 Program, the TIGIT Program, the CD73 Program or the Adenosine Receptor Program, if Arcus desires not to (i) perform its obligations under Section 4.2 with respect to the R&D Plan and Budget for such Optioned Program and (ii) share Research and Development Costs with respect to such Optioned Program, then, in each case ((i) and (ii)), Arcus shall have the right to opt-out of performing such obligations and sharing such Research and Development Costs upon written notice to Gilead stating that Arcus is opting-out of such Optioned Program (such notice from Arcus to Gilead, with respect to any Optioned Program, an “Opt-Out Notice”).”

(a) Royalty Payments. Subject to any other terms of this Agreement relevant in this Section 9.5(a), in partial consideration of the license granted by Arcus under Section 8.4, during the applicable Royalty Term only, and on an Optioned Product-by-Optioned Product basis, Gilead shall pay to Arcus royalties in each Calendar Year on the amount of aggregate Net Sales of the applicable Optioned Product in the Gilead Royalty Territory (excluding (A) for clarity, Net Sales in any country for the period in which such country is included in the Third Party Territory or the Shared Territory and (B) Net Sales in the Access Territory) (such aggregate Net Sales, excluding the foregoing clauses (A) and (B), “Included Net Sales”) as calculated by multiplying the applicable royalty rates set forth below by the corresponding amount of incremental Included Net Sales of such Optioned Product in such Calendar Year (the “Royalties”). For clarity, if Arcus delivers an Opt-Out Notice with respect to a given Optioned Program pursuant to Section 4.7(a), the Net Sales in the U.S. for each Optioned Product included in such Optioned Program shall be included in Included Net Sales, on an Optioned Product-by-Optioned Product basis.

With respect to (x) the PD-1 Program and (y) all Optioned Programs other than (i) the 2021 Optioned Programs and (ii) the Optioned Target Programs for which Gilead exercises its option prior to the expiration of the applicable Selected Target Option Exercise Window,

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the Parties agree that the following Royalty Rate Table A applies ((x) and (y), collectively, “Royalty A Programs”):

Royalty Rate Table A

With respect to each 2021 Optioned Program (the “Royalty B Programs”), the Parties agree that the following Royalty Rate Table B applies:

Royalty Rate Table B

With respect to each Optioned Target Program for which Gilead exercises its option prior to expiration of the applicable Selected Target Option Exercise Window (collectively, “Royalty C Programs”), the Parties agree that the following Royalty Rate Table C applies:

Royalty Rate Table C

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(a) Conditions for Permitting Arcus Independent Activities. For each Optioned Program, following [***], if Arcus has not undergone any Change of Control, Arcus has not exercised its opt-out pursuant to Section 4.7, and, subject to Section 4.1(a) and 7.2(a), Arcus desires to conduct Development activities (including the inclusion of such Optioned Molecule in an Optioned Combination, but not the inclusion of such Optioned Molecule in any other Combination) that Gilead does not agree to include in the applicable R&D Plan and Budget following completion of the dispute resolution process set forth in Section 2.5(b)(ii)(B) and such activities would not be reasonably expected to have a material adverse effect on the Development or Commercialization of any Optioned Molecule or

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Optioned Product in the Gilead Territory (any such activities, “Arcus Independent Activities”), then Section 4.8(b) shall apply.

3.1 Arcus R&D Activities.

(a) Generally. Arcus shall be solely responsible, in its discretion and at its sole cost and expense, for conducting all (a) Pre-Program Activities and (b) Development activities with respect to Arcus Programs, including, in each case ((a) and (b)) (as applicable), all applicable pre-clinical and non-clinical research activities, regulatory activities (including filing INDs) and clinical activities (collectively, the “Arcus R&D Activities”), except to the extent otherwise agreed by the Parties in writing, set forth in this Agreement or as set forth in Section 3.1(b).

(b) Gilead Selected Targets for Arcus R&D Activities.

(i) Initial Selection. “Selected Targets” are the Target(s) selected by Gilead for Arcus R&D Activities from the list mutually agreed by the Parties in writing pursuant to Amendment No. 1. With respect to each Selected Target, Arcus shall use commercially reasonable efforts to conduct Arcus R&D Activities with respect to such Selected Target from the prompt initiation of Pre-Program Activities, through the establishment of an Arcus Program Directed To such Selected Target and the Completion Date of the Triggering Clinical Trial with respect to such Arcus Program. The Parties agree that the conduct of the Arcus R&D Activities with respect to the Selected Targets shall be overseen by the Joint Research Committee previously established by the Parties. For the avoidance of doubt, subject to the terms of this Section 3.1(b), Arcus shall retain discretion over the manner in which it conducts the Pre-Program Activities for the Selected Targets.

(ii) Validation Plan and Validation Data Package. Notwithstanding Sections 2.5(b)(i)(B) and 3.1(a) with respect to the Pre-Program Activities for each Selected Target, the Parties shall mutually agree on the scope of activities [***] intended to assess a lead Arcus Molecule Directed To such Selected Target (collectively, such specific Pre-Program Activities in (A) and (B), the “Validation Activities” for such Selected Target). With respect to each Selected Target, promptly upon completion of the Validation Activities, Arcus shall deliver to Gilead a written notice including instructions and credentials with which Gilead may access a Data Room containing all data and information arising from all Pre-Program Activities, including the Validation Activities, performed with respect to such Selected Target up to the date of such completion (such information package, a “Validation Data Package”).

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(iii) Replacement of Selected Targets. For the period of time from Gilead’s receipt of the Validation Data Package for each Selected Target until [***] days thereafter (“Target Evaluation Period”), Gilead shall have a one-time right to replace such Selected Target upon providing written notice to Arcus identifying the Selected Target to be replaced prior to expiration of the Target Evaluation Period. If Gilead provides such notice, Gilead shall provide written notice to Arcus identifying a new Target in replacement of such Selected Target within [***] days from the expiration of the Target Evaluation Period; provided, that the new Target must be from the list of Targets mutually agreed by Arcus and Gilead in writing pursuant to Amendment No. 1. Upon Arcus’ receipt of such written notice from Gilead identifying the replacement Target, such replacement Target shall be treated as a Selected Target, the replaced Selected Target will no longer be deemed a Selected Target under this Agreement, and Gilead shall have no further replacement right under this Section 3.1(b)(iii) with respect to any such replacement Selected Target. For each Selected Target, if a Target Program Data Package is delivered to Gilead pursuant to Section 8.3(b)(ix) prior to delivery of a Validation Data Package for such Selected Target, Gilead’s right to replace such Selected Target shall expire concurrent with the expiration of the Selected Target Option Exercise Window for such Selected Target.

(iv) Material Transfer. If and to the extent requested by Gilead, Arcus shall provide to Gilead an amount of chemical or biological materials that have been, are being, or are proposed to be studied by Arcus with respect to such Selected Target(s) for pre-clinical and non-clinical studies to be performed by Gilead in Gilead’s sole discretion. Any such material transfer shall be made pursuant to the terms of Section 3.5(d) of this Agreement.

(ix) For each Selected Target, subject to Section 8.3(d), Arcus hereby grants to Gilead an exclusive option to obtain the exclusive licenses and other rights described in Section 8.4 with respect to all Arcus Molecules Directed to such Selected Target and any Related Arcus Molecules with respect to such Arcus Molecules, and any Arcus Products containing such Arcus Molecules or such Related Arcus Molecules (a “Target Program”). Following [***], Arcus shall promptly deliver to Gilead a written notice including instructions and credentials with which Gilead may access a Data Room containing the [***] to the extent then existing with respect to such Target Program (a “Target Program Data Package”). With respect to a Target Program, during the window beginning with the date of Gilead’s selection of a Selected Target and ending [***] days after receipt of such notice (the “Selected Target Option Exercise Window”), Gilead shall have the right to exercise such option for such Target Program by providing Arcus written notice thereof during such window. During the Selected Target Option Exercise Window for a Target Program, Arcus may continue with any Pre-Program Activities and Development Activities, but, in no event shall [***]. If Gilead exercises such option for a Target Program during the Selected Target Option Exercise Window, the option closing process set forth in Sections 8.3(c) and (d) applicable to an Arcus Program shall apply to the Target Program, mutatis mutandis, and, from and after the Option Exercise Closing (or, if there is more than one (1) closing for the Target Program, the Initial Option Closing), the Target Program shall be deemed an Optioned Program (each, an “Optioned Target Program”) and shall thereafter be

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subject to all of the terms and conditions of the Agreement applicable to Optioned Programs. If Gilead does not exercise such option for a Target Program during the Selected Target Option Exercise Window, such Target Program shall be deemed an Arcus Program from and after at least one (1) Molecule included in such Target Program becomes the subject of an IND filed with a Regulatory Authority in any jurisdiction and shall thereafter be subject to all of the terms and conditions of the Agreement applicable to Arcus Programs, including Gilead’s right to exercise the Option with respect to such Target Program pursuant to Section 8.3. If Gilead exercises its option for a Target Program during the applicable Selected Target Option Exercise Window, responsibilities for the conduct of activities under the applicable R&D Plan and Budget shall be assigned to Arcus and Gilead in accordance with the terms and conditions of the Agreement, including as contemplated by Section 4.2(a) and Section 5.2(c)(i). By way of example, the applicable R&D Plan and Budget may [***].

“Without limiting any of Gilead’s rights under this Agreement, Arcus acknowledges and agrees that, as contemplated by Section 4.2(a), responsibility for the activities under each R&D Plan and Budget shall be allocated between Arcus and Gilead. If and to the extent requested by Gilead via the JDC, the JDC may assign to Arcus, and Arcus shall perform, at least fifty percent (50%) of the clinical activities for each 2021 Optioned Program in accordance with the R&D Plan and Budget for such 2021 Optioned Program. If such assignment is made, the Parties shall promptly amend the R&D Plan and Budget as necessary to reflect the assignment of such activities to Arcus.”

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9.2 Option Payments.

(a) Option Payment for Arcus Programs. (i) For each Optioned Program other than the PD-1 Program, the TIGIT Program, the Adenosine Receptor Program, the CD73 Program and any Target Program, Gilead shall pay to Arcus an amount equal to One Hundred Fifty Million Dollars ($150,000,000), (ii) for the TIGIT Program, if Gilead exercises its Option during the Option Exercise Period for AB154, then Gilead shall pay to Arcus an amount equal to Two Hundred Seventy-Five Million Dollars ($275,000,000), and if Gilead exercises its Option during the Option Exercise Period for AB308, then Gilead shall pay to Arcus an amount equal to One Hundred Fifty Million Dollars ($150,000,000), (iii) for the Adenosine Receptor Program, Gilead shall pay to Arcus an amount equal to Two Hundred Fifty Million Dollars ($250,000,000), and (iv) for the CD73 Program, Gilead shall pay to Arcus an amount equal to Two Hundred Million Dollars ($200,000,000) (each such payment, an “Option Payment”), in each case, within thirty (30) days after the applicable Arcus Program has become an Optioned Program pursuant to Section 8.3.

(b) Option Payment for Target Programs. For each Target Program, if Gilead exercises its option during the Selected Target Option Exercise Window, Gilead shall pay to Arcus an amount equal to Sixty Million Dollars ($60,000,000), in each case, within thirty (30) days after the applicable Target Program has become an Optioned Program pursuant to Section 8.3 of the Agreement.

9.3 Option Continuation Payments. Until the earlier termination of this Agreement pursuant to ARTICLE XIV, (i) within [***] days of either (x) unless the following clause (y) applies, the second (2nd) anniversary of the Effective Date (if applicable) or (y) if, as of the second (2nd) anniversary of the Effective Date, Gilead’s right to rescind its exercise of the Options for the other two (2) 2021 Optioned Programs has not expired, the earlier of (A) Gilead’s rescission of the Option exercise for the other two (2) 2021 Optioned Programs in accordance with Section 1.f of Amendment No. 1 and (B) [***] (the applicable date ((x) or (y)), the “Payment Date”), Gilead shall pay to Arcus a payment of Sixty-Seven Million Dollars ($67,000,000) in partial consideration of the Options granted to Gilead pursuant to Section 8.3 for the two (2) subsequent years, and (ii) within [***] days of each of the fourth (4th), sixth (6th) and eighth (8th) anniversaries of the Effective Date (if applicable), Gilead shall pay to Arcus a payment of One Hundred Million Dollars ($100,000,000) in partial consideration of the Options granted to Gilead pursuant to Section 8.3 for the corresponding two (2) subsequent years (each ((i) and (ii)),

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an “Option Continuation Payment”). Notwithstanding anything to the contrary herein, (a) in the event that Gilead exercises its rights to terminate its obligations for making any further Option Continuation Payments pursuant to Section 14.3(b)(i), Gilead’s payment obligations under this Section 9.3 shall terminate on the effective date of such termination; provided, that [***].

9.3 Option Continuation Payments. Until the earlier termination of this Agreement pursuant to ARTICLE XIV, (i) within [***] days of either (x) unless the following clause (y) applies, the second (2nd) anniversary of the Effective Date (if applicable) or (y) if, as of the second (2nd) anniversary of the Effective Date, Gilead’s right to rescind its exercise of the Option for one (1) of the Optioned Programs has not expired, the earlier of (A) Gilead’s rescission of the Option exercise for such 2021 Optioned Program in accordance with Section 1.f of Amendment No. 1 and (B) [***] (the applicable date ((x) or (y)), the “Payment Date”), Gilead shall pay to Arcus a payment of Thirty-Four Million Dollars ($34,000,000) in partial consideration of the Options granted to Gilead pursuant to Section 8.3 for the two (2) subsequent years, and (ii) within [***] days of each of the fourth (4th), sixth (6th) and eighth (8th) anniversaries of the Effective Date (if applicable), Gilead shall pay to Arcus a payment of One Hundred Million Dollars ($100,000,000) in partial consideration of the Options granted to Gilead pursuant to Section 8.3 for the corresponding two (2) subsequent years (each ((i) and (ii)), an “Option Continuation Payment”). Notwithstanding anything to the contrary herein, (a) in the event that Gilead exercises its rights to terminate its obligations for making any further Option Continuation Payments pursuant to Section 14.3(b)(i), Gilead’s payment obligations under this Section 9.3 shall terminate on the effective date of such termination; provided, that [***].

9.3 Option Continuation Payments. Until the earlier termination of this Agreement pursuant to ARTICLE XIV, within [***] days of each of the fourth (4th), sixth (6th) and eighth (8th) anniversaries of the Effective Date (if applicable), Gilead shall pay to Arcus a payment of One Hundred Million Dollars ($100,000,000) in partial consideration of the Options granted to Gilead pursuant to Section 8.3 for the corresponding two (2) subsequent years (each an “Option Continuation Payment”). Notwithstanding anything to the contrary herein, (a) in the event that Gilead exercises its rights to terminate its obligations for making any further Option Continuation Payments pursuant to Section 14.3(b)(i), Gilead’s payment obligations under this Section 9.3 shall terminate on the effective date of such termination; provided, that [***].

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(e) Structures of Arcus Molecules. [***].

(iii) Consequences of Expiration or Termination of the Collaboration Term.

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[Signature page follows]

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In Witness Whereof, the Parties have executed this Amendment as of the Amendment Execution Date.

[Signature Page to Amendment No. 1 to Option, License and Collaboration Agreement]