License and Collaborations	12 Months Ended
Dec. 31, 2023
License and Collaboration Agreements [Abstract]
License and Collaborations	License and collaborations We enter into licensing agreements, strategic collaborations and other similar arrangements with third parties for the development and commercialization of certain investigational products. These arrangements may be collaborative and involve two or more parties who are active participants in the operating activities of the collaboration and are exposed to significant risks and rewards depending on the commercial success of the activities. These arrangements may include: non-refundable upfront payments; payments for options to acquire certain rights; potential development and regulatory milestone payments and/or sales-based milestone payments; royalty payments; revenue or profit-sharing arrangements; expense reimbursements; and cost-sharing arrangements. See Note 2, Summary of significant accounting policies, for additional discussion of revenues recognized under these types of arrangements. Operating expenses for costs incurred pursuant to these arrangements are reported in their respective expense line items in the Consolidated Statements of Operations, net of any payments due to or reimbursements due from our collaboration partners, with such reimbursements being recognized at the time the party becomes obligated to pay. Our significant arrangements are discussed below. Gilead Collaboration See Note 3, Related party - Gilead Sciences, Inc. Taiho Collaboration In 2017, we entered into an agreement with Taiho under which we granted them exclusive options to programs arising over a five-year period which ended in September 2022 for an upfront payment of $35 million. Upon an option exercise of a program, Taiho would obtain exclusive development and commercialization rights to investigational products under the program for the Taiho Territory. For each option that Taiho exercises, they will be obligated to make a payment of $3 million to $15 million, depending on the development stage of the optioned program. Upon exercise, Taiho is solely responsible for continued development and commercialization in the Taiho Territory. In addition, for each optioned program we would be eligible to receive clinical and regulatory milestones of up to $130 million and commercial milestone payments of up to $145 million with the achievement of certain sales thresholds in the Taiho Territory. We will also receive royalties ranging from high single-digits to mid-teens on net sales of licensed products in the Taiho Territory. Royalties will be payable by product and country commencing on the first commercial sale and ending upon the later of: (a) 10 years; and (b) expiration of the last-to-expire valid claim of our patents covering the manufacture, use or sale. As of December 31, 2023, Taiho has licenses for the Taiho Territory to (i) etrumadenant (the adenosine receptor antagonist program); (ii) zimberelimab (the anti PD-1 program); and (iii) domvanalimab and AB308 (collectively, the anti-TIGIT program). During 2022, Taiho opted to participate in two global Phase 3 trials of domvanalimab and zimberelimab combinations, STAR-121 and STAR-221, and became obligated to make certain milestone payments contingent upon successfully satisfying the related clinical milestones. During the year ended December 31, 2023, the clinical milestones for domvanalimab and zimberelimab for the STAR-221 study were met and Taiho became obligated to pay us $28 million and in early 2024 the clinical milestones for domvanalimab and zimberelimab for the STAR-121 study were met and Taiho became obligated to pay us $26 million. For each of the years ended December 31, 2023, 2022 and 2021, we recognized revenue of $5 million, $5 million and $22 million, respectively, under this agreement. For a more detailed discussion on revenues see Note 5, Revenues. For the year ended December 31, 2023, we recognized net reimbursements from Taiho as a reduction in R&D expense of $8 million. AstraZeneca Collaboration In 2020, we entered into a collaboration with AstraZeneca to evaluate domvanalimab, our investigational anti-TIGIT antibody, in combination with AstraZeneca’s durvalumab in a registrational Phase 3 clinical trial in patients with unresectable Stage 3 NSCLC, known as the PACIFIC-8 trial. The terms of the agreement were amended in January 2024. Under the collaboration, as amended, each company will retain existing rights to their respective molecules and any future commercial economics. AstraZeneca will conduct the trial, and each company will supply their respective investigational product to support the trial. We may incur milestones of up to $24 million upon the achievement of certain clinical trial progress milestones or under certain circumstances if the agreement is terminated early and we will reimburse AstraZeneca annually for a portion of the trial costs. The portion of the costs that we consider to be unavoidable are accrued as incurred and milestones that are deemed probable of occurring are accrued in advance of the achievement of the milestone. For the years ended December 31, 2023, 2022 and 2021 under this arrangement we recognized as R&D expense $6 million, $4 million, and $1 million respectively, before expected recoveries from our cost-sharing agreement with Gilead. At December 31, 2023 and 2022, we have recognized liabilities of $11 million and $5 million, respectively, related to our obligation to AstraZeneca which is recorded in Other noncurrent liabilities. As of December 31, 2023, the PACIFIC-8 trial formed part of the Arcus and Gilead joint development program for domvanalimab and our portion of the trial costs were shared with Gilead. At December 31, 2023 and 2022, we have recognized receivables due from Gilead for these shared costs of $6 million and $2 million, respectively, which is recorded in Other noncurrent assets. On January 29, 2024, under the Third Gilead Collaboration Agreement Amendment, we agreed to solely fund our share of PACIFIC-8, subject to Gilead’s right to reinstate PACIFIC-8 as part of the parties’ joint development activities for the TIGIT Program in the first quarter of 2026. On the date of this amendment, we will incur $6 million of R&D costs reflecting our additional share of incurred costs to date. WuXi Biologics License – anti-PD-1 In 2017, we entered into an agreement with WuXi Biologics which, as amended, provides us with exclusive rights to (i) develop, use and manufacture products that include an anti-PD-1 antibody, including zimberelimab, worldwide and (ii) commercialize any such products worldwide, except in Greater China. Under the agreement, as of December 31, 2023 we may incur (i) regulatory milestone payments of up to $50 million for zimberelimab, and commercialization milestone payments of up to $375 million, (ii) tiered royalties that range from the high single-digits to low teens on net sales of the licensed products and (iii) fees related to any sublicenses. During the year ended December 31, 2021, we incurred milestones of $10 million related to this agreement which were recorded as R&D expense. WuXi Biologics License – anti-CD39 In 2020, we entered into an agreement with WuXi Biologics, under which we obtained the exclusive worldwide license to develop and commercialize anti-CD39 antibodies discovered under the agreement. As of December 31, 2023 we may incur additional clinical and regulatory milestone payments of up to $14 million and royalty payments in the low single digits on net sales of the licensed products under this agreement. During the years ended December 31, 2023 and 2022, we incurred development milestones of $1 million and $2 million, respectively, related to this agreement, which were recognized as R&D expense. Abmuno License In 2016, we entered into an agreement with Abmuno, under which we obtained the exclusive worldwide license to develop, use, manufacture, and commercialize products that include an anti-TIGIT antibody, including domvanalimab. Under the agreement, as of December 31, 2023 we may incur additional clinical, regulatory and commercialization milestone payments of up to $88 million. During the years ended 2022 and 2021, we incurred development milestone expenses of $5 million and $5 million, respectively, related to this agreement, which were recorded as R&D expense. Exelixis Collaboration In 2023, we entered into a clinical trial collaboration with Exelixis for STELLAR-009, a Phase 1b/2 trial to evaluate casdatifan, our investigational inhibitor of the transcription factor HIF-2⍺, in combination with Exelixis’s zanzalintinib, a next-generation tyrosine kinase inhibitor, in patients with ccRCC. Under the collaboration, each company will retain existing rights to their respective molecules and any future commercial economics. Exelixis will conduct the STELLAR-009 trial, and each company will supply their respective investigational product to support the trial. We will reimburse Exelixis for a portion of the trial costs. Patient enrollment for STELLAR-009 opened at the end of 2023. For the year ended December 31, 2023, we recognized R&D expense of $3 million under this arrangement.

We enter into licensing agreements, strategic collaborations and other similar arrangements with third parties for the development and commercialization of certain investigational products. These arrangements may be collaborative and involve two or more parties who are active participants in the operating activities of the collaboration and are exposed to significant risks and rewards depending on the commercial success of the activities. These arrangements may include: non-refundable upfront payments; payments for options to acquire certain rights; potential development and regulatory milestone payments and/or sales-based milestone payments; royalty payments; revenue or profit-sharing arrangements; expense reimbursements; and cost-sharing arrangements. See Note 2, Summary of significant accounting policies, for additional discussion of revenues recognized under these types of arrangements.

Operating expenses for costs incurred pursuant to these arrangements are reported in their respective expense line items in the Consolidated Statements of Operations, net of any payments due to or reimbursements due from our collaboration partners, with such reimbursements being recognized at the time the party becomes obligated to pay. Our significant arrangements are discussed below.

In 2017, we entered into an agreement with Taiho under which we granted them exclusive options to programs arising over a five-year period which ended in September 2022 for an upfront payment of $35 million. Upon an option exercise of a program, Taiho would obtain exclusive development and commercialization rights to investigational products under the program for the Taiho Territory.

For each option that Taiho exercises, they will be obligated to make a payment of $3 million to $15 million, depending on the development stage of the optioned program. Upon exercise, Taiho is solely responsible for continued development and commercialization in the Taiho Territory. In addition, for each optioned program we would be eligible to receive clinical and regulatory milestones of up to $130 million and commercial milestone payments of up to $145 million with the achievement of certain sales thresholds in the Taiho Territory. We will also receive royalties ranging from high single-digits to mid-teens on net sales of licensed products in the Taiho Territory. Royalties will be payable by product and country commencing on the first commercial sale and ending upon the later of: (a) 10 years; and (b) expiration of the last-to-expire valid claim of our patents covering the manufacture, use or sale.

As of December 31, 2023, Taiho has licenses for the Taiho Territory to (i) etrumadenant (the adenosine receptor antagonist program); (ii) zimberelimab (the anti PD-1 program); and (iii) domvanalimab and AB308 (collectively, the anti-TIGIT program).

During 2022, Taiho opted to participate in two global Phase 3 trials of domvanalimab and zimberelimab combinations, STAR-121 and STAR-221, and became obligated to make certain milestone payments contingent upon successfully satisfying the related clinical milestones. During the year ended December 31, 2023, the clinical milestones for domvanalimab and zimberelimab for the STAR-221 study were met and Taiho became obligated to pay us $28 million and in early 2024 the clinical milestones for domvanalimab and zimberelimab for the STAR-121 study were met and Taiho became obligated to pay us $26 million.

For each of the years ended December 31, 2023, 2022 and 2021, we recognized revenue of $5 million, $5 million and $22 million, respectively, under this agreement. For a more detailed discussion on revenues see Note 5, Revenues.

In 2020, we entered into a collaboration with AstraZeneca to evaluate domvanalimab, our investigational anti-TIGIT antibody, in combination with AstraZeneca’s durvalumab in a registrational Phase 3 clinical trial in patients with unresectable Stage 3 NSCLC, known as the PACIFIC-8 trial. The terms of the agreement were amended in January 2024. Under the collaboration, as amended, each company will retain existing rights to their respective molecules and any future commercial economics. AstraZeneca will conduct the trial, and each company will supply their respective investigational product to support the trial. We may incur milestones of up to $24 million upon the achievement of certain clinical trial progress milestones or under certain circumstances if the agreement is terminated early and we will reimburse AstraZeneca annually for a portion of the trial costs. The portion of the costs that we consider to be unavoidable are accrued as incurred and milestones that are deemed probable of occurring are accrued in advance of the achievement of the milestone.

For the years ended December 31, 2023, 2022 and 2021 under this arrangement we recognized as R&D expense $6 million, $4 million, and $1 million respectively, before expected recoveries from our cost-sharing agreement with Gilead. At December 31, 2023 and 2022, we have recognized liabilities of $11 million and $5 million, respectively, related to our obligation to AstraZeneca which is recorded in Other noncurrent liabilities.

As of December 31, 2023, the PACIFIC-8 trial formed part of the Arcus and Gilead joint development program for domvanalimab and our portion of the trial costs were shared with Gilead. At December 31, 2023 and 2022, we have recognized receivables due from Gilead for these shared costs of $6 million and $2 million, respectively, which is recorded in Other noncurrent assets. On January 29, 2024, under the Third Gilead Collaboration Agreement Amendment, we agreed to solely fund our share of PACIFIC-8, subject to Gilead’s right to reinstate PACIFIC-8 as part of the parties’ joint development activities for the TIGIT Program in the first quarter of 2026. On the date of this amendment, we will incur $6 million of R&D costs reflecting our additional share of incurred costs to date.

In 2017, we entered into an agreement with WuXi Biologics which, as amended, provides us with exclusive rights to (i) develop, use and manufacture products that include an anti-PD-1 antibody, including zimberelimab, worldwide and (ii) commercialize any such products worldwide, except in Greater China. Under the agreement, as of December 31, 2023 we may incur (i) regulatory milestone payments of up to $50 million for zimberelimab, and commercialization milestone payments of up to $375 million, (ii) tiered royalties that range from the high single-digits to low teens on net sales of the licensed products and (iii) fees related to any sublicenses.

In 2020, we entered into an agreement with WuXi Biologics, under which we obtained the exclusive worldwide license to develop and commercialize anti-CD39 antibodies discovered under the agreement. As of December 31, 2023 we may incur additional clinical and regulatory milestone payments of up to $14 million and royalty payments in the low single digits on net sales of the licensed products under this agreement.

In 2016, we entered into an agreement with Abmuno, under which we obtained the exclusive worldwide license to develop, use, manufacture, and commercialize products that include an anti-TIGIT antibody, including domvanalimab. Under the agreement, as of December 31, 2023 we may incur additional clinical, regulatory and commercialization milestone payments of up to $88 million.

In 2023, we entered into a clinical trial collaboration with Exelixis for STELLAR-009, a Phase 1b/2 trial to evaluate casdatifan, our investigational inhibitor of the transcription factor HIF-2⍺, in combination with Exelixis’s zanzalintinib, a next-generation tyrosine kinase inhibitor, in patients with ccRCC. Under the collaboration, each company will retain existing rights to their respective molecules and any future commercial economics. Exelixis will conduct the STELLAR-009 trial, and each company will supply their respective investigational product to support the trial. We will reimburse Exelixis for a portion of the trial costs. Patient enrollment for STELLAR-009 opened at the end of 2023.