Gilead and Arcus Announce Amended Collaboration and Equity Investment

Gilead Sciences, Inc. and Arcus Biosciences, Inc. announced an amendment to their collaboration agreement and a separate equity investment by Gilead of $320 million in Arcus common stock at $21.00 per share. The equity investment and collaboration amendment enable accelerated growth of the companies’ joint development programs that span multiple indications. Additionally, Johanna Mercier, Chief Commercial Officer at Gilead Sciences, will join the Arcus Board, bringing Gilead’s total director designees to three. The amendment also includes governance enhancements enabling streamlined decision-making and reflecting the continued growth of the collaboration.

“This amendment allows Gilead to accelerate the domvanalimab program and enables Arcus to focus on progressing multiple pipeline assets, including both Gilead-optioned and non-optioned programs,” said Merdad Parsey, MD, PhD, Chief Medical Officer, Gilead Sciences. “We look forward to strengthening our collaboration as we explore the collective power of our cross-portfolio combinations to help transform how cancer is treated.”

Gilead and Arcus have reprioritized the joint domvanalimab development program to focus on advancing and potentially accelerating the Phase 3 studies STAR-121 (lung cancer) and STAR-221 (gastrointestinal cancer), which are both expected to be fully enrolled by year-end. This prioritization focuses on domvanalimab-containing regimen research in areas where it may have significant impact in combination with chemotherapy and in settings with high unmet need through all-comer study designs. The companies also plan to initiate STAR-131, a new registrational Phase 3 lung cancer study that includes the domvanalimab plus zimberelimab regimen. This prioritization reflects the companies’ continued conviction in the TIGIT pathway and the Fc-silent design of domvanalimab, which has the potential for differentiation in both efficacy and safety.

“Since the inception of our partnership with Gilead in 2020, the companies have moved increasingly closer in all aspects of our research and development efforts,” said Terry Rosen, PhD, Chief Executive Officer, Arcus. “This investment and prioritization enable both companies to leverage their respective strengths and focus on efficiently advancing novel combinations that have the potential to change the landscape of cancer treatment. The additional investment by Gilead, which extends our cash runway into 2027, will enable us to fund our Phase 3 studies of quemliclustat in pancreatic cancer and AB521 in kidney cancer, as well as to begin preparation for our first potential product approvals.”

Additional changes during this prioritization will include discontinuing further enrollment in the Phase 3 ARC-10 study evaluating domvanalimab plus zimberelimab compared to pembrolizumab monotherapy in first-line locally advanced or metastatic, PD-L1-high NSCLC. The discontinuation of the ARC-10 study is based on strategic prioritization to advance and potentially accelerate the Phase 3 studies STAR-121 and STAR-221, which have the potential to address a higher unmet need for patients with lung and gastrointestinal cancers.

Gilead and Arcus are grateful to the patients and investigators who have made the choice to participate in ARC-10, which will continue to generate data and insights that will be shared at future scientific conferences. Patients currently enrolled in ARC-10, or who consented prior to January 29, 2024, and choose to enroll in the study, may continue their treatment and be monitored according to the study protocol. No changes to the safety and efficacy profile of domvanalimab and zimberelimab have been observed.

Also, under the terms of the amended collaboration agreement, the planned Phase 3 first-line study in pancreatic cancer evaluating the investigational small molecule CD73 inhibitor quemliclustat will become an Arcus independent study.

Domvanalimab, zimberelimab and quemliclustat are investigational molecules. Neither Gilead nor Arcus has received approval from any regulatory authority for any use of these molecules, and their safety and efficacy for the treatment of lung, gastrointestinal and pancreatic cancers have not been established.