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.

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. 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. 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.