South San Francisco, CA — December 12, 2025 — Leads & Copy —
Arcus Biosciences (NYSE:RCUS) and Gilead Sciences, Inc. are discontinuing their Phase 3 STAR-221 study due to futility, based on an Independent Data Monitoring Committee recommendation after reviewing interim analysis of overall survival (OS) data.
The STAR-221 study evaluated domvanalimab plus zimberelimab and chemotherapy versus nivolumab plus chemotherapy for first-line treatment of advanced gastric and esophageal cancers. The domvanalimab combination didn’t improve OS compared to nivolumab plus chemotherapy; its safety profile was similar, with no new concerns.
Arcus’s chief medical officer, Richard Markus, MD, expressed disappointment but reaffirmed commitment to cancer and immune-related disease research. The STAR-221 and Phase 2 EDGE-Gastric studies will end, and Arcus and Gilead will analyze the results and determine next steps for patients.
Arcus will now focus on casdatifan, a HIF-2a inhibitor, and its I&I programs. CEO Terry Rosen noted the company is well capitalized and will prioritize casdatifan development, studying new combinations in kidney cancer and broadening its use to other tumor types.
Contact:
Investor Relations
investors@arcusbio.com
Source: Arcus Biosciences
