Arcus Biosciences Discontinues Phase 3 TIGIT Study Due to Futility; Gilead Reduces Collaboration Scope
Summary
Arcus Biosciences announced the discontinuation of its Phase 3 STAR-121 study for metastatic non-small cell lung cancer due to futility and a reduction in the scope of its collaboration with Gilead Sciences.
Key Events
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Phase 3 STAR-121 Study Discontinued
The Phase 3 STAR-121 study, evaluating domvanalimab plus zimberelimab and chemotherapy for metastatic non-small cell lung cancer, was discontinued due to futility based on an Independent Data Monitoring Committee recommendation. The Phase 2 EDGE-Lung study will also be discontinued.
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Gilead Collaboration Scope Reduced
Gilead Sciences will not make the option continuation payment, ending its option rights to additional early-stage programs (CCR6, CD89, CD40L) as of July 14, 2026. Gilead retains existing time-limited options for other programs.
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Arcus Retains Full Rights to Casdatifan
Arcus Biosciences confirmed it retains full rights to its casdatifan development program, excluding rights licensed to Taiho in Japan and certain other Asian territories.
Analysis
The discontinuation of the Phase 3 STAR-121 study, evaluating the anti-TIGIT antibody domvanalimab, represents a significant clinical setback for Arcus Biosciences. This futility decision, based on an Independent Data Monitoring Committee recommendation, indicates the combination did not meet efficacy endpoints, impacting a key program in the company's pipeline. Concurrently, Gilead Sciences' decision not to exercise options for additional early-stage programs signals a reduced commitment to expanding their partnership, although existing options for other programs remain. These developments collectively cast a negative outlook on the company's near-term clinical progress and future collaboration potential.
At the time of this filing, RCUS was trading at $24.25 on NYSE in the Life Sciences sector, with a market capitalization of approximately $3B. The 52-week trading range was $7.06 to $26.40. This filing was assessed with negative market sentiment and an importance score of 9 out of 10.