Arcus Biosciences Inc. (NASDAQ: RCUS) announced the discontinuation of its Phase 3 STAR-121 study after an independent data monitoring committee recommended halting the trial due to futility.

The study, conducted in collaboration with Gilead Sciences Inc., evaluated domvanalimab plus zimberelimab and chemotherapy versus pembrolizumab plus chemotherapy as first-line treatment for metastatic non-small cell lung cancer. The decision followed a pre-planned futility analysis, though no new safety issues were identified during regular committee reviews.

An exploratory endpoint showed zimberelimab plus chemotherapy performed consistently with pembrolizumab plus chemotherapy regarding overall survival. The company will also discontinue the related Phase 2 EDGE-Lung study.

Separately, Arcus announced changes to its collaboration with Gilead Sciences. Gilead's option rights under their 2020 agreement will end July 14, 2026, after Gilead decided against making an option continuation payment. This means Gilead will not have rights to additional programs in Arcus's early-stage pipeline, including CCR6, CD89 and CD40L programs.

Gilead retains existing time-limited options to several programs including AB801, AB598, AB102, and a TNF small molecule inhibitor. Arcus maintains full rights to casdatifan and its development program, except for rights previously licensed to Taiho in Japan and certain other Asian territories excluding China.

The information was disclosed in a regulatory filing with details based on company statements.