Arcus Biosciences and partner Gilead announced termination of phase III development for their anti‑TIGIT antibody domvanalimab in first-line gastric and esophageal cancer after an independent data monitoring committee concluded the regimen will not improve overall survival versus the comparator. The finding halted the Star-221 study and prompted Arcus to reallocate resources toward other pipeline assets. Arcus said it will shift focus to casdatifan, a hypoxia-inducible factor 2α inhibitor showing single-agent activity in clear-cell renal cell carcinoma. The companies characterized the decision as data-driven; investors reacted to the readout with immediate share pressure. The development adds to a string of recent setbacks for TIGIT-targeted therapies and is likely to reshape partner strategies around that immune checkpoint target.