Arcus Biosciences and partner Gilead announced a Phase III failure for the anti‑TIGIT antibody domvanalimab in upper gastrointestinal cancers, prompting Arcus to stop related phase III work and refocus its R&D strategy. An independent data monitoring committee (IDMC) flagged futility in the trial, and Arcus said it will reallocate resources toward other pipeline assets and discovery platforms. Company statements indicate program wind‑down and a strategic shift; investors and collaborators will watch how asset reallocation and cost management plans unfold. For drug developers: the setback underscores clinical-risk concentration on immune-checkpoint biology and the need to validate mechanism-of-action across tumor types before broad late‑stage investment.