Arcus Biosciences and Gilead reported that the Phase 3 program for the anti‑TIGIT antibody domvanalimab missed its primary endpoints, prompting an immediate pause and strategic refocus. The clinical failure was announced after a randomized late‑stage study testing domvanalimab in upper gastrointestinal cancers failed to show added benefit when combined with anti‑PD‑1 therapy and chemotherapy. Arcus said it will stop several ongoing trials of the asset and rework its R&D priorities with Gilead while assessing next steps for the program. The companies—Arcus as developer and Gilead as partner—cited the negative efficacy readouts as the basis for discontinuing certain domvanalimab studies. TIGIT has been a high‑profile checkpoint target for multiple developers; this setback joins other recent late‑stage TIGIT failures and will likely reshape near‑term investment and trial design choices across immuno‑oncology. Industry watchers will watch how Arcus reallocates resources and whether Gilead adjusts its checkpoint pipeline strategy in response.