Arcus Biosciences and partners reported a Phase 3 failure for the anti‑TIGIT antibody domvanalimab when added to PD‑1 blockade and chemotherapy, prompting the company to pause multiple domvanalimab trials and refocus R&D priorities. The Phase 3 readout showed no efficacy benefit at a preplanned checkpoint, leading the sponsors to stop enrollment and reassess the clinical strategy. Gilead, Arcus’s collaborator, and Arcus have initiated internal reviews to understand mechanism and patient selection factors. The failure follows a string of setbacks for TIGIT as a target and is likely to influence investor appetite, ongoing TIGIT programs and portfolio prioritization across oncology developers. Biotech and pharma teams will watch subsequent translational analyses for biomarkers or combination hypotheses that could salvage TIGIT approaches, but the immediate impact is a contraction of resources and an industry re-evaluation of TIGIT’s clinical value.