At AACR Annual Meeting 2026, researchers reported cohort 2 data from the single-arm INFINITY phase II trial testing tremelimumab plus durvalumab as an organ-preserving option in resectable MSI-H/dMMR, EBV-negative gastric or gastroesophageal junction cancer. In 18 patients, the study reported a 100% alive rate at two years, a 71% clinical complete response rate, and a 94.1% progression-free survival rate. Safety outcomes showed three grade 3 immune-related adverse events, with no grade 4 or 5 events and no treatment discontinuations. The investigators also reported gastrectomy-free survival of 70.6% at two years and noted that quality of life did not deteriorate significantly during follow-up. Exploratory ctDNA analyses indicated clearance in 11 of 13 evaluable baseline-positive patients, supporting the trial’s translational biomarker work alongside efficacy readouts.