RATIONALE-305 (NCT03777657) is a randomized, double-blind, placebo-controlled, global Phase 3 trial comparing the efficacy and safety of tislelizumab combined with platinum and fluoropyrimidine chemotherapy to placebo combined with platinum and fluoropyrimidine chemotherapy as a first-line treatment for patients with advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma (GC/GEJC).

This factsheet describes the final analysis of the Phase 3 RATIONALE-305 trial, where tislelizumab plus chemotherapy significantly improved overall survival (OS) in the intention-to-treat (ITT) population compared to chemotherapy alone. The safety profile of tislelizumab plus chemotherapy was manageable in patients with unresectable, locally advanced or metastatic GC/GEJC. No new safety signals were identified.