KEYTRUDA significantly improved DFS as adjuvant therapy versus observation for patients with localized MIUC and locally advanced urothelial carcinoma First positive study for KEYTRUDA as adjuvant therapy for these patients Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced that the Phase 3 AMBASSADOR (A031501) trial (KEYNOTE-123) evaluating KEYTRUDA, Merck’s anti-PD-1 therapy, met one of its dual primary endpoints of disease-free survival (DFS) for the adjuvant treatment of patients with localized muscle-invasive urothelial carcinoma (MIUC) and locally advanced urothelial carcinoma versus observation. At a pre-specified interim analysis review conducted by an independent Data Monitoring Committee, KEYTRUDA demonstrated a statistically significant and clinically meaningful improvement in DFS versus observation in these patients after surgery. The trial will continue to evaluate its other dual primary endpoint of overall survival (OS). The safety