Merck announced results from the Phase 3 AMBASSADOR (A031501)/KEYNOTE-123 trial evaluating KEYTRUDA for the adjuvant treatment of high-risk patients with localized muscle-invasive urothelial carcinoma (MIUC) and locally advanced resectable urothelial carcinoma. 
 
At the trial’s first pre-specified interim analysis, after a median follow-up of 22.3 months, KEYTRUDA demonstrated a statistically significant and clinically meaningful improvement in one of the study’s dual primary endpoints of disease-free survival (DFS), reducing the risk of disease recurrence or death by 31% versus observation in these patients after surgery. Median DFS was 29.0 months for KEYTRUDA and 14.0 months for observation, an improvement of 15 months. 
 
The trial’s other dual primary endpoint of overall survival (OS) did not reach statistical significance at the time of this interim analysis. After a median follow-up of 36.9 months, median OS was 50.9 months for KEYTRUDA versus 55.8 months for observation.
 
“These Phase 3 data mark the first time KEYTRUDA has shown a clinically meaningful improvement in DFS as adjuvant therapy in urothelial carcinoma,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “Results from this pivotal study support KEYTRUDA as a potential new adjuvant option for these patients and demonstrate the expanding role of KEYTRUDA into earlier stages of resectable muscle-invasive bladder cancer.”