Merck , known as MSD outside the U.S. and Canada, announced positive topline results from its Phase 3 KEYNOTE-905 (EV-303) trial in patients with muscle-invasive bladder cancer (MIBC) who are ineligible for cisplatin-based chemotherapy.
In the study, KEYTRUDA® (pembrolizumab) plus Padcev® (enfortumab vedotin-ejfv), administered before and after radical cystectomy, achieved statistically significant and clinically meaningful improvements in event-free survival (EFS), as well as overall survival (OS) and pathologic complete response (pCR) rates, compared to surgery alone.
Dr. Christof Vulsteke, principal investigator, noted that this is the first time a systemic therapy used pre- and post-surgery has extended survival beyond standard surgery for this patient group, addressing a major unmet need.
The trial, conducted with Pfizer (formerly Seagen) and Astellas, builds on the success of the combination in advanced urothelial cancer. Safety results were consistent with known profiles of both drugs, with no new safety signals.
Merck plans to share the findings with global regulators and present the data at an upcoming medical meeting. KEYTRUDA plus Padcev is already approved for locally advanced or metastatic urothelial cancer in multiple countries, and five additional Phase 3 studies are ongoing across all stages of bladder cancer, including three in MIBC.