US pharmaceutical company Merck & Co Inc (NYSE:MRK), known as MSD outside the US and Canada, announced on Tuesday that the Phase 3 KEYNOTE-905 trial met its primary and key secondary endpoints in patients with muscle-invasive bladder cancer (MIBC) who are ineligible for cisplatin-based chemotherapy.

The combination of Keytruda (pembrolizumab) and Padcev (enfortumab vedotin-ejfv), administered before and after surgery, significantly improved event-free survival, overall survival, and pathologic complete response rates compared to surgery alone.

This represents the first positive Phase 3 study in this patient population and the first systemic therapy to improve survival when used before and after surgery. The trial was conducted in collaboration with Pfizer Inc (NYSE:PFE) and Astellas Pharma Inc (TSE:4503).

The safety profile of the combination was consistent with known data for each therapy, with no new safety signals observed. Merck and its partners plan to present the results at an upcoming medical meeting and engage with regulatory authorities worldwide.

Keytruda plus Padcev is already approved for locally advanced or metastatic urothelial cancer in multiple regions, including the United States, European Union, and Japan. Merck is also advancing five additional Phase 3 studies across all stages of bladder cancer, including three in MIBC.