Merck, Pfizer, Astellas Drug Combo Succeeds in 2nd Phase 3 Bladder Cancer Study

By Colin Kellaher

A cancer-drug combination from Merck, Pfizer and Astellas Pharma has hit its goal in a second late-stage study in patients with a hard-to-treat form of bladder cancer.

The companies on Wednesday said Merck's Keytruda coupled with Padcev from Pfizer and Astellas showed significantly improved survival for patients with muscle-invasive bladder cancer who are eligible for cisplatin-based chemotherapy.

The study met its primary endpoint, demonstrating clinically meaningful and statistically significant improvements in event-free survival, as well as in overall survival, a key secondary endpoint, the companies said.

Merck, Pfizer and Astellas, which in August reported similar results from a Phase 3 study of the combination in patients with muscle-invasive bladder cancer who are ineligible for cisplatin-based chemotherapy, said they plan to discuss the study results with global health authorities for potential regulatory filings.

Merck in 2019 inked a deal to evaluate the combination of its blockbuster cancer drug Keytruda with Padcev from Astellas and Seagen, which Pfizer acquired in a $43 billion deal that closed in late 2023.

The combination is already approved for the treatment of adults with locally advanced or metastatic urothelial cancer in the U.S., the European Union, Japan and several other countries around the world.

Write to Colin Kellaher at colin.kellaher@wsj.com

(END) Dow Jones Newswires

December 17, 2025 07:53 ET (12:53 GMT)