MRK Pins Hopes on New PAH Drug Winrevair Amid Looming Keytruda LOE

Key Takeaways MRK is focused on Winrevair's growth as Keytruda, its top revenue driver, faces patent expiration in 2028. Winrevair showed significant efficacy in PAH phase III trials, leading to early study stoppages. The FDA granted priority review to MRK's sBLA to update Winrevair's label, with a decision due on Oct. 25.Merck’s (MRK) blockbuster PD-L1 inhibitor, Keytruda, approved for several types of cancer indications, is the company's biggest revenue driver. The drug alone accounts for around 50% of ...