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

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 the company’s pharmaceutical sales and is a key driver of Merck’s top-line growth.However, Merck remains heavily dependent on Keytruda for growth. Moreover, the...