Key Takeaways Keytruda made up over half of MRK's pharma sales in H1 2025, reaching $15.16B, up 7% year over year.Merck eyes H2 growth from Keytruda, Animal Health, Winrevair, and Capvaxive, offset by weaker Gardasil sales.MRK is developing combos, an mRNA vaccine with Moderna, and a subcutaneous Keytruda to boost growth.Merck’s (MRK) strong foothold in the oncology space is propelled by its biggest revenue driver, Keytruda. The blockbuster PD-L1 inhibitor alone accounted for more than 50% of the company’s ...