FuzeBio written research, as of 2026-09-17
Merck makes prescription medicines, vaccines, and animal-health products, with its business centered on human health and cancer care. Its most important medicine is Keytruda, which helps the immune system attack cancer by blocking PD-1, and Keytruda generated $8.4 billion of sales in the second quarter of 2026. Keytruda is already marketed worldwide and remains Merck’s commercial lead, while the company is testing new combinations, formulations, and uses; Merck also markets newer growth products such as Winrevair, which generated $588 million in the second quarter of 2026. (sec.gov) (sec.gov)