Keytruda (Merck) is expected to face US biosimilar competition from 2028. Primary US compound patent expires December 2028. Includes subcutaneous Keytruda Qlex. EU exclusivity to 2031.
Keytruda's US exclusivity date is based on company guidance. The date comes from the company's own filings or guidance. Secondary patents, new formulations or litigation can still move it. It is a biologic, so copies are biosimilars. Biosimilars are harder to make and usually erode sales more gradually than generics.
Keytruda is 49% of Merck's 2025 revenue ($31.7B of $65.0B). With Gardasil, the drugs tracked here add up to 57% of Merck's revenue losing US exclusivity by 2028.
Bars show each company's tracked drugs as a share of its total 2025 revenue. Keytruda is highlighted.