Repatha (Amgen) is expected to face US biosimilar competition from 2029. Amgen 10-K: US antibody patent expires 27 August 2029; a methods-of-treatment patent runs to May 2032.
Repatha's US exclusivity date is based on patent-expiry estimate. It is estimated from patent expiry rather than a fixed entry date, so it may move as patents are challenged or extended. It is a biologic, so copies are biosimilars. Biosimilars are harder to make and usually erode sales more gradually than generics.
Among past biologics facing biosimilars: Humira's US sales fell to 65% of their 2022 level in its first full year of biosimilars (2023) and 16% two years later; Stelara's US sales fell to 57% of their 2024 level in its first full year of biosimilars (2025). See how past cliffs played out →
No US filing found We found no confirmed US biosimilar filing or late-stage program for Repatha as of September 2026. Amgen's US antibody patent runs to August 2029 and a methods patent to 2032.
Checked September 2026. Sources: Amgen 10-K 2025
Repatha is 8.2% of Amgen's 2025 revenue ($3.0B of $36.8B). With Prolia, Xgeva, Otezla and Enbrel, the drugs tracked here add up to 38% of Amgen's revenue losing US exclusivity by 2029.
Bars show each company's tracked drugs as a share of its total 2025 revenue. Repatha is highlighted.