On 4 October 2024, Amgen filed a BPCIA complaint against Fresenius Kabi in the US District Court for the Northern District of Illinois (Eastern Division) asserting infringement of 33 US patents relating to denosumab and methods of its manufacture.
The litigation follows Fresenius Kabi’s submission of an abbreviated Biologic Licence Application (aBLA) to the US FDA seeking approval to manufacture and sell its FKS518, biosimilar to Amgen’s Prolia® and Xgeva® (denosumab). Fresenius’ aBLA for denosumab was accepted for review by the US FDA on 27 May 2024.
Amgen’s complaint against Fresenius Kabi is the fourth BPCIA litigation it has filed in relation to denosumab. In August 2024, Amgen filed a complaint against Samsung Bioepis (24-cv-08417-CPO-EAP) and, in May 2024, it filed a complaint against Celltrion (24-cv-06497-CPO-EAP), alleging infringement of US patents relating to denosumab. Those complaints remain pending. In May 2023, Amgen sued Sandoz in the US over its denosumab biosimilars (Jubbonti® and Wyost®) asserting infringement of 21 denosumab patents. That dispute was resolved in April 2024, enabling Sandoz to launch Jubbonti® and Wyost® from 31 May 2025 (or earlier in certain undisclosed circumstances).