On 7 March 2025, the US District Court for the District of New Jersey ordered the dismissal of all claims and counterclaims in Amgen’s BPCIA patent infringement proceeding against Fresenius Kabi in relation to its denosumab biosimilar. The order followed a stipulation by the parties as to their settlement of the litigation, which was filed with the Court on 4 March 2025.
Neither Amgen nor Fresenius Kabi have issued press releases about the settlement as at the date of this report and the terms on which the proceeding was settled, including the US launch date for Fresenius’ denosumab biosimilars, are currently unknown.
Amgen originally commenced proceedings against Fresenius Kabi on 4 October 2024 in the US District Court for the Northern District of Illinois (Eastern Division) alleging infringement of 33 US patents relating to denosumab. The litigation followed Fresenius’ submission of an abbreviated Biologics 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 FDA on 27 May 2024.
In the context of the litigation, Amgen issued a subpoena to Cytiva subsidiary media supplier HyClone Laboratories requesting information including the full formulation of HyClone’s off-the-shelf cell culture supplement, HyClone™ Cell Boost™ 7a (CB7A). Amgen has now withdrawn that subpoena given the settlement of the underlying litigation with Fresenius.
The BPCIA proceeding against Fresenius was one of five that Amgen had commenced in the US in relation to denosumab biosimilars, which were centralised in the US District Court for the District of New Jersey in February 2025. A dispute with Sandoz, commenced in May 2023, was resolved in April 2024, enabling Sandoz to launch Jubbonti® and Wyost® from 31 May 2025 (or earlier in certain undisclosed circumstances). Amgen also settled its US litigation against Celltrion in January 2025, permitting launch of Celltrion’s yet to be US-approved denosumab biosimilar from 1 June 2025. The remaining court proceedings, against Samsung Bioepis (Ospomyv™/Xbryk™/SB16 approved February 2025, litigation commenced August 2024) and Accord/Intas (INTP23, litigation commenced November 2024), remain pending.