On 4 February 2025, Cytiva subsidiary media supplier HyClone Laboratories filed a motion in the US District Court for the District of Utah, seeking to quash a subpoena issued to it by Amgen in the context of denosumab BPCIA patent infringement litigation Amgen commenced against Fresenius Kabi in October 2024. Cytiva’s HyClone is not a party to the BPCIA litigation, which relates to Fresenius’ FKS518, biosimilar to Amgen’s Xgeva® and Prolia® (denosumab).
Amgen’s subpoena requests HyClone Laboratories to provide information that includes the full formulation of its off-the-shelf cell culture supplement, HyClone™ Cell Boost™ 7a (CB7A). Amgen alleges that Fresenius’ process for producing FKS518 uses CB7A and that the resulting cell culture medium infringes claims of Amgen’s patents (eg. US 10,167,492).
HyClone argues that the subpoena should be quashed for a number of reasons, including that the information sought is irrelevant and the request is overly burdensome because it would require the disclosure of trade secrets.
The litigation against Fresenius is one of five US proceedings commenced by Amgen in relation to denosumab biosimilars. A dispute with Sandoz, commenced in May 2023, was resolved in April 2024, enabling Sandoz to launch its denosumab biosimilars, Jubbonti® and Wyost®, from 31 May, 2025 (or earlier in certain undisclosed circumstances). Amgen also settled its litigation against Celltrion in January 2025, permitting US launch of Celltrion’s denosumab biosimilar, CT-P41, from 1 June 2025. The remaining court proceedings, against Fresenius, Samsung Bioepis (SB16/commenced August 2024) and Accord/Intas (INTP23/commenced November 2024), remain pending.