On January 24, 2025, Amgen announced it had reached a settlement with Celltrion in Case No. 1:24-cv-06497 (D.N.J.) related to Celltrion’s proposed biosimilar of Prolia^® / Xgeva^® (denosumab), CT-P41.  The lawsuit involved allegations of infringement of 29 of Amgen’s patents (previously reported Amgen Files BPCIA Lawsuit Against Celltrion’s Proposed Prolia^® / Xgeva^® (Denosumab) Biosimilar CT-P41).  According to the press release, the Court issued an order holding the claims of Amgen’s U.S. patents asserted against Celltrion valid, enforceable, and infringed by CT-P41.  Additionally, the parties reached a confidential settlement that allows Celltrion to launch its biosimilar products in the U.S. as early as June 1, 2025, if approved by the FDA.  Celltrion submitted its aBLA for CT-P41 to the FDA, with a request for interchangeability, in November 2023.

This is the second settlement related to Prolia^® / Xgeva^® biosimilars.  In April 2024, Amgen and Sandoz settled their dispute (Case No. 1:23-cv-02406 (D.N.J.)) related to Sandoz’s interchangeable biosimilars Jubbonti^® / Wyost^® (denosumab-bddz), agreeing to a U.S. market entry date of May 31, 2025, or earlier under certain undisclosed circumstances (previously reported Amgen and Sandoz Settle Prolia^® / Xgeva^® Biosimilar Litigation).

Numerous lawsuits for Prolia^® / Xgeva^® biosimilars remain pending, including for Samsung Bioepis’s SB16 (Case No. 1:24-cv-08417 (D.N.J.)), Fresenius Kabi’s FKS518 (Case No. 1:24-cv-09555 (N.D. Ill.)), and Accord / Intas’s INTP23 (Case No. 5:24-cv-00642 (E.D.N.C.)).  A pending request for transfer to a Multidistrict Litigation (MDL #3138 in D.N.J.) was filed in November 2024, with a panel hearing set for January 30, 2025.

Amgen reported 2023 U.S. sales for Prolia^® of $2.73 billion, and $1.52 billion for Xgeva^®.

_____________________________________________________

The author would like to thank April Breyer Menon for her contributions to this article.