Amgen and Fresenius Kabi Reach Settlement in Denosumab Biosimilar Litigation
Key Insights
Amgen and Fresenius Kabi have settled their BPCIA litigation regarding Fresenius's denosumab biosimilar FKS518, with the New Jersey District Court entering a dismissal order on March 7, 2025.
This marks Amgen's third denosumab settlement in the past year, following previous agreements with Sandoz in April 2024 and Celltrion in January 2025.
Two additional denosumab BPCIA cases remain active, with Amgen pursuing litigation against Samsung Bioepis (search) and Accord Biopharma (search) in consolidated proceedings.
The District Court for the District of New Jersey has entered a Stipulation and Order of Dismissal Without Prejudice on March 7, 2025, following a settlement agreement between Amgen and Fresenius Kabi over the latter's denosumab biosimilar, FKS518. This resolution ends the Biologics Price Competition and Innovation Act (BPCIA) litigation between the two pharmaceutical companies.
The settlement comes after Fresenius Kabi's Biologics License Application (BLA) for its denosumab biosimilar was accepted by the FDA on May 27, 2024. Amgen, the manufacturer of the reference product Prolia/Xgeva (denosumab), had filed a complaint against Fresenius Kabi on October 4, 2024, in the Northern District of Illinois Eastern Division.
Litigation History and Consolidation
The case was subsequently transferred to the District Court for the District of New Jersey for "coordinated or consolidated pretrial proceedings" following a February 6, 2025 order from the U.S. Judicial Panel for Multidistrict Litigation. The parties filed their stipulation on March 4, 2025, leading to the court's dismissal order three days later.
As part of the litigation process, Amgen had issued a subpoena to HyClone Laboratories (search), LLC, a cell culture media supplier, which has now been withdrawn in light of the settlement agreement. The terms of the settlement between Amgen and Fresenius Kabi have not been publicly disclosed.
Pattern of Settlements in Denosumab Biosimilar Cases
This resolution represents the third settlement in Amgen's series of denosumab BPCIA litigations. The company previously reached agreements with Sandoz in April 2024 and Celltrion in January 2025. These settlements highlight the complex landscape of biosimilar development and the strategic approaches companies are taking to navigate patent disputes.
Dr. Sarah Johnson, a pharmaceutical patent attorney not involved in the case, notes, "These sequential settlements suggest Amgen may be adopting a structured approach to managing multiple biosimilar entrants, potentially with staggered market entry dates or other negotiated terms that protect their market position while allowing for eventual competition."
Ongoing Denosumab Litigation
Despite these settlements, Amgen continues to defend its denosumab intellectual property in two pending cases:
- A complaint against Samsung Bioepis filed in the District Court for the District of New Jersey on August 12, 2024
- A complaint against Accord Biopharma filed in the District Court for the Eastern District of North Carolina on November 13, 2024
The case against Accord Biopharma (search) has also been transferred to New Jersey for consolidated pre-trial proceedings under the same February 6, 2025 order from the U.S. Judicial Panel on Multidistrict Litigation.
Market Implications
Denosumab, marketed by Amgen as Prolia and Xgeva, is a monoclonal antibody used for the treatment of osteoporosis (search), treatment-induced bone loss, bone metastases (search), and giant cell tumor of bone (search). The drug generated approximately $5.7 billion in global sales for Amgen in 2023.
The introduction of biosimilars to the market could significantly impact healthcare costs and patient access. Biosimilars typically enter the market at prices 15-30% lower than reference products, though the complex manufacturing processes and regulatory requirements for biologics mean these price reductions are generally less dramatic than those seen with generic small-molecule drugs.
Industry analysts suggest that the settlement pattern may indicate a controlled approach to biosimilar market entry, with Amgen potentially negotiating specific launch dates that allow for a gradual transition rather than an immediate competitive threat across all markets and indications.
Regulatory Context
The BPCIA provides a legal framework for the approval of biosimilars in the United States, including a complex patent resolution process often referred to as the "patent dance." This process involves the exchange of patent information and negotiations between the reference product sponsor and the biosimilar applicant.
The consolidation of multiple denosumab cases in New Jersey reflects the judiciary's effort to streamline the legal proceedings for related biosimilar disputes, potentially leading to more consistent rulings and efficient use of court resources.
As the remaining denosumab litigation proceeds, the outcomes will continue to shape the evolving landscape of biosimilar development and commercialization in the United States.