Amgen Settles Denosumab Biosimilar Patent Dispute with Accord BioPharma
Key Insights
Amgen and Accord BioPharma (search) reached a settlement agreement on July 16, 2025, resolving patent litigation over Accord's denosumab biosimilar INTP23 (search), with Accord agreeing to delay U.S. market entry until October 1, 2025.
The settlement represents the fourth resolved denosumab biosimilar litigation for Amgen, which has filed eight total BPCIA cases to protect its Prolia® and Xgeva® franchises worth over $4.3 billion in annual U.S. sales.
Three denosumab biosimilars from Sandoz, Fresenius Kabi, and Celltrion have already launched in the U.S. market following their respective settlements with Amgen in 2025.
Amgen and Accord BioPharma (search) have resolved their patent litigation over denosumab biosimilars through a settlement agreement that delays Accord's market entry until October 1, 2025. The District Court for the District of New Jersey entered a Consent Judgment and Injunction on July 16, 2025, concluding the BPCIA litigation regarding Accord's denosumab biosimilar, INTP23 (search).
Settlement Terms and Patent Protection
Under the settlement agreement, Accord acknowledged that all 34 of Amgen's asserted patents are valid, enforceable, and infringed by INTP23 (search). The company agreed to an injunction preventing it from making, using, selling, or importing its denosumab biosimilar into the U.S. market until October 1, 2025, contingent on FDA approval. The settlement allows market entry prior to the latest expiring asserted patent, providing Accord with earlier access than full patent expiration would permit.
Accord's denosumab biosimilars, marketed as OSVYRTI® and JUBEREQ®, received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) in April 2025, though they remain unable to enter the U.S. market under the current settlement terms.
Expanding Biosimilar Competition
The settlement marks the fourth resolved denosumab biosimilar litigation for Amgen, following previous agreements with Sandoz in April 2024, Celltrion in January 2025, and Fresenius Kabi in March 2025. These settlements have enabled rapid market entry for competing biosimilars, with three products launching in the U.S. since June 2025.
Sandoz launched its interchangeable biosimilars Jubbonti® and Wyost® (denosumab-bbdz) in June 2025, followed by Fresenius Kabi's Conexxence™ and Bomyntra™ (denosumab-bnht) and Celltrion's Stoboclo® and Osenvelt® (denosumab-bmwo) in July 2025.
Ongoing Patent Litigation
Despite multiple settlements, Amgen continues to face patent challenges from other biosimilar developers. Four denosumab BPCIA litigations remain pending, including cases against Samsung Bioepis (search) for Ospomyv™/Xbryk™ (denosumab-dssb), Hikma Pharmaceuticals for RGB-14, Shanghai Henlius Biotech (search) for HLX14, and Biocon Biologics (search) for Bmab 1000.
Amgen filed three additional BPCIA complaints in June 2025 against Hikma Pharmaceuticals USA Inc., Shanghai Helius Biotech, Inc., and Biocon Biologics (search), Inc., bringing the total number of denosumab BPCIA litigations to eight cases.
Market Impact and Financial Stakes
The denosumab market represents significant revenue for Amgen, with the company reporting fiscal year 2024 U.S. sales of $2.885 billion for Prolia® and $1.507 billion for Xgeva®, totaling over $4.3 billion in combined annual revenue. Denosumab is a human IgG2 monoclonal antibody that inhibits osteoclast (search) activation, preventing bone breakdown and treating conditions associated with bone loss, including osteoporosis (search) and bone cancers (search).
The litigation consolidation in the District Court for the District of New Jersey, ordered on February 6, 2025, has streamlined the multiple patent disputes surrounding this high-value therapeutic area. As biosimilar competition intensifies, the settlements demonstrate Amgen's strategy of negotiating controlled market entry dates while maintaining patent protection for its blockbuster bone health franchise.