Amgen Inc. v. Amneal LLC et al.

Amgen Inc. initiated this Biologics Price Competition and Innovation Act (BPCIA) lawsuit against Amneal LLC and mAbxience S.A.U. in the District of New Jersey. Amgen, a multinational biopharmaceutical company headquartered in Thousand Oaks, California, is the innovator behind denosumab, marketed as Prolia® and Xgeva®, which are critical treatments for osteoporosis and cancer-related bone diseases. Defendant Amneal LLC, a global biopharmaceutical company based in Bridgewater, New Jersey, specializes in developing and commercializing generic, brand, and biosimilar products in the U.S. Co-defendant mAbxience S.A.U., a global biotech company with headquarters in Spain, focuses on the development and manufacture of biologics, particularly biosimilars. Under their partnership, mAbxience is responsible for the development and manufacturing of the accused denosumab biosimilars, while Amneal handles regulatory approval and exclusive U.S. commercialization rights. The accused products are Amneal and mAbxience's proposed denosumab biosimilars, identified as "MB09" in the lawsuit, which were later approved by the FDA on December 22, 2025, as BONCRESA (referencing Prolia) and OZILTUS (referencing Xgeva).

The litigation, filed on November 6, 2025, asserts infringement of 31 U.S. patents, including US Patent 7364736. US Patent 7364736 describes antibodies that interact with osteoprotegerin ligand (OPGL), also known as RANKL, which is the biological target of denosumab. The patent also covers methods of treating osteopenic disorders by administering these antibodies. The case is ongoing in the U.S. District Court for the District of New Jersey, under District Judge Claire C. Cecchi and Magistrate Judge Edward A. Pagano. The District of New Jersey is a prominent venue for BPCIA litigation, favored by pharmaceutical companies due to its substantial experience with complex patent cases and established local rules, and it is a key location for pharmaceutical headquarters and subsidiaries.

This case is part of a broader, highly active period of litigation surrounding denosumab biosimilars, a market that has seen numerous FDA approvals and product launches. Amgen's reference products, Prolia and Xgeva, generate billions in annual U.S. sales, making the biosimilar market particularly lucrative and competitive. Notably, there has been an absence of Patent Trial and Appeal Board (PTAB) proceedings (e.g., IPRs) challenging the Prolia/Xgeva patents, which is uncommon for biosimilar disputes and may be attributed to a significant number of asserted patents being manufacturing-related, a category less frequently targeted by IPRs. This pattern of extensive litigation against multiple biosimilar applicants underscores Amgen's vigorous defense of its intellectual property in the face of significant market competition.

The BPCIA litigation, Amgen Inc. v. Amneal LLC et al., case number 1:25-cv-17278-CPO-EAP, is currently ongoing in the District Court of New Jersey. This case involves Amgen's denosumab products, Prolia® and Xgeva®.

Here are the key legal developments to date:

• Filing of Complaint (2025-11-06): Amgen Inc. filed a BPCIA complaint against Amneal LLC and mAbxience S.A.U. on November 6, 2025. The lawsuit asserts infringement of 31 U.S. patents, including US Patent 7,364,736, related to denosumab, its compositions, and manufacturing methods. The complaint arose after the FDA accepted for review Amneal/mAbxience's Biologics License Application (BLA) for their proposed denosumab biosimilar, designated MB09. Amgen also named Genhelix and Universal Farma as defendants.
• FDA Approval of Biosimilar (2025-12-22): The FDA approved mAbxience and Amneal's denosumab biosimilars, BONCRESA (denosumab-mobz) and OZILTUS (denosumab-mobz), referencing Amgen's PROLIA® and XGEVA®, respectively, on December 22, 2025. mAbxience is responsible for development and manufacturing, while Amneal holds exclusive U.S. commercialization rights.
• Answer and Affirmative Defenses (2026-01-23): Amneal Pharmaceuticals, Inc. and Amneal Pharmaceuticals LLC filed their Answer and Affirmative Defenses to Amgen's Complaint on January 23, 2026. They denied allegations of infringement. The case is part of a Multi-District Litigation (MDL 3138).
• Current Status: The case remains pending in the U.S. District Court for the District of New Jersey.

Parallel PTAB IPR/PGR Proceedings:

While there is information indicating that Amgen's U.S. Patent No. 7,364,736 was previously challenged and found valid, enforceable, and infringed by Sandoz's denosumab biosimilars in a separate litigation, which settled in April 2024, no specific parallel PTAB IPR/PGR proceedings initiated by Amneal or mAbxience against US Patent 7,364,736 in relation to this specific litigation (1:25-cv-17278) have been identified in the provided search results. Given the early stage of the current litigation (filed in late 2025), IPR filings might occur later or might not be publicly reported in the initial news of the lawsuit.

Outcome:

The litigation is still ongoing, and there has been no final disposition, verdict, or settlement reported for this specific case as of the current date (2026-05-30).

Amgen Inc. v. Amneal LLC et al. (1:25-cv-17278-CPO-EAP) - Plaintiff's Counsel

While specific appearances for this case are best confirmed via the PACER docket, a review of Amgen's typical patent litigation counsel and general information about prominent intellectual property litigators suggests the following attorneys and firms are likely representing Amgen Inc. in this BPCIA action:

Kirkland & Ellis LLP
Kirkland & Ellis is a prominent firm in patent litigation, frequently representing pharmaceutical and biotechnology companies in high-stakes disputes, including BPCIA and Hatch-Waxman cases.

• Benjamin A. Lasky - Partner (likely lead counsel)
  • Firm & Office: Kirkland & Ellis LLP, New York, NY
  • Experience: Mr. Lasky is a partner in Kirkland's New York office with extensive experience in patent litigation across diverse technological fields, including small-molecule pharmaceuticals and biologics (Hatch-Waxman and BPCIA litigation). He has also represented clients before the Patent Trial and Appeal Board (PTAB) in inter partes review (IPR) proceedings and has significant trial experience.
• Mark C. McLennan - Partner (likely lead counsel)
  • Firm & Office: Kirkland & Ellis LLP, New York, NY
  • Experience: Mr. McLennan is an intellectual property partner with a technical background in pharmacology, representing clients in the pharmaceutical, biotechnology, and medical device industries. His experience includes pre-suit strategy, discovery, bench and jury trials, and IPRs. He has been recognized as a "Key Lawyer" in The Legal 500: Life Sciences.
• Austin Pennington - Associate (likely litigation team member)
  • Firm & Office: Kirkland & Ellis LLP, New York, NY
  • Experience: Mr. Pennington is an intellectual property associate focusing on patent infringement litigation and contract litigation involving high-tech disputes.

Hogan Lovells
Hogan Lovells possesses a strong intellectual property practice, particularly in life sciences and pharmaceutical patent matters, with attorneys experienced in federal district courts nationwide, including New Jersey.

• Jennifer Swan - Partner (likely lead counsel)
  • Firm & Office: Hogan Lovells, Silicon Valley (likely works with East Coast teams)
  • Experience: Ms. Swan is an experienced patent attorney whose practice centers on the enforcement and defense of patent rights, with extensive experience representing innovator companies in complex patent litigation, including Hatch-Waxman proceedings, in various federal district courts, including New Jersey.

FBT Gibbons (formerly Gibbons P.C.)
As the case is filed in the District of New Jersey, local counsel from a firm with a strong New Jersey presence is typically required. Gibbons P.C., which combined with Frost Brown Todd in February 2026 to form FBT Gibbons, has a significant intellectual property litigation practice and multiple offices in New Jersey. Specific attorneys from FBT Gibbons would likely serve as local counsel.

Amgen Inc. (In-house Counsel)
Amgen's in-house legal team plays a crucial role in developing and driving case strategies for its patent disputes.

• Jonathan Graham - Executive Vice President, General Counsel, and Secretary (in-house counsel)
  • Firm & Office: Amgen Inc., Thousand Oaks, CA (corporate headquarters)
  • Experience: Mr. Graham leads Amgen's global Law function and has a distinguished career, including prior roles as General Counsel at Danaher Corporation and Vice President, Litigation and Legal Policy at General Electric Company. He was also a partner at Williams & Connolly LLP, trained as a litigator. Other senior counsel within Amgen's Intellectual Property Litigation group would also be actively involved.

Note: Without direct access to the docket for 1:25-cv-17278-CPO-EAP to confirm specific appearances, the roles and definitive inclusion of each attorney listed above are inferred based on their known practice areas, firm's representation of Amgen in similar matters, and the requirements for patent litigation in federal court. Filings are not sealed, but public web search does not provide immediate docket details for specific attorney appearances in this newly filed case.

Based on available docket information, the defendants Amneal LLC and mAbxience S.A.U. are represented by the following counsel:

• Name: Stephanie L. Jonaitis
• Role: Counsel for Defendants Amneal Pharmaceuticals, Inc., Amneal Pharmaceuticals LLC, GH Genhelix S.A., Universal Farma S.L., and mAbxience Research S.L. (Likely lead or significant counsel given her filing activity).
• Firm: Troutman Pepper Hamilton Sanders LLP
• Office Location: Princeton, NJ
• Experience: Stephanie Jonaitis is an attorney at Troutman Pepper, a firm known for its intellectual property and litigation practices. Her appearance in this BPCIA case suggests experience in pharmaceutical patent litigation, particularly involving generic and biosimilar drug approvals. She has a listed email address of Stephanie.Jonaitis@troutman.com.

No other specific attorneys or in-house counsel have explicitly appeared on the public docket for the defendants as of the last retrieval date (April 7, 2026) mentioned in the Justia docket, or from the provided search results. While Amneal Pharmaceuticals has in-house legal leadership like Jason B. Daly (Executive Vice President, Chief Legal Officer, and Corporate Secretary), they are not listed as counsel of record in the publicly available docket information for this specific case.