Amgen Inc. v. Celltrion, Inc.

This BPCIA (Biologics Price Competition and Innovation Act) action involves Amgen Inc., a leading American multinational biopharmaceutical company focused on innovative human therapeutics, as the plaintiff, and Celltrion, Inc., a prominent South Korean biopharmaceutical company specializing in biosimilar development, as the defendant. The dispute centers on Celltrion's proposed denosumab biosimilar product, CT-P41, which references Amgen's blockbuster drugs Prolia® and Xgeva®. Prolia is used to treat osteoporosis, while Xgeva addresses skeletal-related events in patients with bone metastases from solid tumors; both utilize the active ingredient denosumab, a RANK ligand inhibitor. Amgen initially asserted 29 U.S. patents against Celltrion, including US7364736. Patent US7364736 broadly covers antibodies that interact with osteoprotegerin ligand (OPGL, also known as RANK Ligand), and methods for treating osteopenic disorders using these antibodies.

The litigation, filed in the District of New Jersey under case number 1:24-cv-06497-CPO-EAP, was presided over by Chief Judge Christine P. O'Hearn and Magistrate Judge Elizabeth A. Pascal. The District of New Jersey is a frequent venue for BPCIA cases, and Judge O'Hearn gained significant familiarity with denosumab and its manufacturing processes through previous related litigations. This case was notable as part of a larger multidistrict litigation (MDL No. 3138) concerning Amgen's denosumab patents, highlighting the intense competition in the high-value biosimilar market for Amgen's Prolia and Xgeva, which reported U.S. sales of $2.73 billion and $1.52 billion respectively in 2023.

Although initially facing a trial date of April 7, 2025, the parties reached a confidential settlement, leading to a Consent Judgment and Injunction entered by the District Court on January 23, 2025. Under the settlement terms, Celltrion acknowledged the validity and infringement of Amgen's asserted patents related to denosumab, and was permitted to launch its biosimilar products (Stoboclo® and Osenvelt®) in the U.S. as early as June 1, 2025, following FDA approval. Celltrion subsequently received FDA approval for its denosumab biosimilars in March 2025 and launched them in July 2025, making this a pivotal case in the market entry of denosumab biosimilars.

Amgen Inc. v. Celltrion, Inc. (1:24-cv-06497-CPO-EAP) saw a rapid resolution through settlement and consent judgment, preempting extensive pre-trial proceedings and a trial.

Here's a chronological overview of the key legal developments:

• Filing of Complaint (May 2024): Amgen Inc. filed a BPCIA action against Celltrion, Inc. in the District of New Jersey, asserting infringement of 29 patents, including US7364736, related to its denosumab products (Prolia and Xgeva). This case was assigned to Judge O'Hearn and Magistrate Judge Pascal.

• Related Discovery Matter (July - August 2024): A separate discovery dispute arose in July 2024 when Amgen sought discovery from Fujifilm Irvine Scientific, a third-party supplier to Celltrion, in the Central District of California. Amgen's motion to transfer this action to the District of New Jersey was granted on August 28, 2024, and the matter was subsequently assigned to Judge O'Hearn.

• Rule 16 Conference and Scheduling Order (November 2024): A Rule 16 Conference was held on November 6, 2024. A case management schedule was subsequently ordered on November 25, 2024 (filed December 6, 2024). This order set forth specific deadlines for disclosures, including plaintiffs' asserted claims and infringement contentions by December 6, 2024, and defendants' non-infringement and invalidity contentions by December 20, 2024. It also mandated that Amgen narrow its infringement claims to five patents by January 15, 2025, and Celltrion narrow its invalidity theories. Fact discovery was to be completed by February 21, 2025, and fact depositions by January 31, 2025. The order also indicated that no case-dispositive motions, such as summary judgment, would be permitted.

• Section 1782 Discovery Application (Ongoing through June 2025): Amgen filed an application under 28 U.S.C. § 1782 in the District of New Jersey to subpoena Celltrion USA for documents and testimony related to Celltrion Korea's denosumab products, to support parallel patent infringement suits in South Korea. The Magistrate Judge granted Amgen's application, and the District Court affirmed this order. Celltrion USA appealed this decision to the Third Circuit. On June 5, 2025, the Third Circuit dismissed the appeal for lack of jurisdiction, finding that the order granting discovery under § 1782 was not a final order because the scope of permissible discovery had not been conclusively defined.

• Settlement and Consent Judgment (January 23, 2025): Amgen and Celltrion reached a confidential settlement, executing a Binding Settlement Term Sheet on January 23, 2025. On the same date, a Consent Judgment and Injunction was entered by the court. As part of this settlement, Celltrion agreed that its biosimilar products infringe the asserted U.S. patents, including US7364736, and that these patents are valid and enforceable. The settlement allows Celltrion to launch its denosumab biosimilar products in the U.S. as early as June 1, 2025, if approved by the FDA.

• Dismissal of Remaining Claims (January 23, 2025): Pursuant to the settlement, the parties' remaining claims and counterclaims in the litigation were dismissed with prejudice.

• Centralization Efforts (February 2025): Although the Amgen v. Celltrion case was settled, it was part of broader discussions regarding the centralization of denosumab patent litigation into an MDL (MDL No. 3138) in the District of New Jersey. The Judicial Panel on Multidistrict Litigation noted the Celltrion settlement in its February 6, 2025, transfer order for other pending denosumab cases, indicating that the Celltrion action had reached a consent judgment and injunction.

Outcome:
The litigation concluded with a confidential settlement and a Consent Judgment and Injunction entered on January 23, 2025. Celltrion acknowledged the validity, enforceability, and infringement of Amgen's asserted patents, including US7364736. The settlement permits Celltrion to launch its denosumab biosimilar products in the U.S. starting June 1, 2025, subject to FDA approval. The case was resolved before any claim construction (Markman) hearing or trial.

Parallel PTAB IPR/PGR Proceedings:
No specific parallel PTAB IPR/PGR proceedings directly impacting the outcome of this particular Amgen v. Celltrion litigation were found in the provided search results. The rapid settlement, which included Celltrion's agreement on patent validity and infringement, likely obviated the need for or the impact of any such proceedings on this case's disposition.

Here is the counsel of record representing Amgen Inc. in Amgen Inc. v. Celltrion, Inc., Case No. 1:24-cv-06497-CPO-EAP:

External Counsel:

• Gourdin W. Sirles

  • Role: Likely lead counsel or significant external counsel (appeared Pro Hac Vice for Plaintiffs).
  • Firm: Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
  • Office Location: Boston, MA (Mintz has offices in Boston, New York, Washington D.C., and others).
  • Experience: Concentrates on intellectual property litigation with a particular emphasis on biopharmaceutical patent disputes, including cases under the Biologics Price Competition and Innovation Act (BPCIA) and Hatch-Waxman Act. He represents clients with approved FDA biological products as well as prospective generic or biosimilar entrants.

• Other Potential External Counsel: While specific appearances beyond Gourdin W. Sirles for Amgen in this exact case were not explicitly detailed in the search results available, large BPCIA litigations typically involve teams from multiple firms, often including local counsel. Firms frequently involved in Amgen's broader patent litigation, particularly in the biosimilar space, include DLA Piper, which has a significant patent litigation practice with experience in pharmaceuticals and biotech, and Susman Godfrey L.L.P., known for high-stakes patent disputes. However, direct evidence of their appearance for Amgen in this specific case is not present in the provided search snippets. Arnold & Porter Kaye Scholer has represented parties against Amgen in other high-profile antibody patent disputes.

In-House Counsel:

Amgen maintains a robust in-house intellectual property litigation team for its biosimilar and innovator molecules. These in-house attorneys play a direct role in developing and driving case strategies in partnership with outside counsel. Specific names of in-house counsel directly appearing in this case were not identified in the public search results, but their involvement is integral to Amgen's patent litigation strategy. They are responsible for various aspects, including identifying relevant patents, prior art searches, legal arguments, and supporting trial preparation.

It is important to note that the status of the case is "Pending" according to the prompt, although some search results (e.g.,) indicate that the Celltrion action in the District of New Jersey reached a settlement in October 2025 as part of Amgen's broader denosumab BPCIA litigations. However, adhering to the provided case metadata, the case is treated as pending.

The counsel of record representing Celltrion, Inc. in Amgen Inc. v. Celltrion, Inc., Case No. 1:24-cv-06497-CPO-EAP, includes:

• Koren L. Bell
  • Role: Lead Counsel (in patent litigation, typically lead counsel handles strategy and arguments).
  • Firm: Willkie Farr & Gallagher LLP, with offices in Los Angeles, CA (2029 Century Park East, Los Angeles, CA 90067) and New York, NY (787 Seventh Avenue, New York, NY 10019-6099).
  • Experience: Koren Bell is a partner in Willkie's Litigation Department, focusing on high-stakes trials, white-collar defense, and investigations. She has a strong record in complex civil litigation, including serving as trial counsel for Netflix in a high-profile patent infringement case where she largely defeated claims seeking approximately $300 million in damages. She is recognized as a nationally prominent litigator and a Fellow of the American College of Trial Lawyers.

Regarding other potential counsel for Celltrion, publicly available information is less definitive for this specific patent infringement case. While "James Richter" has been mentioned in connection with MDL filings on behalf of Celltrion, pinpointing a specific James Richter with his firm, office location, and explicit role in this particular patent litigation has proven challenging through public web searches. There are multiple attorneys named James Richter, including a "James S. Richter" at Winston & Strawn LLP in Newark, NJ, whose practice areas include intellectual property, making him a potential candidate for local counsel. However, without direct PACER access to the comprehensive docket for case 1:24-cv-06497-CPO-EAP, a definitive confirmation of his specific role and firm representation for Celltrion in this case cannot be made at this time. Filings for pro hac vice admissions or initial appearances on the docket sheet would typically confirm such details.

It is important to note that this case, initially filed in May 2024, was settled on January 24, 2025. The settlement included a consent judgment and injunction preventing Celltrion from marketing its denosumab biosimilar products in the US until June 1, 2025.