Defendant
1 case as defendant.
Celltrion, Inc. is a South Korean biopharmaceutical company headquartered in Incheon, South Korea, founded in 2002 by Seo Jung-jin. It is a publicly traded company on the Korea Exchange (KRX: 068270). As of December 2025, Celltrion, Inc. had approximately 3,002 employees. In 2025, the company reported annual revenue of approximately $3.1 billion USD. Celltrion Healthcare, a subsidiary, handles the worldwide marketing, sales, and distribution of Celltrion's biological medicines.
Celltrion specializes in the research, development, and manufacture of biosimilars and novel biopharmaceuticals, operating through its Biopharmaceuticals and Chemical Drugs segments. Their product portfolio includes biosimilar drugs for autoimmune diseases and cancer, such as Remsima™ (infliximab), Truxima™ (rituximab), Herzuma™ (trastuzumab), Yuflyma® (adalimumab), Vegzelma® (bevacizumab), and Eydenzelt® (aflibercept). The company offers end-to-end solutions, encompassing R&D, clinical trials, regulatory affairs, production, and distribution.
Celltrion, Inc. primarily appears as a defendant in patent litigation, indicating a posture of an operating company defending its commercialization efforts. The company has been tracked in one case, "Regeneron Pharmaceuticals, Inc. v. Celltrion, Inc.," where it was the defendant. This case involved litigation in the U.S. District Court for the Northern District of West Virginia, the U.S. Court of Appeals for the Federal Circuit, and the Patent Trial and Appeal Board (PTAB).
The notable case, "Regeneron Pharmaceuticals, Inc. v. Celltrion, Inc.," concerned patent infringement related to Celltrion's biosimilar product of EYLEA® (aflibercept). Celltrion had filed inter partes review (IPR) petitions at the PTAB challenging patents owned by Regeneron related to aflibercept. A settlement was reached in October 2025, allowing Celltrion to launch its aflibercept biosimilar, Eydenzelt, in the U.S. on December 31, 2026, and dismissing all related intellectual property litigation between the two companies in the U.S.
Regeneron sued Celltrion for infringement of US Patent 11084865. The district court granted a preliminary injunction, which the Federal Circuit affirmed. A related IPR challenge (IPR2025-00456) at the PTAB was denied institution.