On 14 March 2025, the US Court of Appeals for the Federal Circuit upheld the ruling of the District Court for the Northern District of Virginia refusing Regeneron’s application for a preliminary injunction preventing launch of Amgen’s Pavblu®/APB 938 (aflibercept), biosimilar to Regeneron’s Eylea®.
The Appeals Court agreed with the District Court’s September 2024 ruling that Pavblu® did not infringe the asserted claims of Regeneron’s US Patent No. 11,084,865 regarding ophthalmic formulations of aflibercept. An application to the US Appeals Court by Regeneron for an injunction preventing Amgen from launching Pavblu® pending the substantive appeal had also been rejected in October 2024. Amgen launched Pavblu® in the US immediately following the October 2024 decision.
The Appeals Court determined that the relevant claims of the US 865 patent required an aflibercept formulation that included a separate buffer component, but Amgen’s formulation did not contain any such separate buffer. Instead, the evidence was that “Amgen had discovered a way to prepare and formulate” aflibercept in a manner that eliminates the need for a separate buffer as the aflibercept itself provides sufficient buffering capacity to stabilise the formulation.
The litigation against Amgen is part of consolidated, multi-district BPCIA litigation brought by Regeneron regarding aflibercept biosimilars against each of Samsung Bioepis (2 actions; Opuviz™/SB15 approved May 2024), Biocon (Yesafili™ approved May 2024), Formycon (Ahzantive®/FYB203 approved June 2024), Celltrion (2 actions, aBLA for CT-P42 submitted to FDA in June 2023) and Sandoz (Enzeevu™ approved August 2024, litigation pending).
The Court’s refusal to grant a preliminary injunction against Amgen differs from decisions of the US District Court for the Northern District of Virginia to grant preliminary injunctions against Samsung Bioepis (14 June 2024, upheld on appeal on 29 January 2025), Formycon (21 June 2024, upheld on appeal on 29 January 2025) and Celltrion (June-July 2024, upheld on appeal on 5 March 2025), and a permanent injunction against Biocon (11 June 2024), based on findings of infringement of the US 865 patent. Biocon filed a Notice of Appeal from the permanent injunction order on 21 June 2024. That appeal remains pending. The aflibercept biosimilars of each of Samsung Bioepis, Formycon, Celltrion and Biocon are buffered.
Samsung Bioepis, Formycon and Celltrion are challenging the validity of Regeneron’s ‘865 patent before the USPTO, each having filed a petition for IPR (inter partes review) in November 2024, December 2024 and January 2025, respectively.