On 14 July 2025, Fresenius Kabi filed petitions for IPR (inter partes review) against Regeneron’s US Patent No. 11,084,865 to ophthalmic formulations of aflibercept and US Patent No. 10,828,345 to methods of treating angiogenic eye disorders. Fresenius is seeking to overturn claims 1-5, 7-30, and 32-50 of the 865 patent based on anticipation, and all claims of the 345 patent based on anticipation and obviousness.
Samsung Bioepis, Formycon and Celltrion had previously also challenged the validity of Regeneron’s US 11,084,865 before the USPTO, filing petitions for IPR in November 2024, December 2024 and January 2025, respectively. On 2 June 2025, the PTAB denied institution of Samsung Bioepis’ and Formycon’s petitions, including because the 865 patent is already the subject of pending BPCIA litigation involving the parties. Celltrion’s petition was denied on 26 June 2025 for similar reasons. Notably, Fresenius is not currently a party to any BPCIA aflibercept litigation brought by Regeneron.
Regeneron is in BPCIA litigation against each of Amgen (Pavblu™), Samsung Bioepis (2 actions; Opuviz™/SB15), Formycon (Ahzantive®/FYB203), Celltrion (2 actions, CT-P42) and Sandoz (Enzeevu™) regarding biosimilar aflibercept. Preliminary injunctions were granted, and remain in place, preventing biosimilar aflibercept launches by 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).
Fresenius entered into a licensing agreement with Sam Chun Dang in December 2024 for the exclusive commercialisation of SCD-411, biosimilar to Regeneron’s Eylea® (aflibercept, 2mg), in the US and various South American countries. The only biosimilar aflibercept currently available in the US is Amgen’s Pavblu™, which launched in October 2024 after the US Court of Appeals for the Federal Circuit’s denial of Regeneron’s application for an injunction in relation to the biosimilar. Regeneron has since commenced new BPCIA litigation against Amgen for Pavblu™ (in June 2025). Biocon and Regeneron settled US BPCIA litigation regarding aflibercept in April 2025, paving the way for a US launch of Biocon’s biosimilar, Yesafili™, in the second half of 2026, or earlier under certain undisclosed circumstances.