On 2 October 2025, Formycon announced that it and its licence partners, Klinge Biopharma and Valorum Biologics, have entered a settlement and licence agreement with Regeneron to resolve all US patent disputes relating to FYB203/Ahzantive®, biosimilar to Regeneron’s Eylea® (aflibercept). Under the terms of the agreement, Valorum may launch Ahzantive® in the US in Q4/2026, or earlier under certain undisclosed circumstances.
FYB203 was approved in the US in June 2024 and had been subject to a preliminary injunction granted by the US District Court for the Northern District of West Virginia in June 2024, resulting from a patent infringement proceeding brought by Regeneron in November 2023. The injunction was upheld on appeal in January 2025 but has now been vacated as a result of the parties’ settlement.
Sandoz has also recently (in September 2025) settled BPCIA aflibercept litigation with Regeneron, with a US launch date for Sandoz’s Enzeevu® set for Q4/2026 (or earlier under certain undisclosed circumstances).
The only aflibercept biosimilar to have launched in the US to date is Amgen’s Pavblu™, which launched in October 2024 following 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™ (June 2025), which remains pending.
Klinge, Formycon’s exclusive global licensee of FYB203, entered an exclusive licence agreement with Valorum in June 2025 for the commercialisation of FYB203 in the US and Canada. Under the agreement, Klinge receives royalties on net sales and is eligible to receive upfront and milestone payments, with Formycon receiving a single to low double-digit percentage of those payment streams. Formycon will additionally receive service payments and a volume-based profit component for organising the commercial market supply on behalf of Klinge.
The dispute between Regeneron/Bayer and Formycon in relation to FYB203 is not limited to the US, with legal proceedings in the US, UK, Italy, Belgium, the Netherlands, and France. On 25 September 2025, the Munich Regional Court granted Regeneron and Bayer a cross-border preliminary injunction (PI) preventing Formycon from launching FYB203 in a number of European countries, including Germany. The PI was based on a finding of infringement by equivalence of Regeneron’s formulation patent, EP 2 364 691.