On July 14, 2025, Fresenius Kabi filed IPR2025-01268 against Regeneron’s U.S. Patent No. 11,084,865 (“the ’865 patent”) and IPR2025-01269 against U.S. Patent No. 10,828,345 (“the ’345 patent”), both relating to EYLEA^® (aflibercept).  The ’865 patent claims ophthalmic formulations of a vascular endothelial growth factor (VEGF) and the ’345 patent claims methods of treating an angiogenic eye disorder using a VEGF antagonist.

Previously, the ’865 patent has been challenged in three IPRs by Samsung Bioepis (IPR2025-00176), Formycon (IPR2025-00233) and Celltrion (IPR2025-00456), all of which were denied in June 2025 by the Acting PTO Director for discretionary reasons, particularly ongoing BPCIA litigations between the parties (previously reported Samsung Bioepis and Formycon’s EYLEA^® IPRs Discretionarily Denied Institution Among Wave of Fintiv Denials; Regeneron Files Second BPCIA Lawsuit Against Amgen’s Pavblu™; Acting PTO Director Discretionarily Denies Celltrion’s IPR Against EYLEA^® Patent).  This patent was also the subject of numerous BPCIA litigations, including Regeneron v. Mylan, Case No. 1:22-cv-00061 (N.D.W. Va.) / MDL 1:24-md-03103 (N.D.W. Va.) where the district court found claims 4, 7, 9, 11, 14-17 valid (appeal dismissed due to settlement).  The ’345 patent has not been subject to a previous IPR.

In the IPR2025-01268 Petition, Fresenius challenges claims 1-5, 7-30, 32-50 of the ’865 patent as anticipated by the Dix reference, an issue which was resolved for many of these claims in favor of Regeneron in the district court Mylan case.  However, Fresenius notes that the Federal Circuit called this decision into question during oral argument, but it was never decided on appeal because the parties settled.  The Dix reference was not raised in the other ’865 patent IPRs that were discretionarily denied.

Fresenius is developing an EYLEA^® biosimilar, SKD411, with Sam Chun Dang but has not yet publicly announced an aBLA filing with the FDA.  Unlike the Petitioners filing the IPRs that were discretionarily denied, Fresenius does not have a pending litigation related to its EYLEA^® biosimilar.

Regeneron reported EYLEA^® U.S. sales of $4.767 billion in FY2024.

For more information about these and other biosimilar patent disputes, please visit BiologicsHQ.

 

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The author would like to thank April Breyer Menon for her contributions to this article.