On June 14, 2024, the PTAB issued a Final Written Decision (FWD) in Samsung Bioepis’s IPR2023-00442 (“the -00442 IPR) determining that the challenged claims of Regeneron’s U.S. Patent No. 10,130,681 (the ’681 patent) that covers EYLEA® (aflibercept) are unpatentable. The ’681 patent is directed to methods for treating angiogenic eye disorders by sequentially administering multiple doses of a vascular epithelial growth factor (VEGF) antagonist to a patient. Samsung Bioepis’s Petition challenged claims 1, 3-11, 13-14, 16-24, and 26 of the ’681 patent as obvious, all of which were previously found unpatentable as anticipated in Mylan Pharms. Inc. v. Regeneron Pharms., Inc., IPR2022-01225 (the “-01225 IPR”).  In the -00422 IPR FWD, the Board incorporated by reference and adopted its reasoning and conclusions from the -01225 IPR FWD and Mylan’s IPR2021-00881 (the “-00881 IPR”) that challenged Regeneron’s related U.S. Patent No. 9,254,338 (the ’338 patent).  The Board concluded that because the claims are anticipated by Dixon they are also obvious over Dixon.

In the -01225 IPR FWD, the Board found that each challenged claim of the ’681 patent was identical to the challenged claims of the ’338 patent (found unpatentable in the -00881 IPR FWD), except for certain exclusion criteria as an additional limitation.  Because the Board found the exclusion criteria limitations were not entitled to patentable weight, it found the ’681 patent claims unpatentable as anticipated by the same prior art Dixon reference as relied upon in the -00881 IPR FWD (previously reported The PTAB Finds Claims of Two EYLEA® Patents Unpatentable and Regeneron Files its Sixth Complaint Against a Proposed EYLEA® Biosimilar).

Samsung Bioepis’s EYLEA® biosimilar Opuviz™ (aflibercept-yszy) was FDA-approved as an interchangeable biosimilar on May 20, 2024 (previously reported FDA Approves First Two Interchangeable EYLEA® Biosimilars – Biocon’s Yesafili™ (aflibercept-jbvf) and Samsung Bioepis’s Opuviz™ (aflibercept-yszy)).  In related litigations where the ’681 patent is also at issue ((1:23-cv-00094 (N.D.W. Va.), 1:23-cv-00106 (N.D.W. Va.), MDL 1:24-md-03103 (N.D.W. Va.)), the Court, on June 14, 2024, issued a preliminary injunction preventing the commercial launch of Opuviz™.  On June 20, 2024, Samsung Bioepis filed CAFC appeals to the preliminary injunction decision (Nos. 24-1965 and 24-1966), which are ongoing.

Regeneron reported EYLEA® sales of $5.89 billion in 2023.

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



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



    Information contained in the Venable BiologicsHQ database relates to FDA-approved drug products listed in the CDER Purple Book or on the FDA website ( Information relating to FDA licensed products, FDA-approved indications, and aBLA and 505(b)(2) applications is obtained from public sources including the U.S. FDA website ( Information relating to litigations is given only for cases active from January 31, 2010 onward. Information relating to foreign biosimilar / biologics follow-on products approved in Australia, Canada, the E.U., Japan and South Korea is from public sources. Statistics graphics are compiled from information contained in the Venable BiologicsHQ database.


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