On September 17, 2025, Alvotech USA Inc. and Alvotech hf. (“Alvotech”) filed a Petition for Post Grant Review of U.S. Patent No. 12,168,036 (“the ‘036 patent”), assigned to Regeneron Pharmaceuticals, Inc. (“Regeneron”). The ‘036 patent, entitled “Methods for treating angiogenic eye disorders with high doses of VEGF receptor fusion proteins,” issued on December 17, 2024 and is generally directed to methods of treating an angiogenic eye disorder using a intravitreal administration of a high concentration formulation of a VEGF receptor fusion protein with a viscosity of about 5-15 centiPoise at 20 oC. Independent claim 1 is directed to a method of treatment using a volume of “about 100 microliters or less” of “at least about 8 mg” of a VEGF receptor fusion protein, at a concentration of “at least 100 mg/ml.” Independent claim 35 is directed to a method of treatment using a volume of “about 70 microliters” of “about 103-126 mg/ml” of aflibercept.
In the petition, PGR2025-00085, Alvotech raises four grounds for unpatentability for obviousness over multiple combinations of prior art, including Regeneron patents and publications. Alvotech argues that “Regeneron has repeatedly disclosed high-concentration formulations of aflibercept, including 100 mg/ml and higher, along with the high doses, including up to 10 mg” and that the ‘036 patent was only granted because Regeneron “convinc[ed] the Examiner” that “the higher-concentration formulations had problems with viscosity, and that Regeneron solved that problem.” Alvotech contends that “there was no viscosity problem to be solved” and that the ‘036 patent “doesn’t claim a viscosity-problem solution.”
Alvotech also contends that the claims of the ‘036 patent are invalid for lack of written description because “the specification does not show that the inventors possessed formulations reflecting the full scope of the claims that would achieve the required viscosity levels.” According to Alvotech, the claims do not “specify any components of the formulation other than the VEGF fusion protein itself,” and therefore “recite a broad genus of pharmaceutical formulations with functional requirements,” but the “specification discloses only a small number of species that achieve the required viscosity, and all those species contain a buffer.”
Regeneron’s EYLEA HD®, an 8 mg injection of aflibercept (114.3 mg/ml), was approved by the FDA in August 2023. As we have previously reported, Alvotech is currently developing AVT29, a biosimilar candidate for EYLEA HD®.