On July 14, 2025 Fresenius filed two IPR petitions challenging Regeneron's patents related to aflibercept. Regeneron has not asserted that Fresenius infringes either of these patents in district court litigation; however, there are a number of district court actions against other parties related to the patents challenged in Fresenius's IPRs.
The first petition (IPR2025-01268) challenges U.S. Patent No. 11,084,865, directed to stable formulations of a VEGF-specific protein antagonist, and having a priority date of June 16, 2006. The '865 patent was previously challenged in three other IPR petitions that were discretionarily denied. The '865 patent was also previously at issue in BPCIA litigation with Mylan and Biocon where certain claims of the patent were held non-obvious at the district court. That decision was appealed but was dismissed before a decision from the Federal Circuit could issue. Fresenius argued in its petition that the challenged claims are invalid as anticipated over a prior art reference not relied on in the previous IPRs referred to as Dix '226. Dix '226 is a patent that was issued to Regeneron on September 10, 2019 titled "Method of Manufacturing VEGF Antagonist Fusion Proteins" that claims priority to a provisional application filed March 25, 2006. Although Dix '226 shares two of the same inventors as the challenged '865 patent, Fresenius argued it qualifies as prior art under 102(e)(2) based on several other differences in inventorship between the two patents.
The second petition (IPR2025-01269) challenges U.S. Patent No. 10,828,345, directed to methods of using a VEGF antagonist to treat angiogenic eye disorders, and having a priority date of January 21, 2011. Fresenius argued in the petition that the challenged claims are invalid as anticipated or obvious over a series of references referred to as Dixon, NCT-377, NCT-795, Regeneron (8-May-2008), and Regeneron (8-May-2010). According to the petition, Dixon is a peer-reviewed publication from 2009 that discloses the use of anti-VEGF agents for treating AMD. NCT-377 and NCT-795 are Clinicaltrial.gov on-line records related to the VIEW-1 clinical study investigating the use of anti-VEGF agents for treating AMD. Regeneron (8-May-2008) and Regeneron (8-May-2010) are press releases by Regeneron reporting positive results of clinical studies investigating the use of anti-VEGF agents in AMD.
Each of the IPRs were accorded a notice of filing date on July 23, 2025, making discretionary denial briefs due September 23, 2025. Oppositions to discretionary denial briefs and patent owner preliminary responses are due October 23, 2025. Stay tuned to Big Molecule Watch for further updates on these IPRs.
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