On March 15, 2022, the Patent Trial and Appeal Board (PTAB) denied institution of post-grant review (PGR) proceedings initiated by Celltrion Inc. concerning Regeneron Pharmaceutical’s U.S. Patent No. 10,857,231 (the ’231 Patent) after Regeneron disclaimed the patent.  The ’231 patent has claims directed to formulations of aflibercept, the active ingredient in Regeneron’s product Eylea, which is indicated for treatment of age-related macular degeneration and other ophthalmic disorders.  Celltrion is conducting clinical trials of an aflibercept biosimilar.

In the decision denying institution, the PTAB stated that on March 14, 2022, Regeneron had notified the PTAB that it intended to disclaim the ’231 patent.  The same day, Regeneron also filed a Notice of Disclaimer with the U.S. Patent and Trademark Office disclaiming all 114 claims of the ’231 patent.  In the decision, the PTAB also acknowledged that it would be permitted to enter adverse judgment against Regeneron following cancellation of all claims of the ’231 patent, but opted instead to deny institution as “sufficient to dispose” of the case.