Mylan Pharmaceuticals Inc. (“Mylan”) filed a Petition to institute an inter partes review of claims 1, 2, 4, 6–22, 25–30, 32–37, and 39–42 of U.S. Patent No. US RE44,186 E. The ’186 patent is directed to “cyclopropyl-fused pyrrolidine-based inhibitors of dipeptidyl peptidase IV (DP-4) and to a method for treating diabetes.”

PTAB initially denied institution of an inter partes review of all the challenged claims. Mylan subsequently filed a Request for Rehearing. On May 2, 2016, PTAB granted the Request for Rehearing and concurrently instituted an inter partes review of all the challenged claims. An oral hearing for this proceeding was held on January 25, 2017.

PTAB issued its decision on Aug 18, 2017 & determined that Petitioners have not established, by a preponderance of the evidence, that claims 1, 2, 4, 6–22, 25–30, 32–37, and 39–42 of the ’186 patent are unpatentable. Specifically PTAB determined that Petitioners have not established that claim 25, a saxagliptin-specific claim, would have been obvious and that the secondary considerations weigh in favor of the patentability.