AstraZeneca is involved in patent infringement litigation against several ANDA filers that are seeking FDA approval to market generic versions of Onglyza (saxagliptin hydrochloride). The key patent protecting Onglyza is U.S. Patent No. RE44,186 (set to expire July 31, 2023).
Judge Gregory Sleet presided over a trial in September 2016 involving most of the ANDA filers (Amneal, Aurobindo, Mylan, and Teva). At trial, the ANDA filers conceded that the RE’186 patent covers their proposed generic tablets, but they asserted that the patent is invalid due to obviousness over lead compound Vildagliptin.
Judge Sleet determined that, even if vildagliptin were selected as a lead compound, the ANDA filers failed to prove by “clear and convincing” evidence that modifying vildagliptin to yield saxagliptin would have been obvious. He explained, for example, that the ANDA filers failed to show a motivation to move the hydroxadamantyl group of vildagliptin with any reasonable expectation of success based on the limited structural information on moving from N-linkage to C-linkage, the existence of sufficiently potent compounds, and the inconsistency with an established solution to the stability problem.
Parallel IPR petitions have been filed for this RE’186 patent by few ANDA filers. Patent Office held a hearing in the IPR proceedings on Jan 25, 2017 and is expected to issue its decision on the validity of the RE’186 patent by May 2, 2017.