Global pharmaceutical company Mylan N.V. has announced that the US Patent Trial and Appeal Board (PTAB) has denied the St. Regis Mohawk Tribe's (Tribe) motion to terminate Mylan's patent challenge regarding six patents related to Allergan's Restasis.

Mylan CEO Heather Bresch commented, "Mylan has always been vocal in its efforts to challenge and break down barriers to access. The PTAB's ruling reinforces our belief that Allergan's maneuvers to engage the St. Regis Mohawk Tribe for patent protection were a sham. We will continue to be steadfast in our efforts on both the legal and regulatory fronts to bring a generic version of Restasis to patients as quickly as possible."

In a move admittedly designed to protect the Restasis patents from cancellation by the PTAB, Allergan announced last September that it had assigned the rights of six patents to the Tribe. The Tribe immediately moved to dismiss the proceedings, arguing that its tribal sovereign immunity prevented the PTAB from reviewing the patents.

On Feb. 23, the PTAB denied the Tribe's motion on multiple grounds. The PTAB held that the Tribe did not establish that the doctrine of tribal sovereign immunity applied to inter partes review (IPR) proceedings. Alternatively, the PTAB held that even if tribal sovereign immunity did apply, the IPR proceedings could continue without the Tribe because Allergan retained ownership interests in the patents.

The PTAB tentatively scheduled an oral hearing on the merits for April 3, 2018, and stated that it would render a final written decision on the patentability of the challenged patents by June 6, 2018.   

Mylan previously announced that the Eastern District of Texas held Allergan's patents invalid after a trial on the merits. The case is currently on appeal before the US Court of Appeals for the Federal Circuit.