Shire LLC, subsidiary of Shire plc, global specialty biopharmaceutical company has filed a lawsuit in the US District Court for the District of Delaware against Teva Pharmaceuticals USA, Inc and Teva Pharmaceutical Industries, Ltd (collectively Teva) for the infringement of US Patent Nos. 6,287,599 (the ’599 patent) and 6,811,794 (the ’794 patent).

The lawsuit results from an Abbreviated New Drug Application (ANDA) filed by Teva for generic versions of 1 mg, 2 mg, 3 mg and 4 mg guanfacine hydrochloride extended release tablets, Intuniv, which seeks to market such generic products before the expiration of the ’599 and ’794 patents. Teva’s ANDA did not challenge, and the lawsuit does not currently assert, the third Orange Book listed patent (US Patent No. 5,854,290, Use of Guanfacine in the Treatment of Behavioral Disorders) which expires in 2015. The regulatory exclusivity period for Intuniv runs through September 2, 2012.