Shire Files Suit Against Impax and Watson

Shire plc SHPGY announced that its subsidiary Shire LLC has filed a lawsuit in the U.S. District Court for the Northern District of California against Impax Laboratories, Inc. and Watson Pharmaceuticals, Inc., Watson Laboratories, Inc.-Florida, Watson Pharma, Inc and ANDA, Inc. for the infringement of U.S. Patent Nos. 5,854,290, 6,287,599, and 6,811,794. The lawsuit results from Abbreviated New Drug Applications filed by Impax and Watson for generic versions of 4 mg guanfacine hydrochloride extended release tablets, INTUNIV, which seek to market such generic products before the expiration of the '290, '599, and '794 patents. The regulatory exclusivity period for INTUNIV runs through September 2, 2012.