Shire plc a global specialty biopharmaceutical company, has announced that its subsidiary Shire LLC has filed a lawsuit in the U.S. District Court for the District of Delaware against Actavis Elizabeth LLC and Actavis Inc. for the infringement of U.S. Patent Nos. 5,854,290 (the ’290 patent), 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 Actavis for generic versions of 1 mg, 2 mg, 3 mg and 4 mg guanfacine hydrochloride extended release tablets, INTUNIVTM, which seeks 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.