Salix Pharmaceuticals and Dr. Falk Pharma filed a lawsuit against Lupin (defendant) on Friday, September 7, 2012 in the U.S District of Delaware (case no. 1:12-cv-01104) for patent infringement.

Raleigh-based Salix is a pharmaceutical company focusing on the prevention and treatment of gastrointestinal (GI) disorders. Dr. Falk Pharma specializes in development and sales of medication in hepatology and gastroenterology. The patent involved in this suit is assigned to Dr. Falk Pharma GmbH (as per the patent face page) and Salix is the exclusive licensee of the patent US6551620 with rights to enforce the patent. The patent titled ‘Pellet Formulation for the Treatment of the Intestinal Tract’ issued on April 22, 2003.

According to the complaint, Salix is the current holder of New Drug Application (NDA) no. 22-301 for extended release Apriso® capsules with 0.375g Mesalamine (5-aminosalicylic acid) to maintain ulcerative colitis remission in patients 18 and older.

The plaintiffs have filed the suit after receiving notification under paragraph IV[1] from Lupin Limited stating that Lupin had filed an ANDA (Abbreviated NDA) application to seek approval to market a generic version of APRISO®. The notification letter asserted non-infringement and invalidity of the Orange Book-listed U.S. Patent No. 6,551,620 which covers Apriso®* (source: Maxval’s Patent Marker). This patent has not been asserted in a suit before.