Singapore: Sucampo (an affiliate of Sucampo Pharmaceuticals), R-Tech Ueno, Takeda Pharmaceutical, and certain affiliates of Takeda have filed a patent infringement lawsuit in the US District Court of Delaware against Anchen Pharmaceuticals, Par Pharmaceuticals.

The law suit is related to an abbreviated new drug application (ANDA) that Anchen filed with the US FDA to market a generic version of Amitiza (lubiprostone) oral capsules, 8 micro gram and 24 micro gram. The lawsuit claims that the infringement of six patents that are listed in the FDA's Orange Book and are scheduled to expire between 2020-27.

Sucampo commenced the lawsuit within 45 days from the receipt of a notice letter sent by Anchen, dated December 26, 2012, regarding its filing of its ANDA. Under the Hatch-Waxman Act, as a result of the patent infringement lawsuit, final FDA approval of Anchen's ANDA will be stayed for up to 30 months from the January 2, 2013.

"Sucampo's patent estate for Amitiza is strong, and the company intends to vigorously defend our intellectual property. We believe that the Amitiza patents, granted by the US Patent and Trademark Office, are valid, enforceable, and infringed by Anchen's proposed lubiprostone products," said Mr Thomas J Knapp, executive vice president, chief legal officer, and corporate secretary of Sucampo.