Shire files suit against Cadila/Zydus Cadila for Lialda patent infringement

Ireland-based Shire has filed a law suit in the US District Court for the District of Delaware against Cadila Healthcare, doing business as Zydus Cadila and Zydus Pharmaceuticals (USA), for the infringement of US Patent No 6,773,720 (the '720 patent).

The law suit was filed as a result of an Abbreviated New Drug Application filed by Zydus seeking US Food and Drug Administration approval to market and sell generic versions of Lialda (mesalamine), for the treatment of ulcerative colitis, prior to the expiration of the '720 patent, of which Shire was advised at the end of May (The Pharma Letter June 1).

Under the Hatch-Waxman Act, because Shire filed its patent infringement law suit within 45 days of receiving the Paragraph IV notification letter from Zydus, the FDA must refrain from approving Zydus' ANDA for 30 months, or until a district court decision finding that the patent is invalid or not infringed, whichever occurs earlier. The stay on generic approval will expire in November 2012 unless terminated earlier.