Mayne Pharma Loses Patent Litigation to AstraZeneca

Australian-based Mayne Pharma has lost a patent infringement lawsuit in the U.S. Court of Appeals for the Federal Circuit for an anesthetic drug Propofol, which upholds a U.S. District Court for the Southern District of New York decision finding that Mayne’s injectable formulation of propofol infringed patents held by AstraZeneca. Earlier on June 28, 2002 ESI filed an abbreviated new drug application (ANDA) along with Para IV certification, seeking marketing approval for generic propofol formulation. In respone, AstraZeneca filed a patent infringement lawsuit against ESI on October 04, 2002 alleging that ESI proposed generic propofol infringes AstraZeneca’s U.S. Patent Nos. 5,714,520 (the ‘520 patent), 5,731,355 (the ‘355 patent) and 5,731,356 (the ‘356 patent). Thereafter, Mayne, an indirect assignee of ESI, sent AstraZeneca a notice letter dated July 15, 2003 informing its intent to commercially manufacture, use or sell its generic propofol formulation in 50ml and 100ml vials. AstraZeneca reacted by filing a second lawsuit, and both actions were consolidated. On December 28, 2004 the District Court issued a Markman ruling, construing three contested terms including “edetate” which timely appealed by Mayne. After eleven day of bench trial, the District Court entered judgment in the favor of AstraZeneca concluding that the filing of Mayne’s ANDA infringed asserted claims of the patents in suit.