On May 11, 2007 Smithkline Beecham filed a patent infringement lawsuit against Teva Pharmaceutical Industries alleging that the Teva’s submission of ANDA for approval of sell generic version of Smithkline’s Avandaryl would constitute an act of infringement pursuant to 35 USC § 271(e)(2). In its complaint, Smithkline alleged that the Teva proposed generic formulation would infringe Avandaryl Orange Book listed patents – US 5,002,953 (the ‘953 patent) and US 5,741,803 (the ‘803 patent). Earlier Teva submitted ANDA with Para IV certification to the FDA for marketing approval of generic version of Avandaryl (combination of rosiglitazone maleate and glimepiride) before the expiration of the ‘953 and ‘803 patents. The ‘953 patent is directed to substituted thiazolidinedione derivatives exemplified by markush structural formula which covers rosiglitazone as 5-(4-[2-(N-methyl-N-(2-pyridyl) amino) ethoxy] benzyl) 2, 4-thiazolidinedione. The ‘803 patent is species patent covering maleic acid salt of rosiglitazone.