Ranbaxy, India’s largest generic drug manufacturer has announced to reached an agreement with GlaxoSmithKline to dismiss Valacyclovir US patent litigation over US Patent No. 4,957,924 (the ‘924 patent) covering Valacyclovir hydrochloride, the active ingredient of million-dollar anti-viral drug Valtrex with an annual market sales of US $ 1.3 billion. As per the agreement, Ranbaxy will enter the US Valtrex generic market in late 2009 and will enjoy 180-days market exclusivity. Ranbaxy also obtained license to other two Orange Book listed Patent Nos. 5,879,706 and 6,107,302. Earlier in May 2003, GSK filed a patent infringement lawsuit in the US District Court for the District of New Jersey against Ranbaxy alleging that Ranbaxy’s Abbreviated New Drug Application (ANDA) would infringe the ‘924 patent expiring in June 2009. In February 2007, Ranbaxy received the US FDA final approval to market and manufacture generic Valacyclovir tablets.