Ranbaxy Laboratories has settled a patent litigation in the US with drug major GlaxoSmithKline (GSK) relating to Imitrex (sumatriptan succinate tablets), a migrane and headache drug.As per the terms of the settlement, Ranbaxy may distribute a generic version of in the 25 mg, 50 mg and 100 mg strengths in the United States with an expected launch date in December, 2008, Ranbaxy said in a communication to the stock exchanges.Additional terms of the settlement agreement were not disclosed.The annual market sales for Imitrex is valued $985 million, according to the data of IMS, a market research agency.Earlier, Ranbaxy had entered into a similar out of Court settlement with GSK over Valacyclovir hydrochloride, the active ingredient of million-dollar anti-viral drug Valtrex, which has an annual market sales of $1.3 billion.
