Dr Reddy's Laboratories has filed an Abbreviated New Drug Application (ANDA) with the US FDA for Sumatriptan Succinate oral tablets, equivalent to 25 mg, 50 mg and 100 mg base, with a Paragraph IV certification on four of the five Orange Book patents listed for the drug.

Dr Reddy's notified GlaxoSmithKline, upon which the latter filed a lawsuit against the company in the United States District Court for the Southern District of New York alleging patent infringement on the '845 patent.

Sumatriptan Succinate is the generic version of GlaxoSmithKline's Imitrex and is indicated for the treatment of migraine. The brand has annual sales of $773 million in the US.