Patent litigation relating to a generic version of GlaxoSmithKline's Imitrex Injection, Spectrum Pharmaceuticals Inc's sumatriptan injection, has been dismissed by the United States District Court for the District of Delaware. The dismissal was pursuant to the previously announced November 2006 settlement agreement between Spectrum, US, and GSK, UK.

In 2004, Spectrum filed an Abbreviated New Drug Application (ANDA) containing a paragraph IV certification with the US Food and Drug Administration seeking marketing clearance for sumatriptan injection, which was tentatively approved by the FDA in October 2006. The terms of the confidential settlement between GSK and Spectrum provide that Spectrum may exclusively distribute authorized generic versions of certain sumatriptan injection products in the US. The launch is expected to be during GSK's sumatriptan paediatric exclusivity period, which begins on August 6, 2008, but occurring not later than November 6, 2008. Spectrum will launch sumatriptan injection through Par Pharmaceutical Companies, Inc, US, its partner for the sale and distribution of the drug.