Spectrum begins Glaxo patent challenge

The exclusivity afforded patent, listed in the Orange Book for Imitrex (sumatriptan succinate) injection, expires on February 6, 2009. Spectrum’s abbreviated new drug application (ANDA) for sumatriptan succinate injection alleges that the Orange Book listed patent is invalid, unenforceable and/or would not be infringed by Spectrum’s product.

Spectrum submitted its ANDA for a generic Imitrex injection product with the FDA in October 2004, and received notification of acceptance with Paragraph IV certification in January 2005.

Following receipt of the notice from the FDA, Spectrum notified GlaxoSmithKline and on February 18, 2005, GlaxoSmithKline filed suit in US federal court to prevent Spectrum from proceeding with the commercialization of its product. This action formally initiates the patent challenge process under the Hatch-Waxman Act.

Imitrex is marketed by GlaxoSmithKline for the acute treatment of migraine attacks with or without aura and the acute treatment of cluster headache episodes in adults.