Morristown, NJ -- February 24, 2009 -- Today Actavis filed papers in the U.S. District Court for the District of Columbia challenging the Food and Drug Administration's grant of five-year New Chemical Entity (NCE) exclusivity for lisdexamfetamine, which is currently marketed by Shire US Inc. for the treatment of attention-deficit hyperactivity disorder under the name Vyvanse™.

The challenge comes after the FDA refused to accept for filing Actavis' Abbreviated New Drug Application (ANDA) for lisdexamfetamine on the basis that NCE exclusivity prevented an ANDA filing before 2011.

Actavis believes that the statute and regulations governing NCE exclusivity render lisdexamfetamine ineligible for NCE status because the only active ingredient responsible for lisdexamfetamine's physiological action, dextroamphetamine, was approved by the FDA more than two decades ago. The statute prohibits the award of five-year exclusivity to active ingredients that have already been approved.

If the challenge succeeds, Actavis believes it is the first to file an ANDA for lisdexamfetamine. Vyvanse™ was approved by the FDA in February 2007 and had sales of $319 million in 2008.