Actavis plc, has filed an Abbreviated New Drug Application (ANDA) with the US  Food and Drug Administration (US FDA) seeking approval to market dalfampridine extended-release tablets, 10 mg.  Actavis' ANDA product is a generic version of Acorda Therapeutics' Ampyra, which is indicated as a treatment to improve walking in patients with multiple sclerosis.

Acorda Therapeutics, Inc. filed suit against Actavis on July 7, 2014, in the US District Court for the District of Delaware seeking to prevent Actavis from commercialising its ANDA product prior to the expiration of certain US Patents.  The lawsuit was filed under the provisions of the Hatch-Waxman Act, resulting in a stay of final FDA approval of Actavis' ANDA until July 22, 2017, or final resolution of the matter before the court, whichever occurs sooner, subject to any other exclusivities.

Based on available information, Actavis believes it may be a "first applicant" to file an ANDA for the generic version of Ampyra and, should its ANDA be approved, may be entitled to 180 days of generic market exclusivity.

For the 12 months ending April 30, 2014, Ampyra had total US sales of approximately $231 million, according to IMS Health data.