Actavis plc has filed an Abbreviated New Drug Application (ANDA) with the US Food and Drug Administration (FDA) seeking approval to market ambrisentan tablets, 5 mg and 10 mg.  Actavis' ANDA product is a generic version of Gilead Sciences, Inc.'s Letairis, which is a treatment for pulmonary arterial hypertension.

Gilead Sciences, Inc. and Royalty Pharma Collection Trust filed suit against Actavis on April 1, 2015 in the US District Court for the District of Delaware seeking to prevent Actavis from commercializing its ANDA product prior to the expiration of US Patent number RE42,462.  The lawsuit was filed under the provisions of the Hatch-Waxman Act, resulting in a stay of final FDA approval of Actavis' ANDA for up to 30 months from the date the plaintiffs received notice of Actavis' ANDA filing or until 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 Letairis® and, should its ANDA be approved, may be entitled to 180 days of generic market exclusivity.

For the 12 months ending December 31, 2014, Letairis had global sales of approximately $595 million, according to Gilead.


Actavis plc, headquartered in Dublin, Ireland, is a unique, global pharmaceutical company and a leader in a new industry model - Growth Pharma.  Actavis is focused on developing, manufacturing and commercializing innovative branded pharmaceuticals, high-quality generic and over-the-counter medicines and biologic products for patients around the world.