Actavis confirmed last week that it has filed an abbreviated new drug application with the U.S. Food and Drug Administration (FDA), requesting approval to market Ambrisentan, and has confirmed a patent challenge.
Actavis’ Ambrisentan is a generic version of Gilead Sciences Inc.’s Letairis, a treatment for pulmonary arterial hypertension. According to Gilead, Letairis has global sales of approximately $595 million for the 12 months preceding Dec. 31, 2014.
On April 1, Gilead Sciences and Royalty Pharma Collection Trust filed suit against Actavis in the U.S. District of Delaware. The two filing parties are seeking to keep Actavis from commercializing its abbreviated new drug application product before the expiration of U.S. patent number RE42,462.
Actavis believes it may be the first applicant to file an abbreviated new drug application for the generic version of Letairis, according to available information. Should the application be approved, Actavis may be entitled to 180 days of generic market exclusivity.
The lawsuit was filed under the requirements of the Hatch-Waxman Act, which will result in a stay of final FDA approval of Actavis’ application for up to 30 months from the date the plaintiffs were made aware of Actavis’ application filing, or until the matter is resolved.