Actavis Files for Generic Letairis Approval

Actavis is seeking FDA approval for its generic version of Gilead Sciences’ Letairis pulmonary arterial hypertension treatment.

Since Actavis believes it may be the first to file an Abbreviated New Drug Application (ANDA) for generic Letairis, it may be entitled to 180 days of generic market exclusivity for its ambrisentan 5-mg and 10-mg tablets upon FDA approval.

To prevent Actavis from commercializing generic ambrisentan before the expiration of the drug’s patent, Gilead and Royalty Pharma Collection Trust filed a patent infringement lawsuit against Actavis on April 1, 2015, under the provisions of the Hatch-Waxman Act. Given this suit, the FDA cannot grant approval to Actavis's ANDA for up to 30 months from the date the plaintiffs received notice of the ANDA filing, or until final resolution of the matter before the court, whichever occurs sooner.

Letairis is indicated to treat high blood pressure in the arteries of the lungs. Common side effects of the drug include loss of appetite, fever, nausea, and itching, while serious side effects include swelling all over the body, low red blood cell levels, and sperm count reduction.

According to Gilead, Letairis had global sales of approximately $595 million in 2014.