Allergan plc, a global pharmaceutical company and a leader in a new industry model - growth pharma, has filed an Abbreviated New Drug Application (ANDA) with the US Food and Drug Administration (FDA) seeking approval to market treprostinil inhalation solution, 0.6 mg/ml, 2.9 ml ampules.

Allergan's ANDA product is a generic version of United Therapeutics Corporation's Tyvaso, which is indicated for the treatment of pulmonary arterial hypertension (PAH) to improve exercise ability.

United Therapeutics filed suit against Allergan on July 22, 2015 in the US District Court for the District of New Jersey seeking to prevent Allergan 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 Allergan's ANDA for up to 30 months from the date the plaintiffs received notice of Allergan's ANDA filing or until final resolution of the matter before the court, whichever occurs sooner, subject to any other exclusivities.

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

For the 12 months ending December 31, 2014, Tyvaso had US sales of approximately $463 million, according to United Therapeutics.