Swiss drugmaker Actelion has submitted an application to market macitentan for the treatment of patients with pulmonary arterial hypertension (PAH) in the all important US market.

Macitentan, which will be sold in the US under the brand name Opsumit, is a novel dual endothelin receptor antagonist for which the firm has high hopes in driving its future growth.

The submission to the US Food and Drug Administration included data from the Phase III SERAPHIN trial, which involved 742 patients with PAH randomized to receive either placebo or once-daily macitentan in a 3mg or 10mg dose.

Data from this trial showed that the risk of morbidity and a mortality event was slashed 45% in patients taking the 10mg dose of its drug compared to those given a placebo.

In addition, the observed risk reduction was 30% for patients in the 3mg dose.

Actelion also noted that patients were treated up for up three and a half years, giving a solid set of safety data, which showed that macitentan was well tolerated with the most common side effects being nasopharyngitis, headache and anemia.

If its gets the regulatory green light, the drug could be on the market sometime next year.