Switzerland-based Actelion ( ALIOF ) recently submitted a New Drug Application (NDA) to the US Food and Drug Administration (FDA) for the approval of its pulmonary arterial hypertension (PAH) candidate, macitentan (Opsumit).

Actelion also announced data from its phase III outcome study on macitentan. The phase III outcome study, SERAPHIN, enrolled 742 patients having PAH. Results from the study revealed that treatment with macitentan (10mg once daily) reduced the risk of morbidity and mortality event by 45% compared to placebo. The risk was reduced by 30% in PAH patients treated with the 3 mg dosage of the drug.

Data from the study also revealed that the risk of death or hospitalization due to PAH was 50% and 33% lower for patients in the 10 mg and 3 mg arms respectively compared to placebo. Patients in the study were treated for a period of three and a half years and the candidate was well tolerated among these patients. Actelion reported that the number of serious adverse events was lower in patients treated with macitentan than placebo.

Our View

Actelion currently has three marketed products, Tracleer, Ventavis and Veletri, for the treatment of PAH. We remind investors that during the first nine months of 2012 the company reported a decline in sales in Tracleer and Ventavis from the year-ago period. Veletri, launched in 2010, however did very well during the period.

Actelion currently competes with players such as Gilead Sciences ( GILD - Analyst Report ) and United Therapeutics ( UTHR - Analyst Report ) in the PAH space. We believe that if macitentan is cleared by the FDA, then Actelion’s position in the PAH market would be strengthened further.

Actelion carries a Zacks #2 Rank (Buy) in the short run.