Swiss bio-technology company Actelion has reported positive results from its macitentan in the treatment of Inoperable chronic thromboembolic pulmonary hypertension (Merit) study of macitentan in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH), a form of pulmonary hypertension.

The Merit study has been conducted as a Phase II prospective, randomised, placebo-controlled, double-blind, multi-centre, parallel-group trial intended to examine the efficacy, safety and tolerability of macitentan.

The study included 80 inoperable patients who were randomised to be administered with 10mg of macitentan and placebo for a period of 24 weeks.

Results suggested that macitentan exhibited a positive impact on exercise capacity of the patients compared to placebo, with a 16% reduction in pulmonary vascular resistance (PVR) observed in the macitentan treatment group.

"The company will now fully analyse the data and discuss the findings with health authorities."

The study also suggsted the safety and tolerability of macitentan consistent with the previous clinical studies. 

Actelion global clinical development head Guy Braunstein said: “Inoperable chronic thromboembolic pulmonary hypertension is associated with a poor prognosis if left untreated, and additional therapeutic options are needed for these patients who are not candidates for surgery. 

"I am very pleased that the study has shown a significant decrease in PVR with macitentan and by the significant improvement in exercise capacity. I would like to thank everyone who has participated in this study.

"The company will now fully analyse the data and discuss the findings with health authorities.”

Actelion has developed macitentan as an orally administered endothelin receptor antagonist.