Actelion has reported that its macitentan drug, a dual endothelin receptor antagonist, met its primary endpoint in a study involving 742 patients suffering from pulmonary arterial hypertension (PAH).
The Study with an Endothelin Receptor Antagonist in Pulmonary Arterial Hypertension to Improve Clinical Outcome (SERAPHIN) is a randomised controlled pivotal Phase III trial designed to evaluate the efficacy and safety of macitentan.
At both 3mg and 10mg dose, macitentan decreased the primary endpoint of time to morbidity and all-cause mortality event in patients with symptomatic PAH compared to placebo.
In the 10mg dose group, the risk of morbidity/mortality was reduced by 45%, while at 3mg dose the observed risk reduction was 30%.
The study's secondary efficacy endpoints included change from baseline to month six in six-minute walk-distance, change from baseline to month six in WHO functional class and time over the whole treatment period to either death due to PAH or hospitalisation due to PAH.
Elevations of liver alanine or aspartate aminotransferases greater than three times the upper limit of normal were observed in 4.5% of patients receiving placebo, in 3.6% of patients on 3mg of macitentan and in 3.4% of patients on 10mg of macitentan.
Actelion chief executive officer Jean-Paul Clozel said they are committed to working with the Health Authorities to bring the important advancement in PAH to patients as soon as possible.
"Submission of the registration dossier to Health Authorities worldwide is expected by the fourth quarter of 2012," Clozel added.
Hospital Antoine Beclere-Clamart, France, Department of Pulmonary Disease and Intensive Care Unit head and senior advisor on SERAPHIN Gerald Simonneau said the study data represent an important milestone in the history of clinical trials in PAH and show that macitentan has the potential to offer a new treatment paradigm for the patients.
Pulmonary arterial hypertension is a chronic, life-threatening disorder characterised by abnormally high blood pressure in the arteries between the heart and lungs of an affected individual.