Actelion’s GRIPHON Study on PAH Drug Selexipag Yields Promising Data

Actelion Ltd. announced that it will give poster presentation of results from the Phase III GRIPHON clinical trial of selexipag (Uptravi^®). The presentation, to be held at the American College of Chest Physicians’ CHEST Congress in Montréal, Canada, will discuss safety and efficacy results of the investigational drug in pulmonary arterial hypertension (PAH) patients. The abstract for the poster presentation, entitled “Individualized Dosing of Selexipag Based on Tolerability in the GRIPHON Study Shows Consistent Efficacy and Safety in Patients with Pulmonary Arterial Hypertension (PAH),” has been made available online at the CHEST Journal.

PAH is a life-threatening disease characterized by abnormal constriction of the pulmonary artery, leading the heart to work faster and elevating blood pressure in arteries within the lungs, potentially causing heart failure. Selexipag is a highly selective oral prostacyclin receptor (IP) agonist. Activation of the IP receptor induces vasodilation, which decreases blood pressure, and inhibits growth and proliferation of vascular smooth muscle cells.

The GRIPHON study included 1,156 PAH patients between the ages of 18 and 75, representing the largest trial conducted in PAH. Patients were randomly distributed in the selexipag group (574 patients) and the placebo group (582 patients). Those in the medicine group were distributed according to their individualized maintenance dose (IMD) into three groups: low, medium and high. Dosing in the study varied from 200 micrograms initially in the low dose group to a maximum of 1600 micrograms in the high dose group. Actelion had previously announced that, in an initial analysis of the study’s results, selexipag had, up to the end of treatment, significantly decreased the risk of morbidity/morbility events, a primary endpoint, by 40 % when compared to the control (placebo) group. The poster presentation will discuss further data analysis from the study, relating to selexipag dose. Researchers conclude that the effect of selexipag on the primary endpoint was consistently observed in all dose groups. Furthermore, researchers theorize that the IMD, the highest tolerated dose for the drug, was not influenced by patients’ characteristics, such as body mass index or previous therapy for PAH. Adverse events were observed in all dose groups, namely jaw pain, headache, diarrhea, and nausea.

The results, to be presented on October 28 by Dr. Richard Channick from Massachusetts General Hospital, reveal that the study met its primary endpoint, with high statistical significance, and that selexipag is indeed effective and safe as a PAH therapy.