The FDA today approved macitentan (Opsumit,\u00a0Actelion), a new oral endothelin-receptor antagonist that is an enhanced version of the company’s bosentan (Tracleer).\u00a0The drug is indicated to delay disease progression in patients who have\u00a0pulmonary arterial hypertension (WHO Group I).<\/p>\n
Last August the results of the pivotal phase 3 trial, SERAPHIN (Study with an Endothelin Receptor Antagonist in Pulmonary Arterial Hypertension to Improve Clinical Outcome), were\u00a0published in the\u00a0New England Journal of Medicine<\/em><\/a>. After 2 years of treatment with macitentan or placebo, significant reductions in the primary endpoint (a composite endpoint of\u00a0death, atrial septostomy, lung transplantation, initiation of treatment with intravenous or subcutaneous prostanoids, or worsening of pulmonary arterial hypertension) occurred in the patients who took macitentan. The best results were seen in the group which took 10 mg of macitentan, the dose approved by the FDA.<\/p>\n The Opsumit label will contain a boxed warning that the drug should not be used in pregnant women since it can harm the fetus. Women will be only able to receive the drug through a\u00a0Risk Evaluation and Mitigation Strategy (REMS) Program. The program will require prescribers and pharmacies to be certified. Female patients will need to be enrolled in the program and comply with applicable pregnancy testing and contraception requirements, the FDA\u00a0said<\/a>.<\/p>\n