The FDA approved macitentan as a treatment for adults with pulmonary arterial hypertension (PAH).
Macitentan (Opsumit, Actelion Pharmaceuticals) is an endothelin receptor blocker. It has a boxed warning that explains the drug should not be used in pregnant women because it can harm the fetus. Female patients can receive the drug only through the Opsumit Risk Evaluation and Mitigation Strategy Program.
The FDA assessed its safety and efficacy based on a placebo-controlled randomized clinical trial that enrolled 742 participants with a two-year follow-up. Results showed that macitentan delayed progression of PAH.