Opsumit

Macitentan, sold under the brand name Opsumit, is an endothelin receptor antagonist (ERA) developed by Actelion and approved for the treatment of pulmonary arterial hypertension (PAH).[2] The other two ERAs marketed as of 2014 are bosentan and ambrisentan.[2] Macitentan is a dual ERA, meaning that it acts as an antagonist of two endothelin (ET) receptor subtypes, ETA and ETB.[2] However, macitentan has a 50-fold increased selectivity for the ETA... [wikipedia]