Gilead (Myogen / GSK)

Ambrisentan® is a non-sulfonamide, propanoic acid-class, endothelin receptor antagonist that is selective for the endothelin type-A (ETA) receptor. Activation of the ETA receptor by endothelin, a small peptide hormone, leads to vasoconstriction and cell proliferation. PAH is associated with elevated endothelin blood levels. Ambrisentan has been granted orphan drug designation for the treatment of PAH in both the United States and European Union. Currently in Phase III trials.