The FDA has removed the Risk Evaluation and Mitigation Strategy (REMS) requirement for the endothelin receptor antagonists ambrisentan (Letairis, and generics), bosentan (Tracleer, and generics), macitentan (Opsumit, and generics; Opsynvi), and aprocitentan (Tryvio), and the endothelin receptor antagonist and angiotensin II receptor antagonist sparsentan (Filspari) that was initially implemented because of a possible risk of embryofetal toxicity.