New P2Y12 blockers.

A number of new antiplatelet agents currently in development are anticipated to improve clinical outcomes and safety benefits in patients with acute coronary syndrome (ACS). This article reviews the pharmacology and clinical development of three of these agents: prasugrel, cangrelor, and ticagrelor. Prasugrel, a third-generation, oral thienopyridine, has been shown to be superior to clopidogrel, the current gold standard, in preventing ischemic events in patients with ACS undergoing percutaneous coronary intervention (PCI), although the bleeding rate was higher. Cangrelor, a chemical analog of adenosine triphosphate, is a potent direct platelet P2Y12 antagonist. In development as an intravenous agent, cangrelor is currently being evaluated in two phase III studies in patients requiring PCI. Ticagrelor is the first of a new class of orally available antiplatelet agents antagonizing the effects of ADP mediated by P2Y12; it is currently being studied in a phase III trial in patients with ACS.