Cangrelor: a novel intravenous antiplatelet agent with a questionable future.

Current percutaneous coronary intervention (PCI) guidelines recommend the use of a P2Y12 inhibitor with aspirin and an injectable anticoagulant. However, available oral P2Y12 inhibitor therapy is limited by significant drug interactions, unclear oral absorption in selected clinical conditions, and delayed onset and offset of activity that may be cumbersome for patients requiring coronary artery bypass graft (CABG) surgery. Cangrelor, a novel intravenous P2Y12 inhibitor, offers potential advantages compared with currently available oral agents, particularly in regard to rapid onset and offset of platelet inhibition. The Cangrelor versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition (CHAMPION) trials compared cangrelor versus an oral loading dose of clopidogrel, given before or after PCI, in patients with both stable and acute coronary syndromes. The results were conflicting, but some evidence demonstrated a lower rate of stent thrombosis compared with clopidogrel and lower rates of a composite cardiovascular end point, with comparable bleeding rates. The BRIDGE study assessed cangrelor as a replacement for oral P2Y12 inhibitors in patients awaiting CABG surgery and demonstrated that cangrelor maintained platelet inhibition during the preoperative period and enabled a rapid return to baseline platelet function upon cessation of the infusion. A new drug application was submitted to the Food and Drug Administration (FDA) for use during PCI to prevent thrombotic events and as bridging therapy for patients awaiting surgery who require therapy with P2Y12 inhibitors. In February 2014, the FDA's Cardiovascular and Renal Drugs Advisory Committee recommended against approval due to concerns over an appropriate risk-benefit ratio for use during PCI and a lack of evidence supporting the bridging indication. On April 30, 2014, the FDA issued a Complete Response letter for the PCI and bridging indications, denying approval and requesting further data. The future of this once promising novel intravenous antiplatelet agent is now in question.