A new, reversible antiplatelet drug did not demonstrate superiority over a current irreversible one in reducing the composite of death, heart attack or ischemia-related revascularization in the 48 hours after angioplasty, researchers reported in a late-breaking clinical trial presentation at the American Heart Association's Scientific Sessions 2009.
The primary endpoint for CHAMPION PCI was not met, but study researchers say they did find some potential benefit of the new drug, cangrelor, that warrants further investigation.
"Our findings combined with those from a companion trial (CHAMPION PLATFORM) suggest that cangrelor reduces the risk of some clinically meaningful ischemic events in patients undergoing percutaneous coronary intervention (PCI)," said Robert A. Harrington, M.D., principal investigator of the study and professor of medicine at Duke University and director of the Duke Clinical Research Institute in Durham NC. "That includes a possible reduction in Q wave infarction and stent thrombosis."
In CHAMPION PCI -- a phase III, multi-national (200 sites, 18 countries), randomized, double-blind, placebo-controlled trial-- researchers tested the hypothesis that cangrelor provides superior or at least non-inferior performance compared to a 600 milligram (mg) dose of clopidogrel during the 48 hours after PCI.
Investigators planned to enroll about 9,000 patients, but the trial was stopped early (May 2009) with 8,820 patients enrolled after an interim review panel concluded it was unlikely to meet its primary endpoint.
Patients were randomly assigned to receive cangrelor or clopidogrel, the FDA-approved antiplatelet drug that binds irreversibly to platelets.
Those in the cangrelor group got 30 micrograms (mcg) of cangrelor per kilogram (kg) of body weight intravenously, followed by a 4 mcg/kg/per minute infusion for at least two hours. At the end of the procedure, they received a 600 milligram (mg) dose of clopidogrel.
Patients in the clopidogrel group received a standard 600 mg loading dose immediately prior to their PCI. Following the procedure all patients received a maintenance dose of 75 mg of clopidogrel and aspirin therapy (75 mg to 325 mg/day) for at least 30 days thereafter.
Patients received all other anti-clotting therapies according to care standards at their treatment site.