Credit: Andre E.X. Brown
SAN FRANCISCO—The novel antiplatelet agent cangrelor is more effective than clopidogrel as thromboprophylaxis for patients undergoing coronary stent procedures, results of the CHAMPION PHOENIX trial suggest.
Researchers found that intravenous cangrelor reduced the overall odds of complications from stenting procedures, including death, myocardial infarction, ischemia-driven revascularization, and stent thrombosis.
Treatment with cangrelor also resulted in significantly higher rates of major and minor bleeding as compared to clopidogrel. But the rates of severe bleeding were similar between the treatment arms.
These data were presented on March 10 at the 2013 American College of Cardiology Scientific Session and simultaneously published in NEJM. The study was sponsored by The Medicines Company, the makers of cangrelor.
“We are very excited about the potential for this new medication to reduce complications in patients receiving coronary stents for a wide variety of indications,” said investigator Deepak L. Bhatt, MD, MPH, of Brigham and Women’s Hospital in Boston.
“In addition to being much quicker to take effect and more potent than currently available treatment options, this intravenous drug is reversible and has a fast offset of action, which could be an advantage if emergency surgery is needed.”
In this randomized, double-blind trial, Dr Bhatt and his colleagues compared cangrelor to clopidogrel in 11,145 patients treated at 153 centers around the world.
The study included patients who were undergoing elective or urgent percutaneous coronary intervention. Patients with a high risk of bleeding or recent exposure to other anticoagulants were excluded.
The study’s primary efficacy endpoint was the incidence of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis.
At 48 hours, 4.7% of patients in the cangrelor arm had met this endpoint, compared to 5.9% of patients in the clopidogrel arm (P=0.005). At 30 days, the incidence was 6.0% in the cangrelor arm and 7.0% in the clopidogrel arm (P=0.03).
A secondary endpoint was the rate of stent thrombosis alone. At 48 hours, 0.8% of patients in the cangrelor arm had stent thrombosis, as did 1.4% of patients in the clopidogrel arm (P=0.01). At 30 days, the rate was 1.3% in the cangrelor arm and 1.9% in the clopidogrel arm (P=0.01).
The primary safety endpoint was severe bleeding according to GUSTO criteria. At 48 hours, it measured 0.16% in the cangrelor arm and 0.11% in the clopidogrel arm (P=0.44).
Secondary endpoints included major and minor bleeding (not related to coronary artery bypass grafting) according to ACUITY criteria.
Major bleeding occurred in 4.3% of patients on cangrelor and 2.5% of patients on clopidogrel (P<0.001). And minor bleeding occurred in 11.8% of patients on cangrelor and 8.6% of patients on clopidogrel (P<0.001).
Other treatment-emergent adverse events included agitation, diarrhea, chest pain, dyspnea, and procedural pain. There were significantly more cases of transient dyspnea with cangrelor
than with clopidogrel, at 1.2% and 0.3%, respectively (P<0.001). But there were no statistically significant differences with regard to adverse events other than those mentioned here.
The overall rate of treatment-related adverse events was 20.2% in the cangrelor arm and 19.1% in the clopidogrel arm (P=0.13). And these events led to treatment discontinuation in 0.5% of patients in the cangrelor arm and 0.4% of patients in the clopidogrel arm.
“The investigators feel the data are compelling,” Dr Bhatt concluded. “The data we’ve shown are clear and consistent across all relevant subgroups or patient populations. [Cangrelor] has several advantages, and nothing out there right now has quite the same biological properties.”
