A novel therapy that would allow doctors to turn the body's blood-clotting ability off and on in a more controlled way was about as effective as established anticoagulants in patients undergoing angioplasty but was associated with higher rates of moderate to severe bleeding, according to an analysis of data from a terminated Phase III trial presented at the American College of Cardiology's 64th Annual Scientific Session. The study was officially halted in August due to an excess of severe allergic reactions, so authors caution that the data should be considered exploratory given the early termination.
Before the trial was stopped, 3,232 patients undergoing angioplasty, a procedure to open blocked coronary arteries, were enrolled in the study at 225 hospitals in 17 countries including North America and Europe. The study was designed to compare the safety and efficacy of the REG1 Anticoagulation System and bivalirudin--a commonly used anticoagulant--in a total of 13,200 patients. Patients were equally randomized to the bivalirudin or REG1 in an open-label fashion and data was collected at three and 30 days.
No differences were found between patients receiving REG1 compared to bivalirudin in terms of the study's primary efficacy endpoint--a composite of all-cause death, heart attack, stroke or urgent revascularization, which was reported in 6.7 percent of patients in the REG1 arm and 6.4 percent of patients receiving bivalirudin three days after angioplasty. Efficacy was still comparable at 30 days.
The REG1 system failed to show a benefit in the primary safety endpoint of bleeding compared to bivalirudin. Using a validated bleeding scale, patients receiving REG1 had a 0.4 percent rate of severe or fatal bleeding compared to 0.1 percent with patients who were given bivalirudin for anticoagulation. Moderate to severe bleeding was significantly higher in the REG1 group compared with bivalirudin.