Dabigatran used beyond the initial 3 months of treatment at a dose of 150 mg twice daily reduced the risk of recurrent venous thromboembolism (VTE), according to a study published February 21 in the New England Journal of Medicine.
VTE is the third most common cardiovascular disorder after heart disease and stroke, and consists of two related conditions caused by blood clots: deep vein thrombosis and pulmonary embolism. There are an estimated 900,000 VTE events per year in the United States. Further, roughly one-third of people with VTE will have a recurrence within 10 years.
In two double-blind, randomized trials, RE-MEDY and RE-SONATE, the researchers compared dabigatran at a dose of 150 mg twice daily with warfarin (active-control study) or with placebo (placebo-control study) in patients with VTE who had completed at least 3 initial months of therapy.
In RE-MEDY, 2,856 patients were randomized to dabigatran 150 mg (n=1,430) or warfarin (n=1,426) for an extended treatment period of 6 to 36 months. RE-MEDY demonstrated that treatment with dabigatran 150 mg twice daily was non-inferior to warfarin (P=0.01) in preventing recurrent VTE, including VTE-related death. There were fewer major bleeding events in patients with a prior history of VTE receiving dabigatran compared with those receiving warfarin. There was also a significantly lower risk (46%) of major or clinically relevant bleeding events in this same set of patients.
The RE-SONATE trial included 1,343 VTE patients, randomized to dabigatran 150 mg (n=681) or placebo (n=662) for 6 months with extended follow-up to evaluate the long-term risk of recurrence (12 months after completion of study treatment). RE-SONATE demonstrated dabigatran was superior to placebo for the prevention of first recurrent or fatal VTE with a risk reduction of 92% during the treatment period (P<.001). Lower event rates were reported across all secondary efficacy end points for dabigatran over placebo.
The incidence of major bleeding was two patients in the dabigatran group versus none in the placebo group. Combined rates of major or clinically relevant bleeding were significantly higher in patients receiving dabigatran (n=36) as compared with those receiving placebo (n=12).
“Patients who suffer one VTE event are at increased risk of suffering another, with the risk accumulating over time, so it is important to investigate treatment that might help reduce the risk over an extended period of time,” said Sam Schulman, MD, PhD, FRCPC(C), lead study author and professor, department of medicine, McMaster University, Ontario, Canada.
“Most patients with VTE receive treatment for at least 3 months, longer for patients with risk factors for recurrence,” Dr. Schulman said. “These trials assessed duration of treatment beyond 3 to 6 months, showing that dabigatran 150 mg twice daily reduces the risk of recurrent VTE. The results also indicate lower risk of clinically relevant bleeding with dabigatran compared to warfarin and a higher risk compared to placebo.”