In clinical trials, the drug was compared with warfarin and placebo.

After an initial course of treatment for venous thromboembolism (VTE), extended warfarin therapy lowers risk for recurrent VTE — but at the expense of excess risk for bleeding. Dabigatran (Pradaxa) now has been examined for this indication in two placebo-controlled, industry-sponsored trials.

One trial included nearly 2900 VTE patients at especially high risk for recurrence; after initial treatment (mean, 7 months), they were randomized to receive either dabigatran or warfarin. During extended treatment that averaged 16 months, the incidence of symptomatic or fatal VTE was 1.8% with dabigatran and 1.3% with warfarin, a result that met criteria for “noninferiority” of dabigatran. Major or clinically relevant bleeding was significantly less common with dabigatran than with warfarin (5.6% vs. 10.2%).

Another trial included about 1300 VTE patients at lower risk for recurrence than patients in the first trial; after initial treatment (mean, 10 months), they were randomized to receive either dabigatran or placebo. During extended treatment that averaged 5.5 months, the incidence of symptomatic or fatal VTE was significantly lower with dabigatran than with placebo (0.4% vs. 5.6%). Major or clinically relevant bleeding was significantly more common with dabigatran than with placebo (5.3% vs. 1.8%).

Comment: Dabigatran’s efficacy was similar to that of warfarin and superior to that of placebo; dabigatran caused less bleeding than warfarin but more bleeding than placebo. One worrisome observation was a small excess of adverse coronary events with dabigatran in the high-risk trial — an outcome that has been noted in previous dabigatran trials (JW Cardiol Feb 15 2012). Dabigatran has not yet been FDA approved for deep venous thrombosis treatment or prophylaxis.

Source: Journal Watch General Medicine