Fondaparinux for the treatment of superficial vein thrombosis in the legs

Abstract

The efficacy and safety of anticoagulant treatment for patients with acute, symptom- atic superf icial-vein thrombosis in the legs, but without concomitant deep-vein thrombosis or symptomatic pulmonary embolism at presentation, have not been es- tablished.

Methods In a randomized, double-blind trial, we assigned 3002 patients to receive either fonda- parinux, administered subcutaneously at a dose of 2.5 mg once daily, or placebo for 45 days. The primary eff icacy outcome was a composite of death from any cause or symptomatic pulmonary embolism, symptomatic deep-vein thrombosis, or symp- tomatic extension to the saphenofemoral junction or symptomatic recurrence of superf icial-vein thrombosis at day 47. The main safety outcome was major bleeding. The patients were followed until day 77.

Results The primary eff icacy outcome occurred in 13 of 1502 patients (0.9%) in the fonda- parinux group and 88 of 1500 patients (5.9%) in the placebo group (relative risk reduction with fondaparinux, 85%; 95% conf idence interval [CI], 74 to 92; P<0.001). The incidence of each component of the primary efficacy outcome was significantly reduced in the fondaparinux group as compared with the placebo group, except for the outcome of death (0.1% in both groups). The rate of pulmonary embolism or deep-vein thrombosis was 85% lower in the fondaparinux group than in the pla- cebo group (0.2% vs. 1.3%; 95% CI, 50 to 95; P<0.001). Similar risk reductions were observed at day 77. A total of 88 patients would need to be treated to prevent one instance of pulmonary embolism or deep-vein thrombosis. Major bleeding occurred in one patient in each group. The incidence of serious adverse events was 0.7% with fondaparinux and 1.1% with placebo.

Conclusions Fondaparinux at a dose of 2.5 mg once a day for 45 days was effective in the treat- ment of patients with acute, symptomatic superf icial-vein thrombosis of the legs and did not have serious side effects. (Funded by GlaxoSmithKline; ClinicalTrials .gov number, NCT00443053.)