Low dose apixaban as secondary prophylaxis of venous thromboembolism in cancer patients – 30 months follow‐up

BACKGROUND: There are no data on the effect of low-dose anticoagulation as secondary prophylaxis for venous thromboembolism (VTE) in cancer patients. We assessed the efficacy and safety of low-dose apixaban for 30 months, after initial 6 months of full-dose treatment. METHODS: We included 298 patients with cancer and any type of VTE in a single arm interventional clinical trial. All patients were treated with full-dose apixaban (5 mg twice daily) for 6 months. Total 196 patients with active cancer after 6 months treatment continued with apixaban 2.5 mg twice daily for another 30 months. The main endpoints were recurrent VTE, major bleeding and clinically relevant non-major bleeding. RESULTS: During the 30 months of treatment with low-dose apixaban 14 (7.6%; 95% confidence interval (CI) 4.0%-11.7%) patients experienced recurrent VTE, six (3.1%; 95% CI 1.1%-6.5%) experienced major bleeding and 16 (8.1%, 95% CI: 4.7%-12.8%) experienced clinically relevant non-major bleeding. The incidence rate per person month of recurrent VTE was 0.8% (95% CI 0.41-1.6) at 2-6 months with full-dose apixaban, and 1.0% (95% CI 0.5-1.9) at 7-12 months with low-dose apixaban. The incidence rate of major bleeding was 1.1% (95% CI 0.6-2.0) at 2-6 months, and 0.3% (95% CI 0.1-1.0) at 7-12 months. Between 12 and 36 months the incidence rate of recurrent VTE and major bleedings remained low. CONCLUSION: Dose reduction of apixaban to 2.5 mg twice daily seems safe after 6 months of full-dose treatment. After 12 months the incidence rate of recurrent VTE and major bleeding remained low.