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.