Meta-analysis of the efficacy and safety of new oral anticoagulants in patients with cancer-associated acute venous thromboembolism

Introduction: Treatment of acute venous thromboembolism (VTE) in cancer patients is challenging, owing to a high risk of recurrent VTE and bleeding complications. The anticoagulants of choice are low molecular weight heparins (LMWHs), because of a proven higher efficacy than vitamin K antagonists (VKAs) and a similar bleeding profile. The recently introduced new oral anticoagulants (NOACs) have the potential to be alternative options for these patients, as these drugs share practical advantages with LMWH, are administered orally, and had similar efficacy to VKAs but a lower bleeding risk in phase 3 studies in the general VTE population. Methods: A systematic literature search was performed to identify phase 3 trials investigating NOACs for the treatment of VTE. The efficacy outcome was recurrent VTE, and the safety outcome was major and clinically relevant non-major bleeding. Pooled incidence rates and risk ratios (RRs) were calculated for cancer patients and non-cancer patients separately. Results and discussion: Five studies were included, with 19 060 patients, of whom 973 (5.1%) had active cancer. The pooled incidence rates of recurrent VTE were 4.1% (95% confidence interval [CI] 2.6-6.0) in cancer patients treated with NOACs, and 6.1% (95% CI 4.1-8.5) in patients treated with VKAs (RR 0.66, 95% CI 0.38-1.2). The pooled incidence rates of major or non-major clinically relevant bleeding were 15% (95% CI 12-18) in cancer patients treated with NOACs, and 16% (95% CI 9.9-22) in patients treated with VKAs (RR 0.94, 95% CI 0.70-1.3). These results form a solid basis for the initiation of a head-to-head comparison of NOACs with LMWH in cancer patients.