Direct Oral Factor Xa Inhibitors for the Treatment of Acute Cancer-Associated Venous Thromboembolism: A Systematic Review and Network Meta-analysis

Objective: To explore the efficacy and safety of direct oral factor Xa inhibitors in the treatment of cancer-associated acute venous thromboembolism (VTE). Patients and Methods: MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), and Embase databases were searched for trials comparing direct oral anticoagulants (DOACs) to dalteparin for the management of cancer-associated acute VTE. Databases were searched from inception to September 19, 2018. A network meta-analysis using both frequentist and Bayesian methods was performed to analyze VTE recurrence and major and clinically relevant nonmajor bleeding. Results: We identified 3 randomized controlled trials, at low risk of bias, that enrolled 1739 patients with cancer-associated VTE. Direct comparison revealed a lower rate of VTE recurrence in DOAC compared with dalteparin groups (odds ratio [OR], 0.48; 95% CI, 0.24-0.96; I²=46%). Indirect comparison suggested that apixaban had greater reduction in VTE recurrence compared with dalteparin (OR, 0.10; 95% CI, 0.01-0.82) but not rivaroxaban or edoxaban. Apixaban also had the highest probability of being ranked most effective. By direct comparisons, there was an increased likelihood of major bleeding in the DOAC group compared with dalteparin (OR, 1.70; 95% CI, 1.04-2.78). Clinically relevant nonmajor bleeding did not differ. Indirect estimates were imprecise. Subgroup analyses in gastrointestinal cancers suggested that dalteparin may have the lowest risk of bleeding, whereas estimates in urothelial cancer were imprecise. Conclusion: Direct oral anticoagulants appear to lower the risk of VTE recurrence compared with dalteparin while increasing major bleeding. Apixaban may be associated with the lowest risk of VTE recurrence compared with the other DOACs.