Rivaroxaban vs Dalteparin in Cancer-Associated Thromboembolism A Randomized Trial

BACKGROUND: Direct oral anticoagulants (DOACs) are an alternative to low-molecularweight heparin for treating cancer-associated VTE. RESEARCH QUESTION: Is rivaroxaban as efficient and safe as dalteparin to treat patients with cancer-associated VTE? STUDY DESIGN AND METHODS: In a randomized open-label noninferiority trial, patients with active cancer who had proximal DVT, pulmonary embolism (PE), or both were assigned randomly to therapeutic doses of rivaroxaban or dalteparin for 3 months. The primary outcome was the cumulative incidence of recurrent VTE, a composite of symptomatic or incidental DVT or PE, and worsening of pulmonary vascular or venous obstruction at 3 months. RESULTS: Of 158 randomized patients, 74 and 84 patients were assigned to receive rivaroxaban and dalteparin, respectively. Mean agewas 69.4 years, and 115 patients (76.2%) hadmetastatic disease. The primary outcome occurred in 4 and 6 patients in the rivaroxaban and dalteparin groups, respectively (both the intention-to-treat and per-protocol populations: cumulative incidence, 6.4% vs 10.1%; subdistribution hazard ratio [SHR], 0.75; 95% CI, 0.21-2.66). Major bleeding occurred in 1 and 3 patients in the rivaroxaban and dalteparin groups, respectively (cumulative incidence, 1.4% vs 3.7%; SHR, 0.36; 95% CI, 0.04-3.43). Major or clinically relevant nonmajor bleeding occurred in 9 and 8 patients in the rivaroxaban and dalteparin groups, respectively (cumulative incidence, 12.2% vs 9.8%; SHR, 1.27; 95% CI, 0.49-3.26). Overall, 19 patients (25.7%) and 20 patients (23.8%) died in the rivaroxaban and dalteparin groups, respectively (hazard ratio, 1.05; 95% CI, 0.56-1.97). INTERPRETATION: In this trial comparing rivaroxaban and dalteparin in the treatment of cancer-associated VTE, the number of patients was insufficient to reach the predefined criteria for noninferiority, but efficacy and safety results were consistent with those previously reported with DOACs. An updated meta-analysis of randomized trials comparing DOACs with low-molecular-weight heparin in patients with cancer-associated VTE is provided.