Safe and effective use of rivaroxaban for treatment of cancer-associated venous thromboembolic disease: a prospective cohort study.

Low-molecular weight heparin (LMWH) has been the standard of care for treatment of venous thromboembolism (VTE) in patients with cancer. Rivaroxaban was approved in 2012 for the treatment of pulmonary embolism (PE) and deep vein thrombosis (DVT), but no prior studies have been reported specifically evaluating the efficacy and safety of rivaroxaban for cancer-associated thrombosis (CAT). Under a Quality Assessment Initiative (QAI), we established a Clinical Pathway to guide rivaroxaban use for CAT and now report a validation analysis of our first 200 patients. A 200 patient cohort with CAT (PE or symptomatic, proximal DVT), whose full course of anticoagulation was with rivaroxaban, were accrued. In competing risk analysis, primary endpoints at 6 months included new or recurrent PE or symptomatic proximal lower extremity DVT, major bleeding, clinically-relevant non-major bleeding leading to discontinuation of rivaroxaban, or death. In competing risk analysis, the 6 months cumulative incidence of new or recurrent VTE was 4.4 % (95 % CI = 1.4-7.4 %), major bleeding was 2.2 % (95 % CI = 0-4.2 %) and all-cause mortality 17.6 % (95 % CI = 11.7-23.0 %). In this cohort of 200 patients with active cancer and CAT the rates of new or recurrent VTE and major bleeding were comparable to the cancer subgroup analysis from the EINSTEIN studies. The results of our Clinical Pathway provide guidance on Rivaroxaban use for treatment of CAT, and suggest that safety and efficacy is preserved, compared with past-published experience with LMWH.