Clot-regression effects of rivaroxaban in venous thromboembolism treatment in cancer patients-a prospective interventional study.

Rivaroxaban, a direct oral anticoagulant, is effective against venous thromboembolism (VTE) recurrence without increasing the risk of major bleeding in patients with cancer-associated venous thromboembolism (CAT). However, its clot regression effects are poorly understood. This single-arm, prospective interventional study aimed to investigate the clot regression effects of rivaroxaban in 40 CAT patients, through a contrast-enhanced computed tomography at baseline, 3 weeks, and 3 months of rivaroxaban treatment. The primary endpoint was the clot-regression ratio calculated from the thrombus volumes at 3 weeks and 3 months. Compared with baseline, the total clot volume was significantly reduced at both 3 weeks and 3 months after initiation (p < 0.01). The clot-regression rates were statistically significant with 83.1% (95% confidence interval [CI], 73.8-92.3%) at 3 weeks and 98.7% (95% CI, 97.1-100.2%) at 3 months, with complete resolution in 36.1% and 80.8% of patients at 3 weeks and 3 months, respectively. One patient had recurrent VTE after dose reduction, and seven had non-fatal major bleeding. Therefore, rivaroxaban had a sufficient clot-regression effect against CAT with caution of bleeding complication.

Clot regression effects of rivaroxaban in the treatment of venous thromboembolism in patients with cancer (CRERIT-VTE cancer): study protocol.

INTRODUCTION: Anticoagulant therapy in patients with cancer with venous thromboembolism (VTE) increases the risk of both VTE recurrence and haemorrhagic complication. Direct oral anticoagulants (DOACs) have been shown to be effective in preventing VTE recurrence, and comparable to conventional therapy in preventing VTE recurrence in patients with advanced cancer. Rivaroxaban is a DOAC that causes thrombus regression, possibly through a profibrinolytic effect. Thrombus regression with initial treatment is essential for VTE patients. However, the thrombolytic effect of DOAC for VTE patients with cancer has not been fully examined. Therefore, in this study, we investigate the thrombolytic effect of rivaroxaban in patients with cancer who develop VTE. METHODS AND ANALYSIS: This study is a single-arm, open-label, prospective interventional study. Forty patients aged from 20 to 75 years old at the time of consent who have been diagnosed with acute VTE and have active cancer are included. Patients are excluded if they have received thrombolytic therapy, have creatinine clearance of less than 30 mL/min, have expected a life expectancy of less than 6 months or have deep vein thrombosis limited to the distal lower leg. Eligible patients receive standard treatment with rivaroxaban (15 mg two times daily for 3 weeks, followed by 15 mg QD). The primary study endpoint is clot regression ratio as evaluated by contrast-enhanced CT imaging. CT imaging is obtained at baseline, 21±4 and 90±14 days after the start of rivaroxaban treatment. Secondary endpoints are the recurrence of VTE and haemorrhagic complications. ETHICS AND DISSEMINATION: This study was approved by the institutional review board of the Kyoto Prefectural University of Medicine. Study results will be disseminated through peer-reviewed journals.Trial registration numberUMIN000027793.