Background: Extended thromboprophylaxis with full-dose betrixaban is effective in preventing venous thromboembolism (VTE). However, its effect on the hard endpoint of VTE-related mortality has not been assessed.
Methods: In the APEX trial, 7,513 acutely ill hospitalized medical patients were randomized to receive either extended-duration betrixaban (35 to 42 days) or standard-duration enoxaparin (10 ± 4 days) for VTE prevention. The full-dose regimen (betrixaban 80 mg daily) was administered to subjects who had a creatinine clearance of > 30 mL/min and were not administered a strong P-glycoprotein inhibitor. On an “as-treated” basis (which includes those patients who were stratified to the 40 mg dose but received 80 mg), the rate of VTE-related mortality was compared between two arms at 42 days (end of extended thromboprophylaxis) and at 77 days (end of follow-up) to assess the “legacy effect” of thromboprophylaxis.
Results: At 42 days, VTE-related death occurred in 9 (0.31%) and 14 (0.59%) patients in the betrixaban and enoxaparin group, respectively (HR = 0.65 [95% CI: 0.28-1.49]; P = 0.30). At 77 days, the risk was significantly lower among patients who received betrixaban, with 10 (0.34%) events in the betrixaban group vs. 22 (0.79%) in the enoxaparin group (HR = 0.46 [0.22-0.96]; P = 0.0348; number needed to treat = 223).
Conclusions: Patients who were administered the full 80 mg dose of extended duration betrixaban experienced a lower rate of mortality compared with standard duration / dose enoxaparin.
Figure: Cumulative incidence of VTE-related mortality in patients who received full-dose regimen of extended-duration betrixaban vs. standard-duration enoxaparin