Once-Daily Versus Twice-Daily Enoxaparin for the Treatment of Acute Venous Thromboembolism in Cancer Patients

Background: No randomized controlled trials have investigated enoxaparin once versus twice daily for venous thromboembolism (VTE) treatment in cancer patients. Objective: To compare the safety and efficacy of enoxaparin 1 mg/kg twice daily versus enoxaparin 1.5 mg/kg/day for the treatment of acute VTE in cancer patients. Methods: This was a single-center, retrospective, observational cohort study. Adults with active cancer and an acute VTE were included. The primary outcome evaluated was the incidence of clinically relevant (major and nonmajor) bleeding (CRB) within 30 days of enoxaparin initiation. Secondary outcomes included the incidence of CRB, thrombosis, and death at 30, 90, and 180 days. The study protocol was approved by the institutional review board. Results: A total of 123 patients met inclusion criteria; 85 patients (69%) were treated with once-daily and 38 patients (31%) with twice-daily enoxaparin. CRB was numerically higher at 30 days in the twice-daily enoxaparin group compared with the once-daily group (5.3% vs 2.4%, P = 0.587). There was a nonsignificant higher incidence of CRB in the once-daily enoxaparin group compared with the twice-daily group at 90 days (8.3% vs 8%, P = 1.0) and 180 days (12.5% vs 7.1%, P = 1.0). The composite outcome of CRB, thrombosis, and death was higher at all time points with enoxaparin once daily. Conclusions: Lack of statistical power in this study precludes definitive conclusions. Clinicians may consider twice-daily enoxaparin because of potentially fewer adverse events but may be limited by patient preference and/or financial constraints.