Safety and Efficacy of Apixaban vs Enoxaparin for Preventing Postoperative Venous Thromboembolism in Women Undergoing Surgery for Gynecologic Malignant Neoplasm

Importance: Current guidelines recommend a 28-day course of enoxaparin for thromboprophylaxis after surgery for gynecologic cancer. The high cost of this medication and the low adherence rates observed in prior studies provide an opportunity to benefit patients by demonstrating the safety of a more cost-effective, easier to use thromboprophylactic. Objective: To investigate the safety and efficacy of an oral treatment alternative for thromboprophylaxis in postoperative patients with gynecologic cancer. Design, Setting, and Participants: This was a patient-based, multicenter, open-label, blinded, end point, randomized clinical trial conducted May 2015 to March 2019 in outpatient and inpatient gynecologic oncology settings. Women undergoing surgery for suspected or confirmed gynecologic cancer were approached for recruitment. The trial compared rates of major bleeding and clinically relevant nonmajor bleeding events during a 90-day follow-up period in patients taking apixaban or enoxaparin for postoperative thromboprophylaxis using a modified intent-to-treat analysis. Data analysis was performed from October to December 2019. Interventions: Women were randomized to 28 days of apixaban (2.5 mg orally twice daily) or enoxaparin (40 mg subcutaneously daily). Main Outcomes and Measures: The primary outcome was major bleeding and clinically relevant nonmajor bleeding events. Secondary outcomes included incidence of venous thromboembolic events, adverse events, medication adherence, participant quality of life, and medication satisfaction. Results: Of 500 women recruited for the study, 400 were enrolled and randomized (median age, 58.0 years; range, 18.0-89.0 years); 204 received apixaban and 196 received enoxaparin. Treatment groups did not differ in terms of race/ethnicity, cancer stage, or surgery modality (open vs robotic). There were no statistically significant differences between the apixaban and enoxaparin groups in terms of rates of major bleeding events (1 patient 0.5% vs 1 patient 0.5%; odds ratio OR, 1.04; 95% CI, 0.07-16.76; P > .99), clinically relevant nonmajor bleeding events (12 patients 5.4% vs 19 patients 9.7%; OR, 1.88; 95% CI, 0.87-4.1; P = .11), venous thromboembolic events (2 patients 1.0% vs 3 patients 1.5%; OR, 1.57; 95% CI, 0.26-9.50; P = .68), adverse events, medication adherence, or quality of life between the groups. Participant satisfaction was significantly greater in the apixaban group with regard to ease of taking the medication (186 patients 98.9% vs 110 patients 58.8%; OR, 0.06; 95% CI, 0.01-0.25; P < .001) and pain associated with taking the medication (4 patients 2.1% vs 92 patients 49.2%; OR, 9.20; 95% CI, 2.67-31.82; P < .001). Conclusions and Relevance: These findings suggest that oral apixaban is a potentially safe, less painful, and easier-to-take alternative to subcutaneous enoxaparin for thromboprophylaxis after surgery for gynecologic cancer. The efficacy of apixaban to prevent venous thromboembolic events is hypothesized as being equivalent. Trial Registration: ClinicalTrials.gov Identifier: NCT02366871.