Oral apixaban for the treatment of venous thromboembolism in cancer patients: results from the AMPLIFY trial

The AMPLIFY trial compared apixaban with enoxaparin followed by warfarin for the treatment of acute venous thromboembolism (VTE). To perform a subgroup analysis to compare the efficacy and safety of apixaban and enoxaparin followed by warfarin for the treatment of VTE in patients with cancer enrolled in AMPLIFY. Patients with symptomatic VTE were randomized to a 6-month course of apixaban or enoxaparin followed by warfarin. The primary efficacy outcome and principal safety outcome were recurrent VTE or VTE-related death and major bleeding, respectively. Of the 5395 patients randomized, 169 (3.1%) had active cancer at baseline, and 365 (6.8%) had a history of cancer without active cancer at baseline. Among patients with active cancer, recurrent VTE occurred in 3.7% and 6.4% of evaluable patients in the apixaban and enoxaparin/warfarin groups, respectively (relative risk [RR] 0.56, 95% confidence interval [CI] 0.13-2.37); major bleeding occurred in 2.3% and 5.0% of evaluable patients, respectively (RR 0.45, 95% CI 0.08-2.46). Among patients with a history of cancer, recurrent VTE occurred in 1.1% and 6.3% of evaluable patients in the apixaban and enoxaparin/warfarin groups, respectively (RR 0.17, 95% CI 0.04-0.78); major bleeding occurred in 0.5% and 2.8% of treated patients, respectively (RR 0.20, 95% CI 0.02-1.65). The results of this subgroup analysis suggest that apixaban is a convenient option for cancer patients with VTE. However, additional studies are needed to confirm this concept and to compare apixaban with low molecular weight heparin in these patients