Thrombosis and bleedings in a cohort of cancer patients treated with apixaban for venous thromboembolism

Introduction: The direct oral anti-coagulants (DOAC) edoxaban and rivaroxaban are suggested treatment alternatives for cancer-associated venous thromboembolism (VTE) together with low molecular-weight heparins. New studies indicate that the DOAC apixaban also is an option for cancer-associated VTE. The current study assessed recurrent VTE, arterial thrombosis, bleedings and adverse events in a cohort of apixaban treated cancer patients with VTE. Materials and methods: Single-arm, interventional study of apixaban as treatment of cancer-associated VTE. Inclusion criteria were cancer with objectively verified VTE. Patients received apixaban 10 mg bid for seven days, then 5 mg bid for six months. Primary efficacy and safety outcomes were recurrent VTE and bleeding respectively. This trial is registered with ClinicalTrials.gov identifier NCT02581176. Results: We recruited 298 cancer patients with VTE. During six months treatment, recurrent VTE or death related to VTE occurred in 12 patients (4.0%, 95% confidence interval (CI) 2.1-6.9%). Major bleeding occurred in 16 patients (5.4%, 95% CI 2.8-7.9), most frequently gastrointestinal bleeding. There were no overrepresentation of major bleedings among patients with gastrointestinal cancer (7/126, 5.5%, 95% CI 2.3-11%). Twenty-six patients experienced one or more clinically relevant non-major bleedings (8.9%, 95% CI 5.5-12%). Twelve patients had arterial thrombosis (4.0%, 95% CI 2.1-6.9%), of which the majority were strokes in patients with pancreatic cancer. Death occurred in 35 patients (12%, 95% CI 8.3-16%). Conclusion: The frequency of recurrent VTE and major bleedings are in line with other studies on apixaban in cancer-associated VTE. Arterial thrombosis was a frequent serious adverse event.