Safety and efficacy of direct oral anticoagulants in pediatric oncology patients: real-world data from two quaternary care pediatric centers

Background Pivotal, phase 3 randomized controlled trials have led to the approval of direct oral anticoagulants (DOACs) for both the management of venous thromboembolism (VTE) and thromboprophylaxis in children. However, few children with cancer-associated thrombosis were enrolled in these trials. There is consequently a need for well-designed observational studies to address current gaps in the pediatric literature. Objectives The principal objective of this retrospective cohort study was to investigate the safety and efficacy of DOACs for both treatment and prophylaxis of cancer-associated VTE in children. Methods Prospectively maintained databases at 2 quaternary care children’s hospitals were queried for children diagnosed with cancer who received a DOAC for either treatment of VTE or thromboprophylaxis. Medical records of eligible subjects were reviewed for clinical and radiological characteristics. Results Fifty-one patients (53% female) met eligibility. Forty-seven (92%) patients received DOACs in the setting of a VTE diagnosis (treatment and secondary thromboprophylaxis), while 4 (8%) patients received DOACs for primary thromboprophylaxis. The median age at VTE diagnosis was 14.4 years. Rivaroxaban and apixaban were used in 55% and 45% of patients, respectively. Therapeutic and prophylactic-intensity DOACs were administered in 86% and 78% of patients, respectively, with many patients receiving both. Recurrent/progressive thrombosis occurred in 4 patients (8%). Major and clinically relevant nonmajor bleeding were reported in 6% and 20% of patients, respectively. No deaths were attributed to thrombosis or anticoagulant-related bleeding. Conclusion Rates of recurrent/progressive thrombosis and clinically relevant bleeding in our cohort of children with cancer-associated thrombosis are higher than those reported in previous studies, highlighting the importance of real-world data.