Data on the clinical use of the oral, direct factor Xa inhibitor apixaban in pediatric patients with heart disease correlated well with experiences in adults, according to findings of a multinational, randomized trial. Bleeding and thromboembolism were infrequent on apixaban, and the current standard of care (SOC), vitamin K antagonists or low-molecular-weight heparin, has “significant disadvantages,” the authors write. “These results support the use of apixaban as an alternative to SOC for thromboprophylaxis in pediatric heart disease.”
Children (ages, 28 days to <18 years) with heart disease requiring thromboprophylaxis were enrolled in the phase 2, open-label trial of apixaban or SOC for 1 year. With a primary endpoint of a composite of adjudicated major or clinically relevant nonmajor bleeding, the study showed the following: “From 2017 to 2021, 192 participants were randomized, 129 apixaban and 63 SOC. Diagnoses included single ventricle (74%), Kawasaki disease (14%), and other heart disease (12%). One apixaban participant (0.8%) and 3 with SOC (4.8%) had major or clinically relevant nonmajor bleeding (% difference −4.0 [95% CI: −12.8 to 0.8]). Apixaban incidence rate for all bleeding events was nearly twice the rate of SOC (100.0 vs 58.2 per 100 person-years), driven by 12 participants with ≥4 minor bleeding events. No thromboembolic events or deaths occurred in either arm. Apixaban pediatric PK steady-state exposures were consistent with adult levels.”