Abstract
BACKGROUND: Evidence regarding the safety and efficacy of anticoagulant thromboprophylaxis among pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) is limited. We sought to evaluate safety, dose-finding, and preliminary efficacy of twice-daily enoxaparin as primary thromboprophylaxis among children hospitalized for symptomatic COVID-19, including primary respiratory infection and multisystem inflammatory syndrome in children (MISC). METHODS: We performed a phase 2, multicenter, prospective, open-label, single-arm clinical trial of twice-daily enoxaparin (initial dose: 0.5mg/kg per dose; max: 60mg; target anti-Xa activity: 0.20-0.49IU/mL) as primary thromboprophylaxis for children <18 years of age hospitalized for symptomatic covid-19. study endpoints included: cumulative incidence of international society of thrombosis and haemostasis-defined clinically relevant bleeding; enoxaparin dose-requirements; and cumulative incidence of venous thromboembolism within 30-days of hospital discharge. descriptive statistics summarized endpoint estimates that were further evaluated by participant age (±12 years) and clinical presentation. results: forty children were enrolled and 38 met analyses criteria. none experienced clinically relevant bleeding. median (interquartile range) dose to achieve target anti-xa levels was 0.5 mg kg (0.48-0.54). dose-requirement did not differ by age (0.5 [0.46-0.52] mg kg for age ≥12 years versus 0.52 [0.49-0.55] mg kg for age><12 years, p=".51)" but was greater for participants with misc (0.52 [0.5-0.61] mg kg) as compared with primary covid-19 (0.48 [0.39-0.51] mg kg, p=".010)." two children (5.3%) developed central-venous catheter-related venous thromboembolism. no serious adverse events were related to trial intervention. conclusions: among children hospitalized for covid-19, thromboprophylaxis with twice-daily enoxaparin appears safe and warrants further investigation to assess efficacy.>
