FondaKIDS II: long-term follow-up data of children receiving fondaparinux for treatment of venous thromboembolic events.

BACKGROUND: The incidence of venous thrombotic events (VTE) and use of anticoagulants in children have both risen over time. It is imperative that safety and efficacy studies of newer anticoagulants include children.

OBJECTIVES: The purpose of this study was to investigate the long-term safety, dosing, and efficacy of fondaparinux in children.

PATIENTS/METHODS: The study included children 1-18 years old treated with fondaparinux at Children's Hospital Los Angeles. Descriptive statistics were used to present our findings.

RESULTS: Data from 35 patients were collected and analyzed. Fourteen of 22 evaluable patients (63.6%) had complete resolution of their thrombus, 6/22 (27.3%) had partial resolution, and 2/22 (9.1%) had no change. Ten patients needed a total of 16 dose adjustments over a median 152 days treatment duration to achieve therapeutic levels. Two patients (9.1%) had VTE recurrence. There were 3 major (intracranial hemorrhage- prior to initiation of fondaparinux, pulmonary hemorrhage, and subretinal hemorrhage) and 6 minor (2 with blood in stool, 1 with injection site, 1 CVC site, 1 tracheostomy bleed, 1 epistaxis) bleeding events.

CONCLUSIONS: In this long-term follow-up study on children treated with fondaparinux for VTE, 90.9% of patients had either complete or partial resolution while the recurrence rate was in line with previous studies. There were 9 bleeding events (3 major and 6 minor), though only 1 event required the discontinuation of fondaparinux. Given the advantages of fondaparinux over other anticoagulants, this study suggests that fondaparinux could be considered a safe and effective alternative for the management of VTE in children.