Management of von Willebrand Disease With a Factor VIII-Poor von Willebrand Factor Concentrate: Results From the Paediatric Cohort of a Prospective Observational Post-Marketing Study.

INTRODUCTION

Although clinical experience of a triple-secured, plasma-derived, von Willebrand factor (pdVWF), almost devoid of Factor VIII (FVIII) in adults with von Willebrand disease (VWD), is widely reported, its use in children is less documented.

AIM: To explore the safety and efficacy of this concentrate in real-life, in children <12 years old.

METHODS

Data from 30 paediatric patients enrolled in a prospective, 3-year observational, post-marketing study in France were analysed. Efficacy and safety were assessed in two cohorts: 0-6 and 6-11 years old.

RESULTS

The population included 14 children <6 years of age and 16 children aged 6-11 years. Most patients (80%) were severely affected (von Willebrand factor ristocetin cofactor activity [VWF:RCo] ≤ 15 IU/dL), including 30% with Type 3 VWD. Children received pdVWF for 16 major bleeds, 138 minor bleeds, 7 major surgeries, 8 minor surgeries and 12 invasive procedures. Efficacy was rated excellent or good in 100% of major bleeds or surgeries. The dose per infusion was approximately 50 IU/kg. By age group, median doses per infusion varied from 49 to 73 IU/kg for patients <6 years and from 46 to 59 IU/kg for patients 6-11 years, according to clinical situation. FVIII coadministration/correction was more frequent in Type 3 VWD, regardless of patient's age. Of five children receiving long-term prophylaxis, breakthrough bleeding occurred in 1.6% of infusions and median annualised bleeding rate was 0.8. No safety concerns were raised.

CONCLUSION

This analysis enlarges clinical experience of an FVIII-poor pdVWF in the paediatric population. This concentrate offers safe and effective treatment regardless of VWD severity.