Results of a Prospective, Open-Label Trial to Assess the Efficacy, Safety and Immunogenicity of Wilate^® in Children Under 6 Years of Age with Inherited Von Willebrand Disease,

Wilate^® is a new-generation plasma-derived concentrate of von Willebrand factor (VWF) and factor VIII (FVIII) developed for treatment of patients with von Willebrand disease (VWD) and haemophilia A. The objective of this study was to assess efficacy, safety and immunogenicity of Wilate in children below 6 years of age with inherited VWD.

The prospective, multi-centre trial included patients with inherited VWD of any type below 6 years of age with insufficient response to DDAVP. Any clinical event requiring VWF/FVIII concentrate treatment within 1 year was treated with Wilate. Efficacy was recorded by using a 4-point VRS and in vivo recovery of FVIII:C and VWF:RCo was analyzed. Immunogenicity was assessed by determination of inhibitors against VWF and FVIII. Safety was measured by monitoring of adverse events. Tolerability was rated as “very good” or “good” for all cases by the investigator.

Fifteen subjects (6 type 3) were analyzed. Dosing regimens were dependent on specific clinical situations of each subject. The mean incremental in vivo recovery was 1.2 IU/dL per IU/kg for VWF:RCo and 1.6 IU/dL per IU/kg for FVIII:C (n = 7). Forty five bleeding episodes required treatment with Wilate. In all cases the overall haemostatic efficacy ratings by the investigator were “excellent” or “good”. The mean dose was 35.9 IU VWF:RCo/kg. Nine surgical procedures (3 major) were performed in 7 subjects, requiring 2 to 12 infusions/procedure with a mean dose per exposure day of 61.7 VWF:RCo/kg. Haemostatic efficacy for a total of 419 infusions was rated as “excellent” for 362, “good” for 54, “moderate” for 2 (1 missing) infusions. No notable changes in thrombogenicity markers and no thromboembolic events occurred. No inhibitors against VWF or FVIII were detected.

This study demonstrates the efficacy, safety and tolerability of Wilate^® in treatment of VWD in patients below 6 years of age.

Jansen:Octapharma: Employment. Knaub:Octapharma AG: Employment. Off Label Use: the product, Octanate, is approved in many countries worldwide but is not currently approved in the US.