Efficacy, Safety and Tolerability of a Novel High-Purity, Double Virus-Inactivated VWF/FVIII-Concentrate in the Treatment of Von Willebrand Disease (VWD) - Clinical Experience in the Treatment of Bleeding and Surgery.

Introduction: Wilate is a highly purified, double viral inactivated, VWF/FVIII-concentrate developed for the treatment of VWD. A program of prospective studies was conducted in VWD patients to investigate the clinical efficacy and safety of Wilate® in acute bleeding episodes, prophylaxis and surgical procedures.

Methods: In these prospective open label studies 70 VWD patients (37 VWD of type 3) were treated with the VWF/FVIII concentrate Wilate and followed to assess clinical efficacy and tolerability. Dosing and monitoring were performed using FVIII assays. This is standard practice in most of the study sites and was feasible because of the product’s physiological 1:1 ratio and parallel PK profiles of FVIII and VWF. Dosing decisions were based on established guidelines and the investigators’ clinical judgment. The efficacy of the product was rated on a four-point scale by the investigator.

Results: Bleeding- 43 patients (25 of type 3) were treated for a total number of 1088 bleeding episodes (BE). The median dose per exposure day (ED) was calculated to be 31 IU VWF/FVIII:C/kg and were treated for a median of 1.2 days, with excellent or good efficacy achieved in 96% of treatments. Surgery- Efficacy and safety was also studied in 31 VWD patients who underwent 54 elective or urgent surgical procedures of which 27 were classified as major; the overall efficacy was rated as excellent or good in most cases (94%), with a mean dose per infusion being 34 IU VWF/FVIII:C/kg. Pediatric Use- A total of 8 children below 12 years of age with 310 BE s were treated, with an excellent/good efficacy in 98% of bleedings. Prophylaxis- 19 patients were on a prophylactic regimen for more than 10 consecutive weeks (total of 2,338 ED), with an overall reduction of bleeding frequency. Tolerability - Out of 5,662 rated infusions in all studies, the tolerability was assessed as “very good” or “good” in 99% of the cases.

Conclusions: The results of the prospective clinical trial program demonstrate the safety, efficacy and tolerability of this VWF/FVIII concentrate for the treatment of acute bleeding episodes, prophylaxis and surgical procedures in patients with VWD.