Abstract
Purpose: Wilate® represents a new generation VWF/FVIII-concentrate for the treatment of von Willebrand patients with high purity and two independent virus inactivation steps. The high purity of the product was developed to preserve the functionality of Wilate®’s VWF/FVIII complex at a physiological ratio of about 1:1.
Methods: A prospective multicenter study is conducted in 47 VWD patients to investigate the pharmacokinetics (PK) and clinical efficacy and safety of Wilate® in acute bleedings and surgical prophylaxis. For PK studies, plasma levels of VWF:RCo, FVIII:C, VWF:Ag were measured up to 72 hrs after injection of 50 IU of FVIII/kgBW. Clinical efficacy and tolerability was rated on a four-point scale. Final decisions on dosing were based on the investigators’ clinical judgment.
Summary of results: Mean half-life of VWF:RCo in type 3 patients (n=9) was 17.1 hrs. Mean recovery for VWF:RCo was 1.5 [% per IU/kg] and 2.0 [% per IU/kg] for FVIII:C. The clearance for VWF:RCo was 2.5 [ml/h/kg] for all and 3.9 [ml/h/kg] in type 3 patients. 33 patients have been treated for a total number of 658 bleeds. Of these, 31 patients (69%) were type 3 patients. The average dose/kgBW/ED was calculated to 29.3 IU FVIII:C. Furthermore efficacy and safety was studied in 16 patients undergoing 24 surgical procedures. The overall efficacy (achievement of haemostasis) of Wilate® was rated as excellent or good for 23/24 procedures (96%). One patient with a laparoscopic cholecystectomy required two additional blood transfusions. The tolerability was assessed as very good/good by investigators and patients in all surgical cases.
Conclusion: Wilate® documented favourable PK-properties in VWD patients. The interim results of these prospective clinical studies demonstrate the safety and efficacy of the double-virus-inactivated Wilate® for the treatment of acute bleeding episodes and surgical procedures in patients with VWD.
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