Pharmacokinetic studies on Wilfactin®, a von Willebrand factor concentrate with a low factor VIII content treated with three virus-inactivation/removal methods

Abstract

; LFB) that adopted one virusinactivation method only. Results: For both the measurements evaluated in this study (VWF antigen, VWF:Ag; and VWF ristocetin co-factor activity, VWF:RCo), Wilfactin Ò had a PK profile similar to that of the FVIII/VWF concentrates and of Facteur Willebrand-LFB Ò . VWF:RCo and VWF:Ag recoveries were 2.1 ± 0.3 and 1.8 ± 0.3 per IU kg , respectively, and the half-lives were 12.4 ± 1.8 and 15.9 ± 1.5 h. The FVIII synthesis rate was 5.8 ± 1.0 IU dL, with a half-life of 15.8 ± 2.4 h. Conclusion: The PK of VWF and FVIII have not been altered by the three virus-inactivation/removal steps during the manufacturing of Wilfactin Ò .

Hemostatic efficacy, safety, and pharmacokinetics of a recombinant von Willebrand factor in severe von Willebrand disease

“…[9][10][11][12][13] Several high purity plasma-derived VWF/FVIII products are available on the market that are effective in the treatment and prevention of bleeds in VWF patients. However, plasma-derived products are limited by plasma donor availability, and the theoretical risk of pathogen transmission cannot be excluded despite viral screening and attenuation measures that have been instituted to minimize such concerns.…”

Principles of care for the diagnosis and treatment of von Willebrand disease

“…Because VWD patients have an intact endogenous production of FVIII and in order to avoid excessive post-infusion FVIII:C levels, a highly purified plasma VWF concentrate containing very little FVIII has been developed for exclusive use in VWD (Wilfactin®). 43 However, as post-infusion levels of FVIII:C rise slowly reaching a peak between 6 and 8 h, co-administration of a priming dose of FVIII may be required if prompt hemostasis is required in patients with baseline FVIII:C levels of 30 U/dL or lower. 44 In patients with high basal levels of FVIII, the concentrate could be useful when prolonged treatment is anticipated (e.g.…”

How I treat type 2 variant forms of von Willebrand disease

“…A highly purified plasma VWF concentrate containing very little FVIII has also been developed for the exclusive use in VWD. 56 However, as postinfusion levels of FVIII:C rise slowly, reaching a peak between 6 and 8 hours, co-administration of a priming dose of FVIII may be required if prompt hemostasis is required in patients with baseline FVIII:C levels of 30 IU/dL or lower. 57 As reported in Table 2, the goal of treatment in patients undergoing major surgery (or having a major bleeding) is to maintain VWF/FVIII plasma levels around 80 to 100 IU/dL for at least a couple of days and trough level above 50 IU/dL for an additional 5 to 7 days thereafter.…”