Haemate P/Humate-P for the treatment of von Willebrand disease: considerations for use and clinical experience.

von Willebrand disease (VWD) is a heterogeneous bleeding disorder with symptoms in affected patients ranging from mild effects to potentially devastating haemorrhagic events. Desmopressin (DDAVP) and von Willebrand factor/factor VIII (VWF/FVIII) concentrates are the principal treatments. Haemate P/Humate-P is an intermediate-purity VWF/FVIII concentrate with extensive clinical experience in VWD. This concentrate has been shown to correct haemostatic defects of VWD, with efficacy ratings of good/excellent in nearly all patients treated for bleeding or surgical events. Haemate P/Humate-P has a high content of the high molecular weight (HMW) VWF multimer fraction, which has been shown to be very effective in achieving haemostasis. The HMW VWF multimer pattern in Haemate P/Humate-P is more similar to that of normal human plasma (94% for Haemate P/Humate-P vs. 100% for normal human plasma) than that of other VWF/FVIII concentrates and correlates with functional VWF activities including ristocetin cofactor activity (VWF:RCo) and collagen-binding activity. The recommended dosing of Haemate P/Humate-P is based preferentially on VWF:RCo activity, which is approximately twice that of FVIII:C (2.4:1). Haemate P/Humate-P has been shown to be safe; no serious adverse events or cases of thrombosis have been observed in clinical trials and no documented cases of viral transmission in nearly three decades of clinical use. While DDAVP is effective in a large proportion of VWD patients, it may not provide adequate haemostasis in all situations. In such cases, Haemate P/Humate-P is an effective replacement concentrate for all types of VWD in both adult and paediatric patients.