Composition, quality control, and labeling of plasma-derived products for the treatment of von Willebrand disease.

Different plasma-derived products have been used to treat patients affected with von Willebrand disease (vWD). To ensure optimal product selection, the purification process and viral elimination methods should be considered. Unfortunately, details regarding the degree of purification and viral attenuation achieved for each product typically are limited to the information provided by the package insert. Recently published studies have compared the in vitro characteristics of some of these products. All vary in terms of protein composition, proteins copurified with von Willebrand factor (vWF) and factor (F) VIII, and the characteristics of the active substance. There currently remains a lack of consensus regarding the in vitro characteristics essential to ensure a concentrate optimized for the treatment of vWD. We suggest that the minimal requirements for products on the market for the substitutive treatment of vWD are that they must (1) have the same level of safety in terms of eliminating the potential of blood-borne infections provided by plasma-derived products currently available for hemophilia A patients, (2) contain vWF that promotes adhesion and aggregation of platelets as well as transport and stabilization of FVIII, (3) have been tested for pharmacokinetics and efficacy in patients with different types of vWD before their clinical use for this indication, and (4) be labeled with both vWF and FVIII potency.