High-purity factor VIII concentrates produced without using monoclonal antibodies.

Manufacturers are attempting to increase the purity of FVIII concentrates. A strategy pursued by some is that of including a purification step (gel filtration, ion-exchange or affinity chromatography) that yields concentrates with an intermediate or final specific activity of 35 to 250 IU FVIII/mg of protein. The specific activity of the final product may be lower because serum albumin is added to some concentrates to stabilize FVIII. In hemophiliacs treated with these concentrates, FVIII recovery and half-life are at least as good as those for less pure concentrates. In patients with von Willebrand disease, these concentrates increase plasma levels of FVIII, but their capacity to normalize the bleeding time is not well established. The hypothesis that their reduced alloantigen load might slow the progression of human immunodeficiency virus (HIV) infection is still not validated, but a few prospective studies are now attempting to address this issue. All the concentrates undergo virucidal procedures based on pasteurization or treatment with solvent/detergent. It is well established that these virucidal methods and donor screening avoid HIV transmission. A recent large study has shown that a pasteurized concentrate carries a low risk of transmitting viral hepatitis. The assessment of safety from hepatitis of concentrates treated with solvent/detergent is based on favorable preliminary results.