Inhibitors Don’t Differ for Previously Untreated Patients Given Plasma-Derived and Recombinant Factor VIII: Systematic Review

A number of studies have examined the impact of plasmaderived or recombinant factor VIII (FVIII) replacement therapy on inhibitor antibody development in hemophilia A patients, with conflicting results. In order to shed light on this controversial issue, Italian investigators at the University Hospital of Parma performed a systematic review and meta-analysis of published prospective studies evaluating the incidence rate of inhibitors in previously untreated patients (PUPs) with severe hemophilia A.

Data from a total of 800 patients enrolled in 25 prospective studies published between 1990 and 2007 were included in this review, which incorporated selective criteria for assessment of study quality. Overall, the inhibitor incidence rate did not differ significantly between recipients of plasma-derived and recombinant FVIII concentrates (respective weighted means: 21 percent; 95% confidence interval [CI], 14-30 versus 27 percent; 95% CI, 21-33). Similarly, high-titer inhibitors did not differ significantly between patients treated with plasma-derived (weighted means: 14 percent; 95% CI, 8-25) or recombinant FVIII concentrates (weighted means: 16 percent; 95% CI, 13-20).

The main conclusion of this systematic review is that administration of a plasma-derived or recombinant FVIII product does not appear to influence the inhibitor rate in PUPs with severe hemophilia A.