First study of extended half-life rFVIIIFc in previously untreated patients with hemophilia A: PUPs A-LONG final results

Severe hemophilia A is routinely managed with prophylactic replacement of factor VIII (F8), but a significant minority of patients develop anti-F8 antibodies. Extended half-life (EHL) products were developed to reduce the frequency of infusions required. In the first prospective trial of a recombinant F8-EHL product in previously untransfused patients, Königs et al report a low 15.6% incidence of development of high-titer inhibitors.