Konkle BA, Shapiro AD, Quon DV, et al. - This study was sought to evaluate whether and how BIVV001 fusion protein as factor VIII replacement therapy for hemophilia A. Researchers designed a phase 1–2a open-label trial to consecutively assign 16 previously treated men (18 to 65 years of age) with severe hemophilia A (factor VIII activity, < 1%) to receive a single intravenous injection of recombinant factor VIII at a dose of 25 IU per kilogram of body weight (lower-dose group) or 65 IU per kilogram (higher-dose group). The results of this study demonstrate that a single intravenous injection of BIVV001 resulted in high sustained factor VIII activity levels, with a half-life that was up to four times the half-life correlated with recombinant factor VIII, an increase that could signal a new class of factor VIII replacement therapy with a weekly treatment interval in a small, early-phase study involving men with severe hemophilia A.