Timing of inhibitor development in >1000 previously untreated patients with severe hemophilia A

TO THE EDITOR: Inhibitory antibodies (inhibitors) against factor VIII (FVIII) develop in 25% to 35% of previously untreated patients (PUPs) with severe hemophilia A (SHA). It is the most serious complication of classic hemophilia treatment.[1][1][⇓][2]-[3][3] Most inhibitors develop during the