An Open-label Safety and Efficacy Study of Recombinant FVIII in Patients With Severe Hemophilia A

This multicenter, open-label, phase 3 extension study will investigate the safety and efficacy of rVIII-SingleChain for prophylaxis and on-demand treatment of bleeding episodes in at least 200 previously treated patients (PTPs) with severe congenital hemophilia A and previous exposure to FVIII products who achieve at least 100 exposure days (EDs) to rVIII-SingleChain in this study, as well as in previously untreated patients (PUPs) with no previous exposure to any FVIII product who achieve at least 50 EDs to rVIII-SingleChain in this study. A substudy (open to both PTPs and PUPs) will investigate the use of rVIII-SingleChain in surgery. A substudy (open to PUPs who develop an inhibitor to rVIII-SingleChain) will investigate the use of rVIII-SingleChain in immune tolerance induction (ITI) therapy.