Study to Evaluate the Safety, Efficacy, and Pharmacokinetics of Recombinant Coagulation Factor VIII Fc Fusion Protein (rFVIIIFc) in Previously Treated Pediatric Subjects With Hemophilia A

An Open-Label, Multicenter Evaluation of Safety, Pharmacokinetics, and Efficacy of Recombinant Coagulation Factor VIII Fc Fusion Protein, BIIB031, in the Prevention and Treatment of Bleeding Episodes in Pediatric Subjects With Hemophilia A

The primary objective of the study is to evaluate the safety of Recombinant Coagulation Factor VIII Fc Fusion Protein (rFVIIIFc) in previously treated pediatric subjects with hemophilia A. Secondary objectives of this study in this study population are as follows: to evaluate the efficacy of rFVIIIFc for prevention and treatment of bleeding episodes; to evaluate and assess the pharmacokinetics (PK) of rFVIIIFc; and to evaluate rFVIIIFc consumption for prevention and treatment of bleeding episodes.

Previously treated pediatric participants will be treated with a prophylactic regimen of rFVIIIFc. PK analysis of pre-study factor VIII (FVIII) and rFVIIIFc will be performed in a sub-group of the study participants prior to commencement of prophylactic treatment. After these PK results are available, remaining participants have the option of proceeding directly to prophylactic treatment. After completing the end of study assessments, eligible participants would be able to continue treatment in Study 8HA01EXT.

Key Inclusion Criteria:

• Severe hemophilia A defined as <1 IU/dL (<1%) endogenous FVIII
• Male <12 years of age and weight ≥13 kg
• History of at least 50 documented prior exposure days to FVIII
• No current, or history of, inhibitor development to FVIII

Key Exclusion Criteria:

• Other coagulation disorders in addition to Hemophilia A
• History of anaphylaxis associated with any FVIII or IV immunoglobulin administration

NOTE: Other protocol-defined Inclusion/Exclusion criteria may apply.