The objective of this study is to assess the efficacy and safety of a Von Willebrand Factor/Factor VIII (VWF/FVIII), Biostate, and to investigate the pharmacokinetics of Biostate in children with haemophilia A.

Inclusion Criteria:

• Male subjects between 0 and <12 years of age.
• Diagnosed with severe haemophilia A (FVIII:C <1%), and pre-treated for a minimum of 20 to 50 exposure days.
• Have evidence of vaccination against hepatitis A and B (or presence of antibodies against hepatitis A and B due to either a previous infection or prior immunisation), as documented in the medical notes at enrolment.
• The subject and/or legal guardian understand(s) the nature of the study and has/have given written informed consent to participate in the study and is/are willing to comply with the protocol.

Exclusion Criteria:

• For all subjects at Day 1: Are actively bleeding.
• Have received an infusion of any FVIII product, cryoprecipitate, whole blood, plasma or desmopressin acetate in the 4 days prior to their dosing within the PK component.
• Have a known history of, or who are suspected of having FVIII inhibitors.
• Have received aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) within 7 days of administration of the IMP.
• Have an impaired liver function ie, bilirubin >1.5 x upper limit of normal (ULN) and/or aspartate/alanine aminotransferase (AST/ALT) >2.5 x ULN (referring to limits of the laboratory that performs the determination) at Screening.
• Are human immunodeficiency virus [HIV]-1/-2 antibody positive with a viral load of >200/µL.
• Suffer from an acute or chronic medical condition, other than haemophilia A, which may, in the opinion of the Investigator, affect the conduct of the study.
• Suffering from von Willebrand disease (VWD) with von Willebrand factor: ristocetin cofactor (VWF:RCo) level <50 IU/dL at Screening.
• Have a known or suspected hypersensitivity or previous evidence of severe side effects to a plasma-derived FVIII product or to human albumin.
• Have participated in a clinical study or used an investigational compound in another study (eg, a new chemical entity not registered for clinical use) in the 3 months preceding the first day of IMP administration, or are planning to enter such a study during the study period.
• Unwillingness and/or inability to comply with the study requirements.