The purpose of this study is to evaluate whether rAHF-PFM is effective and safe in the treatment of children with hemophilia A. The study consists of 2 parts. Part 1 of the study is a pharmacokinetic evaluation, and Part 2 is an evaluation of efficacy and safety.

Inclusion Criteria:

• Subject is less than 6 years of age
• Severe or moderately-severe hemophilia A as defined by a baseline factor VIII level <= 2%, documented at screening or on the basis of historical data (e.g., at hemophilia diagnosis)
• Documented medical history of at least 50 exposure days for treatment with all other factor VIII products
• Subject's parent or legally authorized representative has provided informed consent

Exclusion Criteria:

• Detectable inhibitor to factor VIII measured in the screening sample by the local or central hemostasis laboratory

• History of inhibitor to factor VIII at any time prior to screening

• Subject has any one of the following laboratory abnormalities at the time of screening:

  1. platelet count < 100,000/mm3
  2. hemoglobin concentration < 10 g/dL (100 g/L)
  3. serum creatinine > 1.5 times the ULN for age
  4. total bilirubin > 2 times the ULN for age

• Subject has an inherited or acquired hemostatic defect other than hemophilia A (e.g., platelet dysfunction secondary to uremia, liver failure, von Willebrand's Disease)

• Subject has known hypersensitivity to RECOMBINATE rAHF

• Subject is currently participating in another investigational drug study or has participated in any clinical study involving an investigational drug within 30 days of study entry

• Subject is identified by the investigator as being unable or unwilling to cooperate with study procedures