Study Evaluating of Recombinant Human Factor IX (BeneFIX) and a New Formulation of BeneFIX (rFIX-R) in Moderate to Severe Hemophilia B

Inclusion Criteria:

• Moderate to severe hemophilia B (FIX: C ≤2%)
• Previously treated patients (PTPs) with ≥150 documented exposure days
• Age ≥ 12 years (US sites only)

Exclusion Criteria:

• Detectable factor IX inhibitor defined as ≥0.6 Bethesda Units for pooled plasma reported by the local laboratory (family history of inhibitors will not exclude the patient)
• Patient history of factor IX inhibitor replacement therapy
• Patient unable to be off factor IX replacement therapy for at least 5 days without bleeding