Study Evaluating BeneFIX in Patients With Haemophilia B, Previously Treated With Plasma Derived Factor IX

The switch to BeneFIX has already been decided by the investigator. Patients will be followed up to 3 months after the switch.

Inclusion criteria

• Moderately to severe haemophilia B patient (FIX activity < or equal to 2%) for whom the switch from pdFIX to BeneFIX has already been decided by the investigator
• Previously treated patients (PTP) with > or equal to 150 ED to any FIX product
• Male patients, aged > or equal to 12 years
• Absolute CD4 count > or equal to 300/microL
• Normal platelet count (> or equal to 100 000/microL)
• Patient is in a non-bleeding state and has not received any coagulation FIX within five (5) days of recovery
• Written informed consent obtained prior to study entry (for patients aged < 18 years, parents' signature or subject legally acceptable representative obtained prior to study entry)

Exclusion criteria

• Any other known bleeding disorder in addition to haemophilia B
• History of, or current detectable factor IX inhibitor (> or equal to 0.6 BU by Bethesda inhibitor assay)
• History of anaphylaxis to any coagulation factor IX
• Patient with a known hypersensitivity to hamster protein
• Patient with a hypersensitivity to the active substance or to any of the excipients
• Patient unable to be off FIX replacement therapy for at least 5 days without bleeding Patient with hepatic or renal impairment (ALT [SGPT] and AST [SGOT] > 5 x Upper Limit Normal (ULN), total bilirubin > 20mg/l, albumin < 25 g/l, prothrombin time > 1.25 x ULN, serum creatinine > 1.25 x ULN)
• Treatment with any investigational drug or device within the past 30 days
• Any condition that, in the Investigator's judgment, makes participation in the study not advisable