The project is a controlled observational, multicenter, prospective data collection on secondary prophylaxis with Kogenate Bayer in adolescents and adults with severe haemophilia A (FVIII < 1%).

The observational period will cover at least 5 years per patient.

The long-term secondary prophylaxis group will be compared versus on-demand treatment group by the assessment of orthopedic status progression and pharmacoeconomics evaluation.

Inclusion Criteria:

• age ≥ 12 years and ≤ 55 years
• severe haemophilia A (FVIII < 1%)
• absence of inhibitors (Bethesda titre < 0.6 BU/ml)
• Previous Treated Patients (prior exposure days > 200)
• Kogenate Bayer administered 20-30 IU/kg -3 times a week, for the prophylaxis group
• ≥ 6 joint bleeds requiring treatment with FVIII concentrates in the previous 6 months before enrollment, for on-demand group
• written informed consent

Exclusion Criteria:

• concomitant severe and chronic diseases or congenital skeletal malformation
• unreliability of patient or likelihood of follow-up failure
• presence of inhibitors or history of inhibitors (in the previous 2 years)
• currently on immune tolerance treatment
• hepatic cirrhosis or liver disease in rapid progression
• AIDS
• platelet count < 75,000/mm3
• presence of conditions that influence negatively patient´s compliance
• participation in another study

Haemophilics