International, post-authorisation non-interventional study to evaluate real-life effectiveness, safety and utilisation patterns of Octapharma's FVIII concentrates Nuwiq, Octanate, and Wilate in previously untreated and minimally treated severe haemophilia A patients in routine clinical practice.

Octapharma's FVIII concentrates have been tested in clinical trials and registered for treatment of haemophilia A; however, as haemophilia A is a rare disease, the numbers of patients treated in studies so far are limited. For previously untreated patients (PUPs), who are typically young children, and for minimally treated patients (MTPs), who have been exposed to only minimal FVIII dosages, there is a general interest to increase the body of data on treatment effectiveness and safety, particularly related to inhibitor development. Also, specifically for PUPs, treatment algorithms are not standardized, e.g. with respect to utilisation, dosage, frequency or optimal start age of FVIII prophylaxis. Real world evidence derived from a non-interventional study (NIS) can describe product utilisation and demonstrate value over a product's life cycle and facilitate benefit-risk assessments. The purpose of this study is thus to evaluate product utilisation, effectiveness and safety, including inhibitor development information, in severe haemophilia A PUPs and MTPs, who have been prescribed Octapharma's FVIII concentrates.

Inclusion Criteria:

• Male and female patients of any age and ethnicity
• Severe haemophilia A (FVIII:C<1%)
• Decision to prescribe Octapharma's FVIII concentrate before enrollment into the study
• Either
• No previous treatment with FVIII concentrates or other blood products containing FVIII (PUPs) OR
• Less than 5 Exposure Days (EDs) to FVIII concentrates or other blood products containing FVIII (MTPs), if
• data are available on all previous treatment, AND
• they did not develop an inhibitor at any time point, OR
• they developed an inhibitor during treatment with an Octapharma FVIII concentrate AND continue treatment with THIS Octapharma FVIII concentrate (in the presence or absence of emicizumab).
• Voluntarily given, fully informed written and signed consent obtained before any study-related data documentation is conducted (obtained from the patient's parent/legal guardian)

Exclusion Criteria:

• Diagnosis with a coagulation disorder other than haemophilia A
• Concomitant treatment with any systemic immunosuppressive drug
• Participation in an interventional clinical trial during the time period evaluated
• Participation in another non-interventional study of Octapharma

A total of 200 patients, either previously untreated patients (PUPs) or minimally treated patients (MTPs), are planned to be documented in the study