Based on the successful pioneer work of Dr Nilsson and her colleagues in Sweden that started in the late 1950's, prophylaxis is recommend as the standard of care for boys with severe haemophilia by WHO and World Federation of Hemophilia (WFH). The efficacy and safety of prophylaxis in preventing bleeds and arthropathy in patients with hemophilia has been confirmed in well-designed clinical studies.To keep the factor level above 1%, the standard dosage for patients with severe hemophilia A is 20-40 Units /kg/infusion (average 30 Units /kg) every other day or three times a week. This dosage has a very high consumption of factor, up to 5000-6000 international unit(IU)/kg/year. The high consumption of factor and cost present a major barrier to use the standard prophylaxis in many countries particularly in the developing world.

But after the Recombinant Human Coagulation Factor VIII for injection (ADVATE) Patient Assistance Program(Golden Key) was launched in 24 Apr 2014 in Nanjing China, the affordability of patients was solved and many patients will get more chance to receive standard prophylaxis.

This study is designed to evaluate the Annual Bleeding rate (ABR), joint health outcomes and QoL outcomes in subjects using standard prophylaxis under the conditions of routine practice.

Hemophilia A is an X-linked recessive, congenital bleeding disorder caused by deficient or defective coagulation factor VIII (FVIII). The absence or severe reduction of FVIII leads to 'spontaneous' bleeding episodes (occurring primarily in joints, muscles, and less commonly, in soft tissues) and to excessive bleeding following trauma or injury. Estimations based on the WFH's annual global surveys indicate that the number of people with hemophilia in the world is approximately 400,000. [1] China accounts for a quarter of about 100,000.

Currently, based on the successful pioneer work of Dr Nilsson and her colleagues in Sweden that started in the late 1950's, prophylaxis is recommend as the standard of care for boys with severe haemophilia by WHO and WFH. [2] The efficacy and safety of prophylaxis in preventing bleeds and arthropathy in patients with hemophilia has been confirmed in well-designed clinical studies.[3,4,5]To keep the factor level above 1%, the standard dosage for patients with severe hemophilia A is 20-40 Units /kg/infusion (average 30 Units /kg) [6] every other day or three times a week. This dosage has a very high consumption of factor, up to 5000-6000 international unit(IU)/kg/year. [7] The high consumption of factor and cost present a major barrier to use the standard prophylaxis in many countries particularly in the developing world. [8] Many families are looking forward to standard prophylaxis to reducing bleeding episodes, stop or slow the deterioration of joint disease in their sons with severe hemophilia and thus improving their quality of life (QoL). But in China the majority of boys with severe hemophilia A cannot afford the high costs of standard prophylaxis .They can only pay for on-demand treatment or low-dose prophylaxis. But after the Advate Patient Assistance Program(Golden Key) was launched in 24 Apr 2014 in Nanjing China, the affordability of patients was solved and many patients will get more chance to receive standard prophylaxis.

This study is designed to evaluate the Annual Bleeding rate (ABR), joint health outcomes and QoL outcomes in subjects using standard prophylaxis under the conditions of routine practice.

Inclusion Criteria:

1. Subject has hemophilia A with FVIII≤2 %.
2. Previously treated patients (PTPs).
3. Age from 2 to 18 years.

Exclusion Criteria:

1. Subject has known hypersensitivity to the active substance or any of the excipients.
2. Subject has known allergic reaction to mouse or hamster proteins.
3. Subject has participated in another clinical study involving an investigational product (IP) or device within 30 days prior to study enrollment or is scheduled to participate in another clinical study involving another FVIII concentrate or device during the course of this study.
4. Subject is planned, or likely to have surgery during the study period.
5. Subject has end-stage renal failure or evidence of a severe or uncontrolled systemic disease as judged by the investigator.
6. Subject has full-blown Acquired Immuno Deficiency Syndrome (AIDS),determined by cluster differentiation antigen 4+ (CD4+) and clinical presentation.
7. Subject has active hepatic disease (alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels > 5 times the upper limit of normal).
8. Subject has clinical or laboratory evidence of severe liver impairment including (but not limited to) a recent and persistent international normalized ratio (INR)> 1.4, and/or the presence of splenomegaly and/or significant spider angioma on physical exam, and/or a history of esophageal hemorrhage or documented esophageal varices.
9. The subject in the opinion of the investigator is unable or unwilling to comply with study protocol
10. Subject is a family member of the investigator or site staff