Study Objectives*

1. Provide a systematic evaluation of the treatment outcomes in patients with hemophilia A
2. Emphasize the importance and clinical benefits of rFVIII-Fc in joint and bone health.
3. Compare the clinical outcomes from 1 year before and after switching to EHL.
4. Exploratory: Identify biomarkers that could provide more useful and convenient evaluations of joint and bone health. (Time-saving and easy to monitor)

In this study, we would like to focus on the evaluation of joint and bone health in persons with severe hemophilia A (PwHA) treated with rFVIIIFc prophylaxis. We also aim to identify potential biomarkers for assessing the joint and bone health of PwHA. Since the joint and bone health examinations are time-consuming, expensive, and require special equipment, the patients could only receive the examinations annually to realize the status of their joint health. The biomarkers testing will provide a more convenient and time-saving option on the joint and bone health evaluation for PwHA. Therefore, surrogate of biochemical marker(s) to represent the joint and BMD progression is an unmet need for clinical practice. Investigating different biomarkers and combining them with the joint and BMD results to provide a systematic approach for elucidating the treatment outcomes of PwHA treated with rFVIIIFc is major goal of this study.

Inclusion Criteria:

1. Patients with severe hemophilia A (all ages).
2. Patients with moderate type hemophilia A with hemophilic arthropathy.
3. Currently on rFVIIIFc regular prophylaxis and have previous medical record with regular prophylaxis with standard half-life product for one year
4. Able and willing to undergo joint and bone examinations

Exclusion Criteria:

1. Participants of other interventional studies.
2. Patients with current inhibitors.
3. History of major neurological disease (eg. Stroke, Parkinson's disease, neuropathy, etc.)
4. History of major psychiatric disease (eg. Schizophrenia, bipolar disorder)
5. Significantly impaired vision/hearing

Males with one affected X chromosome is defined hemophilia disease; a female with one affected X chromosome is a "carrier" of hemophilia.

severe hemophilia A patients or moderate hemophilia A patients with hemophilic arthropathy.