Comparing Emicizumab and Factor VIII for Joint and Bone Health in Severe Hemophilia A

Effects of Emicizumab vs. Factor VIII Prophylaxis on Joint and Bone Health in Severe Hemophilia A

Observational Washington Institute for Coagulation · NCT04131036

This study is testing whether emicizumab or standard factor VIII treatment can better protect joint and bone health in people with severe Hemophilia A over three years.

Quick facts

Study typeObservational
Enrollment40 (estimated)
Ages16 Years and up
SexMale
SponsorWashington Institute for Coagulation Academic / other
Drugs / interventionsemicizumab
Locations4 sites (Los Angeles, California and 3 other locations)
Trial IDNCT04131036 on ClinicalTrials.gov

What this trial studies

This study aims to longitudinally assess changes in joint health and bone density in patients with severe Hemophilia A over a period of three years. Participants will be divided into two groups based on their current treatment regimen: those receiving standard factor VIII prophylaxis and those receiving emicizumab prophylaxis. Using musculoskeletal ultrasound, the study will evaluate joint health at baseline and after three years, while also exploring other health outcomes and potential biomarkers. The study will enroll participants over a 12-month period and will involve regular assessments and follow-ups.

Who should consider this trial

Good fit: Ideal candidates include males aged 16 and older with severe Hemophilia A who are currently on either factor VIII or emicizumab prophylaxis.

Not a fit: Patients with current FVIII inhibitors, other bleeding disorders, or conditions affecting joint health may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into the optimal prophylactic treatment for improving joint and bone health in patients with severe Hemophilia A.

How similar studies have performed: While there have been studies on factor VIII and emicizumab, this specific longitudinal comparison of joint and bone health is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Male gender
* Severe hemophilia A (factor VIII \< 1%)
* Age ≥ 16 year
* Either on prophylaxis with factor VIII or emicizumab with the intention to stay on the current regimen for the next 3 years
* Willing and able to give written informed consent/assent
* Willing to undergo MSKUS, DEXA scan +/- collection of blood sampling for repository biomarkers
* Willing to come in for baseline and 3 yearly visits
* Willing to answer phone survey for bleeding and safety every 3 months

Exclusion Criteria:

* Current FVIII inhibitor of \> 0.6 BU
* Unable to take FVIII replacement
* Other known bleeding disorder
* Other rheumatologic disorder affecting joints
* Other known neuromotor defect (making physical exam difficult)

Where this trial is running

Los Angeles, California and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Hemophilia AJoint HealthBone DensityEmicizumabfactor VIII prophylaxis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.