NCT07582276 · Arkansas Children's Hospital Research Institute
A Prospective Assessment of Bone Health in Patients With Severe Hemophilia A on Factor VIII vs Factor Mimetic Prophylaxis (Efa Emi Bone Health Study)
What this study is about
This study will compare bone mineral density in patients with severe hemophilia A receiving prophylaxis with emicizumab or efanesoctocog alfa. Participants will undergo assessments of bone mineral density, bone remodeling biomarkers, thrombin generation, plasmin generation, and joint health over a five-year period.
View original scientific description
This study will compare bone mineral density in patients with severe hemophilia A receiving prophylaxis with emicizumab or efanesoctocog alfa. Participants will undergo assessments of bone mineral density, bone remodeling biomarkers, thrombin generation, plasmin generation, and joint health over a five-year period. The study aims to evaluate whether differences in prophylactic therapy are associated with differences in bone health outcomes.
Primary outcome measures
Longitudinal change in femoral neck bone mineral density (g/cm²)
Time frame: Baseline and annually through 5 years.
Bone mineral densitometry
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The participant or legally authorized representative is willing and able to provide written informed consent.
- Diagnosis of severe hemophilia A (factor VIII activity \< 1%).
- Age between 30 and 50 years (inclusive).
- BMI between 18.5 and 40 kg/m2
- The participant must have been on prophylaxis with Efanesoctocog alfa or Emicizumab for at least 3 months prior to enrollment and intend to remain on the current regimen for the next 5 years.
- Willingness to undergo all research procedures, including DEXA scans and the collection of blood samples.
- Willingness to complete all standard-of-care bleeding and treatment logs.
Exclusion criteria
- Unwillingness of the participant, parent, or legally authorized representative to provide informed consent.
- Diagnosis of a bleeding disorder other than or in addition to severe hemophilia A.
- Active Factor VIII inhibitors at the time of enrollment
- History of a disease known to influence bone metabolism unrelated to a bleeding disorder. (Examples: Paget's disease, osteogenesis imperfecta, Ehlers Danlos syndrome, Hyperparathyroidism)
- Past or present treatment with any anti-osteoporotic medication, excluding oral vitamin D or oral calcium supplements.
- Documented HIV infection or HCV infection (whether in progress or cured) at the cirrhotic stage.
- Presence of a non-removable metal device that would interfere with research procedures.
- Inability to tolerate a DEXA scan due to limited range of motion or body habitus.
- History of bone fractures or surgical repair within 8 weeks prior to enrollment.
- Participants with weight \>300 pounds, due to limitations of DEXA scanner
Where
- Little Rock, Arkansas
Collaborators
Genzyme, a Sanofi Company
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 5, 2026 · Source of record for eligibility and locations