A Prospective Assessment of Bone Health in Patients With Severe Hemophilia A on Factor VIII vs Factor Mimetic Prophylaxis (Efa Emi Bone Health Study)

May 21, 2026 updated by: Arkansas Children's Hospital Research Institute

A Multi-institution Prospective Assessment of Bone Health in Patients With Severe Hemophilia A on Factor VIII vs Factor Mimetic Prophylaxis (Efa Emi Bone Health Study)

This study is comparing bone mineral density in patients with Severe Hemophilia A on Emicizumab prophylaxis vs patients on Efanesoctocog alfa prophylaxis

Study Overview

Status

Not yet recruiting

Conditions

Detailed Description

Impaired bone health significantly contributes to morbidity and healthcare burden, particularly in patients with bleeding disorders. Identifying and addressing bone health issues early can reduce fracture rates, enhance quality of life, and minimize healthcare utilization. Although previous studies have demonstrated poor bone health in patients with severe hemophilia, limited data exist on the comparative effects of newer therapies, such as emicizumab and efanesoctocog alfa, on bone outcomes.

This study seeks to address this knowledge gap by prospectively investigating bone mineral density in patients with severe hemophilia A on these two prophylactic therapies. Additionally, the study will examine markers of bone remodeling, thrombin generation, and joint health. Insights gained will provide critical information on whether factor-based therapies confer superior bone health benefits compared to non-factor therapies.

In summary, the thrombin/PAR1 axis plays a crucial role in regulating the dynamic structure of bone. Patients with severe Hemophilia A experience decreased thrombin generation, which is hypothesized to contribute to reduced bone formation and increased bone resorption. Given that Efanesoctocog alfa maintains higher factor VIII levels compared to Emicizumab, leading to better thrombin generation, we hypothesize that Efanesoctocog alfa will result in greater improvements in bone mineral density (BMD) in persons with Hemophilia A (PwH) compared to Emicizumab that would prevent future fractures.

Study Type

Observational

Enrollment (Estimated)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients that are seen at dedicated Hemophilia treatment Centers

Description

Inclusion Criteria:

  1. The participant or legally authorized representative is willing and able to provide written informed consent.
  2. Diagnosis of severe hemophilia A (factor VIII activity < 1%).
  3. Male sex.
  4. Age between 30 and 50 years (inclusive).
  5. BMI between 18.5 and 40 kg/m2
  6. 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.
  7. Willingness to undergo all research procedures, including DEXA scans and the collection of blood samples.
  8. Willingness to complete all standard-of-care bleeding and treatment logs.

Exclusion Criteria:

  1. Unwillingness of the participant, parent, or legally authorized representative to provide informed consent.
  2. Diagnosis of a bleeding disorder other than or in addition to severe hemophilia A.
  3. Active Factor VIII inhibitors at the time of enrollment
  4. History of a disease known to influence bone metabolism unrelated to a bleeding disorder. (Examples: Paget's disease, osteogenesis imperfecta, Ehlers Danlos syndrome, Hyperparathyroidism)
  5. Past or present treatment with any anti-osteoporotic medication, excluding oral vitamin D or oral calcium supplements.
  6. Documented HIV infection or HCV infection (whether in progress or cured) at the cirrhotic stage.
  7. Presence of a non-removable metal device that would interfere with research procedures.
  8. Inability to tolerate a DEXA scan due to limited range of motion or body habitus.
  9. History of bone fractures or surgical repair within 8 weeks prior to enrollment.
  10. Participants with weight >300 pounds, due to limitations of DEXA scanner

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
patients with Severe Hemophilia A on factor VIII prophylaxis
patients with Severe Hemophilia A on Efa Emi prophylaxis

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
the longitudinal change in femoral neck bone mineral density (BMD, g/cm²)
Time Frame: Over a 5 year period
The primary endpoint of this study is the longitudinal change in femoral neck bone mineral density(BMD, g/cm²)
Over a 5 year period
Change in femoral neck bone mineral density
Time Frame: over a five-year period
The primary endpoint of this study is the longitudinal change in femoral neck bone mineral density (BMD, g/cm²)
over a five-year period

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Arkansas Children's Hospital Research Institute

Collaborators

Genzyme, a Sanofi Company

Investigators

  • Principal Investigator: Divyaswathi Citla Sridhar, MD, Arkansas Children's Reserach Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

August 1, 2031

Study Completion (Estimated)

August 1, 2032

Study Registration Dates

First Submitted

May 6, 2026

First Submitted That Met QC Criteria

May 6, 2026

First Posted (Actual)

May 12, 2026

Study Record Updates

Last Update Posted (Actual)

May 26, 2026

Last Update Submitted That Met QC Criteria

May 21, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 300130

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared with with other researchers , and each participating site has access to only their centers data; however , aggregated data will be included in future publications and will be made available toparticipating centers following study completion

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Hemophilia a

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Denmark

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe