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

June 3, 2026 updated by: Divyaswathi Citla Sridhar, 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 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.

Study Overview

Status

Not yet recruiting

Conditions

Detailed Description

Reduced bone mineral density, osteoporosis, and fractures are increasingly recognized in persons with severe hemophilia A. The mechanisms underlying impaired bone health in hemophilia are multifactorial and may include reduced physical activity, chronic joint disease, inflammation, and abnormalities in coagulation-related pathways involved in bone remodeling.

Thrombin has been shown to play an important role in bone metabolism through activation of protease-activated receptor-1 (PAR-1) signaling pathways that influence osteoblast and osteoclast activity. Reduced thrombin generation in severe hemophilia A may contribute to decreased bone formation and increased bone resorption.

Efanesoctocog alfa is an extended half-life factor VIII replacement therapy that maintains higher circulating factor VIII levels and supports thrombin generation. Emicizumab is a non-factor prophylactic therapy that effectively prevents bleeding but does not replace factor VIII. The comparative effects of these therapies on long term bone health have not been well established.

This prospective observational study will compare longitudinal changes in bone mineral density among patients with severe hemophilia A receiving prophylaxis with emicizumab or efanesoctocog alfa over 5 years. Participants will undergo serial dual-energy X-ray absorptiometry (DXA) assessments and evaluation of bone remodeling biomarkers, inflammatory cytokines, thrombin generation, plasmin generation, and joint health over a five-year period.

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 Efanesoctocog alfa prophylaxis
Participants with severe hemophilia A receiving prophylaxis with efanesoctocog alfa as part of routine clinical care. Participants will undergo longitudinal assessments of bone mineral density, bone remodeling biomarkers, thrombin generation, plasmin generation, and joint health over a five-year period.
Patients with Severe Hemophilia A on Emicizumab prophylaxis
Participants with severe hemophilia A receiving prophylaxis with emicizumab as part of routine clinical care. Participants will undergo longitudinal assessments of bone mineral density, bone remodeling biomarkers, thrombin generation, plasmin generation, and joint health over a five-year period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Longitudinal change in femoral neck bone mineral density (g/cm²)
Time Frame: Baseline and annually through 5 years.
Bone mineral densitometry
Baseline and annually through 5 years.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Longitudinal change in Lumbar spine (L1-L4) bone mineral density (g/cm²)
Time Frame: Baseline and annually through 5 years.
Bone mineral densitometry
Baseline and annually through 5 years.
Longitudinal change in total hip bone mineral density (g/cm²)
Time Frame: Baseline and annually through 5 years.
Bone mineral densitometry
Baseline and annually through 5 years.
Longitudinal Change in Bone Remodeling Biomarkers and Cytokines
Time Frame: Baseline and annually through 5 years.
PINP, CTX-I, OPG, RANKL, IL-1β, IL-6, and TNF-α
Baseline and annually through 5 years.
Change in Thrombin Generation and Plasmin Generation Parameters
Time Frame: Baseline and annually through 5 years
Simultaneous Thrombin and Plasmin Generation Assay
Baseline and annually through 5 years

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)

July 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)

June 4, 2026

Last Update Submitted That Met QC Criteria

June 3, 2026

Last Verified

June 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.

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