An observational study in Hemophilia A and Factor VIII (FVIII), sponsored by University of Texas Southwestern Medical Center. Recruiting at 1 site in United States. Open to participants aged 6 Months and older. Per ClinicalTrials.gov, last updated 2026-09-29.
Sponsored by University of Texas Southwestern Medical Center · Observational
This is an observational research study to find out if there is a difference in the way children with moderate or severe hemophilia A, treated on two different types of factor replacement, form a clot and also evaluate if they develop tiny bleeds within the joint and subsequently early joint changes when receiving extended half-life factor VIII.
This research study aims to compare the differences in the way children with moderate or severe hemophilia A respond when being treated with prophylactic extended half-life factor VIII based replacement therapy (such as Altuviiio) vs non-FVIII based replacement therapy (such as Hemlibra) as part of their hemophilia treatment to prevent spontaneous joint bleeds. This study will collect information about the patient's joint health, patient outcomes (using questionnaires), and laboratory testing at specific time points over 3 years.
The study will use an overall approach of comparative effectiveness research (CER) methodology. The investigators plan to recruit participants with severe (FVIII \<1%) and moderate (FVIII 1-4%) HA who take extended half-life factor VIII based replacement therapy or non-FVIII based replacement therapy as their clinically prescribed treatment. Both are standard of care treatment for persons with Hemophilia A (PwHA). Using CER principals, this study will analyze differences in 1) hemostatic potential and annualized bleeding rates (Aim 1-3) and 4) joint health (structural and functional) using the Hemophilia Joint Health Score (HJHS) and imaging markers to identify subclinical bleeding and early joint tissue changes in PwHA on novel FVIII and non-FVIII therapies already in use in practice (Aim 4). The proposed study will be the first systematic observational comparative effectiveness study in PwHA on two conventional, standard-of-care novel therapies with differing mechanisms of action to evaluate the overall effectiveness of treatment.
Exclusion Criteria:
The study plans to recruit participants with severe (FVIII \<1%) and moderate (FVIII 1-4%) HA.
Drug: Half-life factor VIII based replacement therapy · Drug: Non-FVIII based replacement therapy
Children with moderate or severe hemophilia A being treated with prophylactic extended half-life factor VIII based replacement therapy (such as Altuviiio) as part of their hemophilia treatment to prevent spontaneous joint bleeds.
Also known as: Altuviiio
Children with moderate or severe hemophilia A being treated with non-FVIII based replacement therapy (such as Hemlibra) as part of their hemophilia treatment to prevent spontaneous joint bleeds.
Also known as: Hemlibra
Thrombin Generation
To determine and compare in vivo thrombin generation parameters; endogenous thrombin potential (ETP) and peak thrombin (PT) for patients on efanesoctocog alfa or emicizumab
Time frame: Thrombin generation assay will be measured at 5 time points within a week of receiving dose of medication
Hemophilia Joint Health Score
To obtain and compare HJHS in patients on efanesoctocog alfa or emicizumab
Time frame: Obtained at baseline and every 6 months, until 3 years
Annualized bleeding rate
To collect bleeding episodes in study participants and to calculate their respective total, treated, and joint annualized bleeding rates
Time frame: From enrollment, every 6 months, until 3 years
Health related quality of life - CHO-KLAT
Canadian Hemophilia Outcomes-Kids Life Assessment Tool (CHO-KLAT) will be used to evaluate the impact of different treatment strategies. CHO-KLAT will be obtained and compared in study participants on efanesoctocog alfa or emicizumab.
Time frame: From enrollment, every 6 months, until 3 years
Health related quality of life - PedHAL
PedHAL is a validated patient-reported outcome measure designed to assess self-perceived functional abilities in children with hemophilia. PedHAL will be obtained and compared in study participants on efanesoctocog alfa or emicizumab
Time frame: From enrollment, every 6 months, until 3 years
Health related quality of life - CATCH
CATCH (Comprehensive Assessment Tool of Challenges in Hemophilia) is a validated, multi-version patient-reported outcome instrument designed to assess the real-world impact of hemophilia on individuals and their caregivers. CATCH will be obtained and compared in study participants on efanesoctocog alfa or emicizumab
Time frame: From enrollment, every 6 months, until 3 years
Joint Tissue Changes
Point-of-care ultrasound using JADE protocol to evaluate joint tissue changes will be obtained and compared in study participants on efanesoctocog alfa or emicizumab
Time frame: From enrollment, every 6 months, until 3 years
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University of Texas Southwestern Medical Center