A Study to Investigate the Course of Synovial Hypertrophy in Patients With Haemophilia A on Efanesoctocog Alfa Prophylaxis

Last updated: March 25, 2025
Sponsor: Swedish Orphan Biovitrum
Overall Status: Active - Recruiting

Phase

4

Condition

Rheumatoid Arthritis

Arthritis And Arthritic Pain

Hemophilia

Treatment

Efanesoctocog alfa

Clinical Study ID

NCT06752850
Sobi.BIVV001-004
2024-512066-33-00
  • Ages > 12
  • All Genders

Study Summary

The rationale for conducting this open-label phase 4 study is to assess whether once-weekly prophylaxis with efanesoctocog alfa (50 IU/kg) improves the disease course of existing synovial hypertrophy and prevents the risk of joint bleeds in patients with moderate or severe haemophilia A. The use of imaging assessments will allow for objective detection and monitoring of synovial hypertrophy, and thus expand on the previous findings demonstrating positive effects of once-weekly prophylaxis with efanesoctocog alfa (50 IU/kg) on joint health.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  1. Capable of giving signed informed consent, which includes compliance with therequirements and restrictions listed in the informed consent form (ICF) and in theprotocol. Parents' or legally designated representatives' consent is required forpatients who are <18 years of age or unable to give consent, or as applicable perlocal laws. Patients who are <18 years of age should provide assent in addition tothe parents'/legally designated representatives' consent, if appropriate.

  2. Male or female patients who are ≥12 years of age and diagnosed with moderate orsevere haemophilia A (defined as ≤5% of normal FVIII clotting activity) at the timeof signing the ICF.

  3. A female patient is eligible to participate if she is not pregnant at enrolment anddoes not plan to become pregnant during the study. A woman of child-bearingpotential (WOCBP) must have a negative highly sensitive serum pregnancy test at theScreening Visit.

  4. Must have received prophylactic treatment per local label with any marketed FVIIIproduct or emicizumab for ≥12 months prior to the Baseline Visit.

  5. Have at least one eligible index joint (ankle, elbow, knee).

  6. Have 12 months of documented pre-study treatment data on haemophilia prescriptionsand on treated bleeding episodes prior to the Baseline Visit.

  7. Willingness and the ability of the patient or their legally designatedrepresentative to complete training in the use of the study patient diary and tocomplete the diary throughout the study.

Exclusion

Exclusion Criteria:

  1. Blood clotting disorders other than haemophilia A

  2. Already on efanesoctocog alfa treatment

  3. Positive inhibitor result (assessed by local laboratory) from the Screening Visit,defined as ≥0.6 Bethesda units (BU)/mL.

  4. History of inhibitors without successful immune tolerance induction (ITI)

  • Successful ITI is defined as:

  • Negative inhibitor titer (<0.6 BU/mL)

  • FVIII recovery > 66% of expected

  • FVIII half-life ≥ 6 hours

  1. ITI performed within the last 2 years prior to the Baseline Visit.

  2. Currently receiving treatment with any of the prohibited concomitant medications, asspecified by the protocol.

  3. Planned major orthopaedic procedure in any eligible index joint during the course ofthe study.

  4. Patients are not eligible for participation in the study if they cannot undergo MRIassessments at the Baseline Visit.

  5. Patients with known hypersensitivity to the active substance or to any of theexcipients.

  6. Patient not suitable for participation, whatever the reason, as judged by theInvestigator, including medical or clinical conditions, or patients potentially atrisk of noncompliance to study procedures.

  7. Enrolment in a concurrent clinical interventional study, or intake of aninvestigational medicinal product (IMP), within 3 months prior to inclusion in thestudy.

Study Design

Total Participants: 35
Treatment Group(s): 1
Primary Treatment: Efanesoctocog alfa
Phase: 4
Study Start date:
December 19, 2024
Estimated Completion Date:
December 31, 2026

Study Description

This is a 12-month, multicentre, open-label, non-randomized, interventional single-arm study to assess the course of synovial hypertrophy in previously treated patients ≥12 years of age with moderate or severe haemophilia A achieving high sustained FVIII levels provided by weekly efanesoctocog alfa prophylaxis. To be eligible to enroll in the study, patients must have existing synovial hypertrophy in at least one of the 6 index joints (ankles, elbows, and knees) as assessed by the HEAD-US scoring system. A retrospective data collection on patients' haemophilia, medical, and surgical history will be performed, including a 12-month history of previous treatment and treated bleeding episodes.

The study will start with the Screening Visit, which can be conducted up to 45 days prior to the Baseline Visit (Day 1), to check whether the patient fulfils all the inclusion criteria and none of the exclusion criteria. Patients will have an ultrasound examination of all non-prosthetic index joints at screening. The ultrasound images will be sent for central reading assessment using the HEAD-US scoring system to determine whether the patient has at least one eligible joint required for study inclusion. Once it is confirmed that a patient is eligible for inclusion, he/she will be enrolled in the study and attend a mix of on-site visits and phone call visits. The results from central reading assessment will be sent to the study sites and included in the baseline characteristics of the patients. MRI examinations can be conducted at the Baseline Visit or up to 28 days afterwards. Images from MRI will also be sent for central reading assessment using the International Prophylaxis Study Group (IPSG) MRI scale. The central reading assessment will be sent to the study sites and included in the patient data. Patients will be treated with once-weekly efanesoctocog alfa (50 IU/kg) prophylaxis and will complete the patient diary with their dosing and bleeding information. Assessments will be conducted during the on-site visits, which will occur every 6 months, and during phone call visits, which will occur halfway between these visits. A Safety Follow-up Call will be conducted 14 (+7) days after the End of Treatment (EoT) Visit. Ultrasound and MRI will be used to detect changes in synovial hypertrophy in index joints of patients. The primary endpoint of improvement in existing synovial hypertrophy from baseline to Month 12 as well as the key secondary endpoint of detection of new synovial hypertrophy and change in joint health status from baseline to Month 6 or Month 12 will be assessed using ultrasound and the HEAD-US scoring system.

To obtain 100 eligible index joints, the target is to enroll approximately 35 patients.

Connect with a study center

  • Sobi Investigational Site

    Milan,
    Italy

    Active - Recruiting

  • Sobi Investigational Site

    Naples,
    Italy

    Active - Recruiting

  • Sobi Investigational Site

    Rozzano,
    Italy

    Site Not Available

  • Sobi Investigational Site

    Oslo,
    Norway

    Active - Recruiting

  • Sobi Investigational Site

    Barcelona,
    Spain

    Active - Recruiting

  • Sobi Investigational Site

    Madrid,
    Spain

    Active - Recruiting

  • Sobi Investigational Site

    Seville,
    Spain

    Active - Recruiting

  • Sobi Investigational Site

    Valencia,
    Spain

    Site Not Available

  • Sobi Investigational Site

    Gothenburg,
    Sweden

    Active - Recruiting

  • Sobi Investigational Site

    Malmö,
    Sweden

    Active - Recruiting

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