Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruitingRare disease

Study on Long-Term Safety and Efficacy of Etranacogene Dezaparvovec for Adults with Severe or Moderately Severe Hemophilia B

Verified siteRegistered drugNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the long-term safety and effectiveness of a gene therapy treatment for adults with Hemophilia B, a genetic disorder that affects the blood's ability to clot properly. The treatment being studied is called AAV5-hFIX, which is a type of gene therapy. It uses a harmless virus to deliver a modified version of the human factor IX gene, which is important for blood clotting, into the patient's liver cells. This therapy aims to help the body produce more of the factor IX protein, potentially reducing bleeding episodes in patients with severe or moderately severe Hemophilia B.

The purpose of this study is to assess the long-term safety of the AAV5-hFIX treatment over a period of 6 to 10 years after it has been administered. Participants in this study have previously received this gene therapy in an earlier phase of the trial. Throughout the study, researchers will monitor participants for any side effects that may be related to the treatment, as well as changes in liver function and the presence of any antibodies that might affect the treatment's effectiveness. Additionally, the study will evaluate how well the treatment works in terms of increasing factor IX activity, reducing the need for additional factor IX treatments, and decreasing the frequency of bleeding events.

Participants will undergo regular check-ups and assessments to track their health and the impact of the gene therapy on their quality of life. This includes monitoring for any bleeding episodes, evaluating joint health, and assessing overall well-being through quality of life questionnaires. The study aims to provide valuable information on the long-term benefits and safety of AAV5-hFIX for individuals living with Hemophilia B.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Participation begins after completing the previous study, CT-AMT-060-01, and providing informed consent.

    Eligibility requires a diagnosis of congenital haemophilia B.

  2. Step 2

    Treatment administration

    The treatment involves a single IV infusion of Hemgenix, which contains the active substance etranacogene dezaparvovec.

    This is a gene therapy designed to introduce a modified human factor IX gene into the body.

  3. Step 3

    Monitoring and follow-up

    The study focuses on assessing the long-term safety and efficacy of the treatment over a period of 6 to 10 years.

    Regular monitoring includes checking for any adverse effects, liver health through ultrasound, and levels of specific proteins in the blood.

  4. Step 4

    Safety assessments

    Safety assessments involve tracking any side effects that may be related to the treatment.

    Blood tests will measure liver enzymes and other markers to ensure liver health.

  5. Step 5

    Efficacy assessments

    Efficacy is evaluated by measuring the activity of factor IX in the blood and the frequency of bleeding events.

    Quality of life is assessed using standardized questionnaires.

  6. Step 6

    Study completion

    The study is expected to conclude by May 31, 2026.

    Final assessments will determine the long-term impact of the treatment on health and quality of life.

Who can join the trial?

4 criteria

  • Must have **congenital hemophilia B**, which means being born with a condition that affects blood clotting.
  • Must have completed a previous study called **Study CT-AMT-060-01**.
  • Must be able to give **informed consent**, meaning you understand the study and agree to participate after receiving all the necessary information.
  • Must be an **adult male**.

Who cannot join the trial?

3 criteria

  • Only males can participate in the study. Females are not eligible.
  • Participants must have severe or moderately severe haemophilia B. If you do not have this condition, you cannot join the study.
  • The study is not open to vulnerable populations. This means people who might need special protection or care are not included.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

AAV5-hFIX is a therapy that uses a viral vector to deliver a modified version of the human factor IX gene into the body. This therapy is designed for patients with severe or moderately severe hemophilia B, a condition where the blood does not clot properly due to a deficiency of factor IX. The goal of this therapy is to provide a long-term solution by enabling the body to produce its own factor IX, potentially reducing the need for regular factor IX injections. This study is focused on assessing the long-term safety and effectiveness of this therapy over a period of 6 to 10 years after it has been administered.

What is already known about the treatment

AAV5-hFIX – This medication is administered systemically, meaning it is given throughout the body, typically through an injection. It is currently being studied in clinical trials to evaluate its long-term safety and effectiveness for treating adults with severe or moderately severe Hemophilia B. The main therapeutic use of AAV5-hFIX is to help manage Hemophilia B by providing a gene therapy approach. At the molecular level, it works by using an adeno-associated viral vector to deliver a modified human factor IX gene, which helps in the production of the factor IX protein necessary for blood clotting. It is classified as a gene therapy product.

Investigated diseases

Haemophilia B – Haemophilia B is a genetic disorder caused by a deficiency of clotting factor IX, which is essential for blood clotting. This condition leads to prolonged bleeding after injuries, surgeries, or even spontaneously, especially in joints and muscles. It is an inherited condition, typically passed from parents to children through genes. The severity of the disease can vary, with some individuals experiencing frequent bleeding episodes, while others may have milder symptoms. Over time, repeated bleeding into joints can cause joint damage and pain. Haemophilia B primarily affects males, although females can be carriers and may have mild symptoms.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase I/IITrial ID2024-512603-39-00Protocol codeCSL220_1002Estimated enrolment9 patientsSponsorCSL Behring LLC

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.