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Study on the Effects of Exagamglogene Autotemcel for Patients with Transfusion-Dependent Beta-Thalassemia or Severe Sickle Cell Disease

Verified siteRegistered drugNo placebo
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What is this trial about?

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

This clinical trial is focused on studying two serious blood disorders: Transfusion-dependent β-thalassemia and Severe Sickle Cell Disease. These conditions often require regular blood transfusions and can lead to significant health challenges. The study is testing a new treatment called CTX001, which involves using a patient's own blood stem cells that have been modified using a technology called CRISPR-Cas9. This technology aims to help the body produce more fetal hemoglobin, a type of hemoglobin that can reduce the symptoms of these diseases.

The purpose of the study is to evaluate the effectiveness and safety of a single dose of CTX001 in patients with these conditions. Participants will receive the treatment and be monitored over time to see how their levels of fetal hemoglobin change. The study will also look at the safety of the treatment by checking for any side effects and monitoring the health of the participants. Other medications used in the study include Filgrastim, Busulfan, and Plerixafor, which are used to prepare the body for the main treatment.

During the study, participants will receive the treatment through an infusion, which is a way of delivering medication directly into the bloodstream. They will be closely monitored by healthcare professionals to ensure their safety and to track the effectiveness of the treatment. The study aims to provide valuable information on whether this new approach can help reduce the need for blood transfusions and improve the quality of life for people with these challenging conditions.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    The trial begins with an initial assessment to confirm eligibility. This includes a review of medical history and a confirmation of diagnosis for either transfusion-dependent β-thalassemia (TDT) or severe sickle cell disease (SCD).

  2. Step 2

    Stem cell collection

    Eligible participants undergo a procedure to collect their own stem cells. This involves the use of filgrastim and plerixafor, both administered as subcutaneous injections, to mobilize stem cells into the bloodstream for collection.

  3. Step 3

    Genetic modification

    The collected stem cells are then modified using CRISPR technology to correct the genetic defect associated with TDT or SCD. This process is conducted in a laboratory setting.

  4. Step 4

    Conditioning treatment

    Before the modified stem cells are returned to the body, a conditioning treatment with busulfan is administered intravenously. This prepares the body to accept the modified cells.

  5. Step 5

    Infusion of modified cells

    The modified stem cells, now referred to as CTX001, are infused back into the body through an intravenous route. This is a single-dose procedure.

  6. Step 6

    Post-infusion monitoring

    After the infusion, regular monitoring is conducted to assess the levels of fetal hemoglobin (HbF) and other blood parameters. This monitoring starts 60 days after the last red blood cell transfusion and continues over time to evaluate the treatment's effectiveness and safety.

  7. Step 7

    Follow-up assessments

    Follow-up assessments are conducted to monitor safety and tolerability, including checking for any adverse events and evaluating clinical laboratory values. The duration of these assessments extends up to 12 months after the CTX001 infusion.

Who can join the trial?

8 criteria

  • Participants must have either **Transfusion-dependent β-thalassemia (TDT)** or **severe sickle cell disease (SCD)**. These are specific blood disorders.
  • Participants must be eligible for an **autologous stem cell transplant**. This means using their own stem cells for the procedure, as determined by the study doctor.
  • For those with TDT, they must have a confirmed diagnosis of TDT. This includes having specific genetic types of β-thalassemia, which will be confirmed by a central laboratory before starting treatment.
  • Participants with TDT should have a history of needing a significant amount of blood transfusions in the past two years. This means at least 100 milliliters per kilogram of body weight per year or 10 units of packed red blood cells per year.
  • For those with SCD, they must have a confirmed diagnosis of severe SCD, which includes specific genetic types of sickle cell disease.
  • Participants with SCD should have experienced at least two severe **vaso-occlusive crisis (VOC)** events per year in the past two years. VOCs are painful episodes caused by blocked blood flow.
  • Participants must be adolescents or adults, as the study includes specific age groups.
  • Both male and female participants are eligible to join the study.

Who cannot join the trial?

4 criteria

  • Patients who are not dependent on blood transfusions for their condition.
  • Patients who do not have severe sickle cell disease.
  • Patients who are not in the age range specified for the study.
  • Patients who are part of a vulnerable population, which means they might need special protection or care.
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Investigated drugs

CTX001 is a treatment that uses a patient's own blood stem cells, which are modified using a technology called CRISPR/Cas9. This modification aims to help people with certain blood disorders, like transfusion-dependent beta-thalassemia or severe sickle cell disease, by potentially increasing the levels of a specific type of hemoglobin in their blood. The goal is to improve the patient's condition by reducing the need for blood transfusions or alleviating symptoms associated with these diseases.

What is already known about the treatment

CTX001 – This medication is administered as a single dose of autologous CRISPR/Cas9 modified CD34+ human hematopoietic stem and progenitor cells. It is currently being studied in clinical trials for its efficacy and safety in treating transfusion-dependent β-thalassemia and severe sickle cell disease. The main therapeutic indication is to increase fetal hemoglobin (HbF) levels in patients, which can alleviate symptoms of these blood disorders. At the molecular level, CTX001 works by using CRISPR/Cas9 technology to edit specific genes in stem cells, promoting the production of HbF. It is classified under gene therapy, a cutting-edge approach in modern medicine.

Investigated diseases

  • Transfusion-dependent β-thalassemia

    This is a genetic blood disorder characterized by reduced production of hemoglobin, leading to severe anemia. Individuals with this condition require regular blood transfusions to manage their symptoms and maintain adequate hemoglobin levels. Over time, the need for transfusions can lead to complications such as iron overload, which may affect various organs. The disease is caused by mutations in the HBB gene, affecting the production of the beta-globin chain of hemoglobin. Symptoms often appear in early childhood and can include fatigue, weakness, and pale skin. Management focuses on maintaining hemoglobin levels and monitoring for complications.

  • Severe sickle cell disease

    This is a genetic disorder affecting hemoglobin, the molecule in red blood cells that carries oxygen. It is characterized by the presence of abnormal hemoglobin, known as hemoglobin S, which causes red blood cells to become rigid and sickle-shaped. These sickle-shaped cells can block blood flow, leading to pain episodes known as vaso-occlusive crises. Over time, the disease can cause damage to organs and increase the risk of infections. Symptoms typically begin in early childhood and can include anemia, pain, and swelling in the hands and feet. The condition is inherited in an autosomal recessive pattern, meaning both copies of the gene in each cell have mutations.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-514641-12-00Protocol codeVX21-CTX001-161Estimated enrolment26 patientsSponsorVertex Pharmaceuticals Inc.

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