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Study on the Safety and Effectiveness of CRISPR-Cas9 Modified Stem Cells for Patients with Transfusion-Dependent Beta-Thalassemia Using Exagamglogene Autotemcel

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 a condition known as Transfusion-Dependent Beta-Thalassemia (TDT). TDT is a blood disorder that requires regular blood transfusions. The study is testing a new treatment called exagamglogene autotemcel, also known by its code name CTX001. This treatment involves using a technique called CRISPR-Cas9 gene editing to modify certain cells in the body. The goal is to help the body produce more of its own healthy blood cells, reducing the need for transfusions.

Participants in the study will receive a single dose of the modified cells. Before receiving the treatment, participants will undergo a process to prepare their body, which includes the use of a medication called busulfan. This medication helps create space in the bone marrow for the new cells to grow. The study will also involve the use of other medications, such as filgrastim and plerixafor, which help in collecting the necessary cells from the body. These medications are given through injections.

The purpose of the study is to evaluate the safety and effectiveness of this new treatment. Participants will be monitored closely for any side effects and to see how well the treatment works in reducing the need for blood transfusions. The study will track various health indicators over time, including how quickly the body starts producing its own blood cells and the overall health of the participants. The study aims to provide a new treatment option for people living with TDT, potentially improving their quality of life by reducing their dependence on regular blood transfusions.

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

    Initial assessment

    The trial begins with an initial assessment to confirm eligibility. This includes a diagnosis of transfusion-dependent β-thalassemia, a history of regular blood transfusions, and eligibility for an autologous stem cell transplant.

  2. Step 2

    Stem cell collection

    Stem cells are collected from the patient. These cells are then modified using CRISPR-Cas9 technology to potentially improve their function.

  3. Step 3

    Preparation for infusion

    Before receiving the modified stem cells, the patient undergoes conditioning with busulfan, administered intravenously. This step prepares the body to accept the new cells.

  4. Step 4

    Infusion of modified stem cells

    The patient receives an infusion of the modified stem cells, known as exagamglogene autotemcel, through an intravenous route.

  5. Step 5

    Post-infusion monitoring

    After the infusion, the patient is monitored for successful engraftment of the stem cells. This includes checking for neutrophil and platelet engraftment and monitoring for any adverse events.

  6. Step 6

    Follow-up assessments

    Regular follow-up assessments are conducted to evaluate the effectiveness of the treatment. This includes monitoring hemoglobin levels, transfusion requirements, and any changes in quality of life.

Who can join the trial?

5 criteria

  • The patient must have a diagnosis of **transfusion-dependent β-thalassemia (TDT)**. This means they have a specific type of blood disorder that requires regular blood transfusions.
  • The patient must have a history of receiving at least 100 mL per kilogram of body weight per year, or at least 10 units of packed red blood cell transfusions each year, in the two years before joining the study.
  • The patient must be eligible for an **autologous stem cell transplant**. This is a procedure where a patient's own stem cells are used to replace damaged or diseased cells, and the decision is made by the study doctor.
  • The study is open to both male and female patients.
  • The study includes patients who are not considered part of a vulnerable population, meaning they are not in a group that needs special protection.

Who cannot join the trial?

5 criteria

  • Patients who are not dependent on blood transfusions for their condition.
  • Patients who are not diagnosed with **β-thalassemia**, a blood disorder that reduces the production of hemoglobin.
  • Patients who are not within the specified age range for the study.
  • Patients who are part of a vulnerable population, meaning they might need special protection or care.
  • Patients who do not meet other specific health criteria set by the study.
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Investigated drugs

CTX001 is a treatment being studied for its safety and effectiveness in patients with Transfusion-Dependent β-Thalassemia. It involves using the patient's own blood stem cells, which are modified using CRISPR-Cas9 technology. This modification aims to correct the genetic defect causing the disease, potentially reducing or eliminating the need for regular blood transfusions.

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, delivered through an intravenous infusion. It is currently being studied in clinical trials for its safety and effectiveness in treating transfusion-dependent β-thalassemia (TDT). The main therapeutic indication is to reduce or eliminate the need for blood transfusions in patients with TDT. At the molecular level, CTX001 works by using CRISPR-Cas9 technology to edit specific genes in the patient's stem cells, aiming to increase the production of fetal hemoglobin. It is classified under gene therapy, focusing on genetic modification to treat or prevent disease.

Investigated diseases

Transfusion-dependent β-thalassemia (TDT) – This is a genetic blood disorder characterized by reduced production of hemoglobin, the protein in red blood cells that carries oxygen. Individuals with TDT often experience severe anemia, which requires regular blood transfusions to manage. Over time, the need for frequent transfusions can lead to complications such as iron overload in the body. The condition is caused by mutations in the HBB gene, which affects the production of the beta-globin chain of hemoglobin. Symptoms typically appear in early childhood and can include fatigue, weakness, and pale skin. The progression of the disease can vary, but it generally involves ongoing management to address anemia and prevent complications.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-516894-57-00Protocol codeCTX001-111Estimated enrolment17 patientsSponsorVertex Pharmaceuticals Inc.

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