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Long-term Safety Study of Exagamglogene Autotemcel for Patients with Sickle Cell Disease or Transfusion-Dependent Thalassemia

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 blood disorders: Sickle Cell Disease and Transfusion-dependent Thalassemia. These conditions affect the blood's ability to carry oxygen effectively, leading to various health issues. The treatment being tested is called CTX001, which is a type of cell therapy. It involves using a technique known as CRISPR-Cas9 gene editing to modify a specific part of the patient's own blood-forming stem cells. This modification aims to restore the natural production of a type of hemoglobin called fetal hemoglobin, which can help improve the symptoms of these diseases.

The purpose of this study is to evaluate the long-term safety of CTX001 in patients who have already received this treatment for either Sickle Cell Disease or Transfusion-dependent Thalassemia. Participants in the study will be monitored over an extended period to observe any new health issues, such as new cancers or blood disorders, and to track their overall health and well-being. The study will also look at changes in hemoglobin levels and the presence of the intended genetic changes in the blood and bone marrow over time.

Throughout the study, participants will undergo regular check-ups to ensure their safety and to gather information on how the treatment affects their health. This includes monitoring for any serious side effects and assessing the overall impact on their quality of life. The study is designed to provide valuable insights into the long-term effects of CTX001 and its potential benefits for individuals with these challenging blood disorders.

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

    Joining the study

    Sign and date the informed consent form. This confirms understanding and agreement to participate in the study.

    Ensure that the CTX001 infusion has been received prior to joining this follow-up study.

  2. Step 2

    Initial assessment

    Undergo a comprehensive health evaluation to establish a baseline for monitoring throughout the study.

    This assessment may include blood tests and other diagnostic procedures to evaluate current health status.

  3. Step 3

    Medication administration

    Receive the medication Casgevy, which is a dispersion for infusion containing exagamglogene autotemcel.

    The medication is administered through an intravenous infusion.

  4. Step 4

    Regular follow-up visits

    Attend scheduled follow-up visits to monitor health and any potential side effects.

    These visits will include assessments of hemoglobin levels and genetic modifications in blood and bone marrow cells.

  5. Step 5

    Monitoring for adverse events

    Report any new or worsening health issues, such as new malignancies or blood disorders, to the study team.

    All serious adverse events will be tracked for up to 15 years after the CTX001 infusion.

  6. Step 6

    Quality of life assessments

    Complete periodic questionnaires to assess changes in quality of life using the EuroQol quality of life scale (EQ-5D-5L).

    These assessments are for participants aged 18 and older from specific previous studies.

  7. Step 7

    Completion of study

    The study is expected to continue until January 1, 2040.

    Upon completion, a final assessment will be conducted to evaluate long-term health outcomes.

Who can join the trial?

4 criteria

  • The patient or their legal representative or guardian must sign and date an informed consent form. This is a document that explains the study and confirms that the patient agrees to participate.
  • The patient must have already received an infusion of **CTX001**. An infusion is a way of delivering medicine directly into the bloodstream.
  • The study is open to both **male** and **female** patients.
  • The study includes patients who are in certain age groups, specifically those who are older children, teenagers, and adults.

Who cannot join the trial?

3 criteria

  • Patients who do not have **Sickle Cell Disease** or **Transfusion Dependent Thalassemia** cannot participate. These are specific blood disorders.
  • Patients who are not within the specified age range cannot participate. The age range is not specified here, but it is important for eligibility.
  • Patients who are part of a vulnerable population cannot participate. This means people who might need extra protection or care.
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Investigated drugs

CTX001 is a therapy that uses a technology called CRISPR-Cas9 to modify a person's own stem cells. This treatment is designed for people with certain blood disorders, specifically transfusion-dependent thalassemia and severe sickle cell disease. The goal of this therapy is to make changes in the stem cells that can help improve the symptoms of these conditions. In this clinical trial, the focus is on understanding the long-term safety of using CTX001 in patients who have already received this treatment.

What is already known about the treatment

CTX001 – This medication is administered through an infusion of genetically modified hematopoietic stem cells. It is currently being studied in clinical trials for its long-term safety and effectiveness in treating sickle cell disease and transfusion-dependent thalassemia. CTX001 works by using the CRISPR-Cas9 gene-editing technology to modify the patient's own stem cells, aiming to correct the genetic defects causing these blood disorders. It is classified as a gene therapy, representing a novel approach in the treatment of genetic blood diseases.

Investigated diseases

  • Sickle Cell Disease

    Sickle Cell Disease is a genetic disorder that affects the shape of red blood cells, causing them to become rigid and sickle-shaped. These abnormally shaped cells can block blood flow, leading to pain and potential organ damage. The disease is characterized by episodes of pain, known as sickle cell crises, and can cause anemia due to the rapid breakdown of the misshapen cells. Over time, individuals may experience complications such as infections, delayed growth, and vision problems. The severity of symptoms can vary widely among individuals. It is a lifelong condition that requires ongoing management.

  • Transfusion-Dependent Thalassemia

    Transfusion-Dependent Thalassemia is a severe form of thalassemia where the body produces an insufficient amount of hemoglobin, leading to anemia. Individuals with this condition require regular blood transfusions to maintain adequate hemoglobin levels. The disease is caused by genetic mutations affecting hemoglobin production, resulting in fatigue, weakness, and pale skin. Over time, frequent transfusions can lead to iron overload, which may affect organs such as the heart and liver. Growth and development may be delayed in children with this condition. It is a chronic condition that necessitates lifelong medical care.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-512654-19-00Protocol codeVX18-CTX001-131Estimated enrolment90 patientsSponsorVertex Pharmaceuticals Inc.

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