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CASPERKID: Study of Exa-cel in Children with Severe Sickle Cell Disease

A Phase 3 Study to Evaluate the Safety and Efficacy of a Single Dose of Autologous CRISPR-Cas9 Modified CD34+ Human Hematopoietic Stem and Progenitor Cells (Exagamglogene Autotemcel or Exa-cel) in Subjects with Severe Sickle Cell Disease


Sickle Cell Disease

Hematological Disorders

Diseases Treated:

Sickle Cell Disease

Eligibility Overview:

  • 211 years old
  • Diagnosed with severe sickle cell disease (SCD)
  1. This study will use CRISPR-Cas9 gene editing to restore fetal hemoglobin (HbF) production in patients with severe sickle cell disease (SCD) and ameliorate clinical symptoms.

    Allogeneic hematopoietic stem cell transplant is the only known cure for SCD. However, the procedure is only available to about 20% of patients who have matched donors and carries the risk of graft-versus-host disease. Approved therapies to prevent SCD complications include hydroxyurea and L-glutamine oral powder, but patients can still have breakthrough vaso-occlusive crises.

    The CRISPR-Cas9 editing-based therapeutic approach aims to restore HbF production by editing a non-coding region in the BCL11A gene. BCL11A is a transcriptional silencer of γ-globin gene expression and acts as an “off switch” for HbF. Turning off BCL11A switches HbF back on.

    St. Jude is one of several sites for the CASPERKID trial sponsored by Vertex Pharmaceuticals.

    Primary Objective

    To evaluate the safety and efficacy of a single dose of autologous CRISPR-Cas9 modified CD34+ human hematopoietic stem and progenitor cells (hHSPCs) (exagamglogene autotemcel or exa-cel) in subjects with severe sickle cell disease

    Eligibility Criteria

    Inclusion criteria include:

    • 2–11 years old (inclusive)
    • Diagnosis of severe sickle cell disease
    • Documented βS/βS βS/β0, or βS/β+ genotype
    • Eligible for autologous stem cell transplant

    Exclusion criteria include:

    • An available 10/10 human leukocyte antigen (HLA)-matched related donor.
    • Prior hematopoietic stem cell transplant
    • Clinically significant and active bacterial, viral, fungal, or parasitic infection

    Study Sites

    St. Jude Children’s Research Hospital, Memphis, Tennessee
    Collaborating sites in and outside the U.S.

  2. About this study

    This is a clinical trial to learn about the safety and possible side effects of exagamglogene autotemcel (exa-cel).

    Exa-cel is investigational. That means the U.S. Food and Drug Administration has not yet approved it. We want to see if a single dose of exa-cel allows your child’s body to:

    • Increase the amount of a type of hemoglobin called hemoglobin F. Hemoglobin is a protein in red blood cells that delivers oxygen to the body’s cells.
    • Decrease the effects of SCD

    Main steps of the study:

    1. We collect bone marrow cells (stem cells) from your child.

    2. We send those cells to a lab. We will change (edit) the DNA of a specific gene in your child’s cells in the lab to create the study product (exa-cel). The technology we use to edit the DNA is called CRISPR/Cas9. It cuts the DNA like scissors. The blood stem cells repair the cut DNA using their natural repair tools. We hope this repair will help your child’s body make more hemoglobin F.

    3. Your child will get an autologous bone marrow transplant using their changed cells. This transplant takes place in the hospital. Your child will take medicine to remove their bone marrow cells and create “room” for the edited cells. We will give the modified cells into your child’s vein with an IV.

    4. We hope that once the changed cells are in the body, the red blood cells will not sickle or cause complications of sickle cell disease..

    Purpose of this clinical trial

    The main goal of this study is to see if a single dose of exa-cel allows your child’s body to increase the amount of hemoglobin F while reducing the painful effects of sickle cell disease.

    Eligibility overview

    • 2–11 years old
    • Diagnosis of severe sickle cell disease
  3. CASPERKID  Quick View
    Sponsor Vertex Pharmaceuticals identifier NCT05329649
    Trial start date January 2023
    Estimated enrollment 12
    Study type Interventional
    Study phase Phase 3

    Sickle Cell Disease

    Ages 2-11 years old (inclusive)
    Site Principal Investigator Akshay Sharma, MBBS 
    Study site St. Jude Children’s Research Hospital and collaborating sites in and outside the U.S.
    For a consultation or to discuss AML16 St. Jude Physician/Patient Referral Office

St. Jude Children’s Research Hospital
262 Danny Thomas Place
Memphis, TN 38105  USA
Voice: 1-888-226-4343 or 901-595-4055
24-Hour Emergency Access Pager: 1-800-349-4334

The above information is intended to provide only a basic description about a research protocol that may be currently active at St. Jude. The details made available here may not be the most up-to-date information on protocols used by St. Jude. To receive full details about a protocol and its status and or use at St. Jude, a physician must contact St. Jude directly.