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Sickle Cell DiseasePhase 1NCT06506461

Gene Editing For Sickle Cell Disease

A Phase 1 study testing Plerixafor, Busulfan and Gene-modified CD34+ cells in people with Sickle Cell Disease, run by St. Jude Children's Research Hospital at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This study is being done to test the safety of a new treatment called gene editing in Sickle Cell Disease (SCD) patients and to see if a single dose of this genetically modified cellular product will increase the amount of a certain hemoglobin called fetal hemoglobin (HbF) and help reduce the symptoms of SCD. Read more about this study

Who is it for?
Ages 18 to 24 years
Conditions the study is for
Sickle Cell Disease
What is being tested?
Plerixafor, Busulfan and Gene-modified CD34+ cells
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
25 participants
Where
1 siteUnited States
Study dates
21 Mar 2025to Dec 2032
Phase
Phase 1
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 24 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Age ≥18 years and ≤24.9 years.
  • Patients with SCD (Hb SS, Hb SB0 and Hb SB+ genotype) who have experienced EITHER (a) 2 or more SCD-related vaso-occlusive events (acute pain events, acute chest syndrome, priapism and splenic sequestration) per year in the 2-year period before screening, OR (b) administration of regular red blood cell (RBC) transfusions (≥8 transfusions in the 12 months preceding enrollment) EXCEPT if the RBC transfusions are being administered for primary or secondary stroke prevention and, in the opinion of the treating hematologist, cannot be safely discontinued after infusion of the gene modified drug product.
  • Failure, intolerance, or refusal of hydroxyurea therapy.
  • Patients must be eligible for autologous stem cell transplant as per investigator's judgment.
  • Females of childbearing potential (i.e., those who are post-menarchal with an intact uterus and at least 1 ovary, and those who are less than 1 year postmenopausal) must agree to use acceptable method(s) of contraception from start of mobilization through at least 6 months post-infusion.
  • Males must agree to use effective contraception from start of mobilization through at least 6 months post-infusion.
  • Patients should be willing to participate in an additional long-term follow-up study after completion of this trial.

Who cannot join

  • Availability of an human leukocyte antigen (HLA)-matched sibling who is willing and able to donate an appropriate graft for hematopoietic cell transplantation (HCT).
  • Karnofsky or Lansky performance score < 80.
  • Pregnant, as confirmed by positive serum or urine pregnancy test within 14 days before enrollment (if female).
  • Breastfeeding.
  • Uncontrolled (undergoing appropriate treatment and with progression of clinical symptoms) or clinically significant bacterial, viral, or fungal infections within 1 month before enrollment.
  • Patients with confirmed Hepatitis B or Hepatitis C infections.
Show all 22Show fewer
  • Patients with confirmed seropositivity or positive nucleic acid amplification test (NAAT) for human immunodeficiency virus (HIV) or human T-cell lymphotropic virus (HTLV).
  • Patients with a history of stroke.
  • Serum conjugated (direct) bilirubin > 2× the upper limit of normal for age, or serum alanine transaminase (ALT) > 3× the upper limit of normal for age as per the local laboratory. Participants with hyperbilirubinemia or elevated aspartate aminotransferase (AST) as the result of hyperhemolysis, or with a severe drop in hemoglobin post blood transfusion, are not excluded as long as these values downtrend and return to acceptable limits subsequently.
  • Left ventricular shortening fraction < 25% or ejection fraction < 45% by echocardiogram.
  • Estimated creatinine clearance less than 60 mL/min/1.73m^2.
  • Diffusion capacity of carbon monoxide (DLCO) < 50% (adjusted for hemoglobin) OR baseline oxygen saturation < 85% in patients unable to perform pulmonary function tests.
  • Prior HCT or gene therapy.
  • Known hepatic cirrhosis, bridging hepatic fibrosis, or active hepatitis. Appropriate ultrasound or magnetic resonance (MR) imaging may be used to define the presence and degree of cirrhosis. Liver biopsy may be performed at the discretion of the attending physician or principal investigator if there are concerns regarding the presence of severe hepatic fibrosis or cirrhosis such that participation in this trial will not be in the patient's best interest.
  • Active known malignancy, myelodysplasia, abnormal cytogenetics, or immunodeficiency.
  • Patients with history of a significant bleeding disorder.
  • Cerebrovascular procedure within 6 months, including pial synangiosis for moyamoya.
  • Patients with history of untreated moyamoya disease or presence of moyamoya disease at screening that in the opinion of the investigator puts the subjects at the risk of bleeding.
  • Evidence of a pathogenic clonal variant in any candidate gene detected by a standard, licensed next-generation sequencing clinical assay for gene mutations associated hematological malignancies.
  • Patients with history of intolerance, contraindication, or known sensitivity to plerixafor or motixafortide or busulfan. Prior anaphylactic reaction with excipients of the proposed product.
  • Patients with participation in another clinical study with an investigational drug/product within 30 days of screening or fewer than 5 half-lives of the investigational agent whichever is longer from screening.
  • Patients with history of alloimmunization to RBC antigens and for whom the investigator anticipates that there will be insufficient RBC units available for the duration of the study.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Akshay Sharma, MBBS, MSc contact

888-226-4343

referralinfo@stjude.org

United States1 site, 1 recruiting
  • St. Jude Children's Research Hospital

    Memphis, Tennessee, 38105

    Akshay Sharma, MBBS, MSc, 888-226-4343, referralinfo@stjude.org

    Recruiting

Other trials in United States

About this study

Official title: St. Jude Autologous Genome Edited Stem Cells For Sickle Cell Disease-1

This study is being done to test the safety of a new treatment called gene editing in Sickle Cell Disease (SCD) patients and to see if a single dose of this genetically modified cellular product will increase the amount of a certain hemoglobin called fetal hemoglobin (HbF) and help reduce the symptoms of SCD.

Primary Objective

  • To assess the safety of autologous infusion of clustered regularly interspaced palindromic repeats (CRISPR)/ CRISPR associated protein (Cas9)-edited CD34+ hematopoietic stem and progenitor cells (HSPCs) in patients with severe SCD.

Secondary Objective

  • To assess the efficacy autologous infusion of CRISPR/Cas9 genome-edited CD34+ HSPCs into patients with severe SCD.
Read the detailed description

Participants will receive a daily subcutaneous (under the skin) dose of motixafortide for up to 3 consecutive days to mobilize their hematopoietic stem and progenitor cells (HSPCs) into peripheral blood. Participants who cannot tolerate motixafortide may receive a daily subcutaneous dose of plerixafor as an alternative for 3-5 consecutive days. The collection of HSPCs will be done via apheresis. The collected HSPCs will be sent to a lab to genetically modify them using CRISPR/Cas9.

In the lab, the researchers will take the stem cells and purify them. The stem cells will then be mixed with the CRISPR-Cas9 gRNA ribonucleoprotein (RNP) complex to change (edit) the genes in the cells and produce the new gene edited cellular product. This gene edited drug product will be frozen until ready for infusion.

Once the cellular product is ready, participants will be given Busulfan (a chemotherapy medicine) intravenously (IV) for 4 days. The thawed gene product will be given IV about 48 hours after the completion of the last dose of busulfan.

Participants will be followed for 3 years on this study. After the three years, participants will be followed for 12 more years on a long-term follow-up study.

Being tested
Plerixafor, Busulfan, Gene-modified CD34+ cells, Motixafortide
Keywords
Plerixafor, Autologous, CD34+ cells, Apheresis, Conditioning, Busulfan, Gene Editing
Medical subject headings
Anemia, Sickle Cell

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PlerixaforDrug

    Also called Mozobil®

    Given Subcutaneous (under the skin)

  • BusulfanDrug

    Also called Myleran®, Busulfex

    Given Intravenous (IV)

  • Gene-modified CD34+ cellsBiological

    Given Intravenous (IV)

  • MotixafortideDrug

    Also called Aphexda

    Given Subcutaneous (under the skin)

Study groups in NCT06506461
Study groupRoleWhat they receive
Autologous, genetically modified CD34+ HSPCs TreatmentExperimentalAll eligible participants receive intervention as described in the Detailed Description with the following: motixafortide, plerixafor, busulfan, and autologous, gene-modified CD34+ cells
Receives: Drug: Plerixafor; Drug: Busulfan; Biological: Gene-modified CD34+ cells; Drug: Motixafortide

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of neutrophil engraftment by day +42 after infusion of the CRISPR/Cas9-edited CD34+ HSPCs.

    Upon completion of the trial, summary statistics will be computed for the time to neutrophil engraftment.

    Measured: Within 42 days of the cellular product infusion

  2. Incidence of platelet engraftment by day +60 after infusion of the CRISPR/Cas9-edited CD34+ HSPCs.

    Upon completion of the trial, summary statistics will be computed for the time to platelet engraftment.

    Measured: Within 60 days of the cellular product infusion

  3. Sustenance of multi-lineage engraftment and polyclonal hematopoiesis as measured by counts of different clones of myeloid cells, T cells, B cells, and NK cells at 1 year after infusion of the CRISPR/Cas9-edited CD34+ HSPCs.

    Sustenance of multi-lineage engraftment will be described using descriptive statistics.

    Measured: Within 1 year of the cellular product infusion

  4. Frequency of off-target editing after infusion of the CRISPR/Cas9-edited CD34+ HSPCs.

    Frequency of off-target editing will be described using descriptive statistics.

    Measured: Within 3 years of the cellular product infusion

  5. Occurrence of secondary graft failure, clonal hematopoiesis, MDS, or AML

    Occurrence will be described using descriptive statistics.

    Measured: Within 3 years of the cellular product infusion

Secondary outcomes (4)
  1. Estimate the change in the annualized rate of SCD-related vaso-occlusive events (such as pain crises and acute chest syndrome events), starting at 3 months after the infusion of autologous CRISPR/Cas9-edited CD34+ HSPCs.

    We will evaluate the change in the annualized rate of SCD-related vaso-occlusive events starting at 3 months after the infusion of autologous gene-edited CD34+ HSPCs relative to the annualized rate calculated during the 2-year period before study enrollment. The changes will be summarized using descriptive statistics and displayed graphically.

    Measured: From 3 months post the cellular product infusion to 3 years post infusion

  2. Compare the change from baseline in the total blood hemoglobin concentration.

    The change from baseline (at the time of screening) in the total blood hemoglobin concentration will be calculated at various timepoints as described in the protocol. The changes will be summarized using descriptive statistics and displayed graphically.

    Measured: From time of screening to 3 years post infusion

  3. Compare the change from baseline in the fraction of red blood cells (RBCs) containing HbF.

    The change from baseline (at the time of screening) in the fraction of RBCs containing HbF by immunostaining will be calculated at various timepoints as described in the protocol. The changes will be summarized using descriptive statistics and displayed graphically.

    Measured: From time of screening to 3 years post infusion

  4. Change in incidence of packed RBC transfusions.

    The change from baseline (at the time of screening) in the incidence of packed RBC transfusions will be calculated at various timepoints as described in the protocol. The changes will be summarized using descriptive statistics and displayed graphically.

    Measured: Within 1 year prior to infusion and within 3 months to 1 year post infusion

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted17 Jul 2024
  2. Study start21 Mar 2025
  3. Primary completionDec 2029 (estimated)
  4. Study completionDec 2032 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Model description
Patients with severe sickle cell disease (SCD)
Masking
None (open label)
Enrolment
25 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06506461
Sponsor's protocol ID
SAGES1
Other IDs
U01HL163983
Status last verified
Oct 2026
First submitted
14 Jun 2024
Last updated
15 Oct 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Individual participant de-identified datasets containing the variables analyzed in the published article will be made available (related to the study primary or secondary objectives contained in the publication). Supporting documents such as the protocol, statistical analyses plan, and informed consent are available through the CTG website for the specific study. Data used to generate the published article will be made available at the time of article publication. Investigators who seek access to individual level de-identified data will contact the computing team in the Department of Biostatistics (ClinTrialDataRequest@stjude.org) who will respond to the data request.

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing Plerixafor, Busulfan and Gene-modified CD34+ cells in people with Sickle Cell Disease, run by St. Jude Children's Research Hospital at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 22 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Akshay Sharma, MBBS, MSc (888-226-4343, referralinfo@stjude.org), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of neutrophil engraftment by day +42 after infusion of the CRISPR/Cas9-edited CD34+ HSPCs. (time frame: Within 42 days of the cellular product infusion). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2026.

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