A Blood Stem Cell Transplant for Sickle Cell Disease

March 3, 2026 updated by: City of Hope Medical Center

Pilot Study to Evaluate the Safety and Feasibility of Induction of Mixed Chimerism in Sickle Cell Disease Patients With COH-MC-17: a Non-Myeloablative, Conditioning Regimen and CD4+ T-cell-depleted Haploidentical Hematopoietic Transplant

Blood stem cells can produce red blood cells (which carry oxygen), white blood cells of the immune system (which fight infections) and platelets (which help the blood clot).

Patients with sickle cell disease produce abnormal red blood cells. A blood stem cell transplant from a donor is a treatment option for patients with severe sickle cell disease. The donor can be healthy or have the sickle cell trait. The blood stem cell transplant will be given to the patient as an intravenous infusion (IV). The donor blood stem cells will then make normal red blood cells - as well as other types of blood cells - in the patient. When blood cells from two people co-exist in the patient, this is called mixed chimerism.

Most children are successfully treated with blood stem cells from a sibling (brother/sister) who completely shares their tissue type (full-matched donor). However, transplant is not an option for patients who (1) have serious medical problems, and/or (2) do not have a full-matched donor. Most patients will have a relative who shares half of their tissue type (e.g. parent, child, and brother/sister) and can be a donor (half-matched or haploidentical donor).

Adult patients with severe sickle cell disease were successfully treated with a half-matched transplant in a clinical study. Researchers would like to make half-matched transplant an option for more patients by (1) improving transplant success and (2) reducing transplanted-related complications.

This research transplant is being tested in this Pilot study for the first time. It is different from a standard transplant because:

  1. Half-matched related donors will be used, and
  2. A new combination of drugs (chemotherapy) that does not completely wipe out the bone marrow cells (non-myeloablative treatment) will be used to prepare the patient for transplant, and
  3. Most of the donor CD4+ T cells (a type of immune cells) will be removed (depleted) before giving the blood stem cell transplant to the patient to improve transplant outcomes.

It is hoped that the research transplant:

  1. Will reverse sickle cell disease and improve patient quality of life,
  2. Will reduce side effects and help the patient recover faster from the transplant,
  3. Help the patient keep the transplant longer and
  4. Reduce serious transplant-related complications.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a pilot study to determine the safety and feasibility of the COH-MC-17 regimen and ability of the regimen to induce a mixed chimeric status in severe sickle cell disease patients (hemoglobin SS or S-βº Thalassemia). The COH-MC-17 regimen consists of a non-myeloablative regimen (cyclophosphamide, pentostatin and rabbit-anti-thymocyte globulin (ATG)) followed by a CD4+ T-cell-depleted haploidentical hematopoietic cell transplant (HaploHCT).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
3

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • Duarte, California, United States, 91010
        • City of Hope Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Description

Inclusion:

  1. Confirmed diagnosis of hemoglobin SS or S-βº Thalassemia sickle cell disease

  2. Severe disease status as defined by presence of one or more of the following:

    1. Clinically significant neurologic event (stroke) or any neurological deficit lasting > 24 hours; or increased transcranial Doppler velocity (>200 m/s). A stroke is defined as a sudden neurologic change lasting more than 24 hours that is accompanied by cerebral magnetic resonance imaging (MRI) changes.
    2. History of ≥ 1 episodes of acute chest syndrome (ACS) in the 2-year period preceding enrollment despite the institution of supportive care measures (i.e. asthma therapy and/or hydroxyurea).
    3. History of ≥ 2 severe vaso-occlusive pain crises (VOC) per year in the 2-year period preceding enrollment despite the institution of supportive care measures (i.e. a pain management plan and/or treatment with hydroxyurea). A severe VOC is defined as an episode of pain lasting more than 2 hours severe enough to require care at a medical facility. Note that priapism that lasts more than 2 hours and requires care at a medical facility is also considered a VOC.
    4. Osteonecrosis of ≥ 2 joints despite the institution of supportive care measures.
    5. Prior treatment with regular RBC transfusion therapy, defined as receiving ≥ 8 transfusions per year for > 1 year to prevent vaso-occlusive clinical complications (i.e. pain, stroke, and acute chest syndrome)
  3. No HLA matched sibling or 10/10 matched unrelated donor

  4. Related donor who:

    1. Is genotypically haploidentical on HLA-A, B, C and DRB1 loci AND
    2. Meets institutional criteria
  5. Failed prior hydroxyurea therapy or have intolerance to hydroxyurea
  6. Meets protocol specified organ function criteria
  7. Women of childbearing potential or sexually active male: Agreement to use adequate contraception prior to study entry and 6 months post-transplant.

Exclusion Criteria

  1. Prior stem cell transplant
  2. Prior bone marrow transplant
  3. Concurrent other investigational agents, chemotherapy, biological therapy or radiation therapy
  4. Planned use of moderate and strong CYP3A4 inhibitors
  5. Active infection
  6. Major surgery within the last 30 days
  7. Clinically significant liver fibrosis or cirrhosis if on chronic transfusion therapy > 6 months
  8. Active malignancy (other than non-melanoma skin cancers)
  9. History of allergic reactions attributed to compounds of similar chemical or biologic composition to any in the pre- or post-transplant regimen.
  10. Women of childbearing potential: pregnant or breastfeeding

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: COH-MC-17 and immunosuppressants

Participants receive COH-MC-17: a 21-day nonmyeloablative conditioning regimen (cyclophosphamide, pentostatin and rabbit anti-thymocyte globulin), followed by CD4+ T-cell-depleted Haploidentical Hematopoietic Transplant on Day 0.

Immunosuppressants (tacrolimus and mycophenolate mofetil) given on Day -1 onwards until discontinuation post-transplant.

The minimally manipulated transplant product is manufactured using the CliniMACS device.
Drug: Cyclophosphamide
Orally daily
Other Names:
  • Cytoxan
Drug: Pentostatin
Intravenous
Other Names:
  • NIPENT
Drug: Rabbit anti-thymocyte globulin
Intravenous
Other Names:
  • Thymoglobulin
  • Rabbit ATG
Drug: Tacrolimus
Initially IV. If patient tolerates, convert to oral.
Other Names:
  • PROGRAF®
Drug: Mycophenolate mofetil
IV or oral
Other Names:
  • Myfortic
  • MMF
  • CellCept®
Biological: CD4+ T-cell-depleted Haploidentical Hematopoietic Transplant
Infusion
Other Names:
  • CD4+ T-cell depleted HaploHCT
  • CD4+ T-cell depleted hematopoietic progenitor cell (HPC) product

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Toxicity per NCI-Common Terminology Criteria for Adverse Events version 4.0
Time Frame: Day -22 to 2 years post-transplant
Day -22 to 2 years post-transplant
Unacceptable Toxicity at least possibly related to COH-MC-17
Time Frame: Day -22 to Day +60 post-transplant
Day -22 to Day +60 post-transplant
Mixed Chimerism defined as 30-90% donor cells
Time Frame: Day +60 post-transplant
Day +60 post-transplant
Feasibility of producing an infusion ready CD4+ T-cell-depleted hematopoietic product
Time Frame: From apheresis to Day 0
From apheresis to Day 0

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Adverse events of Grade 3 or higher
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Neutrophil count ≥ 500/mm3, time to recovery
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Platelet count ≥ 20,000/mm3, time to recovery
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Marrow failure
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Sickle cell disease related complications
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Non-relapse mortality
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Acute Graft versus Host Disease per 1994 Keystone Consensus Criteria
Time Frame: Day + 100 post-transplant
Day + 100 post-transplant
Chronic Graft versus Host Disease per 2014 National Institutes of Health Consensus Criteria
Time Frame: Day+ 180, + 1 year and +2 years post-transplant
Day+ 180, + 1 year and +2 years post-transplant
Overall Survival
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Disease-Free Survival
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Event-Free Survival
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Disease Relapse
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Persistent post-immunosuppressant mixed chimerism
Time Frame: Up to 2 years post-transplant
Between 5% and 95% donor chimerism at two years post- transplant, at least 6 months post- immunosuppressant
Up to 2 years post-transplant
Persistent immunosuppressant -dependent mixed chimerism
Time Frame: +2 years post-transplant
Between 5% and 95% donor chimerism at two years post- transplant and on immunosuppressant
+2 years post-transplant
Complete chimerism: >95% donor chimerism
Time Frame: +2 years post-transplant
+2 years post-transplant
Primary donor graft failure: Defined as < 5% donor chimerism by Day + 30 post- transplant
Time Frame: Day +30 post-transplant
Day +30 post-transplant
Secondary donor graft failure: Defined as < 5% donor chimerism beyond Day +30 in patients with prior documentation of ≥ 5% donor cells by Day +30
Time Frame: > Day + 30 up to 2 years post-transplant
> Day + 30 up to 2 years post-transplant
Donor chimerism in blood
Time Frame: Day +30, Day +60, Day +100, Day+180, and +1 yr, +1.5 yr, +2yr post-transplant
Day +30, Day +60, Day +100, Day+180, and +1 yr, +1.5 yr, +2yr post-transplant
Donor chimerism in bone marrow
Time Frame: Day + 100, Day + 180 and + 1 yr post-transplant
Day + 100, Day + 180 and + 1 yr post-transplant
Percent HbS levels
Time Frame: Baseline, and then Day + 30, Day + 100, Day + 180, +1 yr, +1.5, +2yr post-transplant
Baseline, and then Day + 30, Day + 100, Day + 180, +1 yr, +1.5, +2yr post-transplant

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Time Frame
Ratio donor: recipient de novo thymic T cells
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Ratio donor: recipient FoxP3+ regulatory T cells
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant
Tolerance status of donor: recipient type T cells
Time Frame: Up to 2 years post-transplant
Up to 2 years post-transplant

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
City of Hope Medical Center

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
California Institute for Regenerative Medicine (CIRM)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Joseph Rosenthal, MD, City of Hope Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 4, 2019

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 25, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 25, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 10, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 10, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 15, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 3, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 16453

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Sickle Cell Disease

Clinical Trials on Cyclophosphamide

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings