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

About the study

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

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

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 point of contact

Lisa Pullens, RN
Joseph Rosenthal, MD


1 United States site


18 to 45 Years


Phase 1

Study type









participation restrictions

1. Prior stem cell transplant

2. Prior bone marrow transplant

3. Concurrent other investigational agents, chemotherapy, biological therapy or radiation

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


  • Duarte, California, United States, City of Hope Medical Center, 91010 [Recruiting]
Last updated 2021-06-24