Second Stem Cell Transplant for Sickle Cell Disease Patients with Low Donor Cell Levels

Repeat Peripheral Blood Stem Cell Transplantation for Patients With Sickle Cell Disease or Beta-Thalassemia and Falling Donor Myeloid Chimerism Levels

Phase1; Phase2 Interventional National Institutes of Health Clinical Center (CC) · NCT04008368

This study is testing if a second stem cell transplant can help people with sickle cell disease who still have some donor cells in their body to improve their condition.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment32 (estimated)
Ages2 Years to 80 Years
SexAll
SponsorNational Institutes of Health Clinical Center (CC) NIH
Drugs / interventionsalemtuzumab, cyclophosphamide
Locations1 site (Bethesda, Maryland)
Trial IDNCT04008368 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to provide a second peripheral blood stem cell transplant to patients with sickle cell disease whose condition has returned after an initial transplant, yet still retain some donor cells. The study will assess the effectiveness of this approach in increasing donor cell levels in the bone marrow to potentially cure the disease. Participants will undergo thorough medical evaluations, including blood tests and imaging, to ensure eligibility. The trial focuses on patients aged 4 and older, along with their HLA-matched sibling donors, who will also be screened and prepared for the donation process.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 4 and older with a history of sickle cell disease who have previously undergone a stem cell transplant and have experienced a recurrence of the disease.

Not a fit: Patients who have not undergone a prior stem cell transplant or those without any donor cells remaining in their body may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly improve the chances of curing sickle cell disease in patients who have experienced a relapse.

How similar studies have performed: Previous studies involving peripheral blood stem cell transplants for sickle cell disease have shown promising results, indicating that this approach is based on established methodologies.

Eligibility criteria

Show full inclusion / exclusion criteria
* INCLUSION CRITERIA:

Inclusion criteria- recipient

1. Patient with history of SCD or beta thalassemia who previously underwent allogeneic hematopoietic stem cell transplantation (HSCT)
2. Patient with recurrent SCD defined as HbS greater than or equal to 50% for donors with sickle cell trait and greater than or equal to 10% for donors with HbAA with recurrent clinical manifestations (for example but not limited to recurrent painful crises, acute chest syndrome, priapism, or severe anemia) or patients with recurrent beta thalassemia defined as clinical manifestations such as transfusion-dependence or evidence of extramedullary hematopoiesis. The HbS requirement may be waived by the PI or designee for reasons such as the patient is requiring chronic transfusion therapy or otherwise meets clinical criteria for return of SCD.
3. Persistent donor chimerism levels
4. Age greater than or equal to 4 years
5. Negative beta-HCG
6. Ejection fraction greater than or equal to 35%
7. DLCO greater than or equal to 35% (Note: This criterion may be omitted in young children (e.g. near the age of 5 years old) or other individuals who may have difficulty understanding or complying with the instructions for accurate testing.)

Inclusion- donor

Related donor from original transplant, deemed suitable and eligible, and willing to donate, per clinical evaluations who are additionally willing to donate blood for research. Related donors will be evaluated in accordance with existing Standard NIH Policies and Procedures for determination of eligibility and suitability for clinical donation. Age \>= 2 years \<80 years old

EXCLUSION CRITERIA:

Exclusion criteria- recipient

1. ECOG performance status of 3 or more or if \<16 years of age Lansky score of 50 or lower.
2. Evidence of uncontrolled bacterial, viral, or fungal infections (currently taking medication and progression of clinical symptoms) within one month prior to signing the consent
3. Patients with fever or suspected minor infection should await resolution of symptoms before signing the consent
4. Major anticipated illness or organ failure incompatible with survival from PBSC transplant
5. Pregnant or breastfeeding
6. History of secondary malignancies (other than localized skin cancer)
7. Donor-specific HLA antibodies with mean fluorescent intensity \>= 2,000

Exclusion- donor

None

Where this trial is running

Bethesda, Maryland

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Myeloid ChimerismStem Cell Transplant
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.