Nonmyeloablative Peripheral Blood Mobilized Hematopoietic Precursor Cell Transplantation for Sickle Cell Disease and Beta-thalassemia in People With Higher Risk of Transplant Failure
Active, enrolledPhase 2Results postedLast updated 11 March 2025
What this trial tests
Phase 2 trial testing Alemtuzumab in Sickle Cell Disease in 56 participants. Participants enrolled and being followed up; not accepting new ones.
Adults 4 to 80, any sex, with Sickle Cell Disease or Thalassemia. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Number of Patients Who Have Sustained Donor Type Hemoglobin at One Year Post TransplantPrimary· 1 year
Number of patients who have sustained donor type hemoglobin at one year post transplant. Sustained donor type hemoglobin is based on hemoglobin electrophoresis for patients with SCD and transfusion independence for patients with beta-thalassemia
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
10
Number of Participants With Donor Red Cells at 2 Years Post Stem Cell TransplantPrimary· 2 years
Number of participants with donor red cells at 2 years post stem cell transplant. Number of participants with donor red cells is detected by hemoglobin electrophoresis or donor type red cell antigen, and reticulocyte count ≥30 k/uL at 2 years post-transplant.
Group
Value
95% CI
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
3.12
± 1.37
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
3.29
± 1.57
Median Percent of Donor T-cells and Myeloid ChimerismSecondary· day 30, day 60 , day 100, 1 year and 2 year
Median Percent of donor T-cells and myeloid chimerism. Leukocytes are selected by magnetic beads for CD3 (T-cells) and CD14/15 (myeloid cells), then microsatellite PCR analyses are performed to obtain donor chimerism percent.
myeloid chimerism D30
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
100
80 – 100
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
99.5
68 – 100
myeloid chimerism D60
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
100
54 – 100
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
100
29 – 100
myeloid chimerism D100
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
100
42 – 100
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
100
16 – 100
myeloid chimerism Year 1
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
100
47 – 100
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
100
54 – 100
myeloid chimerism Year 2
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
100
44 – 100
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
99
45 – 100
donor T-cells D30
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
65.5
16 – 94
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
25
1 – 85
donor T-cells D60
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
39
2 – 86
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
23
1 – 100
donor T-cells D100
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
34
0 – 91
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
22.5
2 – 96
Number of Participants Who Developed Acute Graft vs Host Disease (GVHD) Grades I, II, III, IVSecondary· Up to Day 100
Number of participants who developed Acute Graft vs Host Disease (GVHD) Grades I, II, III, IV as defined by CIMBTR criteria for Organ Stages of Acute GVHD.
Grades are defined as:
Grade I: Skin = Maculopapular rash\< 25% of body surface area (BSA); Liver = Total Bilirubin 2-3 mg/dL; Lower GI = stool output/day is 500-999 mL/day.
Grade II: Skin = rash on 25-50 percent body surface area; Liver = Total Bilirubin 3.1-6.0 mg/dL; Lower GI = Diarrhea 1001-1500 mL/day.
Grade III: Skin = Rash on \>50% of body surface; Liver = Total Bilirubin 6.1 - 15.0 mg/dL; Lower GI = Diarrhea \> 1500 mL/day.
Gra
Grade I
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
0
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
0
Grade II
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
0
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
1
Grade III
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
1
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
0
Grade IV
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
0
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
0
Number of Participants Who Developed Moderate or Severe Chronic Graft vs Host Disease (GVHD)Secondary· Day 100 up to 2 years
Number of Participants Who Developed Moderate or Severe Chronic Graft vs Host Disease (GVHD) up to 5 years.
Moderate chronic GVHD involves EITHER 3 organs/sites with no clinically significant functional impairment OR a less than or equal to 1 organ/site with clinically significant functional impairment, but no major disability. Severe GVHD is associated with a major disability caused by chronic GVHD.
Moderate
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
0
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
0
Severe
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
0
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
0
Number of Participants That Experienced Graft Failure or Graft Rejection, or Red Cell Aplasia at 2 Years After TransplantSecondary· Up to 2 years
Number of participants that experienced graft failure or graft rejection, or red cell aplasia at 2 years after transplant. Graft failure or graft rejection is defined as \<5% donor cells in both CD3 and myeloid chimerism. Red cell aplasia is defined as reticulocyte \<30 k/uL and requiring red cell transfusions.
graft failure
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
1
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
0
red cell aplasia
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
0
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
2
Number of Participants That Experienced Regimen FailureSecondary· Up to 2 years
Number of Participants That Experienced Regimen Failure. Regimen failure is defined as those participants that experienced grade 3 or higher acute GVHD, moderate/severe chronic GVHD, graft failure/rejection, or red cell aplasia. Together any one of these count toward the combined endpoint of regimen failure.
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
2
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
2
Number of Participants That Experienced Transplant-related MortalitySecondary· Up to 2 years
Number of participants that experienced transplant-related mortality. Transplant-related mortality is defined as death that is at least possibly related to the transplant (GVHD, toxicity, infection, other causes).
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
0
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
0
Percentage of Participant With Disease-free Survival Following Stem Cell TransplantSecondary· Up to 2 years
Percentage of participant with disease-free survival following stem cell transplant. Disease-free survival is defined as alive and free acute complications related to sickle cell disease.
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
9
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
16
Percentage of Participant Overall Survival Following Stem Cell TransplantSecondary· Up to 2 years
Percentage of Participant Overall Survival up to year 2 following stem cell transplant. Overall survival is defined as being alive following stem cell transplant.
Group
Value
95% CI
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
10
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
17
Adverse events — posted to ClinicalTrials.gov
Time frame: 5 years.
Reporting threshold: 0%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
Female Participants With SCD or Beta-thalassemia Receiving Stem Cell Transplant With Male Donor
Serious: 9/11 (82%)
Deaths: 1/11
Participants With Pre-existing Antibodies and SCD or Beta-thalassemia Receiving Stem Cell Transplant
Serious: 13/18 (72%)
Deaths: 1/18
Human Leukocyte Antigens (HLA) Matched Related Stem Cell Donor
Background:
\- Some sickle cell disease or beta-thalassemia can be cured with transplant. Researchers want to test a variation of transplant that uses low dose radiation and a combination of immunosuppressive drugs. They want to know if it helps a body to better accept donor stem cells.
Objectives:
\- To see if low dose radiation (300 rads), oral cyclophosphamide, pentostatin, and sirolimus help a body to better accept donor stem cells.
Eligibility:
\- People 4 and older with beta-thalassemia or sickle cell disease that can be cured with transplant, and their donors.
Design:
* Participants and donors will be screened with medical history, physical exam, blood test, tissue and blood typing, and bone marrow sampling. They will visit a social worker.
* Donors:
* may receive an intravenous (IV) tube in their groin vein.
* will receive a drug injection daily for 5 or 6 days to move the blood stem cells from the bone marrow into general blood circulation.
* will undergo apheresis: an IV is put into a vein in each arm. Blood is taken from one arm, a machine removes the white blood cells that contain blood stem cells, and the rest is returned through the other arm.
* Participants:
* may undergo red cell exchange procedure.
* will remain in the hospital for about 30 days.
* will receive a large IV line that can stay in their body from transplant through recovery.
* will receive a dose of radiation, and transplant related drugs by mouth or IV.
* will receive blood stem cells over 8 hours by IV.
* will take neuropsychological tests and may complete questionnaires throughout the transplant process.
* must stay near NIH for 4 months. They will visit the outpatient clinic weekly.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
NCT06959771 — Base Editing Hematopoietic Stem Cell and T Cell Gene Therapy for CD40L-HyperIgM Syndrome: Single Patient Study
· Phase 1, PHASE2
· recruiting
NCT06872333 — Allo HSCT for High Risk Hemoglobinopathies
· Phase 2
· recruiting
NCT07516379 — GRAfT 2.0. A Multimodal Prospective Approach to Define the Mechanisms and Clinical Features of Acute and Chronic Rejecti
· not yet recruiting
NCT06948097 — Syk Inhibition in MItigating Lung Allograft Rejection (SIMILAR): A Trial to Evaluate the Safety and Tolerability of Fost
· Phase 1
· not yet recruiting
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by National Heart, Lung, and Blood Institute (NHLBI)
Last refreshed: 11 March 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT02105766.