ClinicalTrials.gg
RecruitingNCT04558736Updated Sep 16, 2026

Haploidentical HCT for Severe Aplastic Anemia

A Phase 2 interventional study of Anti-Thymocyte Globulin (Rabbit) and Fludarabine in Aplastic Anemia and Bone Marrow Failure Syndrome, sponsored by St. Jude Children's Research Hospital. Recruiting at 1 site in United States. Open to participants aged Up to 21 Years. Per ClinicalTrials.gov, last updated 2026-09-16.

Sponsored by St. Jude Children's Research Hospital · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Jan 2021; still recruiting 5 years 9 months later.
Phase
Phase 2
Study type
Interventional
Enrollment
21
Allocation
Not applicable
Ages
Up to 21 Years
Sex
All
01

Study summary

This study is a prospective, single center phase II clinical trial in which patients with Severe Aplastic Anemia (SAA) ) will receive a haploidentical transplantation. The purpose of this study is to learn more about newer methods of transplanting blood forming cells donated by a family member that is not fully matched to the patient. This includes studying the effects of the chemotherapy, radiation, the transplanted cell product and additional white blood cell (lymphocyte) infusions on the patient's body, disease and overall survival. The primary objective is to assess the rate of engraftment at 30 days and overall survival (OS) and event free survival (EFS) at 1 year post-hematopoietic cell transplantation (HCT).

Primary Objectives

  • To estimate the rate of engraftment at 30 days after TCR αβ+ T-cell-depleted graft infusion in patients receiving a single dose of post graft infusion cyclophosphamide.
  • To estimate the overall survival and event free survival at 1-year post transplantation.

Secondary Objectives

  • To calculate the incidence of acute and chronic GVHD after HCT.
  • To calculate the rate of secondary graft rejection at 1-year post transplantation
  • To calculate the cumulative incidence of viral reactivation (CMV, EBV and adenovirus).
  • To describe the immune reconstitution after TCR αβ+ T-cell-depleted graft infusion at 1 month, 3 months, 6 months, 9 months, and 1 year.

Exploratory Objectives

  • To longitudinally assess the phenotype and epigenetic profile of T-cells in SAA patients receiving HCT for SAA.
  • To assess the phenotype and epigenetic profile of T-cells in DLI administered to SAA patients post HCT.
  • To longitudinally assess CD8 T cell differentiation status in SAA patients using an epigenetic atlas of human CD8 T cell differentiation.
  • To examine the effector functions and proliferative capacity of CD8 T cells isolated from SAA patients before and after DLI.
  • Quantify donor derived Treg cells at different time points in patients received HCT.
  • Determine Treg activation status at different stages after HCT.
  • Are specific features of the DLI product associated with particular immune repertoire profiles post-transplant?
  • How does the diversity and functional profile of the DLI product alter the response to pathogens in the recipient?
  • Do baseline features of the recipient's innate and adaptive immune cells correlate with post-transplant immune repertoires and response profiles?
Read the detailed description

Immunosuppressant therapy (IST) is the main treatment for SAA for patients who do not have an HLA-matched sibling donor available for transplant. But some patients with SAA do not respond to IST and some others relapse after IST. HCT using an unrelated but HLA-matched donor is the only curative option for these patients but many patients lack a suitable HLA-matched donor. St Jude is trying to increase donor options for these patients by using novel therapeutic strategies by combining two widely used of GVHD prophylaxis methods: i) selective T cell depletion and ii) use of post-transplant cyclophosphamide. This will allow expansion of the donor pool to include haploidentical donors as well as reduce the risk of GVHD. The goal of this protocol is to test whether combining these GVHD prophylaxis approaches will allow use of haploidentical donors, reduce risk of GVHD, reduce transfusion dependence and improve immune reconstitution.

For this study chemotherapy, antibodies and radiation will be given to prepare the body to receive donor cells. Participants will then be given the donor cell infusion.

Patients will receive two types of donor blood cell products - a progenitor blood cell infusion and then a donor lymphocyte infusion. Both the progenitor blood cell and the donor lymphocyte infusion will be processed in a laboratory at St. Jude using a machine called the CliniMACS™.

In this clinical trial, participants will receive a special type of progenitor blood cells (called TCRαβ- depleted blood cells) from the donor.

After the donor progenitor cells have started to grow within the body (engraftment), participants will receive a second product that contains mature immune cells. These immune cells called CD45RA-depleted lymphocytes or donor lymphocyte infusion (DLI) will help fight infections in the body after the transplant and strengthen the developing immune system.

02

Conditions studied

  • Aplastic Anemia
  • Bone Marrow Failure Syndrome

Keywords

  • Haploidentical Transplant
03

In context

Anemia, Aplastic

371 studies on the registry are indexed under Anemia, Aplastic; 98 are open to participants now.

This study's planned enrollment of 21 is below the median of 37 across 281 interventional studies indexed under Anemia, Aplastic.

Browse Anemia, Aplastic studies →

Lead sponsor

St. Jude Children's Research Hospital is the lead sponsor of 440 studies on the registry; 102 are open to participants now.

Of its 61 completed or terminated interventional studies of FDA-regulated products, 37 (61%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
Up to 21 Years
Sexes eligible
All
Accepts healthy volunteers
No

Eligibility criteria

Inclusion Criteria for Transplant Recipient

  1. Age less than or equal to 21 years at time of enrollment.
  2. Confirmed diagnosis of SAA or a single lineage cytopenia

    (a) SAA or single lineage cytopenia will be defined as follows:

    • i. Bone marrow cellularity \< 25% or hypocellular marrow for age, AND
    • ii. One or more of the following (in peripheral blood): (i) Neutrophils \< 0.5 x10\^9/L (ii) \< 20 x10\^9/L, or platelet transfusion dependence (iii) \<8g/dL, or red blood cell transfusion dependence
  3. Does not have a suitable HLA-matched sibling donor (MSD) or volunteer 10/10 HLA-matched unrelated donor (MUD) available in the necessary time for progenitor cell donation.
  4. Failed at least one trial of therapy (IST) by being (persistence of severe cytopenias and fulfillment of SAA disease criteria at least 3 months after initial IST) or having relapsed (initial improvement of cytopenias after IST but then a later return to fulfillment of SAA disease criteria when IST is decreased or ceased). IST could have included ATG based regimens, calcineurin inhibitors and/or other higher dose therapy directed at the treatment of primary SAA. Patients with very severe aplastic anemia who are likely not to benefit from IST do not need to have failed a trial of IST and can proceed directly to HCT if they meet the rest of the criteria.
  5. Has a suitable single haplotype matched (≥ 3 of 6) family member donor.
  6. Patient and/or legal guardian must sign for HCT.
  7. Adequate organ function defined as:

    1. > 40% or shortening fraction ≥ 25%.
    2. (CrCl) or (GFR) ≥ 50 ml/ min/1.73m2.
    3. Forced vital capacity (FVC) ≥ 50% of predicted value; or pulse oximetry
    4. ≥ 92% on room air if patient is unable to perform pulmonary function testing.
    5. or Lansky (age-dependent) performance score ≥ 50.
    6. ≤ 3 times the for age.
    7. (ALT) or Aspartate aminotransferase (AST) ≤ 5 times the upper limit of normal for age.
  8. Females and males of must agree to practice 2 effective methods of at the same time or agree to abstinence until after the last dose of chemotherapy has been administered

Exclusion Criteria for Transplant Recipient:

  1. Diagnosis of Fanconi anemia. Fanconi anemia must be excluded by diepoxybutane (DEB) or equivalent testing.
  2. Known clinical or genetic diagnosis of dyskeratosis congenita
  3. Clonal cytogenetic abnormalities consistent with pre-myelodysplastic syndrome (pre- MDS) or MDS on marrow examination (e.g. Monosomy 7).
  4. Diagnosis of myelodysplastic syndrome (MDS).
  5. Presence of anti-donor HLA antibodies (positive anti-donor HLA antibody is defined as a positive cross-match test of any titer by complement- dependent cytotoxicity or flow cytometric testing or the presence of anti- donor HLA antibody to the high expression loci HLA-A, B, C, DRB1, or DPB1 with mean fluorescence intensity (MFI) > 1000 by solid phase immunoassay).
  6. Prior hematopoietic cell transplant.
  7. Prior solid organ transplant.
  8. Known life-threatening reaction (i.e., anaphylaxis) to ATG that would prohibit use for the patient.
  9. Uncontrolled bacterial, viral, or fungal infection at the time of enrollment. Uncontrolled is defined as progression or no clinical improvement on appropriate medical treatment.
  10. Female patients who are pregnant (per institutional practice) or breast- feeding.
  11. Prior except resected basal cell carcinoma or treated cervical carcinoma in situ. Cancer treated with curative intent > 5 years previously will be allowed. Cancer treated with curative intent ≤ 5 years previously will not be allowed unless approved by the PI.
  12. Alemtuzumab or ATG within 2 weeks of enrollment.

Inclusion Criteria for Haploidentical Donor

  1. At least single haplotype matched (≥ 3 of 6) family member.
  2. At least 18 years of age.
  3. negative.
  4. Not pregnant as confirmed by negative serum or urine pregnancy test within 14 days prior to enrollment (if female).
  5. Not breast feeding.
  6. Related donors must be ruled out for telomere disease by appropriate clinical and diagnostic measures (for example, clinical evaluation, telomere length testing, genetic testing, and/or bone marrow examination).
  7. The HAPLO donor and/or legal guardian must be able to sign informed consent documents.
  8. The potential HAPLO donor must be willing and able to donate PBSCs.
Terms in these criteria, in plain language(18)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Relapsed and refractory

Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.

Line of therapy

A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.

“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

GFR and eGFR (kidney filtering)

GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².

Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.

Karnofsky performance status (KPS)

A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.

Studies often ask for 60 or 70 and above. Your doctor gives the score.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Allogeneic and autologous transplant

Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
21 participants (estimated)

Study arms

  • Experimental
    Haploidentical HCT

    To assess the safety and efficacy of haploidentical donor transplantation for patients with severe aplastic anemia who lack an available HLA-matched donor. The goal of this study is to develop a novel, reduced-toxicity, post-transplant pharmacologic immunosuppression (GVHD prophylaxis)- free, highly tolerogenic haploidentical transplant regimen that is associated with few post- transplant complications or late toxicities and is available promptly to all patients, irrespective of matched donor availability. Cells for infusion are prepared using the CliniMACS System.

    Drug: Anti-Thymocyte Globulin (Rabbit) · Drug: Fludarabine · Drug: Cyclophosphamide · Drug: Mesna · Drug: G-CSF · Radiation: Total Lymphoid Irradiation (TLI) · Device: CliniMACS · Biological: HPC, A Infusion · Biological: CD45RA-depleted DLI

Interventions

  • Given intravenously (IV)

    Also known as: thymoglobulin, rabbit ATG

  • Given intravenously (IV)

    Also known as: Fludara Flu Dara

  • Given intravenously (IV)

    Also known as: CYTOXAN

  • DrugMesna

    Given intravenously (IV)

    Also known as: MESNEX

  • DrugG-CSF

    Filgrastim is a human granulocyte colony-stimulating factor (G-CSF), produced by recombinant DNA technology. Dosage and Route of Administration: 5mcg/kg subcutaneous or intravenous daily until ANC \>2000 for 2 consecutive days, or as clinically indicated

    Also known as: Neupogen, Filgrastim

  • RadiationTotal Lymphoid Irradiation (TLI)

    TLI will be given at 800 cGy total dose in 4 fractions.

    Also known as: TLI

  • DeviceCliniMACS

    The mechanism of action of the CliniMACS Cell Selection System is based on magnetic-activated cell sorting (MACS). The CliniMACS device is a powerful tool for the isolation of many cell types from heterogeneous cell mixtures, (e.g. apheresis products). These can then be separated in a magnetic field using an immunomagnetic label specific for the cell type of interest, such as CD3+ human T cells.

    Also known as: Cell Selection System

  • BiologicalHPC, A Infusion

    Given intravenously Day 0-HPC, A Infusion (TCR αβ+/CD19+-depleted graft)

  • BiologicalCD45RA-depleted DLI

    CD45RA-depleted DLI will be given at least ONE week after engraftment

06

What researchers measure

Primary outcomes

  1. Engraftment

    Rate of patients engrafting at day 30 after TCR αβ+ T-cell-depleted graft infusion in patients receiving a single dose of post graft infusion cyclophosphamide.

    Time frame: 30 days

  2. Overall and event free survival

    Rate of overall survival and event free survival at 1-year post transplantation.

    Time frame: 1 year

Secondary outcomes

  1. Graft vs host disease

    Incidence of acute and chronic GVHD after hematopoietic cell transplant

    Time frame: 1 year

  2. Graft rejection

    Rate of secondary graft rejection at 1-year post transplantation

    Time frame: 1 year

  3. Viral reactivation

    Cumulative incidence of viral reactivation post-transplant (CMV, EBV and adenovirus)

    Time frame: 1 year

  4. Immune reconstitution

    We will record immune reconstitution parameters, including the order and magnitude of recovery of the different subtypes of leukocytes. Results will be summarized by descriptive statistics. The pattern of immune reconstitution will be evaluated using longitudinal approaches such as mixed effect models or generalized estimating equation (GEE) approach.

    Time frame: 1 year

07

Study locations

1 of 1 sites recruiting
  • St. Jude Children's Research Hospital
    Memphis, Tennessee 38105, United States
    Recruiting
    • Amr Qudeimat, MD · Contactreferralinfo@stjude.org · 866-278-5833
    • Amr Qudeimat, MD · Principal investigator
    • Akshay Sharma, MD · Principal investigator
08

References and documents

Individual participant data

Plan to share: 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.

Supporting information: Study protocol, Statistical analysis plan, Informed consent form

Time frame: Data will be made available at the time of article publication.

Access criteria: Data will be provided to researchers following a formal request with the following information: full name of requestor, affiliation, data set requested, and timing of when data is needed. As an informational point, the lead statistician and study principal investigator will be informed that primary results datasets have been requested.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Jan 2021 (actual). Primary completion is estimated for Jul 2029, 101 months after the start.

Of 52 non-industry phase 2 interventional studies under Anemia, Aplastic, half reached primary completion within 93 months of starting (the median), counting those still running; a quarter within 55 and three quarters within 111. This study's planned 101 months is close to that.

Counting every sponsor, half of 60 studies reached it within 76 months; a quarter within 39 and three quarters within 104.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 9, 2020
First posted
Sep 22, 2020
StartActual
Jan 21, 2021
Primary completionEst.
Jul 1, 2029
CompletionEst.
Jul 1, 2030
Last update
Sep 16, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Sep 16, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04558736
Responsible party
Sponsor
First posted
Sep 22, 2020
Start date
Jan 21, 2021
Primary completion
Jul 1, 2029 (estimated)
Completion
Jul 1, 2030 (estimated)
Last update
Sep 16, 2026

Study contacts

Amr Qudeimat, MD
Contact
referralinfo@stjude.org
866-278-5833
Amr Qudeimat, MD
principal investigator · St. Jude Children's Research Hospital
Akshay Sharma, MBBS
principal investigator · St. Jude Children's Research Hospital

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
View the source record on ClinicalTrials.gov ↗

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Studies of the drugs tested here: Thymoglobulin · Fludarabine · Cyclophosphamide · Mesna · Granulocyte Colony-Stimulating Factor

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