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Bone marrow transplant for severe aplastic anemia

A Phase II Trial of Non-Myeloablative Conditioning and Transplantation of Haploidentical Related, Partially HLA-Mismatched, or Matched Unrelated Bone Marrow for Newly Diagnosed Patients With Severe Aplastic Anemia

Phase 2 Interventional Medical College of Wisconsin · NCT06517641

This study is testing if bone marrow transplants from partially matched or unrelated donors can help people aged 3 to 75 with severe aplastic anemia who haven't had treatment before.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment60 (estimated)
Ages3 Years to 75 Years
SexAll
SponsorMedical College of Wisconsin Academic / other
Drugs / interventionscyclophosphamide, fludarabine
Locations25 sites (Birmingham, Alabama and 24 other locations)
Trial IDNCT06517641 on ClinicalTrials.gov

What this trial studies

This study investigates the effectiveness of hematopoietic stem cell transplantation in treating severe aplastic anemia (SAA) in patients who have not received prior treatment. It is a multicenter Phase II trial focusing on patients aged 3 to 75 years who lack a fully matched related donor. The study aims to restore normal blood cell production by using haploidentical or unrelated donor bone marrow transplants. The approach seeks to improve outcomes for patients who traditionally have limited treatment options.

Who should consider this trial

Good fit: Ideal candidates are patients aged 3 to 75 years with a confirmed diagnosis of severe aplastic anemia and no suitable fully matched related donor.

Not a fit: Patients with fully matched related donors or those with other underlying health conditions that preclude transplantation may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve blood cell production and overall health in patients with severe aplastic anemia.

How similar studies have performed: Other studies have shown promising results with similar transplantation approaches for severe aplastic anemia, indicating potential for success in this trial.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. Age 3 years to 75 years
2. Confirmed diagnosis of acquired SAA defined as:

   a. Bone marrow cellularity \< 25% or variable marrow cellularity but with \< 30% residual hematopoietic cells deemed HYPOcellular for age AND b. Two (2) out of 3 of the following (in peripheral blood). i. Neutrophils \< 0.5 x109/L ii. Platelets \< 20 x109/L iii. Reticulocyte count \< 20 x109/L (\< 60 x 109/L using an automated analysis)
3. No suitable fully matched related donor as per Investigator's discretion (6/6 match for HLA A and B at intermediate or high-resolution and DRB1 at high-resolution using deoxyribonucleic acid \[DNA\]-based typing) available.
4. Available donor as defined in the protocol.
5. Participant and/or legal guardian must sign informed consent.
6. Adequate organ function defined by institutional transplant standards or defined as below:

   1. Cardiac: Left ventricular ejection fraction (LVEF) at rest \> 40% with no clinical signs of cardiac failure. For participants aged \< 13 years, shortening fraction (SF) ≥ 26% by echocardiogram or multigated acquisition (MUGA) may be substituted for LVEF.
   2. Hepatic: Total bilirubin \< 2.0 mg/dL unless Gilbert's disease is present
   3. Renal: For participants \> 13.0 years of age at the time of enrollment: estimated creatinine clearance (CrCl) \> 60 mL/minute (per institutional standard). For participants \< 13.0 years of age at enrollment: glomerular filtration rate (GFR) estimated by the updated Schwartz formula ≥ 90 mL/min/1.73 m2. If the estimated GFR is \< 90 mL/min/1.73 m2, then renal function must be measured by 24-hour creatinine clearance or nuclear GFR, and must be \> 50 mL/min/1.73 m2.
   4. Pulmonary:

   i. For participants \> 13.0 years of age: Diffusing capacity of the lung for carbon monoxide (DLCO, corrected/adjusted for hemoglobin \[Hb\]) \> 50%, or Spirometry with forced expiratory volume 1 (FEV1) \> 50% predicted (without administration of bronchodilator) and forced vital capacity (FVC) \> 50% predicted.

   ii. For participants \< 13.0 years of age unable to perform pulmonary function tests (PFTs) due to age or developmental ability: (1) no evidence of dyspnea at rest and (2) no need for supplemental oxygen and (3) O2 saturation \> 92% on room air at sea level (with lower levels allowed at higher elevations per established center standard of care \[e.g., Utah, 4,200 feet above sea level, does not give supplemental oxygen unless below 90%\]).
7. Karnofsky or Lansky performance status ≥ 60%.
8. Females and males of childbearing potential must agree to practice 2 effective methods of contraception at the same time or agree to abstinence.

Exclusion Criteria:

1. Inherited bone marrow failure syndromes such as Fanconi anemia and short telomere syndromes must be ruled out according to center standards. It is recommended that functional testing for Fanconi Anemia (di-epoxybutane \[DEB\] chromosomal breakage analysis) and telomere length assessment be performed. If available, genetic panels for inherited bone marrow failure syndromes can be considered as an alternative to functional testing.
2. Clonal cytogenetic abnormalities consistent with pre-MDS or MDS on marrow examination (e.g., monosomy 7 and other MDS-defining changes per recent pathology guidelines).
3. Formal diagnosis of MDS by World Health Organization (WHO) 2022 or International Consensus Classification (ICC).
4. Recipient positive for HLA antibodies against a mismatched HLA in the selected donor determined by the presence of donor specific HLA antibodies (DSA) to any mismatched HLA allele/antigen at any of the following loci (HLA-A, -B, -C, -DRB1, DRB3, DRB4, DRB5, -DQA1, -DQB1, -DPA1, -DPB1) with median fluorescence intensity (MFI) \>3000 by microarray-based single antigen bead testing. In patients receiving red blood cell or platelet transfusions, DSA evaluation must be performed or repeated post-transfusion and immediately prior to initiation of recipient preparative regimen to ensure there is confirmation of no DSA to the selected donor when conditioning starts.
5. Prior desensitization attempt for HLA antibodies to chosen donor. Any intervention with the sole intent to reduce the level of HLA DSA, (e.g., plasmapheresis, intravenous immunoglobulin \[IVIG\], MMF, etc.) would constitute a desensitization attempt.
6. Prior treatment for SAA (e.g., immunosuppressive therapy using ATG, calcineurin inhibitors \[CNIs\], thrombopoietin receptor agonists or androgens). Short courses of steroids or IVIG that were not explicitly administered for SAA therapy will be allowed.
7. Prior allogeneic stem cell transplant.
8. Prior solid organ transplant.
9. Known life-threatening reaction (i.e., anaphylaxis) to Thymoglobulin® (Sanofi) that would prohibit use for the participant as this study requires use of the Thymoglobulin® (Sanofi) preparation of ATG.
10. Uncontrolled bacterial, viral, or fungal infection at the time of enrollment. Uncontrolled is defined as currently taking medication and with progression or no clinical improvement on adequate medical treatment.
11. Female participants who are pregnant, as detected using a pregnancy test as per institutional practice, or breast-feeding.
12. Prior malignancies 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 Protocol Chairs and/or Protocol Officer.

Of note, participants with seropositivity for the human immunodeficiency virus (HIV) may be considered if viral load is undetectable. Similarly, carriers of hepatitis B (HepB) or hepatitis C (HepC) may not have a detectable viral load of HepB virus or HepC virus.

Participants with HIV that is well-controlled on combination antiretroviral therapy and no AIDS related complications within the past 12 months are eligible.

Infections other than HIV:

* Prior infections must be controlled
* HepB participants are eligible if on effective suppressive therapy and otherwise meet inclusion/exclusion criteria
* HepC participants are eligible if otherwise meet inclusion/exclusion criteria

Where this trial is running

Birmingham, Alabama and 24 other locations

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.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Severe Aplastic Anemia
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.