A Phase 2 interventional study of Treosulfan and Fludarabine Phosphate in Bone Marrow Failure Syndrome, Congenital Amegakaryocytic Thrombocytopenia and Diamond-Blackfan Anemia, sponsored by Fred Hutchinson Cancer Center. Completed at 24 sites in United States. Open to participants aged 1 Year to 49 Years. Per ClinicalTrials.gov, last updated 2026-03-09.
Sponsored by Fred Hutchinson Cancer Center · Phase 2, Interventional, and Treatment
This phase II trial tests whether treosulfan, fludarabine, and rabbit antithymocyte globulin (rATG) work when given before a blood or bone marrow transplant (conditioning regimen) to cause fewer complications for patients with bone marrow failure diseases. Chemotherapy drugs, such as treosulfan, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Fludarabine may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. rATG is used to decrease the body's immune response and may improve bone marrow function and increase blood cell counts. Adding treosulfan to a conditioning regimen with fludarabine and rATG may result in patients having less severe complications after a blood or bone marrow transplant.
OUTLINE:
CONDITIONING REGIMEN: Patients receive treosulfan intravenously (IV) over 120 minutes on days -6 to -4, fludarabine phosphate IV over 60 minutes on days -6 to -2, and lapine T-lymphocyte immune globulin (rATG) IV over 4-6 hours on days -4 to -2.
TRANSPLANTATION: Patients undergo bone marrow or peripheral blood stem cell transplant on day 0.
GVHD PROPHYLAXIS: Patients receive tacrolimus IV continuously beginning on day -2 and a taper beginning on day 180. Patients may also receive tacrolimus orally (PO). Patients also receive methotrexate IV on days 1, 3, 6, and 11.
Patients undergo echocardiography (ECHO) or multigated acquisition scan (MUGA) as well as possible chest radiography (x-ray) or computed tomography (CT) at baseline and undergo bone marrow biopsy and aspiration at baseline and follow up. Patients also undergo blood sample collection throughout the trial.
After completion of study treatment, patients are followed up at 1 year from transplant.
85 studies on the registry are indexed under Bone Marrow Failure Disorders; 33 are open to participants now.
This study's enrollment of 40 is above the median of 24 across 62 interventional studies indexed under Bone Marrow Failure Disorders.
Browse Bone Marrow Failure Disorders studies →Fred Hutchinson Cancer Center is the lead sponsor of 537 studies on the registry; 79 are open to participants now.
Of its 57 completed or terminated interventional studies of FDA-regulated products, 45 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Shwachman-Diamond syndrome
Criteria for Diagnosis:
For those patients tested but lacking a genetic mutation they must meet both *** criteria below:
Exocrine pancreatic dysfunction as defined by at least one of the following:
Bone marrow failure as evidence by at least one of the following:
Indications for HCT:
Diamond Blackfan Anemia
Criteria for Diagnosis:
For those patients tested but lacking a genetic mutation the patient must meet the first *** criteria and at least one of the subsequent *** criteria listed below:
Indications for HCT:
Congenital Sideroblastic anemia
Criteria for Diagnosis:
For those patients tested but lacking a genetic mutation:
Indications for HCT:
GATA2 mutation with associated marrow failure
Criteria for Diagnosis:
** A pathogenic mutation(s) for GATA2
Indications for HCT:
SAMD9 or SAMD9L disorders
Criteria for Diagnosis:
** A pathogenic mutation(s) for SAMD9 or SAMD9L
Indications for HCT:
Congenital amegakaryocytic thrombocytopenia
Criteria for Diagnosis:
For those patients tested but lacking a genetic mutation the patient must meet criteria below:
Indications for HCT:
Paroxysmal nocturnal hemoglobinuria
Criteria for Diagnosis:
Indications for HCT:
An undefined BMFD: a patient with a BMFD for whom a genetic mutation responsible for their bone marrow failure phenotype has not been identified (excluding PNH) will be eligible for this clinical trial following approval by Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 1904 ERC
* A BMFD with a known genetic mutation but not listed above will be eligible for this clinical trial following approval by BMT CTN 1904 ERC
Note: The following patients MUST be reviewed by the BMT CTN 1904 ERC in order to determine if they are eligible for this trial:
UNRELATED DONOR: Mismatched for a single HLA DQB1 allele or antigen by high-resolution typing
* Note: donor patient (DP) matching per institutional practice
DONOR SELECTION RECCOMENDATIONS: in the case where there are multiple donor options, donors should be selected based on the following priority numbered below:
Exclusion Criteria:
Left ventricular ejection fraction \< 50% by echocardiogram or multi-gated acquisition (MUGA) scan
* For patients unable to obtain a left ventricular ejection fraction, left ventricular shortening fraction of \< 26%
Iron overload - This exclusion criterion only applies to patients who are considered at risk for hepatic or cardiac iron overload. Therefore, not all patients enrolled on this protocol will undergo formal hepatic or cardiac iron assessment
* For patients with a history of significant transfusions defined as >= 8 packed red blood cell transfusions per year for >= 1 year or have received >= 20 packed red blood cell transfusions (lifetime cumulative) will require formal hepatic and cardiac iron measurement. In addition, patients with a prior history of hepatic or cardiac iron overload will also require formal assessment for iron overload. Patients are excluded if:
CONDITIONING REGIMEN: Patients receive treosulfan IV over 120 minutes on days -6 to -4, fludarabine phosphate IV over 60 minutes on days -6 to -2, and rATG IV over 4-6 hours on days -4 to -2. TRANSPLANTATION: Patients undergo bone marrow or peripheral blood stem cell transplant on day 0. GVHD PROPHYLAXIS: Patients receive tacrolimus IV continuously beginning on day -2 and a taper beginning on day 180. Patients may also receive tacrolimus PO. Patients also receive methotrexate IV on days 1, 3, 6, and 11. Patients undergo ECHO or MUGA as well as possible x-ray or CT at baseline and undergo bone marrow biopsy and aspiration at baseline and follow up. Patients also undergo blood sample collection throughout the trial.
Drug: Treosulfan · Drug: Fludarabine Phosphate · Drug: Tacrolimus · Drug: Methotrexate · Biological: Lapine T-Lymphocyte Immune Globulin · Procedure: Peripheral Blood Stem Cell Transplantation · Procedure: Allogeneic Bone Marrow Transplantation · Other: Quality-of-Life Assessment · Procedure: Echocardiography · Procedure: Multigated Acquisition Scan · Procedure: Bone Marrow Biopsy · Procedure: Bone Marrow Aspiration · Procedure: Biospecimen Collection · Procedure: X-Ray Imaging · Procedure: Computed Tomography
Given IV
Also known as: Dihydroxybusulfan, Ovastat, Treosulphan, Tresulfon, Trecondi
Given IV
Also known as: 2-fluoro-9-(5-O-phosphono-.beta.-D-arabinofuranosyl)-, 9H-purin-6-amine, 2-fluoro-9-(5-O-phosphono-beta-D-arabinofuranosyl), Beneflur, Fludara, Fludarabine-5'-Monophosphate, SH T 586
Given IV and PO
Also known as: FK 506, Fujimycin, Hecoria, Prograf, Protopic
Given IV
Also known as: Abitrexate, Alpha-Methopterin, Amethopterin, Brimexate, Emthexat, Emtexate, Farmitrexat, Methotrexate LPF, Methylaminopterin, Methotrexatum, Metotrexato, Novatrex, Rheumatrex, Texate, Tremetex, Trexeron, Trixilem, WR-19039
Given IV
Also known as: Anti-Thymocyte Globulin Rabbit, Grafalon, Rabbit Anti-Human Thymocyte Globulin (RATG), Rabbit Anti-Thymocyte Globulin, Rabbit Antithymocyte Globulin, Rabbit ATG, rATG, Thymoglobulin, Antithymocyte globulin rabbit ATG, Imtix
Undergo PBSC
Also known as: PBPC transplantation, PBSCT, Peripheral Blood Progenitor Cell Transplantation, PERIPHERAL BLOOD STEM CELL TRANSPLANT, peripheral stem cell support, Peripheral Stem Cell Transplant, peripheral stem cell transplantation
Undergo bone marrow transplant
Also known as: Allo BMT, Allogeneic Blood and Marrow Transplantation, Allogeneic BMT
Ancillary studies
Also known as: Quality of Life Assessment
Undergo ECHO
Also known as: EC
Undergo MUGA
Also known as: Blood Pool Scan, Equilibrium Radionuclide Angiography, Gated Blood Pool Imaging, Gated Heart Pool Scan, MUGA, Multi-Gated Acquisition Scan, MUGA Scan, Radionuclide Ventriculogram Scan, Radionuclide ventriculography, RNVG, SYMA Scanning, Synchronized Multigated Acquisition Scanning
Undergo bone marrow biopsy and aspiration
Undergo bone marrow biopsy and aspiration
Undergo blood sample collection
Also known as: Biological Sample Collection
Undergo chest x-ray
Also known as: Conventional X-Ray, Diagnostic Radiology
Undergo chest CT
Also known as: Computed Axial Tomography, CAT Scan, CT Scan
Graft-Versus Host-Disease (GVHD)-Free Event-Free Survival (EFS)
The primary endpoint is the incidence of 1-year GVHD free, EFS (GEFS). An event is defined as death due to any cause, primary or secondary graft failure/rejection, or 2nd HCT whichever occurs first. Grade III-IV acute GVHD and chronic GVHD (using National Institutes of Health \[NIH\] consensus criteria) requiring systemic immune suppression will be considered in this estimate.
Time frame: 1 year post-HCT
Overall Survival
Overall survival at day 100 after HCT
Time frame: Day 100 post-HCT
Overall Survival
Overall survival at 6 months after HCT
Time frame: 6 months post-HCT
Overall Survival
Overall survival at 1 year after HCT
Time frame: 1 year post-HCT
Event-Free Survival
Event-free survival will be estimated at 12 months after HCT. An event is defined as death due to any cause, primary or secondary graft failure/rejection, or 2nd HCT, whichever occurs first
Time frame: 1 year post-HCT
Hematologic Recovery: Neutrophil recovery
Hematologic recovery will be assessed according to neutrophil recovery after transplant. Neutrophil recovery is defined as achieving an absolute neutrophil count (ANC) ≥ to 500/mm3 for 3 consecutive measurements on 3 different days. The first of the three days will be designated the day of neutrophil recovery. The competing event is death without neutrophil recovery.
Time frame: Assessed up to 1 year post-HCT
Hematologic Recovery: Platelet recovery
Hematologic recovery will be assessed according to platelet counts recovery after transplant. Platelet recovery is defined as the first day of a minimum of 3 days that the patient has a sustained platelet count ≥ 20,000/mm3 with no platelet transfusions in the preceding 7 days. The first day of sustained platelet count above these thresholds will be designated the day of platelet engraftment.
Time frame: Day 100 post-HCT
Donor Chimerism (CD3 and Myeloid)
Proportions of patients with full (\>95%), mixed (5-95%), or rejection (\<5%) myeloid
Time frame: Day 28 post-HCT
Donor Chimerism (CD3 and Myeloid)
Proportions of patients with full (\>95%), mixed (5-95%), or rejection (\<5%) myeloid
Time frame: Day 100 post-HCT
Donor Chimerism (CD3 and Myeloid)
Proportions of patients with full (\>95%), mixed (5-95%), or rejection (\<5%) myeloid
Time frame: 1 year post-HCT
Primary graft failure/rejection
Defined as never achieving ANC ≥ 500/μL or never achieving ≥ 5% donor myeloid chimerism assessed by peripheral blood chimerism assays by day +42 post-HCT. Second infusion of hematopoietic cells is also considered indicative of primary graft failure by day +42 post-HCT
Time frame: Day 42 post-HCT
Secondary graft failure/rejection post-HCT
Defined as \< 5% donor myeloid chimerism in peripheral blood beyond day +42 post-HCT in patients with prior documentation of hematopoietic recovery with ≥ 5% donor cells by day +42 post-HCT. Second infusion of hematopoietic cells is also considered indicative of secondary graft failure.
Time frame: Assessed up to 1 year post-HCT
Grade II-IV and grade III-IV GVHD at day 100
The cumulative incidences of acute grade II-IV and III-IV GVHD at day 100 after HCT will be determined.
Time frame: Day 100 post-HCT
Grade II-IV and grade III-IV GVHD at day 180
The cumulative incidences of acute grade II-IV and III-IV GVHD at day 100 after HCT will be determined.
Time frame: Day 180 post-HCT
Chronic GVHD
The cumulative incidence of chronic GVHD (using NIH consensus criteria) requiring systemic immune suppression at 1 year after HCT will be determined. Data will be collected directly from providers and chart review as defined by the NIH Consensus Conference Criteria
Time frame: 1 year post-HCT
Incidence of grade 3-5 toxicities
Grade 3-5 toxicities by day 30 after HCT
Time frame: Day 30 post-HCT
Incidence of grade 3-5 toxicities
Grade 3-5 toxicities by day 100 after HCT
Time frame: Day 100 post-HCT
Incidence of grade 2-3 systemic infections
All microbiologically documented infections or significant infections requiring antibiotic/antifungal therapy occurring up to 6 months after HCT
Time frame: 6 months post-HCT
Incidence of Epstein Barr virus (EBV) reactivation requiring therapy
The incidence of EBV reactivation requiring therapy in the first 180 days after HCT, and of EBV-associated lymphoproliferative disorder in the first 180 days after HCT will be evaluated.
Time frame: Day 180 post-HCT
Incidence of EBV-associated lymphoproliferative disorder
Time frame: Day 180 post-HCT
Incidence of cytomegalovirus (CMV) reactivation requiring therapy by day 180 post-HCT
Time frame: Up to day 180 post-HCT
Documents are hosted by the registry — open the source record to download them.
Plan to share: No
This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Bone Marrow Failure Disorders→
Fred Hutchinson Cancer Center