ClinicalTrials.gg
RecruitingNCT06859424ACCELERATEUpdated Mar 17, 2026

A Platform Protocol to Investigate Post-Transplant Cyclophosphamide-Based Graft-Versus-Host Disease Prophylaxis in Patients With Hematologic Malignancies Undergoing Mismatched Unrelated Donor Peripheral Blood Stem Cell Transplantation

A Phase 2 interventional study of Conditioning Regimen A and Conditioning Regimen B in AML (Acute Myelogenous Leukemia), Acute Lymphoid Leukemia (ALL) and Acute Leukemia (Category), sponsored by Center for International Blood and Marrow Transplant Research. Recruiting at 13 sites in United States. Open to participants aged 18 Years to 66 Years. Per ClinicalTrials.gov, last updated 2026-03-17.

Sponsored by Center for International Blood and Marrow Transplant Research · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Jul 2025; still recruiting 1 year 3 months later.
Phase
Phase 2
Study type
Interventional
Enrollment
358
Allocation
Randomized
Ages
18 Years to 66 Years
Sex
All
01

Study summary

The purpose of this clinical trial is to compare drug combinations to learn which drugs work best to prevent graft-versus-host-disease (GVHD) in people who have received a stem cell transplant. The source of stem cells is from someone who is not related and has a different blood cell type than the study participant. The researchers will compare the new drug combination to a standard drug combination. They will also learn about the safety of each drug combination.

Participants will:

  • Receive the standard or new drug combination after transplant
  • Visit the doctor's office for check-ups and tests after transplant that are routine for most transplant patients
  • Take surveys about physical and emotional well-being
  • Give blood and stool samples.
Read the detailed description

This platform protocol will evaluate the safety and efficacy of post-transplant cyclophosphamide (PTCy) based graft-versus-host disease (GVHD) prophylaxis after mismatched unrelated donor (MMUD) hematopoietic cell transplant (HCT). Participants with malignant hematologic diseases eligible per inclusion criteria, receiving MMUD peripheral blood stem cells (PBSCs) after myeloablative conditioning (MAC) or reduced-intensity conditioning (RIC) will be eligible to be enrolled by participating transplant centers. The platform protocol will estimate endpoints and provide a comparator arm for investigational interventional arms (ISAs).

Two investigational ISAs are part of the platform protocol - ACCEL-001 and ACCEL-002. The ISAs describe the specific features of the intervention being studied and treatment of participants assigned to that intervention, the specific target population, sample size required based on comparison to the control arm, specific study objectives, statistical methods for evaluating the interventions, and other specific intervention-related information and assessments. Additional ISAs may be added or closed throughout the lifetime of the trial.

02

Conditions studied

  • AML (Acute Myelogenous Leukemia)
  • Acute Lymphoid Leukemia (ALL)
  • Acute Leukemia (Category)
  • MDS (Myelodysplastic Syndrome)
  • CML (Chronic Myelogenous Leukemia)
  • CLL (Chronic Lymphocytic Leukemia)
  • Prolymphocyctic Leukemia
  • Chronic Myelomonocytic Leukemia (CMML)
  • Myeloproliferative Neoplasm (MPN)
  • Lymphoma
  • Myelofibrosis

Keywords

  • ACCELERATE
  • ACCEL-001
  • ACCEL-002
03

In context

Leukemia, Myeloid, Acute

3,667 studies on the registry are indexed under Leukemia, Myeloid, Acute; 816 are open to participants now.

This study's planned enrollment of 358 is above the median of 40 across 3,005 interventional studies indexed under Leukemia, Myeloid, Acute.

Browse Leukemia, Myeloid, Acute studies →

Lead sponsor

Center for International Blood and Marrow Transplant Research is the lead sponsor of 32 studies on the registry; 8 are open to participants now.

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

04

Who can participate

Ages eligible
18 Years to 66 Years
Sexes eligible
All
Accepts healthy volunteers
No

Eligibility criteria

Inclusion Criteria, MAC RECIPIENTS:

  1. Age 18 to \< 66 years (chemotherapy-based conditioning) or \< 61 years (TBI-based conditioning) at the time of signing
  2. Patient or legally authorized representative has the ability to provide informed consent according to the applicable regulatory and institutional requirements
  3. Stated willingness to comply with all study procedures and availability for the duration of the study
  4. Planned MAC regimen (see Table 8 in Section 7.4 for allowed MAC regimens)
  5. Available partially HLA-MMUD (4/8-7/8 at HLA-A, -B, -C, and -DRB1 is required) with age 16-35
  6. Product planned for infusion is MMUD T-cell replete PBSC as allograft
  7. HCT-CI \< 5 (Appendix H - Hematopoietic Cell Transplant Comorbidity Index Scoring). The presence of prior will not be used to calculate HCT-CI for this trial, to allow for the inclusion of patients with secondary or therapy-related AML or MDS.
  8. One of the following diagnoses:

    1. AML, ALL, or other acute leukemia in first remission or beyond with ≤ 5% marrow blasts and no circulating blasts or evidence of extramedullary disease. Documentation of bone marrow assessment will be accepted within 45 days prior to the anticipated start of conditioning.
    2. Patients with MDS with no circulating blasts and with \< 10% blasts in the bone marrow (higher blast percentage allowed in MDS due to lack of differences in outcomes with \< 5% vs 5-10% blasts in MDS). Documentation of bone marrow assessment will be accepted within 45 days prior to the anticipated start of conditioning.
  9. Cardiac function: ≥ 45% based on most recent echocardiogram or multi-gated acquisition scan (MUGA) results
  10. Estimated ≥ 45mL/min calculated by equation
  11. Pulmonary function: diffusing capacity of the lungs for carbon monoxide (DLCO) corrected for ≥ 50% and forced expiratory volume in first second () predicted ≥ 50% based on most recent PFT results
  12. Liver function acceptable per local institutional guidelines
  13. of ≥ 70% (Appendix I - Performance Status)

Inclusion Criteria, RIC/NMA RECIPIENTS:

  1. Age ≥ 18 years at the time of signing informed consent
  2. Patient or legally authorized representative has the ability to provide informed consent according to the applicable regulatory and local institutional requirements
  3. Stated willingness to comply with all study procedures and availability for the duration of the study
  4. Planned NMA/RIC regimen (see
  5. Table 9 in Section 7.4 for allowed NMA/RIC regimens)
  6. Available partially HLA-MMUD (4/8-7/8 at HLA-A, -B, -C, and -DRB1 is required) with age 16-35
  7. Product planned for infusion is MMUD T-cell replete PBSC allograft
  8. One of the following diagnoses:

    1. Patients with acute leukemia or chronic myeloid leukemia (CML) with no circulating blasts, no evidence of extramedullary disease, and with \< 5% blasts in the bone marrow. Documentation of bone marrow assessment will be accepted within 45 days prior to the anticipated start of conditioning.
    2. Patients with MDS with no circulating blasts and with \< 10% blasts in the bone marrow (higher blast percentage allowed in MDS due to lack of differences in outcomes with \< 5% vs 5-10% blasts in MDS.) Documentation of bone marrow assessment will be accepted within 45 days prior to the anticipated start of conditioning.
    3. Patients with chronic lymphocytic leukemia (CLL) or other leukemias (including prolymphocytic leukemia) with chemosensitive disease at time of transplantation.
    4. Higher-risk chronic myelomonocytic leukemia (CMML) according to CMML-specific prognostic scoring system or high-risk MDS/myeloproliferative neoplasms (MPN) not otherwise specified are eligible, provided there is no evidence of high-grade bone marrow fibrosis or massive splenomegaly at the time of enrollment.
    5. Patients with lymphoma with chemosensitive disease at the time of transplantation.
    6. Patients with primary myelofibrosis or myelofibrosis secondary to essential thrombocythemia, polycythemia vera or MDS with grade 4 fibrosis.
  9. Cardiac function: Left ventricular ejection fraction ≥ 40% based on most recent echocardiogram or MUGA results with no clinical evidence of heart failure
  10. Estimated creatinine clearance ≥ 45mL/min calculated by equation
  11. Pulmonary function: DLCO corrected for hemoglobin ≥ 50% and FEV1 predicted ≥ 50% based on most recent PFT results
  12. Liver function acceptable per local institutional guidelines
  13. KPS of ≥ 60% (Appendix I - Performance Status)

Exclusion Criteria:

  1. Suitable HLA-matched related or 8/8 high-resolution matched unrelated donor available
  2. Subject unwilling or unable to give informed consent, or unable to comply with the protocol including required follow-up and testing
  3. Subjects with a prior transplant
  4. Subjects with an autologous transplant within the past 3 months
  5. Subjects who are breastfeeding or pregnant
  6. Uncontrolled bacterial, viral or fungal infection at the time of the transplant preparative regimen
  7. Concurrent enrollment on a prevention clinical trial
  8. Subjects who undergo desensitization to reduce anti-donor HLA antibody levels prior to transplant
  9. Patients who are -positive with persistently positive viral load. HIV-infected patients on effective anti-retroviral therapy (ART) with undetectable viral load within 6 months are eligible for this trial. Patients with well-controlled HIV are eligible provided resistance panels are negative, the patient is compliant with ART, and their disease remains well controlled.
Terms in these criteria, in plain language(10)

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.

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.

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.

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.

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).

FEV1

From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.

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.

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.

GVHD (graft-versus-host disease)

After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.

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
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
358 participants (estimated)

Study arms

  • Experimental
    Control/SOC

    Shared comparator control group

    Drug: Conditioning Regimen A · Drug: Conditioning Regimen B · Drug: Conditioning Regimen C · Drug: Conditioning Regimen D · Drug: Conditioning Regimen E · Procedure: Hematopoietic Cell Transplantation · Drug: PTCy (50 mg/kg D3, D4) · Drug: Post-transplant Tacrolimus · Drug: Post-transplant Mycophenolate mofetil · Drug: Supportive Care: Growth Factors · Procedure: Supportive Care: Blood Products · Other: Supportive Care: Infection Prophylaxis · Other: Supportive Care: Intravenous immune globulin (IVIG) · Drug: Supportive Care: Seizure prophylaxis · Other: Supportive Care: Monitoring and management of CRS · Other: Study treatment compliance · Other: Prohibited Concomitant Therapy · Other: Permitted Concomitant Therapy

  • Experimental
    ACCEL-001

    Intervention 1

    Drug: Conditioning Regimen A · Drug: Conditioning Regimen B · Drug: Conditioning Regimen C · Drug: Conditioning Regimen D · Drug: Conditioning Regimen E · Procedure: Hematopoietic Cell Transplantation · Drug: PTCy (25 mg/kg D3, D4) · Drug: Post-transplant Tacrolimus · Drug: Post-transplant Abatacept · Drug: Supportive Care: Growth Factors · Procedure: Supportive Care: Blood Products · Other: Supportive Care: Infection Prophylaxis · Other: Supportive Care: Intravenous immune globulin (IVIG) · Drug: Supportive Care: Seizure prophylaxis · Other: Supportive Care: Monitoring and management of CRS · Other: Supportive Care: Prophylaxis against infections · Other: Study treatment compliance · Other: Prohibited Concomitant Therapy · Other: Permitted Concomitant Therapy

  • Experimental
    ACCEL-002

    Intervention 2

    Drug: Conditioning Regimen A · Drug: Conditioning Regimen B · Drug: Conditioning Regimen C · Drug: Conditioning Regimen D · Drug: Conditioning Regimen E · Procedure: Hematopoietic Cell Transplantation · Drug: PTCy (25 mg/kg D3, D4) · Drug: Post-transplant Tacrolimus · Drug: Post-transplant Mycophenolate mofetil · Drug: Post-transplant Ruxolitinib · Drug: Supportive Care: Growth Factors · Procedure: Supportive Care: Blood Products · Other: Supportive Care: Infection Prophylaxis · Other: Supportive Care: Intravenous immune globulin (IVIG) · Drug: Supportive Care: Seizure prophylaxis · Other: Supportive Care: Monitoring and management of CRS · Drug: Supportive Care: Prophylaxis against infections · Other: Supportive Care: Lipid elevations · Other: Study treatment compliance · Other: Prohibited Concomitant Therapy · Other: Permitted Concomitant Therapy

Interventions

  • DrugConditioning Regimen A

    Busulfan and fludarabine Recommended schedule as below: * Days -6 to -3: Busulfan ≥ 9 mg/kg total dose (IV or PO) with pharmacokinetic (PK) monitoring recommended as per institutional practice to achieve a daily area under the curve (AUC) target of 4800-5300 μM\*min47 or busulfan plasma exposure units (BPEU) 19.7-21.75 mg x h/L48. * Days -6 to -2: Flu 30 mg/m2/day (adjusted for renal function) is administered over a 30-60 minute IV infusion (maximum cumulative dose, 150 mg/m2).

  • DrugConditioning Regimen B

    Fludarabine and TBI The recommended fludarabine plus TBI regimen is the following: * Days -7, -6 and -5: Flu (30 mg/m2/day, maximum cumulative dose, 90 mg/m2), IV * Days -4 to -1: TBI (150 cGy administered twice daily, 1200 cGy total dose) * Radiation sources, dose rates, and shielding follow institutional practice. * Although not required, it is recommended that palifermin be used to mitigate the risk of mucosal toxicity with this regimen.

  • DrugConditioning Regimen C

    Fludarabine and busulfan (Flu/Bu) The recommended Flu/Bu regimen is the following: * Days -6 to -2: Flu (30 mg/m2/day, recommended total dose of 150 mg/m2, but not exceeding 180 mg/m2), IV Busulfan options * Days -5 to -4: Busulfan without PK - Busulfan 3.2 mg/kg/day IV or oral equivalent; total dose of 6.4 mg/kg IV or oral equivalent respectively * Days -5 to -4: Busulfan with PK - target doses to AUC of 4000 μMol/min or BPEU of 16.43 mg x h/L (total BPEU of 65.72 mg x h/L) or less is allowed.

  • DrugConditioning Regimen D

    Fludarabine and melphalan (Flu/Mel) The recommended Flu/Mel regimen is the following: * Days -7 to -3: Flu (30 mg/m2/day or 25 mg/m2/day, total dose of 125-150 mg/m2), IV * Day -1: Mel (100-140 mg/m2 IV for recipients aged 18-59; dose of melphalan cannot exceed 100mg/m2 if age 60 or older or calculated glomerular filtration rate (GFR) is \<60 ml/min), IV

  • DrugConditioning Regimen E

    Fludarabine/cyclophosphamide/total body irradiation (Flu/Cy/TBI) The recommended Flu/Cy/TBI regimen is the following: * Days -6 to -5: Cy (14.5 mg/kg/day IV, total dose of 29 mg/kg, or single dose 50 mg/kg on Day -6 \[Minnesota regimen\]) * Days -6 to -2: Flu (30 mg/m2/day, total dose of 150 mg/m2) IV * Day -1: TBI 200 cGy single dose Hydration and Mesna may be administered per institutional standards. For recipients of RIC/NMA AND donors matched at \<7/8, consider the addition of TBI 200-300cGy for the Flu/Bu and Flu/Mel regimens to mitigate the risk of primary graft failure.

  • ProcedureHematopoietic Cell Transplantation

    * On Day 0, the donor PBSC graft is infused. * Donor PBSC will be collected per NMDP/donor registry policies with a target viable CD34+ cell dose of at least 4 × 106 /kg recipient weight (actual, ideal, or adjusted ideal per institutional practice). * Dose of CD34+ cells/kg and CD3 cells/kg infused will be recorded. * If the donor PBSC graft is cryopreserved prior to the start of conditioning, follow institutional practices to ensure a sufficient cell dose is available for infusion after thawing. * The graft cannot be manipulated ex vivo to deplete T cells.

  • DrugPTCy (50 mg/kg D3, D4)

    Cyclophosphamide (50mg/kg ideal body weight (IBW); \[if actual body weight (ABW) \< IBW, use ABW\]) will be given on Day +3 (between 60 and 72 hours after the start of the PBSC infusion) and on Day 4 post HCT (approximately 24 hours after Day +3 cyclophosphamide). Cyclophosphamide will be given as an intravenous (IV) infusion over 1-2 hours (depending on volume), or according to institutional standards. Hydration pre- and post- cyclophosphamide and Mesna administration will be given per institutional standards. No systemic immunosuppressive agents are given until at least 24 hours after the completion of the PTCy. This includes corticosteroids as anti-emetics but excludes any drugs listed in section 7.9.1. Azoles (e.g., posaconazole or voriconazole) must be delayed from beginning of conditioning through completion of Day 4 PTCy dose to avoid potential drug-drug interactions with cyclophosphamide that could lead to increased toxicity.

  • DrugPTCy (25 mg/kg D3, D4)

    Cyclophosphamide (25mg/kg ideal body weight (IBW); \[if actual body weight (ABW) \< IBW, use ABW\]) will be given on Day +3 (between 60 and 72 hours after the start of the PBSC infusion) and on Day 4 post HCT (approximately 24 hours after Day +3 cyclophosphamide). Cyclophosphamide will be given as an intravenous (IV) infusion over 1-2 hours (depending on volume), or according to institutional standards. Hydration pre- and post- cyclophosphamide and Mesna administration will be given per institutional standards. No systemic immunosuppressive agents are given until at least 24 hours after the completion of the PTCy. This includes corticosteroids as anti-emetics but excludes any drugs listed in Table 4 and Table 5 in Section 7.1. Azoles (e.g., posaconazole or voriconazole) must be delayed from beginning of conditioning through completion of Day 4 PTCy dose to avoid potential drug-drug interactions with cyclophosphamide that could lead to increased toxicity.

  • DrugPost-transplant Tacrolimus

    Tacrolimus will be given per institutional practices, at a dose of 0.05 mg/kg per os (PO) or an IV dose of 0.03 mg/kg of IBW starting on Day + 5. The dose of tacrolimus may be rounded to the nearest 0.5 mg for oral formulations. Subsequent dosing will be based on blood levels per institutional guidelines with a suggested range of 5-12 ng/mL. If subjects are on medications which alter the metabolism of tacrolimus (e.g., concurrent CYP3A4 inhibitors), the initial starting dose and subsequent doses should be altered as per institutional practices. Tacrolimus taper is recommended to be initiated at 100 days post HCT if there is no evidence of active GVHD and ended by Day + 180 post HCT.

  • DrugPost-transplant Mycophenolate mofetil

    MMF will be given at a dose of 15 mg/kg 3 times daily (TID) (based upon actual body weight) with the maximum total daily dose not to exceed 3 grams (1g TID, IV or PO). MMF prophylaxis will start Day + 5 and continue until Day + 35 post-transplant, at which time it should be discontinued (no taper necessary). Study site investigators may modify dose/taper early if clinically indicated for the study subject. Dose rounding may be done per institutional practice.

  • DrugPost-transplant Abatacept

    Abatacept will be given at a dose of 10 mg/kg with a maximum of 1000 mg.

  • DrugPost-transplant Ruxolitinib

    Ruxolitinib will be given at a dose of 5 mg/kg twice daily starting at Day 30 post HCT, provided both the absolute neutrophil count (ANC) is \> 1000/μl and platelet count is \>30,000/μl.

  • Granulocyte colony-stimulating factor (G-CSF) to accelerate neutrophil recovery should be administered starting at Day +5 with dose, route of administration, formulation, and duration of administration following institutional guidelines. Filgrastim biosimilars are permissible, but granulocyte-macrophage colony-stimulating factors are not permissible.

  • ProcedureSupportive Care: Blood Products

    Transfusion thresholds for blood product support will be consistent with standard institutional guidelines. All blood products must be irradiated.

  • OtherSupportive Care: Infection Prophylaxis

    Subjects should receive infection prophylaxis according to institutional guidelines and in accordance with the Center for Disease Control (CDC) guidelines49. Infection prophylaxis will include, but is not limited to, agents or strategies (e.g., polymerase chain reaction \[PCR\] screening and preemptive therapy) to reduce the risk of bacterial, viral (e.g., adenovirus, CMV, EBV, herpes simplex), opportunistic (e.g. Pneumocystis jirovecii, Toxoplasma gondii) and fungal (yeast and mold) infections. Infection risk should assess patient-, pathogen-, and immune-related factors that increase susceptibility to infection. Minimal parameters requiring prophylaxis include but are not limited to neutropenia (ANC≤500/μL), lymphopenia (ALC≤500/μL), and exposure to immunosuppression or GvHD. Use of intravenous immunoglobulin (IVIG) should be considered for total IgG\<400 mg/dL during exposure to immunosuppression and/or GvHD.

  • OtherSupportive Care: Intravenous immune globulin (IVIG)

    Intravenous immune globulin (IVIG) administration will be according to local institutional standard practice for hypogammaglobulinemia but is generally not recommended.

  • DrugSupportive Care: Seizure prophylaxis

    Subjects will receive busulfan seizure prophylaxis with levetiracetam, fosphenytoin, or lorazepam per institutional guidelines.

  • OtherSupportive Care: Monitoring and management of CRS

    The use of HLA-mismatched PBSC has been associated with greater risk of CRS relative to bone marrow. Following the infusion of MMUD PBSC on Day 0, subjects should be monitored daily through Day 14 for the development of CRS. High index of suspicion is urged, particularly in the few days following infusion. Many sites have successfully intervened with tocilizumab in order to avoid severe or prolonged CRS. Supportive care is encouraged for CRS Grades 1-2 and tocilizumab (or alternative) is recommended for CRS grade 3-4 where subject outcome may be impacted (Appendix G - CRS Guidance and Management).

  • OtherSupportive Care: Prophylaxis against infections

    Consider monitoring for EBV reactivation during abatacept treatment and continue for six months following HCT. Consider monitoring and prophylaxis for CMV infection/reactivation during abatacept treatment and for six months following HCT.

  • DrugSupportive Care: Prophylaxis against infections

    For participants receiving ruxolitinib, the recommended maximum dose of fluconazole daily is 200 mg.

  • OtherSupportive Care: Lipid elevations

    Assess lipid levels 8-12 weeks from start of therapy with ruxolitinib and treat as needed.

  • OtherStudy treatment compliance

    The administration of study agents must be recorded in the subject's medical chart for verification of study treatment compliance.

  • OtherProhibited Concomitant Therapy

    Prophylactic anti-viral cellular therapies and/or co-enrollment on studies using therapies for the prevention of GVHD is prohibited. Subjects reported to have received prohibited therapy while on this study will be withdrawn and will not be included in the primary and secondary analyses. No concomitant systemic immunosuppressive agents can be administered during PTCy (Day 3 and Day 4). If needed, administer at least 24 hours after completion of Day 4 PTCy. It is crucial that no systemic immunosuppressive agents are given until at least 24 hours after completion of the Day +4 dose of PTCy. This includes corticosteroids as anti-emetics but excludes tacrolimus and MMF. Steroid use is permitted as pre-medication prior to start of conditioning but is prohibited from Day 0 through 24 hours post Day 4 PTCy administration. If prohibited therapies are administered, these data must be reported in the study EDC on the Concomitant Medications form.

  • OtherPermitted Concomitant Therapy

    Pre-medication and/or treatment for possible AEs related to PTCy are permitted. Subjects may continue all medications in compliance with local treatment center and local institutional guidelines, except those described in Section 7.9.1. If GVHD or infection occurs, enrollment on a clinical trial to treat infection or GVHD is permissible. At time of relapse, patients are permitted to enroll on a clinical trial or receive disease targeted therapy. The following medications/therapies must be reported on the study EDC Concomitant Medications form: * Medications taken to treat adverse events that have been reported on the study EDC Adverse Event form. * Antimicrobial prophylaxis (viral, bacterial, fungal, parasitic). * Antimicrobial pharmaceutical and cellular therapies used to treat grade II-III infections per BMT CTN grading criteria (Appendix D - BMT CTN Infection Grading). * Post HCT, primary malignant disease-directed pharmaceutical and cellular therapies. * Planned maintenance therapy

  • OtherProhibited Concomitant Therapy

    Treatment with any other Investigational Medicinal Product (IMP) is not allowed while on study treatment. An IMP is defined as any medication without any known FDA-approved indications. No other investigational drugs for GVHD are allowed.

  • OtherPermitted Concomitant Therapy

    Premedication and/or treatment for possible adverse events (AE)s related to abatacept are permitted.

  • OtherProhibited Concomitant Therapy

    Treatment with any other Investigational Medicinal Product (IMP) is not allowed while on study treatment. An IMP is defined as any medication without any known FDA-approved indications. Concomitant use of ruxolitinib with fluconazole doses of greater than 200 mg daily should be avoided. No other investigational drugs for GVHD are allowed.

  • OtherPermitted Concomitant Therapy

    Premedication and/or treatment for possible AEs related to ruxolitinib are permitted.

06

What researchers measure

Primary outcomes

  1. Graft-versus-host disease-free, relapse-free survival (GRFS)

    To compare GRFS following transplantation of a PBSC product from a MMUD between standard-of-care PTCy-based GVHD prophylaxis (the control arm) and the combination of reduced-dose PTCy, ruxolitinib, tacrolimus, and MMF.

    Time frame: 1 year post-HCT

  2. Graft-versus-host disease-free, relapse-free survival (GRFS)

    To compare GRFS following transplantation of a PBSC product from a MMUD between standard-of-care PTCy-based GVHD prophylaxis (the control arm) and the combination of reduced-dose PTCy, abatacept, and tacrolimus.

    Time frame: 1 year post-HCT

Secondary outcomes

  1. Graft-versus-host disease-free survival (GFS)

    To assess GFS for each of the treatment arms

    Time frame: 1 year post-HCT

  2. Infection-free survival (IFS)

    To assess IFS for each of the treatment arms

    Time frame: 1 year post-HCT

  3. Overall survival (OS)

    To assess OS for each of the treatment arms

    Time frame: 1 year post-HCT

  4. Progression-free survival (PFS)

    To assess PFS for each of the treatment arms

    Time frame: 1 year post-HCT

  5. Non-relapse mortality (NRM)

    To assess NRM for each of the treatment arms

    Time frame: 1 year post-HCT

  6. Cumulative incidence of relapse and disease progression

    To assess the cumulative incidence of relapse and disease progression for each of the treatment arms

    Time frame: 1 year post-HCT

  7. Cumulative incidence of neutrophil engraftment

    To assess the cumulative incidence of neutrophil engraftment for each of the treatment arms

    Time frame: 1 year post-HCT

  8. Cumulative incidence of platelet engraftment

    To assess the cumulative incidence of platelet engraftment for each of the treatment arms

    Time frame: 1 year post-HCT

  9. Primary graft failure (PGS) and secondary graft failure (SGF)

    To assess PGF and SGF for each of the treatment arms

    Time frame: 1 year post-HCT

  10. Incidence of ≥ grade 2 infections

    To assess the incidence of ≥ grade 2 infections for each of the treatment arms (BMT CTN grades II-III infection; Grades 1 ("mild", generally not reported), 2 ("moderate") and 3 ("severe/life threatening"))

    Time frame: 1 year post-HCT

  11. Donor cell engraftment

    To assess donor cell engraftment for each of the treatment arms

    Time frame: 1 year post-HCT

  12. Cumulative incidence of aGVHD

    To assess the cumulative incidence of aGVHD for each of the treatment arms

    Time frame: 1 year post-HCT

  13. Cumulative incidence of cGVHD

    To assess the cumulative incidence of cGVHD for each of the treatment arms

    Time frame: 1 year post-HCT

  14. Incidence of cytokine release syndrome (CRS)

    To assess the incidence of CRS for each of the treatment arms

    Time frame: 1 year post-HCT

07

Study locations

13 of 13 sites recruiting
08

References and documents

Individual participant data

Plan to share: Undecided

No publications or documents are linked to this record.

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 Jul 2025 (actual). Primary completion is estimated for Jun 2028, 35 months after the start.

Of 385 non-industry phase 2 interventional studies under Leukemia, Myeloid, Acute, half reached primary completion within 67 months of starting (the median), counting those still running; a quarter within 40 and three quarters within 108. This study's planned 35 months is below that.

Counting every sponsor, half of 442 studies reached it within 60 months; a quarter within 38 and three quarters within 104.

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

Registered
Feb 28, 2025
First posted
Mar 5, 2025
StartActual
Jul 25, 2025
Primary completionEst.
Jun 2028
CompletionEst.
Jun 2028
Last update
Mar 17, 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 Mar 17, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06859424
Lead sponsor
Center for International Blood and Marrow Transplant Research
Collaborators
National Marrow Donor Program, Incyte Corporation
Responsible party
Sponsor
First posted
Mar 5, 2025
Start date
Jul 25, 2025
Primary completion
Jun 2028 (estimated)
Completion
Jun 2028 (estimated)
Last update
Mar 17, 2026

Study contacts

Leigh Anne Blackmon, MSW
Contact
accelerate@nmdp.org
763-406-8087

Oversight

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

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