ClinicalTrials.gg
Not yet recruitingNCT07762508VABuUpdated Aug 19, 2026

A Study of VABu Conditioning Regimen in Allo-HSCT for AML Patients

An interventional study of Venetoclax and Azacitidine (AZA) in Leukemia, Myeloid, Acute(AML) and Hematopoietic Stem Cell Transplantation (HSCT), sponsored by The First Affiliated Hospital of Soochow University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-08-19.

Sponsored by The First Affiliated Hospital of Soochow University · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
42
Allocation
Not applicable
Ages
18 Years to 70 Years
Sex
All
01

Study summary

This study evaluates the effectiveness and safety of a new conditioning regimen called VABu before stem cell transplantation in patients with acute myeloid leukemia (AML) who are in their first complete remission (CR1), classified as non-high-risk per ELN 2022 guidelines, but have poor physical condition (ECOG performance status ≥ 2) or high comorbidity burden (HCT-CI ≥ 2). VABu combines venetoclax, azacitidine (or decitabine as an alternative), and busulfan. This is a single-arm, prospective study with 42 participants. All participants will receive the VABu regimen followed by stem cell transplantation. The primary outcome measure is 2-year overall survival (OS). Secondary outcomes include 2-year relapse-free survival (RFS), transplant-related mortality (TRM), engraftment failure rate, bloodstream infection (BSI), and 2-year all-cause mortality and non-relapse mortality (NRM). The study is conducted at the First Affiliated Hospital of Soochow University.

Read the detailed description

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. For patients who are unfit for intensive chemotherapy due to poor performance status or high comorbidity burden, allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only potential curative treatment. However, these patients often have low transplantation rates and suboptimal outcomes with reduced-intensity conditioning regimens. Venetoclax combined with azacitidine has been established as the standard of care for unfit AML patients, demonstrating high remission rates and good tolerability. Building on this, our center has previously explored the VABu regimen (venetoclax, azacitidine, and busulfan) as a conditioning therapy in elderly AML patients undergoing allo-HSCT, with preliminary results showing reduced chemotherapy-related toxicity and a 2-year overall survival rate of approximately 70%.

This is a single-arm, prospective, single-center study. A total of 42 participants will be enrolled. Eligible participants are patients aged 18 to 70 years with non-APL AML who have achieved first complete remission (CR1), are classified as non-high-risk per ELN 2022 guidelines, and have either ECOG performance status ≥ 2 (not due to leukemia) or HCT-CI ≥ 2. All participants will receive the VABu conditioning regimen followed by allo-HSCT. The VABu regimen consists of venetoclax 600 mg/m² once daily on days -12 to -7, azacitidine 75 mg/m² once daily on days -11 to -7 (or decitabine 20 mg/m² for 5 days), cytarabine 2.0 g/m² every 12 hours on day -6, busulfan 0.8 mg/kg every 6 hours on days -5 to -3, and antithymocyte globulin (ATG) at 2.5 mg/kg/day according to donor type (haploidentical/unrelated donors on days -5 to -2, or matched sibling donors on days -3 to -2). Hematopoietic stem cell infusion occurs on day 0, followed by standard graft-versus-host disease (GVHD) prophylaxis.

The primary outcome measure is 2-year overall survival (OS). Secondary outcome measures include 2-year relapse-free survival (RFS), transplant-related mortality (TRM), engraftment failure rate, bloodstream infection (BSI), and 2-year all-cause mortality and non-relapse mortality (NRM). Safety will be monitored through adverse event collection and grading per CTCAE 5.0 criteria. Follow-up assessments are scheduled at weeks 1, 2, 3, 4, and months 2, 3, 6, 12 post-transplantation. The study period is from August 2026 to July 2029. Statistical analyses will be performed using SPSS and R, with Kaplan-Meier method for OS, and Cox regression and logistic regression for multivariate analyses.

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Conditions studied

  • Leukemia, Myeloid, Acute(AML)
  • Hematopoietic Stem Cell Transplantation (HSCT)

Keywords

  • Acute Myeloid Leukemia
  • Allogeneic Hematopoietic Stem Cell Transplantation
  • Conditioning Regimen
  • Venetoclax
  • Azacitidine
  • VABu
  • Low Performance Status
  • High Comorbidity Index
  • Single-Arm Study
  • Prospective Study
  • AML
  • Allo-HSCT
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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 42 is close to the median of 40 across 3,005 interventional studies indexed under Leukemia, Myeloid, Acute.

Browse Leukemia, Myeloid, Acute studies →

Lead sponsor

The First Affiliated Hospital of Soochow University is the lead sponsor of 261 studies on the registry; 150 are open to participants now.

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

04

Who can participate

Ages eligible
18 Years to 70 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Age 18 to 70 years.
  2. Diagnosis of acute myeloid leukemia (AML) other than acute promyelocytic leukemia (APL), with first complete remission (CR1) achieved after induction chemotherapy.
  3. Classified as non-high-risk per ELN 2022 risk stratification guidelines.
  4. performance status ≥ 2 (not due to leukemia) OR Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) ≥ 2.
  5. Willing to undergo hematopoietic stem cell transplantation and has a suitable donor.
  6. Voluntarily signs form after full understanding of the study.

Exclusion criteria

Exclusion Criteria:

  1. Allergy to any component of the study drugs.
  2. Psychiatric or psychological disorders that prevent cooperation with treatment.
  3. Uncontrolled systemic or local severe infection.
  4. Severe dysfunction of major organs (heart, lung, liver, kidney) that, in the investigator's opinion, makes the patient unsuitable for enrollment.
  5. Currently participating in or planning to participate in any other clinical study.
  6. Any other conditions that, in the investigator's opinion, make the patient unsuitable for enrollment.
Terms in these criteria, in plain language(3)

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.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

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.

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.

05

Study design

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

Study arms

  • Experimental
    VABu Conditioning Regimen

    Participants receive the VABu conditioning regimen followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). The VABu regimen consists of venetoclax 600 mg/m² once daily on days -12 to -7, azacitidine 75 mg/m² once daily on days -11 to -7 (or decitabine 20 mg/m² for 5 days), cytarabine 2.0 g/m² every 12 hours on day -6, and busulfan 0.8 mg/kg every 6 hours on days -5 to -3. Antithymocyte globulin (ATG) is administered at 2.5 mg/kg/day according to donor type: haploidentical or unrelated donors receive ATG on days -5 to -2 (4 doses), while matched sibling donors receive ATG on days -3 to -2 (2 doses). Hematopoietic stem cell infusion occurs on day 0, followed by standard graft-versus-host disease (GVHD) prophylaxis.

    Drug: Venetoclax · Drug: Azacitidine (AZA) · Drug: Decitabine 20 mg/m²/day for 5 days · Drug: Cytarabine (Ara-C) · Drug: Busulfan (BU) · Drug: Antithymocyte Globulin (ATG)

Interventions

  • Venetoclax 600 mg/m² administered orally once daily on days -12 to -7 as part of the VABu conditioning regimen for allogeneic hematopoietic stem cell transplantation. Venetoclax is a selective BCL-2 inhibitor used to enhance anti-leukemic activity.

  • Azacitidine 75 mg/m² administered subcutaneously once daily on days -11 to -7 as part of the VABu conditioning regimen. This is one of the two optional hypomethylating agents; the alternative is decitabine 20 mg/m² for 5 days. Azacitidine has synergistic anti-leukemic effects when combined with venetoclax.

  • DrugDecitabine 20 mg/m²/day for 5 days

    Drug page: Decitabine

    Decitabine 20 mg/m² administered intravenously once daily for 5 days on days -11 to -7 as an alternative to azacitidine in the VABu conditioning regimen. This is one of the two optional hypomethylating agents; the alternative is azacitidine 75 mg/m² once daily. Decitabine has synergistic anti-leukemic effects when combined with venetoclax.

  • Cytarabine 2.0 g/m² administered intravenously every 12 hours on day -6 as part of the VABu conditioning regimen. Intermediate-dose cytarabine is used to further eliminate minimal residual disease prior to hematopoietic stem cell infusion.

  • Busulfan 0.8 mg/kg administered intravenously every 6 hours on days -5 to -3 as part of the VABu conditioning regimen. Busulfan is an alkylating agent used at reduced intensity to achieve sufficient anti-leukemic effect while minimizing organ toxicity.

  • Antithymocyte globulin (ATG) 2.5 mg/kg/day administered intravenously once daily for graft-versus-host disease (GVHD) prophylaxis. Haploidentical or unrelated donors: ATG given on days -5 to -2 (4 doses). Matched sibling donors: ATG given on days -3 to -2 (2 doses).

06

What researchers measure

Primary outcomes

  1. 2-Year Overall Survival (OS)

    Overall survival is defined as the time from enrollment to death from any cause. Participants alive at the end of follow-up will be censored at their last known alive date.

    Time frame: 2 years

Secondary outcomes

  1. 2-Year Relapse-Free Survival (RFS)

    Relapse-free survival is defined as the time from enrollment to the first occurrence of relapse or death from any cause, whichever occurs first. Participants alive and relapse-free at the end of follow-up will be censored at their last known disease-free date. Relapse is defined as disease recurrence confirmed by bone marrow morphology, cytogenetics, or molecular testing per ELN 2022 criteria.

    Time frame: 2 years

  2. 2-Year All-Cause Mortality, Transplant-Related Mortality (TRM), and Non-Relapse Mortality (NRM)

    All-cause mortality is defined as death from any cause within 2 years of enrollment. Transplant-related mortality (TRM) is defined as death from any cause other than disease relapse or progression, with a focus on transplant-related complications (e.g., infection, GVHD, organ toxicity). Non-relapse mortality (NRM) is defined as death from any cause other than disease relapse or progression, and will be reported as a competing risk for relapse outcomes. The cumulative incidences of TRM and NRM will be estimated separately, and all-cause mortality will be reported as the overall proportion of deaths.

    Time frame: 2 years

  3. Engraftment Failure Rate

    Engraftment failure is defined as the failure to achieve neutrophil engraftment by day 28 post-transplantation. Neutrophil engraftment is defined as an absolute neutrophil count ≥ 0.5 × 10⁹/L for three consecutive days. The rate of engraftment failure will be reported as the proportion of participants who fail to achieve engraftment by day 28.

    Time frame: Day 28 post-transplantation

  4. Bloodstream Infection (BSI) Rate

    Bloodstream infection is defined as the occurrence of at least one positive blood culture for a bacterial or fungal pathogen during the peri-transplantation period. The BSI rate will be reported as the proportion of participants with at least one episode of bloodstream infection from transplantation to day 28 post-transplantation.

    Time frame: Day 28 post-transplantation

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Study locations

1 site
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References and documents

Individual participant data

Plan to share: Undecided — The decision on IPD sharing will be made after the study is completed and the primary results are published, taking into consideration institutional policies, ethical approval, and patient privacy protection.

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 19, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT07762508
Responsible party
Sponsor
First posted
Aug 13, 2026
Start date
Aug 2026 (estimated)
Primary completion
Jul 2029 (estimated)
Completion
Jul 2029 (estimated)
Last update
Aug 19, 2026

Study contacts

Depei Wu, MD, PhD
Contact
wudepei@suda.edu.cn
512-67781856

Oversight

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

Not currently enrolling

This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.

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Discussion

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Studies of the drugs tested here: Venetoclax · Azacitidine · Decitabine · Cytarabine · Busulfan · Antilymphocyte Serum

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