Reduced Intensity Conditioning Regimens for Acute Myeloid Leukemia and Myelodysplastic Syndrome

Reduced Intensity Conditioning With Fludarabine and Busulfan Versus Fludarabine and Melphalan Before Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Randomised, Multi-Center, Phase III Study

The goal of this clinical trial is to compare outcomes of two reduced intensity conditioning (RIC) regimens (fludarabine plus busulfan and fludarabine plus melphalan) in allogeneic hematopoietic stem cell transplantation (HSCT) for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) patients. The main questions it aims to answer are:

• The safety of two reduced intensity conditioning (RIC) regimens (fludarabine plus busulfan and fludarabine plus melphalan) in allogeneic hematopoietic stem cell transplantation for adult AML/MDS patients with HCT-CI≥3 or aged ≥55 years.
• The efficacy of two reduced intensity conditioning (RIC) regimens (fludarabine plus busulfan and fludarabine plus melphalan) in allogeneic hematopoietic stem cell transplantation for adult AML/MDS patients with HCT-CI≥3 or aged ≥55 years.

Participants will be randomized to one of two reduced intensity conditioning (RIC) regimens (fludarabine plus busulfan and fludarabine plus melphalan)

Patients are randomized to one of two reduced intensity conditioning (RIC) regimens: the combination of fludarabine (30 mg/m^2/day, days -6 to days -2, the total dase is 150 mg/m^2) and busulfan (3.2 mg/kg/day, days -3 to days -2, the total dose is 6.4 mg/kg) (Flu/Bu) or fludarabine (30 mg/m^2/day, days -6 to days -2, the total dose is 150 mg/m^2) and melphalan (70 mg/m^2/day, days -3 to days -2, the total dose is 140 mg/m^2) (Flu/Mel). A total of 200 patients (100 to each arm) will be recruited in this study over a period of two years. Patients will be followed for up to 18 months from allogeneic hematopoietic stem cell transplantation.

Inclusion Criteria:

• Age equal or more than 18 years old.
• Patients diagnosed with AML or MDS.
• Patients who have related or unrelated bone marrow or peripheral blood donors and plan to undergo hematopoietic stem cell transplantation.
• Hct-specific complication index score (HCT-CI) more than or equal to 3 or the age of Patients ≥55 years.
• Sign the informed consent, promise to abide by the research procedures, and cooperate with the implementation of the whole process of the research.

Exclusion Criteria:

• Patients with central nervous system involvement.
• Patients with HIV seropositive.
• Patients with other serious diseases and a life expectancy of less than six months
• Patients with severe mental or psychological disorders.
• Patients without written informed consent.