This study is conducted to evaluate the efficacy of post-transplantation cyclophosphamide with myeloablative or reduced-intensity conditioning regimen for allogeneic hematopoietic cell transplantation (HCT) in patients with higher-risk myelodysplastic syndrome (MDS). The efficacy of the treatment will be measured in terms of the GVHD-free, relapse-free survival.

The secondary end points of the study include engraftment, relapse incidence, non-relapse mortality, graft-versus-host disease, donor chimerism, immune reconstitution, infections, and survivals (overall and event-free).

This study is conducted to evaluate the efficacy of post-transplantation cyclophosphamide with myeloablative or reduced-intensity conditioning regimen for allogeneic hematopoietic cell transplantation (HCT) in patients with higher-risk myelodysplastic syndrome (MDS). The efficacy of the treatment will be measured in terms of the GVHD-free, relapse-free survival.

The secondary end points of the study include engraftment, relapse incidence, non-relapse mortality, graft-versus-host disease, donor chimerism, immune reconstitution, infections, and survivals (overall and event-free).

Inclusion Criteria:

• MDS defined by WHO classification, CMML, or AML evolving from MDS A. International Prognostic Scoring System (IPSS) > 1.0 or bone marrow blast ≥ 5% at any time points before HCT or B. AML progressed from MDS or C. CMML with bone marrow blast ≥ 5% at any time points before HCT
• Patients receiving first HCT
• Patients with appropriate hematopoietic cell donors A. HLA-matched sibling donor B. Unrelated donor C. HLA-mismatched familial donor
• 15 years old or older , under 75 years
• Adequate performance status (Karnofsky score of 70 or more)
• Adequate hepatic function (AST or ALT < 3 x upper normal limits and bilirubin < 1.5 x upper normal limit).
• Adequate renal function (creatinine < 2.0 mg/dL or creatinine clearance ≥ 50 mL/min)
• Adequate cardiac function (left ventricular ejection fraction ≥ 50% on heart scan or echocardiogram)
• Adequate pulmonary function: DLCO, FEV1, and FVC ≥ 45% predicted by pulmonary function tests
• Signed and dated informed consent must be obtained from both recipient and donor.

Exclusion Criteria:

• Presence of significant active infection
• Presence of uncontrolled bleeding
• Any coexisting major illness or organ failure
• Patients with psychiatric disorder or mental deficiency severe as to make compliance with the treatment unlike, and making informed consent impossible
• Nursing women, pregnant women, women of childbearing potential who do not want adequate contraception
• Patients with a diagnosis of prior malignancy unless disease-free for at least 5 years following therapy with curative intent (except curatively treated nonmelanoma skin cancer, in situ carcinoma, or cervical intraepithelial neoplasia)
• Presence of contraindications to cyclophosphamide (patients receiving pentostatin, symptomatic cystitis, urinary tract obstruction, with a history of hypersensitivity reactions to the component of the drug)