Replaced by a different study

This protocol using busulfan, cyclophosphamide and melphalan has been designed as conditioning therapy for patients receiving stem cell transplantation for acute leukemia or myelodysplastic syndrome (MDS). The hypothesis is that this new regimen will be well tolerated and will cure the patient.

Subjects will be admitted to the bone marrow transplant unit and put in isolation to reduce exposure to infectious agents.

Prior to transplantation, they will receive BUSULFAN via the central venous line, four times a day for four days, CYCLOPHOSPHAMIDE via the central venous line once a day for two days, and MELPHALAN via the central venous line for one day. Busulfan, cyclophosphamide, and melphalan are given to destroy the subject's cancer. As well, these drugs will destroy their immune system to help ensure the new stem cells take and grow after transplantation.

On the day of transplantation, umbilical cord blood from the donor will be transfused via venous line. These new cells will replace the subject's bone marrow.

After transplantation, the subjects will receive Cyclosporin A and either MMF or MTX

Isolation will be continued until adequate numbers of cells are present in the blood to fight infection. Subjects will be discharged from the hospital when medically ready. They will be expected to return for follow-up to the blood and marrow transplant clinic at specific dates as determined by physicians.

Inclusion Criteria:

• Patients must have a diagnosis of acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) and currently be in complete remission.
• Patients must be either:
• - <18 years of age who are at least 6 months after initial hematopoietic cell transplant (HCT),
• - 19-35 years of age and at least 18 months after initial HCT, or
• - <35 years of age and have received sufficient radiation treatment to be ineligible for total body irradiation (TBI) containing preparative therapy
• Adequate major organ function including:
• - Cardiac: ejection fraction > or = 45%
• - Renal: creatinine clearance > or = 40 mL/min
• - Hepatic: no clinical evidence of hepatic failure (e.g. coagulopathy, ascites)
• - Karnofsky performance status > or = 70% or Lansky score > or = 50%
• Women of child bearing age must be using adequate birth control and have a negative pregnancy test.
• Written informed consent.

Exclusion Criteria:

• Eligible for TBI containing preparative regimen.
• Active uncontrolled infection within one week of HCT.
• Pregnant or lactating females.

1 year post transplant.