Busulfan and Cyclophosphamide Followed By ALLO BMT

This is a single arm trial to evaluate the efficacy of busulfan and cyclophosphamide followed
by an allogeneic hematopoietic stem cell transplant (HSCT) in the treatment of hematological
malignancies. The intent of this study is to provide a protocol that will use unmanipulated
allogeneic hematopoietic stem cells from related and unrelated donors after a common
preparative regimen. Results will be compared to historical controls.

Inclusion Criteria:

- Diagnosis of acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) or
myelodysplastic syndrome (MDS) and current in complete remission meeting one of the
following:

- <45 years of age who are at least 6 months after initial hematopoietic stem cell
transplant (HSCT)

- <45 years of age and have received sufficient radiation treatment to be
ineligible for total body irradiation (TBI) containing preparative therapy

- Karnofsky performance status >70% or if <16 years of age, a Lansky play score >50

- Adequate major organ function including:

- cardiac: left ventricular ejection fraction >45% by echocardiogram (ECHO/MUGA)

- renal: creatinine clearance >40 mL/min/1.73m^2

- hepatic: no clinical evidence of hepatic failure (e.g., coagulopathy, ascites)

- An acceptable source of stem cells according to current University of Minnesota Bone
Marrow Transplant program guidelines. Acceptable stem cell sources include:

- HLA-matched related or unrelated donor bone marrow (6/6 or 5/6 antigen match)

- HLA-matched related or unrelated donor peripheral blood stem cells

- related or single or double unrelated donor umbilical cord blood (6/6, 5/6 or 4/6
match)

- Women of childbearing age must have a negative pregnancy test and all sexually active
participants must agree to use effective contraception during study treatment

- Written consent (adult or parent/guardian)

Exclusion Criteria:

- eligible for TBI containing preparative regimen

- active uncontrolled infection within one week of study enrollment

- pregnant or lactating female