Reduced Intensity Flu/Mel/TBI Conditioning for HAPLO HCT Patients With Hematologic Malignancies

Inclusion Criteria: * Age ≥ 55 years or HCT Co-Morbidity score (HCT-CI) \>/=3 * Lack of a suitable 8/8 HLA-matched sibling donor * Adequate performance status is defined as Karnofsky score ≥ 70% * Patients and selected donor must be HLA typed at high resolution using DNA based typing at the following HLA-loci: HLA-A, -B, -C and DRB1. Donors must be HLA-haploidentical relatives including, but not limited to, children, siblings, or parents, defined as having a shared HLA haplotype between donor and patient at HLA-A, -B, -C, and -DRB1. * Acute Myeloid Leukemia (AML): Must be in remission with morphology (\<5% blasts) * Acute Lymphoblastic Leukemia (ALL)/lymphoma second or greater complete remission (CR) first CR unable to tolerate consolidation chemotherapy due to chemotherapy-related toxicities, first CR high-risk ALL * Biphenotypic/Undifferentiated/Prolymphocytic Leukemias in first or subsequent CR * Myelodysplastic syndrome: any subtype including refractory anemia (RA) if severe pancytopenia or complex cytogenetics. Blasts must be less than 5%. If 5% of more requires chemotherapy for cytoreduction to \</=5% prior to transplantation. * Chronic Myelogenous leukemia in accelerated phase: patient must have failed at least two different Tyrosine Kinase Inhibitor (TKI)s, been intolerant to all TKIs, or have T315l mutation * Myeloproliferative neoplasms/myelofibrosis: Blasts must be less than 5%. If 5% or more requires chemotherapy for cytoreduction to \</=5% prior to transplantati…