Stem Cell Transplantation for Acute Leukemia

Inclusion Criteria: * Patients with newly diagnosed or relapsed acute leukemia. Patients undergoing reinduction due to primary induction failure are also eligible. Patients with acute leukemia will be enrolled to Arm A * Patients with diagnosis of MDS, MPN and MDS/MPN overlap who meet any of the following criteria (based on NCCN guidelines): * Clinically significant cytopenia of at least 2 cell lines affected; Hgb\<10, * Platelet\<100,000, absolute neutrophil count\<1000 * Bone marrow blasts \>5% and any level of circulating blasts * Evidence of disease progression or no response to hypomethylating agents/immunosuppressive treatment or a clinical trial. * IPSS Intermediate-1 and higher * IPSS-R intermediate and higher * All cases of therapy related MDS with excess blasts * In patients with Myelofibrosis: Low risk disease by DIPSS with either refractory, transfusion dependent anemia, circulating blasts cells greater than 2%; or adverse cytogenetics and any patient with DIPSS-intermediate 1 and higher. For patients with post-PV and post-ET myelofibrosis, any patient with MYSEC-PM Intermediate-1 risk or higher is eligible. * Patients with acute leukemia or MDS/MPN who relapse after first allografts. Patients with post-transplant relapse will be enrolled to Arm C. * Patients 18 years of age or older and 80 years of age or younger * For the purposes of this protocol "relapse" is defined as re-emergence of the initial abnormal myeloid blast population (or blast equivalent) comprising 5% or more of marrow WBC or any amount prompting a therapeutic intervention targeting relapsed disease, including, but not limited to withdrawal of immunosuppression, targeted therapies, chemotherapy, etc. * Patients previously enrolled in Arm A or Arm B who experience post-transplant relapse are also eligible for enrollment onto Arm C Exclusion Criteria: * Patients with polycythemia vera (PV) and essential thrombocytosis (ET)