Donor Stem Cell Transplant in Treating Patients With High-Risk Hematologic Malignancies

This is a phase II study in which patients receive a haploidentical HSCT from a single donor. The period between the donor lymphocyte infusion (DLI) and tolerizing doses of CY has been extended to allow for an increased period of allogeneic response against tumor targets. The outcomes of patients undergoing this extra time period will be compared to historical data to assess efficacy. Primary Objective: 1\) To assess 1 year relapse free survival in patients undergoing hematopoietic stem cell transplant (HSCT) using the Thomas Jefferson University (TJU) 2 step approach with an extra day inserted between the DLI and administration of cyclophosphamide (CY). Secondary Objectives: 1. To assess the consistency and pace of engraftment. 2. To assess the pace of T cell and B cell immune recovery. 3. To assess regimen related toxicity, (GVHD) graft-versus-host disease incidence and severity, and overall survival in patients undergoing treatment on this protocol. . 4. To assess the tolerance of the period of fever, diarrhea, and rash in each arm in an effort to determine whether a longer interval prior to cytoxan changes this side effect qualitatively compared to prior patient groups or concurrent patient groups. N.B. Patients with hematologic malignancies in remission will continue to be transplanted without modification to the original 2-step approach and will serve as a concurrent comparison group. 5. To collect leukemia samples prior to transplant and after relapse whenever possible. To assess the overall degree of HLA-class I and class II expression on these paired samples. To test for loss of one or both HLA haplotypes in the relapsed tumor specimens. 6. To determine the number of cluster of differentiation 4 (CD4+) cluster of differentiation 25 (CD25+) FOXP3+ regulatory cells post HSCT and to assess whether this is correlated with the development of GVHD after transplant.