I. To demonstrate efficacy of this approach over the historical 2 step reduced intensity conditioning (RIC) approaches in the "vulnerable" population defined as: patients with hematopoietic cell transplant (HCT)-co-morbidity index (CI)/age scores >= 2, but no more than a score of 5 as based on the Sorror et al. data.
I. To compare the non-relapse mortality (NRM) and relapse related mortality (RRM) rates at 1 year for patients treated on this study to the that of patients undergoing haploidentical RIC hematopoietic stem cell transplantation (HSCT) as reported in the literature and as observed in the 2 step RIC trials.
II. To determine the incidence and severity of graft-versus-host disease (GVHD) in patients undergoing treated on the Thomas Jefferson University (TJU) RIC 2 step approach.
III. To evaluate engraftment rates and lymphoid reconstitution in patients treated on the TJU RIC 2 step approach.
RIC: Patients receive fludarabine phosphate intravenously (IV) over 60 minutes on days -10 to -8 and cyclophosphamide IV over 2 hours on days -3 and -2. Patients also undergo total body irradiation (TBI) followed by a donor lymphocyte infusion (DLI) on day -6.
TRANSPLANT: Patients undergo cluster of differentiation (CD)34+ peripheral blood stem cell transplant on day 0.
GVHD PROPHYLAXIS: Patients receive tacrolimus orally (PO) beginning day -1 with a taper initiated on day 42 and mycophenolate mofetil IV twice daily (BID) on days -1 to 28 in the absence of GVHD.
After completion of study treatment, patients are followed up for 1 year.