Haploidentical Hematopoietic Stem Cell Transplantation

The preparatory regimen will consist of Hydroxyurea from Days -50 to -22, Alemtuzumab from days -21 to -19 (test dose Alemtuzumab on day -22), Fludarabine days -8 to -4, Thiotepa Day -4, Melphalan day -3 to -2 (Table 4a). In patients with intolerance to or have received alemtuzumab in the prior 6 months, alemtuzumab will be replaced with rabbit ATG on days -10 through -7, followed by infusion of a peripheral blood stem cell graft collected from haploidentical family donors that are CD34+ positively selected using the CliniMACS device. Sirolimus will be used for GVHD prophylaxis and given for 9 months post-transplant and then tapered off by one year.