Tacrolimus and Mycophenolate Mofetil as Post-Grafting Immunosuppression

This protocol will evaluate Tacrolimus and MMF after conditioning with fludarabine and low-dose TBI in patients who are not candidates for conventional allografting. A novel approach to immunosuppression will be tested incorporating an early but extended taper of Tacrolimus starting on day +80 or in the case of relapse. The goal is to induce early immunity and GVT effects without compromising GVHD control. The anti-metabolite MMF will be re-introduced on day +100 to try and induce tolerance and block chronic GVHD during the taper of the Tacrolimus. DLI may be given in the presence of disease progression but not for mixed chimerism as in previous protocols.