Reduced Intensity Conditioning Followed by Related and Unrelated Allografts for Hematologic Malignancies: Expanded Analysis and Long Term Follow-Up.

•Our fludarabine + cyclophosphamide + TBI RIC platform produced highly successful outcomes in indolent lymphoma and CML and those with low-risk DRI.•Flat-rate fludarabine dosing decrease did not translate into diminished nonrelapse mortality; thus, personalized pharmacokinetic fludarabine dosing may be needed to achieve that goal.•Our rates of acute GVHD were higher than desired, especially in the URDs receiving PBSCs. Alternative GVHD prophylaxis strategies are proposed for future studies.•More stringent disease burden criteria at transplant and initiation of targeted post-transplant maintenance therapy approaches are needed to improve outcomes for the higher risk hematologic malignancy patients treated with our RIC platform.