Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 16 4 2022 10 15 189 197 EN Eucario Leon Rodriguez Hematopoietic Cell Transplantation Program, Department of Hematology and Oncology, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico Monica Rivera Franco Hematopoietic Cell Transplantation Program, Department of Hematology and Oncology, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico 2020 09 03 2020 10 29 Background: Conditioning regimens are critical for allogeneic hematopoietic cell transplantation (allo-HCT). After unfavorable results using BuCy2 at the beginning of our HCT Program, a restructuring was made with the consequent development of a modified HCT method including a reduced conditioning regimen. The objective of this study was to describe the outcomes using Reduced BuCy2 (rBuCy2) in allo-HCT. Materials and Methods: Data from 38 consecutive patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) who underwent allo-HCT conditioned with rBuCy2 in a 21-year period were retrospectively analyzed. Results: Most patients were males (53%) and the median age was 35 years. The most common disease was myelodysplastic syndrome (55%). Toxicity grades III-IV were observed in 44%; and acute and chronic graft-versus-host disease were observed in 26% and 34%, respectively; the median follow-up was 26 months; 30-day non-relapse mortality (NRM) was 3%, and 1 and 2-year NRM were 8%. Ten-year overall survival (OS) was 60%, and 86%, for AML and MDS, respectively. Conclusion: Our rBuCy2 maintains a myeloablative effect, along with immunosuppression for fast engraftment and more importantly, this regimen reduces grades III-IV acute GVHD and NRM in allo-HCT and improves the OS and it appears to be an option for low and middle-income countries https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/1423 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/1423/946