The Superiority of Allogeneic Hematopoietic Stem Cell Transplantation From Unrelated Donor Over Chemotherapy As Post-Remission Treatment for Patients with High-Risk Acute Lymphoblastic Leukemia in First Remission

Abstract 1986 For adult patients with acute lymphoblastic leukemia (ALL), allogeneic hematopoietic stem cell transplantation (allo-HSCT) from HLA-matched related donor (MSD) is recommended for standard and high-risk patients. The role of unrelated donor transplantation (URD) is not fully determined. In this single-center retrospective analysis, we included all consecutive adult patients with high-risk ALL in 1 st complete remission (CR) without sibling donor between Jan 2007 to June 2012. Overall, 74 patients were included in the analysis in which 32 patients received URD allo-HSCT during 1 st CR with busulfan-cyclophophamide preparation regimen and in vivo T cell depletion with anti-T-lymphoglobulin (ATG). The median time from remission to transplantation was 4.5 months (3∼13). Forty-two patients in the chemotherapy group with 1 st CR more than 6 months received consolidation chemotherapy alone either due to lack of suitable URD (n=21), refuse to URD search (n=14), unwillingness to undergo transplantation with available URD (n=5) and donor refuse to donate (n=2). Salvage allo-HSCT was allowed after relapse and actually 5 patients in the chemotherapy group received transplantation from URD donor (n=2) or haplo-identical donor (n=2) in the subsequent remission. The clinical characteristics such age, sex, initial WBC, and Philadelphia chromosome are all distributed equally in the two groups. With a median follow-up of 18 months for the whole group, 30 patients relapsed with estimated 3-year relapse rate (RR) at 58.1±8.5%. The 3-year event-free survival (LFS), non-relapse mortality (NRM) and overall survival (OS) were 38.0±7.9%, 11.1±4.4% and 46.0±9.0% respectively. In the URD allo-HSCT group, RR was 30.6±11.4% which was significantly lower than chemotherapy group (80.5±10.1%, p Disclosures: No relevant conflicts of interest to declare.