PF274 UNMANIPULATED HID COMPARED TO MUD AND ISD HAD SIMILAR GRAFT ANTI‐LEUKEMIA EFFECT ON MYELOABLATIVE HSCT FOR AML IN CR

Abstract

Background:some study has been confirmed more HLA dispariety between donor and patients has a stronger anti‐leukemia effect acute leukemia in some subgroupAims:To identified whether haploidentical donor(HID) have better graft‐versus‐leukemia effects than matched unrelated donor(MUD) and Identical sibling donors(ISD) in allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia in complete remission(CR).Methods:With this background, Between April 2012 and December 2016, consecutive 480 patients with AML in complete remission(CR) who underwent allogeneic HSCT in our center were analyzed retrospectively. donor sources were HID in 316 (65.8%) cases. MUD in 78(16.2%)cases,ISD in 86(17.9%) cases. The median age was 23(range,1.1 to 65) years. Male to female was 263: 217. The median disease course was 8 (range,2 to 57) months. 368(76.6%) cases transplant at CR1 and 112(23.3%) patients at CR2. according to cytogenetic risk stratification,83(17.2%) in poor risk,264(55.0%) in intermediate risk,133(27.7%) in favourable risk.64(13.3%) patients with FLT3‐ITD.Myeloablative conditioning regimens were administered with either Busulfan (Bu) plus Cyclophosphamide (Cy)/Fludarabine (Flu)‐based in 449(93.5%) patients or total body irradiation (TBI) plus Cy/Flu in 31 (6.4%) patients. Antithymocyte globulin was used in MUD and HID‐HSCT. unmanipulated bone marrow(BM) and peripheral blood stem cells (PBSC) for ISD and HID HSCT,only PBSC for MUD transplant were applied as the grafts. GVHD prophylaxis included mycophenolate mofetil(MMF), cyclosporine‐A with short‐term methotrexate for HID and MUD‐HSCT. MMF are not included in ISD‐HSCT.Results:The survivor median follow‐up time were 38(18–74)months, there were similar 5‐year OS (74.7 ± 3.0% vs 86.0 ± 4.3% vs 77.9 ± 4.5%,P = 0.497) and DFS (74.1 ± 3.0% vs 76.6 ± 7.0% vs 76.7 ± 4.6%, P = 0.729)among HID,MUD,ISD‐cohorts.there were no difference relapse(14.3 ± 2.9%vs11.8 ± 7.1%vs9.2 ± 3.3%,P = 0.857) and NRM (13.2 ± 2.0%vs5.3 ± 3.2% vs13.2 ± 2.0%,P = 0.695) among three donor type. We performed univariate analysis the impact of donor type on OS and LFS,relapse in patients at each disease stage such as: patients age(≤18y or 19–40y or>40y), white blood cell at diagnosis (<50 × 109/L or ≥50 × 109/L),cause of disease (primary or sencodary),cytogenetics risk stratification (low or intermediate or high), FLT3‐ITD (with or none),NCCN risk stratification(low or intermediate or high),CRstatus(CR1or CR2),MRD(negative or positive), Extramedullary lesions (with or none), we found no significant differences in OS,LFS,relapse due to donor type. performed multivariate analysis for all patients of pretransplantation variables showed secondary AML, MRD positive were two adverse factor related to OS. MRD positive, HCT‐CI ≥2 were two risk factor associated to DFS. the patients with MRD positive,disease status in CR2,NCCN in higher risk, HCT‐CI ≥2 were associated with cumulative incidence of relapse(CIR).the patients age over 40‐y was only risk factor related to TRM.Summary/Conclusion:HID‐HSCT compared to MUD and ISD had similar graft verse leukemia effect on allo‐HSCT for AML in CR status and on its each disease stage.