Role of Post-Allogeneic Hematopoietic Stem Cell Transplantation Low-Dose Azacitidine for Prevention of Relapse in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Retrospective Analysis

Abstract

Introduction Relapse after allogeneic hematopoietic stem cell transplantation (HSCT) for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) remains a major cause of treatment failure with associated poor prognosis. Low-dose post-HSCT maintenance azacitidine (AZA) has proved to be beneficial in preventing relapses (de Lima et al. Cancer 2010). Herein, we retrospectively evaluated outcomes of patients (pts) treated with low-dose AZA post-HSCT. Methods Pts with AML and MDS who underwent allogeneic HSCT between 2012-2018 at two centers were evaluated and categorized into AZA group (with low-dose AZA maintenance) and control group (without AZA maintenance). In control group, pts who died or relapsed prior to day +100, had grade III-IV aGVHD or received maintenance therapy other than AZA (e.g. FLT3 inhibitors) were excluded. Using Kaplan-Meier method, event (defined as relapse or death) free survival (EFS) and overall survival (OS) were computed and compared using log-rank test. Results A total of 107 patients were included; 53 (49.5%) in AZA and 54 (50.5%) in control groups. Disease and transplant-related characteristics are shown in table 1. Both groups were comparable with respect to age, diagnosis, disease risk stratification, disease status at HSCT, and MRD status at day +30 and day +100 (table 1). More pts received reduced intensity conditioning (RIC) in the AZA group (71.6% vs 37%, p= Conclusions In our cohort, low-dose AZA maintenance was generally well tolerated. The results of this study indicate that AZA maintenance is feasible and associated with improved EFS and OS. In addition, AZA has the potential of improving relapse rates even in pts who are unable to receive myeloablative conditioning as a significant number of pts in AZA group in this study received RIC. The optimal timing, duration of treatment and selection of pts most suitable for AZA for maximum benefit, however, requires further studies.