The Role of Hypomethylating Agents Prior to Allogeneic Hematopoietic Stem Cells Transplantation in Acute Myeloid Leukemia and Myelodysplastic Syndrome

Abstract

Background & Aims. The aim of the study was to evaluate the efficacy and safety of azacytidine and decitabine prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia and juvenile myelomonocytic leukemia. Materials & Methods. The research included 62 patients who received hypomethylating agents (HMA) prior to allo-HSCT. The median age was 28 years (range from 1 to 68 years), the study population consisted of 27 (43.5 %) women and 35 (56.5 %) men. Results. The overall response (complete + partial remission) was observed in 42 % (n = 26) of cases. At the time of allo-HSCT no disease progression was observed in 41 (66 %) patients. The multivariant analysis showed the overall survival (OS) statistically significantly increased with the graft retention (hazard ratio [HR] 0.002; 95% confidence interval [95% CI] 0.001-0.74; p = 0.03), and also with the administration of HMA after allo-HSCT (HR 0.24; 95% CI 0.08-0.67; p = 0.007). The response (stabilisation, partial or complete remission) due to HMA administration prior to allo-HSCT (HR 6.4; 95% CI 0.75-54.0; p = 0.08) was associated with improved OS. The event-free survival (EFS) was significantly higher with the response to azacytidine and decitabine at the time of allo-HSCT (HR 38.9; 95% CI 1.3-1198.0; p = 0.03) and with the graft retention (HR 0.02; 95% CI 0.005-0.1; p = 0.001). In patients with MDS compared with AML (HR 2.3; 95% CI 0.9-22.0; p = 0.08), there was a tendency to EFS improvement. Progression-free survival rates were higher in patients with a number of blast cells in the bone marrow less than 31 % at the time of diagnosis (HR 1.1; 95% CI 1.1-9.9; p = 0.01). Conclusion. The use of azacytidine and decitabine prior to allo-HSCT allows to safely control the tumor mass in patients with MDS and to maintain the achieved remission with AML. In patients with a response to HMA, the best OS and EFS values are seen after allo-HSCT.