Outcome after azacitidine treatment in patients with high-risk myelodysplastic syndrome and acute myeloid leukemia in the Clinic of Hematology at St. Marina University Hospital, Varna

Introduction: Hypomethylating agents have become a standard therapy for high-risk myelodysplastic syndromes (MDS) and elderly patients with acute myeloid leukemia (AML). Aim: The aim of the study was to assess the efficacy of azacitidine treatment in patients with MDS and AML followed for 18 months. Materials and Methods: Twenty-seven patients with MDS and AML treated in the Clinic of Hematology at St. Marina University Hospital, Varna were included in the study. Azacitidine was administered subcutaneously in at a dose of 75 mg/m 2 for 7 days. Disease assessment was performed on  the 3 rd month, 6 th month, and at progression. Results: Twenty-seven patients were analyzed. Their median age was 71.5 years. Nine had refractory anemia with excess of blasts II (RAEB II), 5 had chronic myelomonocytic leukemia II (CMML II), 1 was with unclassifiable MDS (MDS-U), and 12 with AML. The median number of administered cycles was 6 (1-19). Eleven patients completed 6 cycles of azacitidine. Partial response was achieved in 9 patients (33%) (7 MDS and 2 AML), stable disease in 8 (29%) (5 MDS and 3 AML). Progressive disease was observed in 10 patients (37%). The response correlated with the type of the disease (p=0.03), cytogenetic risk (p=0.01), and survival (p=0.000). At 18 months, 60% of MDS patients were alive compared to 41.7% in the AML group. The median time to death in the AML patient group was 2.5 months. The mean overall survival was 10.4 months (12.6 months for MDS patients and 5.4 months for AML patients). Conclusion: The therapy with azacitidine is an option for elderly patients with high-risk MDS.  In patients with AML a rapid progression is observed during the first two cycles with mortality rate of 58.3%.