5-azacytidine treatment results in myelodysplastic syndrome

Abstract

e18003 Background: Myelodysplastic syndrome (MDS) is a clonal disease of hematopoiesis characterized by dysplasia in one or more series. 5-azacytidine (5-AZA) which is one of the methyl transferase inhibitors, targets the epigenetic changes in MDS and has been used for the last few years. Phase III studies which compare 5-AZA with supportive therapies report response rates up to 60%. Methods: In this study the aim was to retrospectively analyze the response rates of 26 MDS patients who were treated with 5-AZA between years 2002–2008. The patients were; median age 58 (21–84); male/female = 16/10; RAEB-I (7 patients); RAEB-II (18 patients); ve CMML (1 patient); secondary MDS (2 patients). According to an international prognostic scoring system, 6 patients were intermediate-1; 9 patients were intermediate-2; and 11 patients were high risk. Nine patients received 5-AZA as first-line therapy. The median leukocyte counts, absolute neutrophil counts (ANC), hemoglobin values, and thrombocyte counts at the begining of the cycles were; 2.4 (0.5–23)x10e9/L, 0.7 (0.1–16.5)x10e9/L, 8.6(5.3–11.4) gr/dl, 41(4–35)x10e9/L, respectively. The karyotype analysis revealed del5q in 3 patients; -7/del7q in 6 patients; trisomy 8 in 7 patients, del20q, del11q and complex karyotype (del7q+del5q+delY) in 1 patient each. The median cycles completed were 2 (1–6). Results: Seven patient were not elligible for response evaluation. Nine patients (47%) did not respond to the therapy and 8 of them were lost. Ten patients (53%) responded to the therapy with complete remission (n=4), partial remission (n = 2) and hematological improvement (n = 4). The responders and non-responders were similar in terms of median age, sex and pretreatment leukocyte, ANC and hemoglobin levels. However, there was statistically significant difference in terms of initial thrombocyte counts, total number of cycles received and serum ferritin levels. The patients who received 5-AZA as first line therapy had beter response than others (71% versus 29%). Conclusions: The observed response to 5-AZA therapy was similar to the reported rates in the literature. The most important factors for response were initial thrombocyte counts, total number of cycles, other therapies received before 5-AZA and the serum ferritin levels. No significant financial relationships to disclose.