Comparative Analysis for Effectiveness of Azacitidine Versus Decitabine in Acute Myeloid Leukemia and Myelodysplastic Syndromes in New Mexico: A Single Institution Experience

Introduction Prognosis of acute myeloid leukemia (AML) and high-risk myelodysplastic syndromes (MDS) is still very poor due to limited treatment options. Both azacitidine (AZA) and decitabine (DEC) have to been shown to have a significant overall survival benefit in MDS patients. In recent years, both drugs are increasingly used for relapsed refractory AML as well as de novo AML in elderly patients with multiple comorbidities. However, we do not have the results of prospective clinical trials comparing AZA directly to DEC in AML or MDS patients. The goal of this study is to evaluate the overall survival and response duration of the AML and MDS patients who received at least one cycle of AZA or DEC in University of New Mexico Comprehensive Cancer Center (UNMCC). Methods A retrospective chart review was performed to identify clinical characteristics, treatment duration and overall survival in AML and MDS patients. AML patients were risk stratified into favorable, intermediate and poor risk categories based on cytogenetics and molecular abnormalities. MDS patients were also risk stratified into low, intermediate and high-risk categories based on International Prognostic Scoring System. A majority of MDS patients in the study were in intermediate to high-risk categories. The primary patient outcome was overall survival (OS), calculated from the date of diagnosis until the date of death or lost to follow-up. Kaplan-Meier method was applied to compare OS between two groups, azacitidine-treated and decitabine-treated patients. Results In this study, 60 patients (82%) received AZA and 13 patients (18%) received DEC as a treatment for either AML or MDS. Median age at diagnosis for AZA group was 69 years old and DEC group was 62 years old. There were 34 females (57%) in AZA group, compared to 6 females (46%) in DEC group. There were 22 patients with therapy related AML in both groups. DEC group had a higher proportion of patients (8 out of 13, 62%) with relapsed refractory AML, compared to only 25 out of 60 (42%) patients in AZA group with the p value of 0.229. There were 35 De novo AML and MDS patients in AZA group and 5 in DEC group. Median duration of treatment was 3.2 months and median number of treatment cycles was 4 for both groups. There was no significant difference in median overall survival between two groups (AZA 18 months vs DEC 17 months, p=0.082). The median overall survival for relapsed refractory AML in both groups was also similar (AZA 16.6 months versus DEC 18.2 months, p=0.932). However, median overall survival was significantly longer for AZA group with MDS or de novo AML patients (AZA 25 months versus DEC 3 months, p=0.001). Conclusion A significant number of patients with MDS and AML received AZA than DEC in UNMCC and it is similar to the previously reported Surveillance, Epidemiology, and End Results-Medicare database analysis which showed a majority of patients (78%) received AZA. Although we have a limited number of patients in both groups, the median overall survival for de novo AML and MDS patients is significantly higher in AZA group than DEC group. We are awaiting results from the ongoing prospective randomized clinical trials comparing azacitidine versus decitabine in AML and MDS patients to confirm these findings. Disclosures No relevant conflicts of interest to declare.