A comparison of overall survival and quality of life in patients with MDS treated with azacytidine vs decitabine.

Patients with high-risk myelodysplastic neoplasms or syndromes (MDS) are considered for therapy with hypomethylating agents (HMA) to help restore hematopoiesis, delay progression to acute myeloid leukemia, and improve overall survival (OS). Azacytidine (AZA) and decitabine (DEC) have commonly been used without direct clinical trial comparison between the 2 agents. Prior studies have demonstrated no difference in OS; however, these analyses are limited by the lack of patient-level and disease-risk factors that may influence efficacy and tolerability. This study retrospectively evaluated differences in clinical outcomes for patients treated with AZA or DEC, adjusting for disease-risk category and patient-specific factors, using data from the Canadian MDS registry (NCT02537990). The primary outcome for the study was OS, which was compared using the log-rank test, evaluated for the whole cohort, and then stratified by the Revised International Prognostic Scoring System (IPSS-R) disease-risk. Secondary outcomes included leukemia-free survival (LFS), change in transfusion dependence or independence status, and differences in quality-of-life (QoL) measurements. In total, 424 patients were treated with AZA (median of 10 cycles) and 85 patients were treated with DEC (median of 5 cycles). In unadjusted analysis, median OS was longer in the patients treated with DEC (37.0 vs 21.4 months; P = .001), which remained significant for patients with high-risk defined by an IPSS-R score >3.5 (34.4 vs 19.6 months; P = .01). However, in a propensity score-matched analysis, there was no difference in OS or LFS between HMA therapies. There was no significant difference in global, physical, or social QoL scores between patients treated with either HMA.