In this prospective trial, the efficacy of azacitidine in lower-risk myelodysplastic syndromes (LR-SMD) lacking del(5q) was compared to best supportive care (BSC) at 1:1. The primary endpoint was the achievement of erythroid hematologic improvement (HI-E) after nine cycles. Thirty-six patients received at least ≥1 cycle. HI-E was confirmed 44.4% randomized to Aza and in 5.5% of patients receiving BSC (p < .01). After entry in Aza extension period, transfusion independence was achieved in all Aza responders with a median duration of 50 weeks (range: 17-231). No significant differences were observed in secondary endpoints. Importantly, variant allele frequency (VAF) of some mutated genes (RET, SF3B1, ASXL1) decreased after 9 months of treatment in Aza-responder patients. In conclusion, LR-MDS patients lacking del5q and resistant to ESAs, who receive 5 days Aza, achieve TI in a substantial proportion of cases and results in modifications in mutational landscape.
Keywords: Myelodysplastic syndrome; azacitidine; erythroid responses; mutational analysis.