Outcomes and effect of somatic mutations after erythropoiesis stimulating agents in patients with lower-risk myelodysplastic syndromes.

BACKGROUND: Erythropoiesis stimulating agents (ESAs) are the first-line therapy in patients with lower-risk myelodysplastic syndromes (LR-MDS). Some predictive factors for ESAs response have been identified. Type and number of somatic mutations have been associated with prognosis and response to therapies in MDS patients.

OBJECTIVES: The objective was to evaluate the outcomes after ESAs in patients with LR-MDS and to address the potential predictive value of somatic mutations in ESAs-treated patients.

DESIGN: Multi-center retrospective study of a cohort of 722 patients with LR-MDS included in the SPRESAS (Spanish Registry of Erythropoietic Stimulating Agents Study) study. Retrospective analysis of 65 patients with next generation sequencing (NGS) data from diagnosis.

METHODS: ESAs' efficacy and safety were evaluated in patients receiving ESAs and best supportive care (BSC). To assess the potential prognostic value of somatic mutations in erythroid response (ER) rate and outcome, NGS was performed in responders and non-responders.

RESULTS: ER rate for ESAs-treated patients was 65%. Serum erythropoietin (EPO) level <200 U/l was the only variable significantly associated with a higher ER rate (odds ratio, 2.45; p  = 0.036). Median overall survival (OS) in patients treated with ESAs was 6.7 versus 3.1 years in patients receiving BSC ( p  < 0.001). From 65 patients with NGS data, 57 (87.7%) have at least one mutation. We observed a trend to a higher frequency of ER among patients with a lower number of mutated genes (40.4% in <3 mutated genes versus 22.2% in ⩾3; p  = 0.170). The presence of ⩾3 mutated genes was also significantly associated with worse OS (hazard ratio, 2.8; p  = 0.015), even in responders. A higher cumulative incidence of acute myeloid leukemia progression at 5 years was also observed in patients with ⩾3 mutated genes versus <3 (33.3% and 10.7%, respectively; p  < 0.001).

CONCLUSION: This large study confirms the beneficial effect of ESAs and the adverse effect of somatic mutations in patients with LR-MDS.