Early treatment initiation in lower-risk myelodysplastic syndromes produces an earlier and higher rate of transfusion independence

•How does active therapy (AT) timing impact transfusion dependence (TD) in MDS?•Early AT initiation was associated with more transfusion independence (TI).•Fewer early initiators used erythropoietin-stimulating agents before gaining RBC-TI.•RBC-TI was more frequent in patients who met minimum therapy exposure.•Higher rates of RBC-TI were associated with less time between TD and AT initiation.

Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis resulting in refractory cytopenias. Red blood cell (RBC) transfusions can improve anemia; however, prolonged transfusion dependence (TD) is associated with increased morbidity and mortality. Disease-modifying therapy (DMT) for MDS can reduce transfusion requirements, although the optimum timing of DMT initiation is unclear. This retrospective study analyzed linked SEER registry and Medicare claims (2006-2012) to estimate the impact of DMT-initiation (azacitidine, decitabine, or lenalidomide) timing (≤ 3 vs. > 3 months from start of TD) on the likelihood of achieving transfusion independence (TI) among 508 TD patients with MDS. Mean time to DMT was 28 days for early initiators (n = 351) and 187 days for late initiators (n = 157). Fewer early initiators used erythropoiesis-stimulating agents before achieving TI versus late initiators (61.5% vs. 73.9%; P = 0.007). In multivariate analyses, early DMT initiation predicted TI achievement (HR, 1.69; P < 0.001); patients who met minimum active therapy-exposure requirements were more likely to achieve TI (HR, 2.12; P < 0.001). Higher rates of TI were associated with reduced time between onset of TD and DMT initiation. Similarly, patients meeting the minimum treatment-exposure threshold had higher TI rates.