Most patients with lower risk myelodysplastic syndromes (LR-MDS) become red blood cell (RBC) transfusion dependent at some time during their disease course. Hypomethylating agents (HMAs) are frequently used in this setting; however, reported rates of in RBC transfusion independence (TI) achieved with HMA therapy vary significantly between studies. Here we study the real-life clinical effectiveness of HMA in inducing RBC TI in anemic LR-MDS patients using the Surveillance, Epidemiology and End Results (SEER)-Medicare database. We find that approximately 40% of LR-MDS patients who were receiving RBC transfusions and 33% who were dependent on RBC transfusions at HMA initiation ultimately achieved TI. The receipt of ≥3 transfusions in the 8-week period before HMA initiation was significantly associated with lower odds of achieving TI. Our study provides important population level estimates of clinical effectiveness of HMAs in LR-MDS.
