Prognostic score for overall survival. The score was computed (for each patient) based on the presence of PS ≥ 2 (1 point), presence of circulating blasts (1 point), RBC TD ≥ 4 RBC units/8 weeks (1 point), and intermediate- and high-risk cytogenetics (1 and 2 points, respectively). Kaplan-Meier curves of OS for low (score = 0), intermediate (score = 1-3), and high (score = 4-5) risk patients in the development (ATU) and validation (AZA-001) cohorts