Figure 2. Overall time to progression (to refractory anemia with excess blast cells in transformation or to acute myelogenous leukemia) for the 61 patients enrolled in the study.Top. Five-year probability of remaining progression free was 90% (95% CI, 80% to 100%). Dotted lines represent the upper and lower boundaries of confidence intervals. Bottom. Covariate-adjusted time to progression for responders and nonresponders. Response status was ascertained at 8 months after treatment with antithymocyte globulin.