Kaplan-Meier survival curves for overall survival according to MRD status. (A) Status at the start of maintenance therapy. The overall survival at 4 years after the start of maintenance therapy was 94% among MRD⁻ patients, and 79% among MRD⁺ patients (adjusted hazard ratio for death, 0.24; 95% confidence interval, 0.11-0.54). (B) After 12 months of maintenance therapy. The overall survival at 3 years after the completion of maintenance therapy was 96% among MRD⁻ patients, and 86% among MRD⁺ patients (adjusted hazard ratio for death, 0.26; 95% confidence interval, 0.10-0.68). (C) Modified by the Simon-Makuch method. The number of patients at risk in the MRD⁻ group was 0 at the beginning of follow-up, because of the time-dependent nature of MRD. Prior to the start of maintenance therapy, all patients were included in the MRD⁺ group; patients who were found to be MRD⁻ on assessment during maintenance were switched to the MRD⁻ group. MRD was a strong prognostic factor for overall survival (adjusted hazard ratio, 0.16; 95% confidence interval, 0.08-0.32).