EFS of subjects with HR ALL treated on AALL0232 as a function of MRD levels at end of induction. (A) Five-year EFS for patients with <0.01% MRD was 87% ± 1%, 74% ± 4% for those between 0.01% and 0.1%, 63% ± 4% for those between 0.1% and 1%, 44% ± 9% for those between 1% and 10%, and 26% ± 9% for those >10%. The early outcome for subjects with 0.1% to 1% MRD is superior to that of subjects with lower levels of MRD, likely reflecting the effect of intensified therapy, though the curves cross at ∼3 years (dotted line), and the overall outcome of this group is inferior to those with less MRD. (B) OS of subjects whose EFS was shown in panel A. The curves for OS in the cohort of subjects with 0.1% to 1% MRD again crosses that of those with lower MRD levels, but the time of the cross is delayed by ∼1 year. (C) EFS of subjects with 0.1% to 1% MRD as a function of the location of their MRD testing. The unusual shape of this curve is identical in the 2 sites.