OS according to plasma level of lestaurtinib. At the aplasia assessment, 15 of 79 patients from whom lestaurtinib levels were measured had levels in excess of 20μM. Shown are Kaplan-Meier estimates of OS from the time of randomization for these 15 patients (dashed line) compared with the other 64 patients on the lestaurtinib arm (dotted line) and the control arm patients (solid line). The median survival for those patients with lestaurtinib levels more than 20μM is significantly different from both the other lestaurtinib patients (P = .002) and the control patients (P = .01).