EI did not impact engraftment, expansion, or persistence of CAR T cells. All subjects were analyzed for engraftment and expansion of CAR T cells over time in the peripheral blood using flow cytometry. For analysis, all subjects were compared based on the occurrence of sCRS, on the intervention cohort assignment (DLT vs EI), and on the treatment received, regardless of the intervention cohort assignment. (A) The peak number of CAR T cells in the blood was higher in subjects who developed sCRS compared with those who did not. (B) The peak number of CAR T cells was not different between the intervention cohorts. (C) The peak number of CAR T cells was different among the 3 groups based on the immunomodulatory treatment received. (D) The area under the curve of CAR T-cell engraftment was higher in the group of subjects that experienced sCRS (red) vs no sCRS (blue). (E) The area under the curve of CAR T-cell engraftment was similar in the 2 intervention cohorts (red, DLT cohort; blue, EI cohort). (F) The area under the curve of CAR T-cell engraftment was enhanced in the groups that recieved immunomodulatory interventions (red, no intervention; blue, tocilizumab; green, steroids with or without tocilizumab). (G) The probability of having ongoing functional persistence of CAR T cells, as measured by BCA, is demonstrated by Kaplan-Meier curves. There was no difference between patients who developed sCRS (red) and those who did not (blue). There was no difference between the DLT (red) and EI cohorts (blue) (H) or among the immunomodulatory interventions received (red, no intervention; blue, tocilizumab; and green, steroids with or without tocilizumab) (I). NS, not significant; toci, tocilizumab.