Impact of lymphodepletion and alemtuzumab on UCART19 cellular kinetics. A, Total lymphocytes before and after (at the day of UCART19 infusion) lymphodepletion. B, Relationship between alemtuzumab total exposure and UCART19 expansion status. C, Positive correlation between alemtuzumab and UCART19 exposure. D, Correlation between UCART19 and IL7 Cmax. E, Relationship between IL7 Cmax and alemtuzumab doses. F, Relationship between IL7 Cmax and UCART19 expansion status. Statistical comparison was performed using a Wilcoxon test for B, E, and F and a Spearman correlation for D.