Early CAR T-cell expansion correlated with ongoing response. (A) Peak CAR T-cell levels and (B) AUC between days 0 and 28 among patients who received treatment who had evaluable samples who had an ongoing response after axi-cel infusion, along with those who relapsed after responding and those who did not respond to axi-cel. Ongoing response was defined as responders (CR or PR) who did not have PD or die by the data cutoff date. Four patients did not have evaluable postinfusion samples to allow for determination for CAR T-cell peak or AUC. The median is represented by the horizontal line within each box, and the 25th and the 75th percentiles are represented by the lower and upper borders, resepctively, of each box. AUC, area under the curve; PD, progressive disease, PR, partial response.