Fig. 5: Cilta-cel, but not ide-cel, CAR T show a lack of a short-term correlation between TIM3 expression and proliferation with an upregulation of negative regulatory markers on long-term persisting cells.

To explore potential mechanisms underlying long-term persistence of cilta-cel CAR-T we determined levels of negative regulatory markers LAG3, TIM3, and PD1 on the CAR-T in both patient groups right after infusion into the patient and up to 360 days post-infusion. The highest levels of the negative regulatory markers for both (A) cilta-cel (blue) and (B) ide-cel (red) were observed on CD4⁺ and CD8⁺ CAR-T right after infusion followed by a decrease over the next few weeks. C Long-term persisting cilta-cel CAR-T showed a second “late” increase in all three negative regulatory markers, often referred to as exhaustion markers, at around one year after CAR-T infusion. Figures show mean fluorescence intensity (MFI) of the given marker on the given CAR-T subtype as measured by flow cytometry over time. The black lines indicate median values and statistical differences between groups were calculated using a two-sided Mann-Whitney U test. D Only in the ide-cel group (red), but not in the cilta-cel group (blue), the “early” peak in expression of negative regulatory marker TIM3 predicted a reduced CAR-T in vivo proliferation a few days later. E There was an even stronger effect when all three markers were combined. For correlative analyses a Pearson correlation coefficient was calculated. The black line shows the results of a linear regression analysis. Source data are provided as a Source Data file.