Duv-CART cells had lower expression of immune checkpoint molecules and enhanced antileukemia activity against OSU-CLL cells. Control CART cells and Duv-CART cells from 8 patients with CLL were cultured as described in Figure 2. Number of CART cells (A) and transduction efficiency (B). (C) yields of CD8⁺CART cells and CD4/CD8 CART-cell ratios in duvelisib vs control cultures. (D) Absolute number of naive CD27⁺CD45RO⁻CD8⁺ CART cells. (E) Frequencies of CD8⁺ naive and CD4⁺ central memory CART-cell phenotypes. (F) Expression of TIM3, LAG3, and PD1 on CD4⁺ and CD8⁺ subsets of CART cells. (G) Cytotoxicity of control and Duv-CART cells (effectors) from 4 of the patient CLL samples against OSU-CLL cells (targets) at effector-to-target ratios of 0.5:1, 1:1, and 2:1. Duv-CART dells were tested before (with duvelisib) and after (washed) washing to remove residual duvelisib from the reaction mixture. (H) Data from panel G were analyzed to show CD8 effector-to-target ratios and percentage of specific cell lysis. (I) CD8⁺ control CART and Duv-CART cells were sorted (n = 4 donors) and added to target cells at defined ratios. *P < .05; **P ≤ .01; ***P ≤ .001; ****P ≤ .0001.