Long-term oral ibrutinib therapy corrects functional defects in CLL patient T cells and enhances CTL019 cell generation. (A) Kinetics of CD3/CD28 bead–activated T-cell enrichment/expansion using static culture conditions in healthy donors (n = 5), MM patients (n = 5), and CLL patients at baseline, after cycle 1, and after 5 to 11 cycles of ibrutinib therapy (n = 10). (B) Frequency of IFN-γ-expressing CD8⁺ and CD4⁺ T cells shown in unstimulated, CD3/CD28⁻, and phorbol myristate acetate/ionomycin (PMA/Iono.)-stimulated ex vivo samples from CLL patients (n = 6) before and during ibrutinib therapy. (C) Efficiency of anti-CD19 CAR gene transfer into CLL patient T cells at baseline, after cycle 1, and after 5 to 11 cycles of ibrutinib treatment, expressed as the fold change in expression (geometric MFI) over matched untransduced samples (n = 6). (D) Maximum expansion of CTL019 cells generated from a longitudinal series of CLL patient T-cell samples at baseline, or after short-term and prolonged oral ibrutinib treatment (n = 10). Horizontal bars, boxes, and whiskers depict median, 25%/75% quartiles, and range, respectively. *P < .05, **P < .01; error bars represent the mean ± standard error as determined by a 2-tailed Student t test. MFI, mean fluorescence intensity; n.s., not statistically significant.