Fig. 4
h1218-CART19 demonstrates enhanced efficacy than FMC63-CART19. A Schematic of h1218-CART19 targeting the membrane-proximal domain of CD19 in B cell lymphoma/leukemia as compared to standard FMC63-CART19. B Nalm6 tumor killing by UTD, h1218-CART19, or FMC63-CART19 cells at various E:T ratios (n = 3 donors) by flow cytometry. C IFNγ release as measured by ELISA upon stimulation of CD19-expressing tumor cells (Raji, Pfeiffer, Toledo, and Nalm6) at an E:T ratio of 3:1 (n = 2 donors). D (Left) Schematic of the in vivo experiment: either 1.5 × 106 UTD or CART19 cells were infused 7 days after intravenous injection of luciferase + Raji or lNalm6 cells. Tumor progression in mice bearing Raji (middle) or Nalm6 (right) cells is shown. E Quantification of Nalm6 fold change over 14 days in the presence of UTD, FMC63-CART19, or h1218-CART19 at low-E:T ratio model (n = 2 donors) using flow cytometry. F (Left) Schematic of the in vivo xenograft model: 0.75 × 106 UTD or CAR T cells were infused intravenously 5 days after luciferase+ Nalm6 engraftment. (Middle) Tumor progression over time in mice bearing Nalm6 cells treated with UTD (n = 3), FMC63-CART19 (n = 7), or h1218-CART19 (n = 7) measured by luminescence. Bolded lines represent the median tumor burden in the corresponding group. (Right) Tumor burden on day 42 after CART19 injection. G Overall survival in mice bearing Nalm6. H (Left) CAR T cell expansion kinetics in the peripheral blood after CART19 injection. Bolded lines represent the median CAR T expansion. (Right) Quantification of CAR T cells in the blood 14 days after CART19 injection using flow cytometry. All bar graphs and cytotoxicity curves are presented as the mean ± SEM. Student's t-test was used to compare two groups; one-way ANOVA was performed with Tukey’s correction for multiple comparisons; survival curves were compared using the log-rank (Mantel-Cox) test; **** p < 0.0001, *** p < 0.001, ** p < 0.01, and * p < 0.05. All bar graphs are presented as the mean ± SEM. All experiments were repeated at least twice