Fig. 2.

Δ133-CAR T cells exhibit superior tumor clearance in a B cell leukemia xenograft mouse model. (A) NSG mice were injected intravenously with 1 × 10⁶ Nalm6 leukemia cells transduced with GFP-P2A-CBG on day 0. Mice were imaged on day 6 and randomized into three groups, including both treatment groups and an untransduced T cell control. Either 1 × 10⁶ freshly thawed CAR+ T cells or a matched total number of untransduced T cells were injected intravenously on day 7. (B) Tumor progression for mice administered CARs from three healthy donors was monitored using bioluminescent imaging. Data are mean ± SEM of n = 8 to 11 mice depending on the donor. In each graph, data are reported up to the timepoint when the first mouse was lost in the WT or Δ133-CAR group. Statistical significance was determined via two-way ANOVA and is based on the CAR treatment X time interaction term. (C) Time course of tumor progression in individual mice across three experiments shown in B. Statistical significance was determined via two-way ANOVA and is based on the CAR treatment X time interaction term. (D) T cell engraftment on day 12 after injection. Statistical significance was calculated using an unpaired t test. Data not shown for ND451 and ND512 due to sample mishandling preventing measurement at day 12. (E) Kaplan–Meier curves of mice pooled from all experiments showing survival of each group over time. Data were analyzed using a log rank Mantel–Cox test. (F) CD19-directed CAR expression vector with CD28 co-stimulatory domain used in G–I. (G) Tumor progression for mice administered hCD19.28z CARs. Data represent tumor progression for each individual mouse. Statistical significance was determined via two-way ANOVA and is based on the CAR treatment X time interaction term. (H) T cell engraftment at initial bleed measurement. Statistical significance was calculated using an unpaired t test. (I) Kaplan–Meier curves showing survival of each group of mice over time. Data were analyzed using a log rank Mantel–Cox test. ns = not significant, *P $\le$ 0.05, **P $\le$ 0.01, ***P $\le$ 0.001, ****P $\le$ 0.0001.