Figure 4.

Local intratumoral delivery of HER2-CAR T cells eradicates xenograft models of breast cancer brain metastasis. A, Illustration of a mouse brain orthotopically engrafted with BBM1-eGFP/ffluc cells and treated by intratumoral (intracranial, i.c.) delivery of CAR T cells. B, BBM1 tumor-bearing mice (0.2 × 10⁶ cells) were treated 8 days after tumor injection with Mock, HER2–28ζ, or HER2-BBζ CAR T cells (0.5 × 10⁶ cells). The “Tumor only” group was either left untreated or treated with PBS. Representative flux images of BBM1-tumor–bearing mice at indicated time points after T-cell treatment. Bold “X” indicates removal of mice from study because of morbidity (see Materials and Methods). C, Quantification of flux signal from individual mice in each group at indicated time points after tumor injection. D, Kaplan–Meier survival for Mock, HER2–28ζ, or HER2-BBζ CAR T cells, and a “Tumor only” group. N > 4 mice per group. Data are representative of at least two independent experiments. *, P < 0.05.