CART33 treatment results in leukemia eradication and long-term disease-free survival in primary AML engrafted xenografts. (a) Experiment schema: NSG mice transgenic for the human cytokines stem cell factor, interleukin-3, granulocyte macrophages colony-stimulating factor (NSG-S mice) were injected with a primary AML sample (5 × 106 intravenously (IV)). Engraftment was confirmed by retro-orbital bleeding after 2–4 weeks, and then mice were treated with CART33, CART123 or control vehicle (UTD cells). Total number of T cells injected was 1 ×105 IV. CART33 and CART123 cells had comparable transduction efficacy. The mice were followed with serial retro-orbital bleedings to assess the burden of leukemia. (b) Analysis of peripheral blood from mice treated with UTD, CART33 or CART123 at baseline, day 14 and day 70 after T cells injection. AML was not detected in mice treated with CART33 or CART123 starting 4 weeks after T-cell treatment. (c) Summary of disease burden measured by blasts/ul from retro-orbital bleedings at different time points as indicated. (d) Survival of mice treated with CART33, CART123 or UTD (n=8 per group) (P < 0.001 when treatment with CART33 or CART123 is compared with UTD).