GÉTICA 2021

59 [ F I T C á n c e r - 7 ] Figure 5. STAb-T19 cells, but no CAR-T19, prevent relapse in a PDX murine model. NSG mice were transplanted with 1 × 106 human primary CD19+ CD22+ CD10+ B-ALL blasts followed 3 weeks later by infusion of 3 × 106 NT-T (n = 4), CAR-T19 (5 × 105 19-BBζ+) (n = 5) or STAb-T19 (5 × 105 19-BiTE+) (n = 5) cells. Leukemia progression was followed up by weekly PB analysis, BM samples were obtained on day 28 after T cell infusion. Spleen and BM were collected after sacrifice. (a) Timeline of experimental design. (b) Percentage of B-ALL cells (CD19+) in PB over time; each line represents an independent mouse. (c,d) Percentage of human B-ALL cells in spleens (c) and BM (d) of NT-T, CAR-T19 and STAb-T19 treated mice at the indicated time points after T cell infusion; data are shown as mean ± SD; each dot represents an independent mouse. Significance was calcu- lated by an unpaired Student t test. (e) Relative mRNA expression of CD19 in bone marrow at sacrifice. (f) Human T cell (CD3+) persistence over time in PB of each individual mouse. (g,h) Percentage of human T cells (CD3+) in spleen (g) and BM (h) at the indicated time points; data are shown as mean ± SD; each dot represents an independent mouse. Significance was calculated by an unpaired Student t test. (i) Disease-free survival curve according to the percentage of CD19+ B-ALL cells in PB.