FIGURE 5.

Affinity-maturated hu3F8 IgG1 exhibits potent in vivo anti-tumor activity toward neuroblastoma xenografts. Xenografts were established by implanting IMR-32 neuroblastoma cells mixed with human PBMC subcutaneously into immunodeficient mice. Antibodies were administered intravenously twice weekly for a total of four doses. Tumor volumes were measured weekly and shown as the mean ± S.E. (error bars). A, five mice per group were treated with isotype-matched control antibody, 4 × 50 μg of parental hu3F8, 4 × 10 μg of D32H antibody, or 4 × 50 μg of D32H antibody. One mouse died unexpectedly in the 4 × 50 μg of D32H group with no measurable tumor. B, five mice per group were given no treatment, 4 × 50 μg of parental hu3F8, 4 × 50 μg of D32H, or 4 × 50 μg E1K/D32H. All mice survived in the D32H and E1K/D32H antibody groups. Four of five mice in the hu3F8 group survived. No mice survived in the non-treatment group at the end of the experiment.