Figure 6.

In vivo effect of mAb 8B6 + topotecan on tumor growth and event-free survival in IMR5 xenograft model. NSG mice bearing (A) human neuroblastoma IMR5 xenograft were treated with vehicle (PBS, i.p.), topotecan alone (0.36 mg/kg i.p.), control IgG alone (150 µg, i.v.), mAb 8B6 alone (i.p.), or topotecan + mAb 8B6, as indicated. Administration of mAb 8B6 or control antibody treatment started on day 7 after IMR5 cells inoculation and was repeated once on day 11. Topotecan or PBS treatment were started on day 7 and given 5 consecutive days. Tumor growth was monitored and tumor volumes were calculated. Mean tumor volume ± SEM of each treatment group (PBS group, 9 mice; all other groups, 10 mice) are depicted (* p < 0.05 for mAb 8B6 against mAb 8B6 + topotecan, ** p < 0.01 for topotecan against mAb 8B6 + topotecan), as indicated. (B) Event Free Survival Kaplan-Meyer curves were analyzed by log-rank Mantel-Cox test, where p < 0.5 was considered significant. The p values reported refer to the combination treatment compared to vehicle / control antibody / topotecan / mAb 8B6. * p < 0.05, ** p < 0.01, *** p < 0.001. (C) Mean weight for each treatment group, as indicated. Mean weight of mice on day 0 was defined as 100% weight. Weight in each group remained stable for the period of treatment. Data are presented as the mean ± SEM.