Figure 6.

Anti-tumor activity of ch128.1 and ch128.1Av in vitro and in disseminated xenograft mouse models of MM. (A) Thymidine incorporation assay: Cells were treated with various concentrations (ranging from 0.08 to 50 nM for MM ARH-77 cells and 50 to 500 nM for MM KMS-11 cells) of ch128.1/IgG3, ch128.1Av, or an isotype control fusion protein (IgG3-Av) for a total of 96 h. Proliferation was measured by adding ³H-thymidine in the last 16–18 h. Data are presented as a percent of radioactivity incorporated into control cells. The average of triplicate wells is shown and error bars indicate the standard deviation. These results are representative of three independent experiments. (B) In vivo efficacy in two disseminated models of MM. Kaplan–Meier plots indicating survival of SCID-Beige mice challenged i.v. with 5 × 10⁶ ARH-77 (left panel) or KMS-11 (right panel) cells. For experiments with ARH-77 cells 100 μg of each treatment was injected i.v. 2 days after tumor challenge, whereas 125 μg of each treatment was used for the KMS-11 studies. Survival plots are the combined data of two experiments. *p < 0.05, **p < 0.01, and ***p < 0.001 (log-rank test) compared to buffer or the corresponding isotype control, except for the comparison between the antibody fusion protein and the parental antibody. Survival was based on the time from tumor challenge to the development of hind-limb paralysis (HLP), when mice were euthanized. This figure was produced by combining the data from Figures 3, 4 in Daniels et al. (144) with permission from Wolters Kluwer Health, Inc.