Figure 7

²¹³Bi-labeled IIIA4 and control antibody treatments. (a) ²¹³Bi-IIIA4 biodistribution in LK63 xenografts at 5 min, 1, 2 and 3 h after treatment. (b) Distribution of ²¹³Bi-isotype controls in LK63 xenograft at 1 h after treatment (n=4). (c) No differences in single-dose ²¹³Bi-IIIA4-treated (12.5 and 25 μCi) groups and the control groups (saline, 180 mg IIIA4, ²¹³Bi-isotype control 12.5 and 25 μCi). (d) Multidose ²¹³Bi-IIIA4 radioimmunotherapy. Increase in survival of IIIA4 and ²¹³Bi-isotype control (P=0.001) compared with saline control. Significant increase in survival of 12.5 μCi ²¹³Bi-IIIA4 (P=0.01) and 25 μCi ²¹³Bi-IIIA4 (P<0.0001) observed compared with the IIIA4 control group. Significant increase in survival observed for 12.5 μCi ²¹³Bi-IIIA4 compared to 12.5 μCi ²¹³Bi-isotype (P=0.0011). Survival of the 25 μCi ²¹³Bi-IIIA4 treated compared to 25 μCi ²¹³Bi-isotype cohort was significantly improved (P=0.0001) (n=8). The results of radiolabeled antibody biodistribution over time calculated as percentage of injected dose per gram of blood or tissue (% ID/g) and expressed as mean±s.d. for each time point.