The bsAb BiLu reveals high antitumor activity in vivo in 2 different syngeneic tumor models.
(A) C57BL/6 mice (n = 6) received 5 × 103B16-EpCAM cells intraperitoneally on day 0. BsAb treatment was started with 2.5 μg on day 2 and continued with 1 μg each on days 4 and 7 (▪). The group that received parental antibodies (▿) (n = 6) was treated with a combination of the 2 monospecific antibodies C215 (antihuman EpCAM) and 17A2 (antimurine CD3). The control group (+) (n = 6) received no antibody. To clarify the antigen dependency of the treatment one group of mice (■) (n = 6) was challenged with 5 × 103 untransfected B16 cells and injected with bsAb as indicated above. Experiments were repeated 3 times with similar results. (B) BALB/c mice were challenged with 2 × 106A20-EpCAM cells intravenously followed by intraperitoneal injection of 4 μg bsAb (▪) (n = 12) or bsF(ab′)2 (♦) (n = 8) 3 hours later. Again, a control group with parental antibodies (▿) (n = 7) was included, and data were confirmed by another independent experiment.
