Fig. 2.

Pairs of epitope-distinct antibodies to HER2, more than the respective single mAbs, inhibit tumorigenic growth of human pancreatic cancer cells in animals. (A) Human BXPC3 pancreatic cancer cells (5 × 10⁶) were injected into the flank of female athymic mice, and later randomized into groups of 7–8, as described in the legend to Fig. 1. Mice were weekly injected, three times, into the peritoneum with the indicated anti-HER2 mAbs (160 µg per mouse per injection, total: 480 µg per mouse), or their combination (80 µg of each mAb per mouse per injection; total: 480 μg per mouse). Tumor volumes were monitored and the averages (±SEM) are presented, along with the P value of the comparison between single mAbs and their combination. The arrow marks the last injection. (B) Mice were treated as in A, except that seven injections of single antibodies (160 µg per mouse per injection, total: 1,120 µg per mouse ) or the combination (80 µg of each mAb per mouse per injection: total: 1,120 µg per mouse) were performed.