Pharmacokinetics and anti-tumor activity in tumor-bearing mice. a) Pharmacokinetic profile of molecules was analyzed in female CD1 mice (n = 3). Mice received a single i.v. injection of 25 µg of the protein. Serum protein concentrations were determined by ELISA using HER2-His and/or HER3-His. Mean ± 95% CI. b) NCI-N87 cells (5x106 cells per dorsal side in combination with 50% matrigel) were inoculated subcutaneously into the left- and right-hand dorsal side of SCID-beige mice. After tumors reached a mean tumor volume of 100 mm3 mice were treated intravenously with antibodies (trastuzumab, IgG 3–43, combination of both, or Dab-Fc(Δab) 2 × 3) six times (dashed line) in total. Tumor volume was calculated and plotted against the time. Mean ± 95% CI, n = 10 (PBS, trastuzumab, IgG 3–43) or 12 (combination, Dab-Fc(Δab) 2 × 3)), statistics: one-way ANOVA. *p < .05, **p < .01, ***p < .001, ****p < .0001