PDL192 and 19.2.1 inhibit the growth of xenograft tumors. PDL192 and 19.2.1 inhibit the growth of xenograft tumors. A and C, mice bearing established A253 (A) or MiaPaCa2 (C) tumors were treated with PDL192 or a human IgG1 control antibody (huIgG) thrice per week at 10 mg/kg. Dosing groups contained eight animals each. B, mice bearing established A253 tumors were treated with 19.2.1 at 5 mg/kg or a mouse IgG2a control antibody (muIgG) at 10 mg/kg thrice per week. Dosing groups contained 5 animals for each of the two 19.2.1 treatment groups and 10 animals for the mouse IgG2a control antibody control group. Tumor volumes were measured on each dosing day; points, mean; bars, SEM. D, mice bearing established A375 tumors were treated every 3 d with PDL192 at various dose levels or a human IgG1 control antibody at 5 mg/kg. Dosing groups contained 20 animals each. Differences in tumor volumes were significant (P ≤ 0.05) between the control antibody and all dose levels of PDL192 on days 28 to 46. Differences in tumor volumes between the 1 and 5 mg/kg dose levels were not statistically significant, nor were the tumors in the 0.1, 0.3, and 0.6 mg/kg dose groups significantly different from each other (P > 0.05). Patricia A. Culp et al. Clin Cancer Res 2010;16:497-508 ©2010 by American Association for Cancer Research