Figure 6. IL-2^WTFc treatment synergizes with targeted antibody therapy and is highly efficacious against murine colorectal carcinoma.

(a) The antitumour activity of IL-2/mAb, IL-2^WTFc and IL-2^3XFc in combination with the anti-TRP-1 tumour-targeting monoclonal antibody was assessed in the B16F10 melanoma tumour model. C57BL/6 mice were injected subcutaneously (s.c.) in their left flanks with 1 × 10⁵ B16F10 cells on day 0 (n=6). Combination therapy consisted of three doses of anti-TRP-1 (200 μg per dose given i.p. on days 3, 6 and 9) plus low-dose IL-2/mAb (0.5 μg IL-2+2.5 μg mAb per dose) or molar IL-2-Fc equivalent (2.8 μg per dose) given i.p. on days 4, 7 and 10. Following treatment, mice were monitored for tumour growth (left), body weight (bottom right) and survival (top right). (b) The antitumour activity of IL-2/mAb, IL-2^WTFc, IL-2^3XFc and IL-2^WTFc^nil was assessed in the CT26 murine colorectal carcinoma tumour model. Balb/c mice were injected s.c. in their left flanks with 1 × 10⁵ CT26 cells on day 0 (n=5), followed by treatment with a total of nine doses of IL-2/mAb (1 μg IL-2+5 μg mAb per dose), IL-2-Fc molar equivalent (5.6 μg per dose) or PBS control given i.p. on days 1–5 and days 13, 15, 17 and 19. Mean tumour size (left) and tumour growth in individual mice in the PBS and IL-2^WTFc groups (right) are shown. Data are displayed as mean±s.e.m. Asterisks indicate significant differences between specified groups (*P<0.05, ****P<0.0001) as determined by two-way analysis of variance with Bonferroni post hoc test for multiple comparisons. Survival (a, top right) is displayed using Kaplan–Meier plots and compared by the Gehan–Breslow–Wilcoxon test.