Fig. 7. C26-A6 treatment synergizes with anti-PD-1 therapy for metastatic breast cancer.

a,b, FVB-PyMT females with primary tumors established were divided into 4 groups and treated with vehicle, anti-PD-1, and C26-A6 alone or in combination. Six weeks after treatment, primary tumor (a) and lung metastatic (b) burdens were quantified. Anti-PD-1, 200 μg/mouse i.p. injection, twice per week for the first week and then once per week after that; C26-A6, 15 mg/kg i.v. injection, 5 days per week. n=10 mice per group (a). n=5 lungs per group (b). Size bar, 5 mm. Data represent mean ± SEM. Significance determined by one-way ANOVA analysis with Sidak’s test for multiple comparisons. c,d, CD8⁺ T cell infiltration (c) and IFN-γ expression in CD8⁺ T cells (d) of the sample in (a) were determined by flow cytometry. % of CD8⁺ cells (c) and CD8⁺IFN-γ⁺ cells (d) in CD45⁺ populations are shown. Data represent mean ± SEM. n=5 tumors/lungs per group. Significance determined by one-way ANOVA analysis with Sidak’s test for multiple comparisons. e-h, FVB females were injected with 100k of luciferase stably expressed PyMT cells. Three weeks after the injection, lung metastases were established and the mice were randomized into two groups (e). BLI signals were determined before the treatment (f). The mice were treated with vehicle or C26-A6+anti-PD-1 and the metastasis were monitored by BLI (g). Kaplan-Meier survival curves of the two groups are shown (h). n=6 mice per group. Data represent mean ± SEM (f). Significance determined by two tailed Student’s t-test (f), or two-sided Log-rank test (h). Numerical source data for a-d and f-h are provided.