Figure 3.

ChAdOx1/MVA P1A vaccination combined with immune checkpoint blockade enhances tumor control. (A) DBA/2 mice were implanted with 1x10⁶ 15V4T3 cells via s.c. injection. Eight days after tumor implantation, mice were randomized into experimental groupings according to tumor volume. Starting on day 8, mice then received vaccinations of 10⁷ IU ChAdOx1-Ii-P1A / 10⁶ PFU MVA-P1A alternating weekly or a PBS sham, and were treated with 3-doses of 100 μg anti-PD-1, anti-CTLA-4 or an isotype control antibody according to the schedule as shown. Tumor growth was followed for 50 days and mice were culled when tumor size reached size endpoints. (B-D) Mean tumor growth (B), survival curves (C) and individual tumor growth kinetics (D) for each group are shown. Tumor growth data in (B) are presented as mean tumor volume (mm³) ± SEM. Each group contained 6 mice, with data representative of 2 independent experiments. Statistically significant differences in tumor volume between groups were determined by a two-way ANOVA followed by Tukey’s post hoc test and statistical differences in survival data were determined by a log-rank test. *, p ≤ 0.05, **, p ≤ 0.01 ****, p ≤ 0.0001.