FIGURE 3.

Combination treatment of YH29407 and aPD-1 delayed tumor growth and enhanced tumor growth inhibition and survival of syngeneic MC38 tumor-bearing model. Syngeneic MC38 colon tumor was grafted onto C57BL/6 mice and treatment of YH29407 with or without aPD-1 was started when the tumor volume reached 50 mm³. BMS-986205 was treated as comparative drugs, and the control group was treated with a vehicle. (A) Schematic design of experiment. (B) Combination treatment with YH29407 and aPD-1 significantly delayed MC38 tumor growth in C57BL/6 mice compared to treatment with BMS-986205 or aPD-1 alone. (C) Tumor volume and number of individual mice. (D) Tumor growth inhibition was enhanced by IDO1 inhibitor; all mice treated with YH29407+aPD-1 showed more than 70% TGI. (E) Complete response was observed in the treatment group of YH29407 alone and YH29407 + aPD-1. (F) YH29407+aPD-1 treatment group significantly enhanced the overall survival of the MC38 engrafted C57BL/6 mice model. Statistical significance between groups was calculated using two-way ANOVA followed by Tukey’s multiple comparisons tests (*p < 0.05, **p ≤ 0.01, ***p ≤ 0.001, ****p ≤ 0.0001). aPD-1, anti-PD-1 antibody; ANOVA, analysis of variance.