Table 1C.

The preclinical studies of the combination of PD-1/PD-L1 blockade with other ICBs in cancer therapy

Targets	PD-1/PD-L1 blockade	Other ICB	Tumor types	Model	Findings (mechanisms)	References
PD-L1×VISTA	Anti-PD-L1 mAb	Anti-VISTA mAb	Colon cancer	C57BL/6 mice with CT26 colon cancer	Combined treatment showed significant anti-tumor effects in mice with colon cancer, through increased cytokine (IFN-γ, TNF-α, and granzyme B) production by tumor-specific CD8+ T cells from tumor-draining lymph nodes more than single blockade or control.	142
PD-L1×IDO1	Anti-PD-L1 (clone 10F.9G2)	IDO1 inhibitor (PF-06840003)	Colon carcinoma	BALB/c and C57BL/6 mice with colon carcinoma	IDO1 inhibitor PF-06840003, when used in combination with anti-PD-L1, could induce a higher proportion of T cells secreting IFN-γ and the expression of the cytolytic enzyme granzyme A, thereby enhancing anti-tumor effects.	151
PD-L1×IDO	Anti-PD-L1 antibody (clone 10 F.9G2)	IDO inhibitor (INCB23843)	Melanoma	C57BL/6 mice bearing with B16-dsRed-SIY cells	Combination therapy increased IL-2-producing, proliferating polyfunctional T cells in the tumor, prolonged peripheral tumor-reactive lymphocytes' duration and frequency later on, but didn't boost early anti-tumor CD8+ T cells in tumor-draining lymph nodes.	152
PD-L1×IDO	Anti-PD-L1	NLG-RGD NI	Pancreatic cancer	pancreatic cancer cell line Pan02	IDO nano-inhibitor enhanced the anti-tumor efficacy of anti-PD-L1 via decreasing the proportion of Tregs and increasing the proportion of the IFN-γ secreting tumor-infiltrating T cells.	153