Peptide vaccination directed against IDO1-expressing immune cells elicits CD8+ and CD4+ T-cell-mediated antitumor immunity and enhanced anti-PD1 responses.

The in vivo antitumor effects demonstrated with IDO1-based vaccines via targeting of the tumor microenvironment highlight the utility of mouse models for further exploration and refinement of this novel vaccine-based approach to IDO1-directed cancer therapy and its potential to improve patient response rates to anti-PD1 therapy.