LY-3381916

LY-3381916 is a potent, selective and brain permeant IDO1 (Indoleamine 2,3-Dioxygenase1) inhibitor. LY-3381916 specifically targets and binds to IDO1, a cytosolic enzyme responsible for the oxidation of the amino acid tryptophan into the immunosuppressive metabolite kynurenine. By inhibiting IDO1 and decreasing kynurenine in tumor cells, LY3381916 restores and promotes the proliferation and activation of various immune cells, including dendritic cells (DCs), natural killer (NK) cells, and T lymphocytes, and causes a reduction in tumor-associated regulatory T cells (Tregs).