indoximod

Indoximod is a methylated tryptophan derivative and small molecule immunometabolic agent with immune checkpoint inhibitory activity. It acts primarily as an inhibitor of the indoleamine 2,3-dioxygenase (IDO) pathway, which is involved in the degradation of tryptophan—a process exploited by tumors to suppress antitumor immunity. By inhibiting IDO, indoximod helps maintain or increase tryptophan levels important for T cell function and reverses the immunosuppressive effects of low tryptophan and high kynurenine. Mechanistically, unlike direct enzymatic inhibitors of IDO1, indoximod acts downstream to stimulate mTORC1 signaling in T cells under conditions of tryptophan deficiency and modulates immune responses by enhancing effector T cell proliferation, reprogramming regulatory T cells into helper T cells, and downregulating IDO expression in dendritic cells. Indoximod has been investigated as an adjunct to various cancer therapies including chemotherapy, radiotherapy, vaccines, and immune checkpoint inhibitors.

Other names

D-Tryptophan, 1-methyl-D-1MTD1MTD 1MT