Epacadostat is an inhibitor of indoleamine 2,3-dioxygenase 1 (IDO1) with an IC50 value of 7.1 nM in HeLa cells that demonstrates little activity against the related enzymes IDO2 or tryptophan 2,3-dioxygenase (TDO). It has been shown to promote T and natural killer-cell growth, to increase IFN-γ production, and to reduce conversion to regulatory T (Treg)-like cells in a coculture system of human allogeneic lymphocytes with either dendritic cells or tumor cells. Epacadostat can also inhibit tumor growth in tumor-bearing mice in a lymphocyte-dependent manner.
Epacadostat is a potent and novel indoleamine 2,3-dioxygenase (IDO1) inhibitor with IC50 of 10 nM. It has high selectivity over IDO2 and tryptophan 2,3-dioxygenase (TDO).
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