Identification and optimization of a novel series of indoleamine 2,3-dioxygenase inhibitors.

The discovery of a series of structurally-novel biaryl urea IDO inhibitors is described. Optimization of a micromolar hit through iterative cycles of synthesis and screening in an assay measuring IDO-mediated intracellular conversion of tryptophan to kynurenine led to potent inhibitors with favorable selectivity and metabolic stability profiles.