In vitro activity: IDO inhibitor 1 (IDO-IN-2) is a novel and potent small molecule inhibitor of the IDO enzyme (indoleamine-(2,3)-dioxygenase) with an IC50 of 3 nM in cell free assays. Indoleamine 2, 3-dioxygenase (IDO) is an intracellular enzyme that catalyzes the transformation of L-tryptophan to N-formylkynurenine, which is the first and rate-controlling step in the kynurenine pathway. IDO is one of the most important immunoregulator enzyme responsible for metabolism of tryptophan as part of Kynurenin pathway. Tryptophan is catabolized in the tumor tissue by the rate-limiting enzyme IDO expressed in tumor cells or antigen presenting cells.

Kinase Assay: IDO inhibitor 1 (IDO-IN-2) is a novel and potent small molecule inhibitor of the IDO enzyme (indoleamine-(2,3)-dioxygenase) with an IC50 of 3 nM in cell free assays