Presently provided are inhibitors of IDO and TDO and pharmaceutical compositions thereof, useful for modulating an activity of indoleamine 2,3-dioxygenase and tryptophan 2,3 dioxygenase; treating immunosuppression; treating a medical conditions that benefit from the inhibition of tryptophan degradation; enhancing the effectiveness of an anti-cancer treatment comprising administering an anti-cancer agent; treating tumor-specific immunosuppression associates with cancer; and treating immunosupression associated with an infectious disease.