Disclosed herein are 5 or 8-substituted imidazo[1,5-a]pyridines and pharmaceutical compositions comprising at least one such 5 or 8-substituted imidazo[1,5-a]pyridines, processes for the preparation thereof, and the use thereof in therapy. Disclosed herein are certain 5 or 8-substituted imidazo[1,5-a]pyridines that can be useful for inhibiting indoleamine 2,3-dioxygenase and/or tryptophane 2,3-dioxygenase and for treating diseases or disorders mediated thereby.本申請公開了5或8-取代的咪唑並[1,5-a]吡啶和包含至少一種上述5或8-取代的咪唑並[1,5-a]吡啶的醫藥組合物、它們的製備方法,以及它們在治療中的用途。本申請公開了可用於抑制吲哚胺2,3-二加氧酶和/或色胺酸2,3-二加氧酶並治療由其介導的疾病或病症的某些5或8-取代的咪唑並[1,5-a]吡啶。