The present application provides novel inhibitors of indoleamine 2,3-dioxygenase-1 and/or indoleamine 2,3-dioxygenase-2 and/or tryptophan 2,3-dioxygenase, metabolites thereof, and pharmaceutically acceptable salts or prodrugs thereof. Also provided are methods for preparing these compounds. A therapeutically effective amount of one or more of the compounds of formula (I) is useful in treating diseases resulting from dysregulation of the kynurenine pathway. Compounds of formula (I) act by inhibiting the enzymatic activity or expression of indoleamine 2,3-dioxygenase-1 and/or indoleamine 2,3-dioxygenase-2 and/or tryptophan 2,3-dioxygenase. By doing so, these compounds are effective in treating diseases associated with the dysregulation of the kynurenine pathway. A variety of diseases can be treated using these compounds and include diseases which are characterized by abnormal immune suppression, abnormal cellular proliferation and/or inflammation. In one embodiment, the disease is cancer. In another embodiment, the disease is a viral infection. In a further embodiment, the disease is depression. In a still further embodiment, the disease is Alzheimer’s disease.本申請案提供吲哚胺2,3-雙加氧酶-1及/或吲哚胺2,3-雙加氧酶-2及/或色胺酸2,3-雙加氧酶之新穎抑制劑、其代謝物，及其醫藥學上可接受之鹽或前藥。本申請案亦提供製備此等化合物之方法。治療有效量之一或多種式(I)化合物適用於治療因犬尿胺酸途徑失調所造成之疾病。式(I)化合物藉由抑制吲哚胺2,3-雙加氧酶-1及/或吲哚胺2,3-雙加氧酶-2及/或色胺酸2,3-雙加氧酶之酶促活性或表現而起作用。藉此，此等化合物可有效治療與該犬尿胺酸途徑之失調相關之疾病。多種疾病可使用此等化合物治療，且包括特徵為異常免疫抑制、異常細胞增殖及/或炎症之疾病。在一個實施例中，該疾病為癌症。在另一實施例中，該疾病為病毒感染。在另一實施例中，該疾病為抑鬱症。在另一實施例中，該疾病為阿茲海默氏病。
