The present invention is directed to 1,2,5-oxadiazole derivatives, and compositions of the same, which are inhibitors of indoleamine 2,3-dioxygenase and are useful in the treatment of cancer and other disorders, and to the processes and intermediates for making such 1,2,5-oxadiazole derivatives.本發明係關於1,2,5-二唑衍生物及其組合物,其為吲哚胺2,3-雙加氧酶之抑制劑且適用於治療癌症及其他病症,及關於製備該等1,2,5-二唑衍生物之方法及中間物。