Provided is a compound represented by formula (I) or a pharmaceutically acceptable salt thereof, which is useful as an IDO/TDO inhibitor. The compound represented by formula (I) or a pharmaceutically acceptable salt thereof can, for example, be used as a therapeutic agent for a disease or disorder selected from tumors, infectious diseases, neurodegenerative disorders, cataracts, organ transplant rejection, autoimmune diseases, postoperative cognitive dysfunction, and disorders relating to female reproductive health [in formula (I), ring A represents an aromatic ring, an aliphatic ring, a heterocyclic ring, or a fused ring including two or more rings selected from aromatic rings, aliphatic rings, and heterocyclic rings, X, R1, and R2 each represent a substituent of a ring atom forming ring A, m represents an integer of 0-6, X represents, for example, a halogen atom, and R1 and R2 may be the same or different and are, for example, selected from groups represented by formula (a) or formula (b), and in formula (a) and formula (b), Y is selected from the group consisting of O, S, and Se, Z is selected from the group consisting of O, S, and Se, n represents an integer of 1-8, r represents an integer of 1-8, s represents an integer of 1-8, R4 represents, for example, -C(=NH)-HN2, and R6 represents, for example, a substituted or unsubstituted aryl group].具有下述式（I）的化合物或該化合物的藥學上可接受的鹽，做為IDO/TDO抑制劑是有用的。因此，具有式（I）的化合物或該化合物的藥學上可接受的鹽，可做為例如選自腫瘤、感染症、神經退行性疾病、白內障、器官移植導致的排斥反應、自體免疫疾病、術後認知障礙、及女性生殖健康相關疾病的疾病或障礙的治療劑來使用。［下述式（I）中，環A表示芳香族環、脂肪族環、雜環或選自芳香族環、脂肪族環以及雜環的2個以上環的縮合環；X、R1及R2是構成環A的環原子的取代基；m表示0～6的整數；X表示例如鹵素原子；R1及R2可以相同，也可以不同，例如選自式（a）或式（b）的基所成群組；下述式（a）或式（b）中，Y選自O、S、SO、及Se所成群組；Z選自O、S、SO、及Se所成群組；n表示1～8的整數；r表示1～8的整數；s表示1～8的整數；R4表示例如－Ｃ（＝ＮＨ）－ＨＮ２；R6表示例如取代或未取代的芳基］
