[PROBLEMS] To provide a compound useful as a prophylactic or therapeutic agent for a sex hormone-dependent disease or the like. [MEANS FOR SOLVING PROBLEMS] Disclosed are: a nitrogenated fused ring derivative represented by the general formula (I), or a prodrug, salt or the like thereof, which has a GnRH antagonistic activity； a pharmaceutical composition comprising the derivative or the prodrug, salt or the like thereof； use of the the derivative or the prodrug, salt or the like thereof for medical purposes； and others. In the general formula (I), the rings A and B independently represent an aryl or a heteroaryl； R and R independently represent a halogen, a cyano, an alkyl, an alkylsulfonyl, -OW, -SW, -COW, -NWW, -SONWW, an aryl or the like； R represents H or an alkyl； E represents an oxygen atom or the like； U represetns a single bond or an alkylene； and X represents Y, -CO-Y, -SO-Y, -S-(alkylene)-Y, -O-(alkylene)-Y, -SO-(alkylene)-Y or the like [wherein Y represents Z, an amino or the like； and Z represents a cycloalkyl, a heterocycloalkyl, an aryl, a heteroaryl or the like].
