Disclosed is a compound which is useful as a prophylactic or therapeutic agent for a sex hormone-dependent disease or the like. Specifically disclosed are: a nitrogenated fused-ring derivative which is represented by the general formula (I) and which has a GnRH antagonistic activity, or a prodrug or a pharmacologically acceptable salt thereof； a pharmaceutical composition comprising the derivative, the prodrug or the pharmacologically acceptable salt； use of the derivative, the prodrug or the pharmacologically acceptable salt for medical purposes； and others. In the formula (I), the rings A and B independently represent an aryl or a heteroaryl； RA and RB independently represent a halogen, a nitro, an alkyl, -OW1, -COW2, -NW3W4 or the like； E represents an oxygen atom or the like； U represents a single bond or the like； and X represents -SO2-Y, -O-(alkylene)-Y or the like [wherein Y represents Z, an amino or the like； Z represents a heterocycloalkyl, an aryl or the like].
