A fused heterocycle derivative represented by the general formula (I): (wherein R1 represents optionally substituted lower alkyl, or the like; R2 represents an optionally substituted aliphatic heterocyclic group, or the like; R3 represents —C(═Z)NR5R6 (wherein R5 and R6 represent optionally substituted lower alkyl, or the like, and Z represents an oxygen atom or the like), or the like; n represents an integer of 1 to 3; and W represents C—R5 (wherein R5 represents a hydrogen atom or the like)) or a pharmaceutically acceptable salt thereof, and the like are provided.