PROBLEM TO BE SOLVED : To provide a compound for use in a method for the treatment and/or prevention of leukemia. SOLUTION : The present invention is related to a compound of the following formula, a pharmaceutically acceptable salt thereof, a hydrate thereof, a solvate thereof, a metabolite thereof or a prodrug thereof, where X is selected from the group consisting of N-R1, O and S; R1 is selected from the group consisting of alkyl, cycloalkyl, aryl, arylalkyl and H; R2 is selected from the group consisting of indolyl, substituted indolyl, azaindolyl and substituted azaindolyl; and R3 is selected from the group consisting of aryl, substituted aryl, unsubstituted heteroaryl, heterocyclyl and substituted heterocyclyl. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT