The present invention is related to a compound of formula (I): a pharmaceutically acceptable salt thereof, a hydrate thereof, a solvate thereof, a metabolite thereof or a prodrug thereof； for use in a method for the treatment and/or prevention of leukemia, wherein 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 hydrogen； 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.
