Abstract: One or more embodiments of the invention relate to a testing method and kit for testing chronic myelogenous leukemia (CML). One or more embodiments of the invention also relate to a method for isolating tyrosine kinase inhibitor (TKI)-resistant CML cells. One or more embodiments of the invention also relate to an agent for reducing TKI resistance in CML, and to a screening method for the same.

Abstract: An objective of the present invention is to provide compounds and pharmaceuticals useful for the treatment of disease where the inhibition of autophosphorylation of FMS-like tyrosine kinase 3(Flt3) is therapeutically effective. The present invention relates to a pharmaceutical composition for use in the treatment or prevention of diseases where the inhibition of autophosphorylation of Flt3 therapeutically or prophylactically effective, which comprises a compound represented by formula (I) or a pharmaceutically acceptable salt or solvate thereof: wherein X represents CH or N; Z represents O or S; R1, R2, and R3 represent H, OH, or optionally substituted alkoxy; R4 represents H; R5, R6, R7, and R8 represent H, Hal, alkyl or the like; and R9 represents, e.g., alkyl substituted by t-butyl or the like.