Abstract: The invention provides a compound of formula (0): or a pharmaceutically acceptable salt, N-oxide or tautomer thereof; wherein: n is 1 or 2; X is CH or N; Y is selected from CH and C—F; Z is selected from C—Rz and N; R1 is selected from: -(Alk1)t-Cyc1; wherein t is 0 or 1; Optionally substituted C1-6 acyclic hydrocarbon groups R2 is selected from hydrogen; halogen; and C1-3 hydrocarbon groups optionally substituted with one or more fluorine atoms; R3 is hydrogen or a group L1-R7; R4 is selected from hydrogen; methoxy; and optionally substituted C1-3 alkyl; and R4a is selected from hydrogen and a C1-3 alkyl group; wherein Rz, Alk1, Cyc1, L1 and R7 are defined herein; provided that the compound is other than 6-benzyl-3-{2-[(2-methylpyrimidin-4-yl)amino]pyridin-4-yl}-7,8-dihydro-1,6-naphthyridin-5(6H)-one and 3-{2-[(2-methylpyrimidin-4-yl)amino]pyridin-4-yl}-7,8-dihydro-1,6-naphthyridin-5(6H)-one and salts and tautomers thereof.

Abstract: The invention relates to FMS-like tyrosine kinase (FLT3), FLT3 binding pockets or FLT3-like binding pockets. The invention relates to a computer comprising a data storage medium encoded with the structure coordinates of such binding pockets. The invention also relates to methods of using the structure coordinates to solve the structure of homologous proteins or protein complexes. The invention relates to methods of using the structure coordinates to screen for and design compounds that bind to FMS-like tyrosine kinase protein, complexes of FMS-like tyrosine kinase protein, homologues thereof, or FLT-3-like protein or protein complexes. The invention also relates to crystallizable compositions and crystals comprising an FMS-like tyrosine kinase cytoplasmic domain or homologues thereof. The invention also relates to methods of identifying inhibitors of the cytoplasmic domain of FMS-like tyrosine kinase protein.