Compounds having activity as inhibitors of ALK2 kinase and/or JAK2 kinase are disclosed. The compounds have the following structure (I): [FORMULA SHOULD BE INSERTED HERE] including stereoisomers, tautomers, pharmaceutically acceptable salts and prodrugs thereof, wherein R1, R2, R3, R4, R5, R6, R7, R8, X, z and A are as defined herein. Methods associated with preparation and use of such compounds, as well as pharmaceutical compositions comprising such compounds, are also disclosed.