FUSED HETEROCYCLIC COMPOUND AND THROMBOPOIETIN RECEPTOR ACTIVATOR

摘要

Fused heterocyclic compounds useful for prevention, treatment or improvement of diseases against which activation of the thrombopoietin receptor is effective are provided. A compound represented by the formula (I) (wherein R 1 is an aryl group fused to a saturated ring or the like, A, B, L 1 , R 2 , L 2 , L 3 , Y, L 4 , R 3 and X are defined in the description), a tautomer, prodrug or a pharmaceutically acceptable salt of the compound or a solvate thereof.