TRICYCLIC COMPOUND AND JAK INHIBITOR

Novel tricyclic compounds which have JAK inhibitory activities are useful for prevention, treatment or improvement of autoimmune diseases, inflammatory diseases and allergic diseases are provided. Novel tricyclic compound represented by the formula (I), the formula (II) or the formula (III) (wherein : each of A 1 , A 2 and A 3 is a cyclohexane-1,4-diyl group or the like; each of L 1 , L 2 and L 3 is a methylene group or the like; each of X 1 and X 3 is O or NH; each of R 1 and R 3 is a cyano C 1-6 haloalkyl group or the like; and R 2 is an aromatic heterocyclic group), a tautomer or pharmaceutically acceptable salt of the compound or a solvate thereof.