This invention relates to a VLA-4 inhibitory drug, having good oral absorbability and exhibiting sufficient anti-inflammatory effects when administered orally, wherein an active ingredient is represented by formula (I), or a salt thereof:
Q represents an optionally-substituted monocyclic or bicyclic nitrogen-containing heterocyclic group having a nitrogen atom as the bonding site; Y represents an oxygen atom or CH
2
; W represents an optionally-substituted bicyclic aromatic hydrocarbon ring group or an optionally-substituted bicyclic aromatic heterocyclic group; A
1
represents a nitrogen atom or C—R
3d
wherein R
3d
represents a hydrogen atom, a halogen atom, a C1-8 alkoxy group or a C1-8 alkyl group; R
1
represents H or a C1-8 alkyl group; R
2
represents H, a halogen, a C1-8 alkoxy