Disease models in animals demonstrate that the leukocyte integrin alpha 4 beta 1 (VLA-4) is a suitable target for therapy in a number of chronic inflammatory disorders. While in vivo studies have concentrated on the use of anti-alpha 4 antibodies as proof of concept tools, repeated administration to combat human chronic inflammatory conditions is likely to require small antagonists of alpha 4 beta 1. We have developed low molecular weight alpha 4 beta 1 inhibitors which have shown therapeutic promise in animal models of chronic inflammation.