Abstract: Compounds of Formula I are antagonists of VLA-4, and as such are useful in the inhibition or prevention of cell adhesion and cell-adhesion mediated pathologies. These compounds may be formulated into pharmaceutical compositions and are suitable for use in the treatment of inflammatory bowel disease including ulcerative colitis and Crohn's disease, multiple sclerosis, asthma, and rheumatoid arthritis.

Abstract: 4-Thio, 4-sulfinyl and 4-sulfonyl proline derivatives of the present invention are antagonists of the VLA-4 integrin and are useful in the treatment, prevention and suppression of diseases mediated by VLA-4-binding and cell adhesion and activation. Moreover, the compounds of the present invention demonstrate significant receptor occupancy of VLA-4 bearing cells after oral administration and are suitable for once-, twice-, or thrice-a-day oral administration. This invention also relates to compositions containing such compounds and methods of treatment using such compounds.