N-Isonicotinoyl-(l)-4-aminophenylalanine derivatives as tight binding VLA-4 antagonists

A series of isonicotinoyl-(L)-aminophenylalanine derivatives was prepared and evaluated as VLA-4 antagonists. These compounds exhibit subnanomolar binding affinity to VLA-4 and significant off-rates. The interplay between off-rate, protein binding and pharmacokinetics is discussed.