DuP-697 is a member of the diaryl heterocycle group of selective COX-2 inhibitors which includes MK-966 (rofecoxib), SC-58125, and celecoxib. DuP-697 is a potent and time-dependent inhibitor of COX-2.{4313} When tested on isolated recombinant enzymes, DuP-697 is at least 50 times more potent in the inhibition of COX-2 than COX-1.{7452} The IC50 values for human recombinant COX-2 are 80 and 40 nM at 5 and 10 minutes, respectively.{8512} The IC50 for the inhibition of human recombinant COX-1 after the same time intervals is 9 μM.{8512} DuP-697 also attenuates the COX-1 inhibitory activity of non-selective COX inhibitors such as indomethacin.{8048}