FR122047 is a selective inhibitor of COX-1. The IC50 values for inhibition of human COX-1 and COX-2 are 0.028 and 65 µM, respectively. In human platelet-rich plasma, FR122047 inhibits arachidonic acid, collagen, and ADP-induced platelet aggregation with an IC50 of 180-200 nM, which is nearly 100 times more potent than aspirin. Unlike aspirin, FR122047 does not induce gastric damage upon oral administration at doses (100 mg/kg) far in excess of the dose needed for complete suppression of platelet COX-1. In some models of inflammation, such as collagen-induced arthritis in the rat, FR122047 has an anti-inflammatory effect, implying a role for COX-1 in these models.