SC-58125 is a member of the diaryl heterocycle group of selective COX-2 inhibitors which includes MK 966 (rofecoxib), DUP-697, and celecoxib. SC-58125 is a potent and time-dependent inhibitor of COX-2. When tested on the isolated recombinant enzymes, SC-58125 is at least 150 times more potent in the inhibition of COX-2 as COX-1. In cultured HUVEC cells, SC-58125 inhibits COX-2 with an IC50 value of 70 nM. It also inhibits the growth of the COX-2 expressing cell line HCA-7 in nude mice at 5-10 mg/kg when given intraperitoneally.