A drug developer's dream, rationally designed to quell inflammation, COX-2 inhibitors are also prime candidates for preventing cancer or its recurrence. Gary J. Kelloff, chief of the chemoprevention branch at the National Cancer Institute (NCI), lists the requirements for a molecular target such as the COX-2 enzyme: It must be highly expressed in precancer or cancer cells and not in others; blocking it isn't toxic and doesn't disrupt normal function; effects must be measurable; and there must be clinical benefit. "COX-2 is an ideal target," he says.
The COX-2 inhibitors shot to pharmaceutical fame in December 1998, when the Food and Drug Administration approved Celebrex (celecoxib) to treat osteoarthritis and rheumatoid arthritis. Five months later Vioxx (rofecoxib) followed, approved for osteoarthritis, acute pain, and dysmenorrhea.1 But the use for cancer--begun with the 1999 approval of Celebrex to treat a type of colon cancer, familial adenomatous polyposis (FAP)--fits right into NCI's ...
