A synthetic, nonsteroidal derivative of phenyl-furanone with antiinflammatory, antipyretic and analgesic properties and potential antineoplastic properties. Rofecoxib inhibits the enzyme cyclooxygenase-2 (COX-2) in the conversion of arachidonic acid to prostaglandins. COX-related metabolic pathways may represent key regulators of cell proliferation and neo-angiogenesis. Some epithelial tumor cell types overexpress pro-angiogenic COX-2. (NCI04)