Highly selective cyclooxygenase-1 (COX-1) inhibitor (IC50 values are 0.009 and 6.3 μM for COX-1 and COX-2 respectively). Inhibits COX-1-derived platelet thromboxane B2, gastric PGE2 and dermal PDE2 production. Significantly reduces ovarian surface epithelial tumor growth in vivo. Orally active.