High affinity and selective EP4 receptor antagonist (Ki values are 1.3, 30, 790 and 2400 nM for EP4, EP3, FP and TP receptors respectively). Displays no affinity for EP1, EP2, DP or IP receptors (Ki >10 μM). Inhibits PGE2-induced IL-8 production in colonic epithelial caco-2 cells and attenuates PGE2 inhibition of natural killer T cell activation. Suppresses recovery from experimentally-induced colitis and stimulates CD4+ T cell proliferation in C57BL/6 mice. Also reduces metastasis of mammary tumor cells in a murine model of breast cancer. Orally active. Purity 98%. MW (observed): 404.43