KAG-308 is a potent selective and orally active agonist of EP4 receptor (a prostaglandin E2 receptor subtype), suppresses colitis and promotes histological mucosal healing, potently inhibits TNF-α production. KAG-308 shows a Ki and an EC50 of 2.57 nM and 17 nM for human EP4 receptor, respectively, more selective over EP1, EP2, EP3 and IP receptor[1]. EC50: 17 nM (Human EP4 receptor), 160 nM (Human EP3 receptor), 1000 nM (Human EP2 receptor), 1000 nM (Human EP2 receptor)[1]Ki: 2.57 nM (Human EP4 receptor), 32.4 nM (Human EP3 receptor), 52.9 nM (Human IP receptor), 1410 nM (Human EP1 receptor), 1540 nM (Human EP2 receptor)[1]

KAG-308 is a potent selective and orally active agonist of EP4 receptor, suppresses colitis and promots histological mucosal healing. KAG-308 shows a Ki and EC50 values of 2.57 nM and 17 nM for human EP4 receptor, respectively, more selective over human EP1 (Ki, 1410 nM; EC50, 1000 nM), EP2 (Ki, 1540 nM; EC50, 1000 nM), EP3 (Ki, 32.4 nM; EC50, 160 nM) and IP receptor (Ki, 52.9 nM; EC50, >10000 nM). KAG-308 also exhibits potent agonist activity for human and mouse EP4 with an EC50 of 0.15 nM and 1.0 nM, respectively in the dual luciferase reporter assay[1].

[1]. Watanabe Y, et al. KAG-308, a newly-identified EP4-selective agonist shows efficacy for treating ulcerative colitis and can bring about lower risk of colorectal carcinogenesis by oral administration. Eur J Pharmacol. 2015 May 5;754:179-89.