KAG-308 is an effective selective and orally active agonist of the EP4 receptor (Ki: 2.57 nM and EC50: 17 nM for human EP4 receptor), more selective over EP1, EP2, EP3, and IP receptor. KAG-308 suppresses colitis and promotes histological mucosal healing, which potently inhibits TNF-α production.

EP1 receptor (human):1410 nM（ki）, EP4 receptor (human):(EC50)17 nM, EP4 receptor (human):（ki）2.57 nM, EP2 receptor (human):1000 nM(EC50), EP2 receptor (human):1540 nM（ki）, EP3 receptor (human):160 nM(EC50), EP3 receptor (human):32.4 nM（ki）, IP receptor (human):52.9 nM（ki）

KAG-308 shows effective agonist activity for human and mouse EP4 (EC50: 0.15 nM and 1.0 nM, respectively in the dual luciferase reporter assay). 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) [1].