Purity >95%. Exchange protein activated by cAMP (Epac) proteins mediate cAMP signaling independent of protein kinase A (PKA). ESI-09 is an inhibitor of Epac1 and Epac2 with IC50 values of 3.2 and 1.4 μM, respectively. It shows no activity against PKA at concentrations as high as 25 μM. ESI-09 has been shown to block Akt phosphorylation and insulin secretion in pancreatic Beta cells, as well as to block the migration of AsPC-1 and PANC-1 pancreatic cancer cells in vitro .