Spiroglumide (CR2194) is a potent and specific cholecystokinin-B (CCKB)/gastrin receptor antagonist structurally similar to lorglumide. Gastrin receptor blockade with CR2194 alters gastric acid secretion in response to food ingestion or to sham feeding. The results support a physiological role for gastrin in regulating acid secretion in humans. In healthy volunteers, intravenous infusion of spiroglumide was shown to reduce basal and postprandial intragastric acidity. These data also support the thesis that CCK2 receptor antagonism is an effective means to suppression gastric acid secretion. Although the oral bioavailability of spiroglumide was an improvement over L-365,260, it was not very potent and had little selectivity for the CCK2 receptor over the CCK1 receptor. These factors seem likely to have contributed to the decision not to continue its development