Netazepide (YF476) is an orally active, benzodiazepine type, selective cholecystokinin B receptor (CCKBR; CCK2R; gastrin receptor) antagonist with potential gastric acid reducing and antiproliferative activity. Upon administration, netazepide, selectively binds to and blocks the CCKBR, thereby preventing the binding of gastrin and cholecystokinin. This may prevent gastric neuroendocrine enterochromaffin-like (ECL) cell-induced secretion of histamine, ultimately preventing gastric acid secretion from adjacent parietal cells. In addition, YF476 may inhibit ECL cell proliferation and ECL-derived gastric carcinoids. Netazepide has been used in trials studying the prevention and treatment of dyspepsia, hypergastrinaemia, barrett's esophagus, ECL-cell hyperplasia, and rebound hyperacidity, among others. Netazepide once daily for 12 weeks reduced the number of tumours and size of the largest one in 16 patients with autoimmune chronic atrophic gastritis (CAG), achlorhydria, hypergastrinaemia and multiple gastric neuroendocrine tumours (type 1 gastric NETs), and normalized circulating chromogranin A (CgA) produced by enterochromaffin-like cells, the source of the tumours.