Definition

A chimeric dopamine (DA)-somatostatin (SST) compound, with potential antineoplastic activity. Upon administration, onzigolide binds with high affinity to dopamine D2 receptor (D2R) and somatostatin receptor subtype 2 (SSTR2), and to a lesser extent to somatostatin receptor subtype 5 (SSTR5). This agent appears to exert its effect mainly by binding to D2R to activate the ERK1/2 and p38 MAPK pathways, thus inducing apoptosis and inhibiting cellular proliferation in non-functioning pituitary adenoma (NFPA) and neuroendocrine tumors. By binding to SSTR2, this agent may inhibit the secretion of growth hormone (GH) by the pituitary gland.