Definition

A radioconjugate consisting of a gastrin-releasing peptide receptor (GRPR)-targeting antagonist conjugated, through a bifunctional, macrocyclic chelating agent DOTAM (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic amide; TCMC), to the alpha-emitting radioisotope lead Pb 212, with potential antineoplastic activity. Upon administration, lead Pb 212-DOTAM-GRPR1 targets and binds to GRPR-expressing tumor cells. This allows for the specific delivery of a cytotoxic dose of alpha radiation to GRPR-expressing tumor cells. GRPR, also called bombesin receptor 2 (BB2), is a G protein-coupled seven-transmembrane receptor belonging to the bombesin receptor family. It is overexpressed in certain types of cancers.