Tb-DOTA-LM3

Tb-DOTA-LM3 (specifically [161Tb]Tb-DOTA-LM3) is an investigational, peptide receptor radionuclide therapy (PRRT) consisting of the somatostatin receptor subtype 2 (SSTR2) antagonist peptide LM3 conjugated to the chelator DOTA and radiolabeled with the beta- and Auger-electron-emitting radionuclide terbium-161 (161Tb). Developed by the Paul Scherrer Institute and the University Hospital Basel, this radiopharmaceutical is designed to target SSTR2-expressing neuroendocrine neoplasms (NENs), particularly gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Unlike conventional SSTR agonists (such as DOTATOC or DOTATATE), the antagonist LM3 binds to a larger number of receptor sites and remains on the cell membrane. Terbium-161 decays with a half-life of approximately 6.95 days, co-emitting medium-energy beta particles along with low-energy conversion and Auger electrons. These short-range Auger electrons deliver a highly localized, lethal radiation dose to single cancer cells and micrometastases while sparing surrounding healthy tissue, potentially offering a significant therapeutic advantage over standard lutetium-177-based therapies.

Other names

[149Tb]Tb-DOTA-LM3[161Tb]Tb-DOTA-LM3149Tb-DOTA-LM3161Tb-DOTA-LM3terbium (149Tb) DOTA-LM3terbium (161Tb) DOTA-LM3terbium-149-DOTA-LM3terbium149-DOTA-LM3terbium 149-DOTA-LM3terbium-161-DOTA-LM3terbium161-DOTA-LM3terbium 161-DOTA-LM3