Definition

A radioconjugate composed of LM3, a human somatostatin receptor (SSTR) antagonist, conjugated to the albumin-binding dye Evans blue (EB) and linked to the beta-emitting radioisotope lutetium Lu 177 (177Lu), with potential antineoplastic activity against SSTR-expressing tumor cells. Upon administration, lutetium Lu 177-EB-LM3 targets and binds to SSTRs that are present on the cell membranes of many types of neuroendocrine tumors (NETs). Upon binding, SSTR-expressing tumor cells are destroyed by 177Lu through the specific delivery of beta particle radiation. This agent also binds to serum albumin with its EB moiety which increases this agent’s half-life and decreases its rate of clearance. SSTRs have been shown to be present in large numbers on NETs and their metastases, while most other normal tissues express low levels of SSTRs.