111In-DTPA-exendin-4

**111In-DTPA-exendin-4** is a radiolabeled peptide drug consisting of exendin-4 (a glucagon-like peptide 1 receptor agonist), conjugated via diethylenetriaminepentaacetic acid (DTPA) to the radioisotope indium-111. It is designed for molecular imaging and targeted radiotherapy of insulinomas and other tumors expressing high levels of the glucagon-like peptide 1 receptor (GLP‑1R). The drug binds with high affinity to GLP‑1R on tumor cells, allowing for selective localization and visualization using SPECT/CT imaging. In preclinical models and early clinical studies, it has demonstrated high tumor uptake with favorable tumor-to-background ratios and can induce significant reduction in tumor volume through targeted radiation delivery[1][3][5]. Its primary use is in the diagnosis and localization of insulinoma when conventional imaging fails[3], but it also shows potential as a therapeutic agent due to its ability to deliver cytotoxic radiation specifically to GLP‑1R–expressing cells[1].

Other names

[Lys40(Ahx-DTPA-111In)NH2]-exendin-4[Lys(40)(Ahx-DTPA-(111)In)NH2]-exendin-4