111In-CP04

**111In-CP04** is a radiopharmaceutical composed of the synthetic peptide CP04, a cholecystokinin-2 receptor (CCK2R/gastrin receptor) ligand, labeled with the radioisotope indium-111. It is designed for molecular imaging and theranostic applications in patients with advanced or metastatic medullary thyroid cancer (MTC), which frequently overexpresses CCK2R. Upon intravenous administration, 111In emits gamma radiation and X-ray photons that enable tumor localization and distribution assessment using gamma scintigraphy. The compound has demonstrated high safety and tolerability in phase I clinical trials, with only minor transient adverse effects reported. Its mechanism of action involves specific binding to CCK2 receptors on tumor cells, allowing targeted imaging of MTC lesions[1][3][4][5][7]. The agent also serves as a diagnostic companion to potential therapeutic radiolabeled analogs such as [177Lu]Lu-CP04.

Other names

indium In 111 minigastrin analog CP04