technetium Tc 99m maSSS-PEG2-RM26

Technetium Tc 99m maSSS-PEG2-RM26 is an investigational radiopharmaceutical diagnostic imaging agent designed to target the gastrin-releasing peptide receptor (GRPR). Developed through a collaboration between Tomsk National Research Medical Center, Tomsk Polytechnic University, and Uppsala University, the agent consists of RM26, a high-affinity 10-amino acid peptide antagonist (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2), linked via a PEG2 spacer to a mercaptoacetyl-Ser-Ser-Ser (maSSS) chelator. This chelator enables stable labeling with the gamma-emitting isotope technetium-99m. GRPR is frequently overexpressed in various malignancies, including prostate cancer and hormone-driven breast cancer. By binding to these receptors, the tracer allows for the visualization of primary tumors and metastases using Single-Photon Emission Computed Tomography (SPECT). As an antagonist, RM26 binds to the receptor without triggering the physiological signaling or receptor downregulation typically associated with GRPR agonists.

Other names

99mTc-RM26technetium Tc 99m mercaptoacetyl-Ser-Ser-Ser-PEG2-RM26