Definition

A heterodimeric peptide consisting of the heptapeptide monomers KSPNPRF (KSP) and QRHKPRE (QRH) targeting human epithelial growth factor receptor type 2 (EGFR2; HER2; ErbB2) and epidermal growth factor receptor (EGFR), with an E3 spacer, labeled with the near-infrared (NIR) fluorophore IRDye800, with potential imaging activity using the scanning fiber endoscope (SFE) imaging system. Upon spraying of the esophagus with IRDye800-labeled heterodimeric peptide KSP-QRH 919288G, the heterodimeric peptide moiety targets and binds to HER2 and EGFR expressed on dysplastic cells in the pre-cancerous mucosa of the esophagus. Upon fluorescence imaging of the fluorophore IRDye800 with the SFE probe, the HER-2- and EGFR-expressing dysplastic cells can be detected. EGFR and HER2 are tyrosine kinase receptors that are overexpressed on the surfaces of various tumor cell types, and they are expressed in esophageal dysplasia.