SGM-101: An innovative near-infrared dye-antibody conjugate that targets CEA for fluorescence-guided surgery

International audiencePURPOSE:Fluorescence-guided surgery (FGS) provides surgeons with new opportunities to improve real-time cancer nodule detection and tumor margin visualization. Currently, the most important challenge in this field is the development of fluorescent dyes that specifically target tumors. We developed, characterized and evaluated SGM-101, an innovative antibody-dye conjugate in which the fluorochrome BM104, which has an absorbance band centered at 700 nm, is coupled to a chimeric monoclonal antibody (mAb) against carcinoembryonic antigen (CEA).METHODS:The dye to mAb ratio, binding to CEA and photobleaching of SGM-101 were determined. FGS was performed and results analyzed using different mouse models of human digestive tumors.RESULTS:SGM-101 allowed the detection of tumor nodules in three different colon cancer models: LS174T human colorectal adenocarcinoma cell-induced peritoneal carcinomatosis (PC) and liver metastases, and orthotopic grafts of HT29 human colorectal adenocarcinoma cells. In the PC model, submillimeter-sized nodules were detected during SGM-101-based FGS and SGM-101 predictive positive values ranged from 99.04% to 90.24% for tumor nodules >10 mg and nodules