Multimodal fluorescence-guided surgery of colorectal peritoneal metastases, a phase I/II clinical trial.

Abstract

TPS4119 Background: Successful treatment of patients with colorectal peritoneal carcinomatosis highly depends on complete surgical tumor resection of all tumor. Oncological outcomes can potentially be improved by intraoperative imaging using a tumor-targeting antibody conjugated to a fluorophore and a radiotracer. This enables preoperative radionuclide imaging, real-time intraoperative fluorescence imaging and gamma detection. In this study we investigate the feasibility, accuracy and safety of CEA-targeted preoperative SPECT/CT and intraoperative fluorescence imaging in patients with colorectal PC. Methods: In this phase I/II single arm protein dose escalation study patients with peritoneal metastases of colorectal origin who are scheduled for cytoreductive surgery and HIPEC will receive an intravenous injection of the CEA-targeting tracer 111In-DOTA-labetuzumab-IRDye800CW. The first 15 patients will receive a single dose of 2,10 or 50 mg 6 to 7 days prior to surgery. Four to five days after injection SPECT/CT imaging of the thorax and abdomen is performed to determine intra-abdominal tumor load and detect extra-abdominal metatases. At day 6/7 after injection, standard cytoreductive surgical resection extended with real-time near-infrared fluorescence imaging and radio guidance is performed. After surgery, the peritoneal cavity will be re-examined for residual disease with fluorescence imaging. Resected specimens are analyzed microscopically, immunohistochemically (CEA and H&E) and by gamma counting. Blood samples are drawn for farmacokinetics and safety analysis at 180 minutes, 4 days, 6 days and 3 weeks after tracer injection. In the phase II dose expansion cohort, 14 more patients will receive the optimal dose as determined in the phase I trial. The primary objectives of the trial are to assess the safety, feasibility and accuracy of preoperative SPECT/CT and intraoperative fluorescence imaging after administration of 111In- labetuzumab-IRDye800CW in patients with peritoneal carcinomatosis of colorectal origin who will undergo cytoreductive surgery and HIPEC. The secondary objectives are to assess whether additional malignant lesions can be visualized by fluorescence imaging after cytoreductive surgery, to assess the intensity of fluorescence in malignant and non-malignant tissue, to assess the correlation between localization of the dual-labeled antibody and CEA expression in tumor and healthy tissue and to determine blood concentrations of the dual labelled antibody at several time points in patients. Clinical trial information: NCT03699332 .