Dose-Finding Study of a CEA-Targeting Agent, SGM-101, for Intraoperative Fluorescence Imaging of Colorectal Cancer

Kim S. de Valk, Marion M. Deken, Dennis P. Schaap, Ruben P. Meijer, Leonora S. Boogerd, Charlotte E. Hoogstins, Maxime J. van der Valk, Ingrid M. Kamerling, Shadhvi S. Bhairosingh, Bérénice Framery, Denise E. Hilling, Koen C. Peeters, Fabian A. Holman, Miranda Kusters, Harm J. Rutten, Françoise Cailler, Jacobus Burggraaf, Alexander L. Vahrmeijer*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Background: Carcinoembryonic antigen is overexpressed in colorectal cancer (CRC), making it an optimal target for fluorescence imaging. A phase I/II study was designed to determine the optimal imaging dose of SGM-101 for intraoperative fluorescence imaging of primary and recurrent CRC. Methods: Patients were included and received a single dose of SGM-101 at least 24 h before surgery. Patients who received routine anticancer therapy (i.e., radiotherapy or chemotherapy) also were eligible. A dedicated near-infrared imaging system was used for real-time fluorescence imaging during surgery. Safety assessments were performed and SGM-101 efficacy was evaluated per dose level to determine the most optimal imaging dose. Results: Thirty-seven patients with CRC were included in the analysis. Fluorescence was visible in all primary and recurrent tumors. In seven patients, no fluorescence was seen; all were confirmed as pathological complete responses after neoadjuvant therapy. Two tumors showed false-positive fluorescence. In the 37 patients, a total of 97 lesions were excised. The highest mean intraoperative tumor-to-background ratio (TBR) of 1.9 (p = 0.019) was seen in the 10-mg dose. This dose showed a sensitivity of 96%, specificity of 63%, and negative predictive value of 94%. Nine patients (24%) had a surgical plan alteration based on fluorescence, with additional malignant lesions detected in six patients. Conclusions: The optimal imaging dose was established at 10 mg 4 days before surgery. The results accentuate the potential of SGM-101 and designated a promising base for the multinational phase III study, which enrolled the first patients in June 2019.

Original languageEnglish
Pages (from-to)1832-1844
Number of pages13
JournalAnnals of Surgical Oncology
Issue number3
Publication statusPublished - Mar 2021

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