title: Site-specifically labeled CA19.9-targeted immunoconjugates for the PET, NIRF, and multimodal PET/NIRF imaging of pancreatic cancer.
abstract: Molecular imaging agents for preoperative positron emission tomography (PET) and near-infrared fluorescent (NIRF)-guided delineation of surgical margins could greatly enhance the diagnosis, staging, and resection of pancreatic cancer. PET and NIRF optical imaging offer complementary clinical applications, enabling the noninvasive whole-body imaging to localize disease and identification of tumor margins during surgery, respectively. We report the development of PET, NIRF, and dual-modal (PET/NIRF) imaging agents, using 5B1, a fully human monoclonal antibody that targets CA19.9, a well-established pancreatic cancer biomarker. Desferrioxamine (DFO) and/or a NIRF dye (FL) were conjugated to the heavy-chain glycans of 5B1, using a robust and reproducible site-specific (ss) labeling methodology to generate three constructs ((ss)DFO-5B1, (ss)FL-5B1, and (ss)dual-5B1) in which the immunoreactivity was not affected by the conjugation of either label. Each construct was evaluated in a s.c. xenograft model, using CA19.9-positive (BxPC3) and -negative (MIAPaCa-2) human pancreatic cancer cell lines. Each construct showed exceptional uptake and contrast in antigen-positive tumors with negligible nonspecific uptake in antigen-negative tumors. Additionally, the dual-modal construct was evaluated in an orthotopic murine pancreatic cancer model, using the human pancreatic cancer cell line, Suit-2. The (ss)dual-5B1 demonstrated a remarkable capacity to delineate metastases and to map the sentinel lymph nodes via tandem PET-computed tomography (PET/CT) and NIRF imaging. Fluorescence microscopy, histopathology, and autoradiography were performed on representative sections of excised tumors to visualize the distribution of the constructs within the tumors. These imaging tools have tremendous potential for further preclinical research and for clinical translation.
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10075; Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, NY 10075;
authors.forename: Jacob L
authors.initials: JL
authors.lastname: Houghton
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10075; Department of Chemistry, Hunter College and the Graduate Center of the City University of New York, New York, NY 10065;
authors.forename: Brian M
authors.initials: BM
authors.lastname: Zeglis
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10075; Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, NY 10075;
authors.forename: Dalya
authors.initials: D
authors.lastname: Abdel-Atti
authors.affiliation: Foundational Biology Group, Thermo Fisher Scientific, Eugene, OR 97402;
authors.forename: Robert
authors.initials: R
authors.lastname: Aggeler
authors.affiliation: Mabvax, San Diego, CA 92121.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Sawada
authors.affiliation: Foundational Biology Group, Thermo Fisher Scientific, Eugene, OR 97402;
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Agnew
authors.affiliation: Mabvax, San Diego, CA 92121.
authors.forename: Wolfgang W
authors.initials: WW
authors.lastname: Scholz
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10075; Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, NY 10075; lewisj2@mskcc.org.
authors.forename: Jason S
authors.initials: JS
authors.lastname: Lewis
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000493:pharmacokinetics; D018395:CA-19-9 Antigen / Q000276:immunology*; D045744:Cell Line, Tumor; D003676:Deferoxamine / Q000737:chemistry; D004195:Disease Models, Animal; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry / Q000276:immunology* / Q000493:pharmacokinetics; D018345:Mice, Knockout; D008819:Mice, Nude; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D064847:Multimodal Imaging / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D049268:Positron-Emission Tomography / Q000379:methods*; D011868:Radioisotopes / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D014018:Tissue Distribution; D014183:Transplantation, Heterologous; D015040:Zirconium / Q000737:chemistry
chemical_list: D000911:Antibodies, Monoclonal; D018395:CA-19-9 Antigen; D005456:Fluorescent Dyes; D018796:Immunoconjugates; D011868:Radioisotopes; D015040:Zirconium; D003676:Deferoxamine
keywords: CA19.9; PET imaging; molecular imaging; pancreatic cancer