Antibody engineering to generate anti-tumor-associated glycoprotein 72 mouse recombinant CC49 IgG with improved solubility, purity, and thermal stability

Article

Author: Muerhoff, A Scott ; Hemken, Philip M ; Lin, Zhihong ; Tu, Bailin

Tumor-associated glycoprotein 72 (TAG-72) is a mucin that is overexpressed heterogeneously on the surface of cancer cells, and is a potential target for immunotherapies for various cancer types. As a tumor marker, TAG-72 is measured with the cancer antigen (CA) 72-4 immunoassay. The murine monoclonal antibody (mAb) CC49 is a second-generation IgG that targets an antigen on TAG-72; however, CC49 has an unfavorable propensity to aggregate, which results in antibody impurity, instability, and low solubility and thus low potency and efficacy for therapeutic and diagnostic applications. Sequence analysis of CC49 revealed aggregation-prone motifs in the variable domain of the light chain. Using antibody engineering approaches, we developed three aggregation-resistant CC49 mIgG2a mutants (CC49M1, CC49M2, and CC49M3). The engineered CC49 mIgG2a mutants retained compatible binding performance with a significantly higher thermal stability. The CC49 mIgG2a mutants also demonstrated an almost 15-fold improvement in solubility, with 97% purity vs 70% purity of the parent molecule at 0.3 mg/mL. The enhanced stability and improved solubility of engineered CC49 could have significant advantages for diagnostic and therapeutic applications.

17 Oct 2023·ACS omega

Characterization of Structurally Diverse ¹⁸F-Labeled d-TCO Derivatives as a PET Probe for Bioorthogonal Pretargeted Imaging.

Article

Author: Van der Veken, Pieter ; Adhikari, Karuna ; Dewulf, Jonatan ; Vangestel, Christel ; Augustyns, Koen ; Elvas, Filipe ; Stroobants, Sigrid

Background: The pretargeted imaging strategy using inverse electron demand Diels-Alder (IEDDA) cycloaddition between a trans-cyclooctene (TCO) and tetrazine (Tz) has emerged and rapidly grown as a promising concept to improve radionuclide imaging and therapy in oncology. This strategy has mostly relied on the use of radiolabeled Tz together with TCO-modified targeting vectors leading to a rapid growth of the number of available radiolabeled tetrazines, while only a few radiolabeled TCOs are currently reported. Here, we aim to develop novel and structurally diverse ¹⁸F-labeled cis-dioxolane-fused TCO (d-TCO) derivatives to further expand the bioorthogonal toolbox for in vivo ligation and evaluate their potential for positron emission tomography (PET) pretargeted imaging. Results: A small series of d-TCO derivatives were synthesized and tested for their reactivity against tetrazines, with all compounds showing fast reaction kinetics with tetrazines. A fluorescence-based pretargeted blocking study was developed to investigate the in vivo ligation of these compounds without labor-intensive prior radiochemical development. Two compounds showed excellent in vivo ligation results with blocking efficiencies of 95 and 97%. Two novel ¹⁸F-labeled d-TCO radiotracers were developed, from which [¹⁸F]MICA-214 showed good in vitro stability, favorable pharmacokinetics, and moderate in vivo stability. Micro-PET pretargeted imaging with [¹⁸F]MICA-214 in mice bearing LS174T tumors treated with tetrazine-modified CC49 monoclonal antibody (mAb) (CC49-Tz) showed significantly higher uptake in tumor tissue in the pretargeted group (CC49-Tz 2.16 ± 0.08% ID/mL) when compared to the control group with nonmodified mAb (CC49 1.34 ± 0.07% ID/mL). Conclusions: A diverse series of fast-reacting fluorinated d-TCOs were synthesized. A pretargeted blocking approach in tumor-bearing mice allowed the choice of a lead compound with fast reaction kinetics with Tz. A novel ¹⁸F-labeled d-TCO tracer was developed and used in a pretargeted PET imaging approach, allowing specific tumor visualization in a mouse model of colorectal cancer. Although further optimization of the radiotracer is needed to enhance the tumor-to-background ratios for pretargeted imaging, we anticipate that the ¹⁸F-labeled d-TCO will find use in studies where increased hydrophilicity and fast bioconjugation are required.

01 Aug 2020·Journal of Surgical ResearchQ4 · MEDICINE

Humanized Anti–Tumor-Associated Glycoprotein–72 for Submillimeter Near-Infrared Detection of Colon Cancer in Metastatic Mouse Models

Q4 · MEDICINE

Article

Author: Hannah M. Hollandsworth ; Filemoni Filemoni ; Siamak Amirfakhri ; Justin Molnar ; Robert M. Hoffman ; Paul J. Yazaki ; Michael Bouvet

BACKGROUNDTumor-associated glycoprotein (TAG)-72 is a pancarcinoma antigen that is overexpressed in greater than 80% of colorectal adenocarcinomas. CC49 is a TAG-72-specific antibody. The aim of the present study was to demonstrate selective imaging of colon tumors and metastases with the humanized TAG-72 antibody (anti-huCC49) conjugated to a near-infrared fluorophore in orthotopic mouse models.METHODSAnti-huCC49 was conjugated to near-infrared dye IR800CW. Mouse imaging was performed with the Pearl Trilogy Small Animal and FLARE Imaging Systems. Subcutaneous mouse models of colon cancer cell line LS174T were used to determine the optimal dose of administration and timing of imaging. Orthotopic mouse models of LS174T were established by surgical orthotopic implantation of LS174T tumors onto the serosa of the cecum. Peritoneal carcinomatosis models were established by injection of LS174T cells into the peritoneum of nude mice. Mice were administered anti-huCC49-IR800 via tail vein injection. Mice were euthanized 72 h later and imaged after laparotomy.RESULTSSubcutaneous LS174T xenografts demonstrated optimal tumor detection 72 h after administration with 50 μg anti-huCC49-IR800CW. Tumors were visualized with fluorescence imaging with a mean tumor-to-liver ratio of 7.39 (standard deviation: 2.76). In the orthotopic model, metastases smaller than 1 mm were fluorescently visualized that were invisible with bright light.CONCLUSIONSAnti-huCC49-IR800CW provides sensitive and specific imaging of colon cancer and metastases at a submillimeter resolution in metastatic nude mice models. This provides a promising near-infrared probe for the imaging of colon cancer and metastases for preoperative diagnosis and fluorescence-guided surgery.

100 Deals associated with 131I-CC49-SCA

External Link

KEGG	Wiki	ATC	Drug Bank
-	131I-CC49-SCA	-	DB15470

R&D Status

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Indication	Highest Phase	Country/Location	Organization	Date
Cardiovascular Diseases	Phase 2	US	SCA Ventures, Inc.	-
Cardiovascular Diseases	Phase 2	US	National Cancer Institute	-
Neoplasms	Phase 2	US	National Cancer Institute	-
Neoplasms	Phase 2	US	SCA Ventures, Inc.	-
Colonic Cancer	Preclinical	CA	Toronto General Hospital	01 Apr 2004
Colonic Cancer	Preclinical	CA	Ontario Cancer Institute	01 Apr 2004

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