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Cheal SM, Chung SK, Vaughn BA, Cheung NKV, Larson SM. Pretargeting: A Path Forward for Radioimmunotherapy. J Nucl Med 2022; 63:1302-1315. [PMID: 36215514 DOI: 10.2967/jnumed.121.262186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/07/2022] [Indexed: 12/19/2022] Open
Abstract
Pretargeted radioimmunodiagnosis and radioimmunotherapy aim to efficiently combine antitumor antibodies and medicinal radioisotopes for high-contrast imaging and high-therapeutic-index (TI) tumor targeting, respectively. As opposed to conventional radioimmunoconjugates, pretargeted approaches separate the tumor-targeting step from the payload step, thereby amplifying tumor uptake while reducing normal-tissue exposure. Alongside contrast and TI, critical parameters include antibody immunogenicity and specificity, availability of radioisotopes, and ease of use in the clinic. Each of the steps can be optimized separately; as modular systems, they can find broad applications irrespective of tumor target, tumor type, or radioisotopes. Although this versatility presents enormous opportunity, pretargeting is complex and presents unique challenges for clinical translation and optimal use in patients. The purpose of this article is to provide a brief historical perspective on the origins and development of pretargeting strategies in nuclear medicine, emphasizing 2 protein delivery systems that have been extensively evaluated (i.e., biotin-streptavidin and hapten-bispecific monoclonal antibodies), as well as radiohaptens and radioisotopes. We also highlight recent innovations, including pretargeting with bioorthogonal chemistry and novel protein vectors (such as self-assembling and disassembling proteins and Affibody molecules). We caution the reader that this is by no means a comprehensive review of the past 3 decades of pretargeted radioimmunodiagnosis and pretargeted radioimmunotherapy. But we do aim to highlight major developmental milestones and to identify benchmarks for success with regard to TI and toxicity in preclinical models and clinically. We believe this approach will lead to the identification of key obstacles to clinical success, revive interest in the utility of radiotheranostics applications, and guide development of the next generation of pretargeted theranostics.
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Affiliation(s)
- Sarah M Cheal
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York;
| | - Sebastian K Chung
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Brett A Vaughn
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Steven M Larson
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
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Handula M, Chen KT, Seimbille Y. IEDDA: An Attractive Bioorthogonal Reaction for Biomedical Applications. Molecules 2021; 26:molecules26154640. [PMID: 34361793 PMCID: PMC8347371 DOI: 10.3390/molecules26154640] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/26/2022] Open
Abstract
The pretargeting strategy has recently emerged in order to overcome the limitations of direct targeting, mainly in the field of radioimmunotherapy (RIT). This strategy is directly dependent on chemical reactions, namely bioorthogonal reactions, which have been developed for their ability to occur under physiological conditions. The Staudinger ligation, the copper catalyzed azide-alkyne cycloaddition (CuAAC) and the strain-promoted [3 + 2] azide–alkyne cycloaddition (SPAAC) were the first bioorthogonal reactions introduced in the literature. However, due to their incomplete biocompatibility and slow kinetics, the inverse-electron demand Diels-Alder (IEDDA) reaction was advanced in 2008 by Blackman et al. as an optimal bioorthogonal reaction. The IEDDA is the fastest bioorthogonal reaction known so far. Its biocompatibility and ideal kinetics are very appealing for pretargeting applications. The use of a trans-cyclooctene (TCO) and a tetrazine (Tz) in the reaction encouraged researchers to study them deeply. It was found that both reagents are sensitive to acidic or basic conditions. Furthermore, TCO is photosensitive and can be isomerized to its cis-conformation via a radical catalyzed reaction. Unfortunately, the cis-conformer is significantly less reactive toward tetrazine than the trans-conformation. Therefore, extensive research has been carried out to optimize both click reagents and to employ the IEDDA bioorthogonal reaction in biomedical applications.
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Affiliation(s)
- Maryana Handula
- Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands;
| | - Kuo-Ting Chen
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974301, Taiwan;
| | - Yann Seimbille
- Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands;
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
- Correspondence: ; Tel.: +31-10-703-8961
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Liu G. A Revisit to the Pretargeting Concept-A Target Conversion. Front Pharmacol 2018; 9:1476. [PMID: 30618765 PMCID: PMC6304396 DOI: 10.3389/fphar.2018.01476] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/03/2018] [Indexed: 01/22/2023] Open
Abstract
Pretargeting is often used as a tumor targeting strategy that provides much higher tumor to non-tumor ratios than direct-targeting using radiolabeled antibody. Due to the multiple injections, pretargeting is investigated less than direct targeting, but the high T/NT ratios have rendered it more useful for therapy. While the progress in using this strategy for tumor therapy has been regularly reviewed in the literature, this review focuses on the nature and quantitative understanding of the pretargeting concept. By doing so, it is the goal of this review to accelerate pretargeting development and translation to the clinic and to prepare the researchers who are not familiar with the pretargeting concept but are interested in applying it. The quantitative understanding is presented in a way understandable to the average researchers in the areas of drug development and clinical translation who have the basic concept of calculus and general chemistry.
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Affiliation(s)
- Guozheng Liu
- Department of Radiology, University of Massachusetts Medical School Worcester, MA, United States
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Zeglis BM, Brand C, Abdel-Atti D, Carnazza KE, Cook BE, Carlin S, Reiner T, Lewis JS. Optimization of a Pretargeted Strategy for the PET Imaging of Colorectal Carcinoma via the Modulation of Radioligand Pharmacokinetics. Mol Pharm 2015; 12:3575-87. [PMID: 26287993 PMCID: PMC4696756 DOI: 10.1021/acs.molpharmaceut.5b00294] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Pretargeted PET imaging has emerged as an effective strategy for merging the exquisite selectivity of antibody-based targeting vectors with the rapid pharmacokinetics of radiolabeled small molecules. We previously reported the development of a strategy for the pretargeted PET imaging of colorectal cancer based on the bioorthogonal inverse electron demand Diels-Alder reaction between a tetrazine-bearing radioligand and a transcyclooctene-modified huA33 immunoconjugate. Although this method effectively delineated tumor tissue, its clinical potential was limited by the somewhat sluggish clearance of the radioligand through the gastrointestinal tract. Herein, we report the development and in vivo validation of a pretargeted strategy for the PET imaging of colorectal carcinoma with dramatically improved pharmacokinetics. Two novel tetrazine constructs, Tz-PEG7-NOTA and Tz-SarAr, were synthesized, characterized, and radiolabeled with (64)Cu in high yield (>90%) and radiochemical purity (>99%). PET imaging and biodistribution experiments in healthy mice revealed that although (64)Cu-Tz-PEG7-NOTA is cleared via both the gastrointestinal and urinary tracts, (64)Cu-Tz-SarAr is rapidly excreted by the renal system alone. On this basis, (64)Cu-Tz-SarAr was selected for further in vivo evaluation. To this end, mice bearing A33 antigen-expressing SW1222 human colorectal carcinoma xenografts were administered huA33-TCO, and the immunoconjugate was given 24 h to accumulate at the tumor and clear from the blood, after which (64)Cu-Tz-SarAr was administered via intravenous tail vein injection. PET imaging and biodistribution experiments revealed specific uptake of the radiotracer in the tumor at early time points (5.6 ± 0.7 %ID/g at 1 h p.i.), high tumor-to-background activity ratios, and rapid elimination of unclicked radioligand. Importantly, experiments with longer antibody accumulation intervals (48 and 120 h) yielded slight decreases in tumoral uptake but also concomitant increases in tumor-to-blood activity concentration ratios. This new strategy offers dosimetric benefits as well, yielding a total effective dose of 0.041 rem/mCi, far below the doses produced by directly labeled (64)Cu-NOTA-huA33 (0.133 rem/mCi) and (89)Zr-DFO-huA33 (1.54 rem/mCi). Ultimately, this pretargeted PET imaging strategy boasts a dramatically improved pharmacokinetic profile compared to our first generation system and is capable of clearly delineating tumor tissue with high image contrast at only a fraction of the radiation dose created by directly labeled radioimmunoconjugates.
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Affiliation(s)
- Brian M. Zeglis
- Department of Chemistry and Biochemistry, Hunter College and the Graduate Center of the City University of New York, New York, New York 10021, United States
| | - Christian Brand
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Dalya Abdel-Atti
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Kathryn E. Carnazza
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Brendon E. Cook
- Department of Chemistry and Biochemistry, Hunter College and the Graduate Center of the City University of New York, New York, New York 10021, United States
| | - Sean Carlin
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Thomas Reiner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Jason S. Lewis
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
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Abstract
The eradication of cancer remains a vexing problem despite recent advances in our understanding of the molecular basis of neoplasia. One therapeutic approach that has demonstrated potential involves the selective targeting of radionuclides to cancer-associated cell surface antigens using monoclonal antibodies. Such radioimmunotherapy (RIT) permits the delivery of a high dose of therapeutic radiation to cancer cells, while minimizing the exposure of normal cells. Although this approach has been investigated for several decades, the cumulative advances in cancer biology, antibody engineering and radiochemistry in the past decade have markedly enhanced the ability of RIT to produce durable remissions of multiple cancer types.
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Affiliation(s)
- Steven M Larson
- Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
| | - Jorge A Carrasquillo
- Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
| | - Nai-Kong V Cheung
- 1] Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA. [2]
| | - Oliver W Press
- 1] Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, P.O. BOX 19024, Seattle, Washington 98109, USA. [2]
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Abstract
Monoclonal antibody therapy has revolutionized cancer treatment by significantly improving patient survival both in solid tumors and hematologic malignancies. Recent technological advances have increased the effectiveness of immunotherapy leading to its broader application in diverse treatment settings. Immunoconjugates (ICs) consist of a cytotoxic effector covalently linked to a monoclonal antibody that enables the targeted delivery of its therapeutic payload to tumors based on cell-surface receptor recognition. ICs are classified into 3 groups based on their effector type: immunotoxins (protein toxin), radioimmunoconjugates (radionuclide), and antibody drug conjugates (small-molecule drug). Optimization of each individual component of an IC (antibody, linker, and effector) is essential for therapeutic efficacy. Clinical trials have been conducted to investigate the effectiveness of ICs in hematologic malignancies both as monotherapy and in multiagent regimens in relapsed/refractory disease as well as frontline settings. These studies have yielded encouraging results particularly in lymphoma. ICs comprise an exciting group of therapeutics that promise to play an increasingly important role in the management of hematologic malignancies.
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Zeglis BM, Sevak KK, Reiner T, Mohindra P, Carlin SD, Zanzonico P, Weissleder R, Lewis JS. A pretargeted PET imaging strategy based on bioorthogonal Diels-Alder click chemistry. J Nucl Med 2013; 54:1389-96. [PMID: 23708196 DOI: 10.2967/jnumed.112.115840] [Citation(s) in RCA: 222] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
UNLABELLED The specificity of antibodies have made immunoconjugates promising vectors for the delivery of radioisotopes to cancer cells; however, their long pharmacologic half-lives necessitate the use of radioisotopes with long physical half-lives, a combination that leads to high radiation doses to patients. Therefore, the development of targeting modalities that harness the advantages of antibodies without their pharmacokinetic limitations is desirable. To this end, we report the development of a methodology for pretargeted PET imaging based on the bioorthogonal Diels-Alder click reaction between tetrazine and transcyclooctene. METHODS A proof-of-concept system based on the A33 antibody, SW1222 colorectal cancer cells, and (64)Cu was used. The huA33 antibody was covalently modified with transcyclooctene, and a NOTA-modified tetrazine was synthesized and radiolabeled with (64)Cu. Pretargeted in vivo biodistribution and PET imaging experiments were performed with athymic nude mice bearing A33 antigen-expressing, SW1222 colorectal cancer xenografts. RESULTS The huA33 antibody was modified with transcyclooctene to produce a conjugate with high immunoreactivity, and the (64)Cu-NOTA-labeled tetrazine ligand was synthesized with greater than 99% purity and a specific activity of 9-10 MBq/μg. For in vivo experiments, mice bearing SW1222 xenografts were injected with transcyclooctene-modified A33; after allowing 24 h for accumulation of the antibody in the tumor, the mice were injected with (64)Cu-NOTA-labeled tetrazine for PET imaging and biodistribution experiments. At 12 h after injection, the retention of uptake in the tumor (4.1 ± 0.3 percent injected dose per gram), coupled with the fecal excretion of excess radioligand, produced images with high tumor-to-background ratios. PET imaging and biodistribution experiments performed using A33 directly labeled with either (64)Cu or (89)Zr revealed that although absolute tumor uptake was higher with the directly radiolabeled antibodies, the pretargeted system yielded comparable images and tumor-to-muscle ratios at 12 and 24 h after injection. Further, dosimetry calculations revealed that the (64)Cu pretargeting system resulted in only a fraction of the absorbed background dose of A33 directly labeled with (89)Zr (0.0124 mSv/MBq vs. 0.4162 mSv/MBq, respectively). CONCLUSION The high quality of the images produced by this pretargeting approach, combined with the ability of the methodology to dramatically reduce nontarget radiation doses to patients, marks this system as a strong candidate for clinical translation.
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Affiliation(s)
- Brian M Zeglis
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
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Abstract
INTRODUCTION Over a half a century ago, radiolabeled antibodies were shown to localize selectively in tissues based on the expression of unique antigens. Antibodies have since become the de facto targeting agent, even inspiring the development of non-antibody compounds for targeting purposes. AREAS COVERED In this article, we review various aspects of how antibodies are transforming the way cancer is being detected and treated, with the growing demand for unconjugated and many new antibody conjugates. While unconjugated antibodies continue to garner most of the attention, interest in new antibody drug conjugates and immunotoxins has expanded over the past few years. However, there continues to be active research with new radioimmunoconjugates for imaging and therapy, particularly with α-emitters, as well as antibody-targeted cytokines and other biological response modifiers. EXPERT OPINION The increasing number of new agents being developed and tested clinically suggests that antibody-targeted compounds will have an expanding role in the future.
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Affiliation(s)
- David M Goldenberg
- Center for Molecular Medicine and Immunology, 300 The American Road, Morris Plains, NJ 07950, USA
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Nayak TK, Brechbiel MW. 86Y based PET radiopharmaceuticals: radiochemistry and biological applications. Med Chem 2012; 7:380-8. [PMID: 21711222 DOI: 10.2174/157340611796799249] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/14/2011] [Indexed: 11/22/2022]
Abstract
Development of targeted radionuclide therapy with (90)Y labeled antibodies and peptides has gained momentum in the past decade due to the successes of (90)Y-ibritumomab tiuxetan and (90)Y-DOTA-Phe(1)-Tyr(3)-octreotide in treatment of cancer. (90)Y is a pure β(-)-emitter and cannot be imaged for patient-specific dosimetry which is essential for pre-therapeutic treatment planning and accurate absorbed dose estimation in individual patients to mitigate radiation related risks. This review article describes the utility of (86)Y, a positron emitter (33%) with a 14.7-h half-life that can be imaged by positron emission tomography and used as an isotopically matched surrogate radionuclide for (90)Y radiation doses estimations. This review discusses various aspects involved in the development of (86)Y labeled radiopharmaceuticals with the specific emphasis on the radiochemistry and biological applications with antibodies and peptides.
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Affiliation(s)
- Tapan K Nayak
- Imaging Sciences, Translational Research Sciences, Pharma Research and Early Development, F. Hoffmann-La Roche Ltd., Basel, Switzerland
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Erdag B, Balcioglu BK, Bahadir AO, Serhatli M, Kacar O, Bahar A, Seker UOS, Akgun E, Ozkan A, Kilic T, Tamerler C, Baysal K. Identification of novel neutralizing single-chain antibodies against vascular endothelial growth factor receptor 2. Biotechnol Appl Biochem 2011; 58:412-22. [PMID: 22172104 DOI: 10.1002/bab.61] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 09/23/2011] [Indexed: 01/05/2023]
Abstract
Human vascular endothelial growth factor (VEGF) and its receptor (VEGFR-2/kinase domain receptor [KDR]) play a crucial role in angiogenesis, which makes the VEGFR-2 signaling pathway a major target for therapeutic applications. In this study, a single-chain antibody phage display library was constructed from spleen cells of mice immunized with recombinant human soluble extracellular VEGFR-2/KDR consisting of all seven extracellular domains (sKDR D1-7) to obtain antibodies that block VEGF binding to VEGFR-2. Two specific single-chain antibodies (KDR1.3 and KDR2.6) that recognized human VEGFR-2 were selected; diversity analysis of the clones was performed by BstNI fingerprinting and nucleotide sequencing. The single-chain variable fragments (scFvs) were expressed in soluble form and specificity of interactions between affinity purified scFvs and VEGFR-2 was confirmed by ELISA. Binding of the recombinant antibodies for VEGFR-2 receptors was investigated by surface plasmon resonance spectroscopy. In vitro cell culture assays showed that KDR1.3 and KDR2.6 scFvs significantly suppressed the mitogenic response of human umbilical vein endothelial cells to recombinant human VEGF(165) in a dose-dependent manner, and reduced VEGF-dependent cell proliferation by 60% and 40%, respectively. In vivo analysis of these recombinant antibodies in a rat cornea angiogenesis model revealed that both antibodies suppressed the development of new corneal vessels (p < 0.05). Overall, in vitro and in vivo results disclose strong interactions of KDR1.3 and KDR2.6 scFvs with VEGFR-2. These findings indicate that KDR1.3 and KDR2.6 scFvs are promising antiangiogenic therapeutic agents.
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Affiliation(s)
- Berrin Erdag
- TUBITAK Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey.
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Goldenberg DM. Introduction to the supplement, "Cancer Therapy with Antibodies and Immunoconjugates". Cancer 2010; 116:1011-2. [PMID: 20127946 PMCID: PMC2820135 DOI: 10.1002/cncr.24786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
This supplement includes 16 representative articles presented at the 12th Conference on Cancer Therapy With Antibodies and Immunconjugates, Parsippany, New Jersey, October 16-18, 2008, encompassing cancer treatment with unconjugated and isotope-conjugated antibodies targeting selective cancer biomarkers.
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Goldenberg DM. Radiolabelled monoclonal antibodies in the treatment of metastatic cancer. ACTA ACUST UNITED AC 2010; 14:39-42. [PMID: 17576463 PMCID: PMC1891189 DOI: 10.3747/co.2007.112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- D M Goldenberg
- GardenState Cancer Center, Belleville, New Jersey, U.S.A.
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Zoller F, Eisenhut M, Haberkorn U, Mier W. Endoradiotherapy in cancer treatment--basic concepts and future trends. Eur J Pharmacol 2009; 625:55-62. [PMID: 19836381 DOI: 10.1016/j.ejphar.2009.05.035] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 05/07/2009] [Accepted: 05/18/2009] [Indexed: 11/24/2022]
Abstract
Endoradiotherapy represents an alternative therapeutic method in cancer treatment with advantageous features compared to chemotherapy and radiation therapy. Intelligent dose delivery concepts using small drugs, peptides or antibodies as radionuclide carriers enable the verification of a selective accumulation in the tumour lesion and to reduce radiation toxicity for the peripheral organs. The development of endoradiotherapeutic agents, especially chelator-conjugated biomolecules, for example ibritumomab tiuxetan or DOTATOC, gains importance due to the stable complexation of versatile radiometals, such as (90)Y or (177)Lu. The rational design of novel target binding sides and their grafting into a drug scaffold is a highly promising strategy, which may promote further implication in endoradiotherapy. This review highlights the basic concepts of endoradiotherapy and discusses the potential of targeted therapy and the properties of energy-rich particles emitted by radionuclides for tumour therapy.
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Affiliation(s)
- Frederic Zoller
- Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Centre, INF 280, 69120 Heidelberg, Germany
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Abstract
This article provides an overview of a semiempirical pretargeting model now under development. After a brief review of the pretargeting concept, the strategies available, and the complexities of optimizing the dosage and timing, a semiempirical model is described that is not only capable of optimizing dosage and timing but also capable of predicting the results of pretargeting as a function of most pretargeting variables. The model requires knowledge of the pharmacokinetics of both the pretargeting agent (usually an antibody) and the effector, the accessibility of the pretargeting antibody for the effector, and their quantitative relationships in vivo. Several misconceptions that often surround pretargeting are also clarified.
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Affiliation(s)
- Guozheng Liu
- Department of Radiology, Division of Nuclear Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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Liu G, Dou S, Rusckowski M, Hnatowich DJ. An experimental and theoretical evaluation of the influence of pretargeting antibody on the tumor accumulation of effector. Mol Cancer Ther 2008; 7:1025-32. [PMID: 18483292 DOI: 10.1158/1535-7163.mct-07-2203] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In treating tumors by pretargeting, the antitumor antibody and the cytotoxic effector (e.g., toxins and radioactivity) are separately administered. Therefore, pretargeting is more complicated with many variables. We are conducting studies to understand the influence of each variable using a novel recognition pair of mutually complementary phosphorodiamidate morpholino oligomers (MORF/cMORF). Earlier we developed a semi-empirical model capable of accurately predicting the behavior of a radiolabeled cMORF effector with variations in dosages and timing. We have now extended the model to predict the effector behavior, in particular, its maximum percent tumor accumulation (MPTA) in mice pretargeted with three different MORF-conjugated antibodies (MN14, B72.3, and CC49). The MN14 and the CC49 target different antigens in the same tumor, whereas the CC49 and the B72.3 target the same antigen but with very different tumor accumulation. By comparing the pretargeting results of these three antibodies with our prediction, we confirmed that the MPTA of the radiolabeled cMORF effector in the LS174T tumor is independent of the antibodies. In conclusion, the MPTA cannot be improved through the use of different pretargeting antibodies, although different antibodies may improve the maximum absolute tumor accumulation, the heterogeneity, and/or the tumor-to-normal tissue ratios of the effector. This conclusion will apply equally well to effectors carrying a fluorescent probe, an anticancer agent, or a radioactive imaging agent.
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Affiliation(s)
- Guozheng Liu
- Division of Nuclear Medicine, Department of Radiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655-0243, USA.
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Sharkey RM, Karacay H, Vallabhajosula S, McBride WJ, Rossi EA, Chang CH, Goldsmith SJ, Goldenberg DM. Metastatic human colonic carcinoma: molecular imaging with pretargeted SPECT and PET in a mouse model. Radiology 2008; 246:497-507. [PMID: 18227543 DOI: 10.1148/radiol.2462070229] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively determine if a bispecific monoclonal antibody (MoAb) pretargeting method with a radiolabeled hapten peptide can depict small (<0.3 mm in diameter) microdisseminated human colon cancer colonies in the lungs of nude mice. MATERIALS AND METHODS Animal studies were approved in advance by animal care and use committees. Animals injected intravenously with a human colon cancer cell line to establish microdisseminated colonies in the lungs were pretargeted with TF2--a recombinant, humanized, anti-carcinoembryonic antigen (CEA) and anti-histamine-succinyl-glycine (HSG) bispecific MoAb; 21 hours later, a radiolabeled HSG peptide was given. Imaging and necropsy data for tumor-bearing animals given the anti-CEA bispecific MoAb (n = 38, all studies) were compared with those of animals given fluorine 18 ((18)F) fluorodeoxyglucose (FDG) (n = 15, all studies), peptide alone (n = 20, all studies), or an irrelevant anti-CD22 bispecific MoAb (n = 12, all studies). Uptake of these agents in the lungs of non-tumor-bearing animals enabled assessment of specificity (n = 15, 4, and 6 for TF2 pretarget, hapten peptide alone, and (18)F-FDG, respectively). RESULTS TF2-pretargeting helped localize tumors in the lungs within 1.5 hours of the radiolabeled HSG peptide injection, while the peptide alone, irrelevant bispecific MoAb pretargeted peptide, and (18)F-FDG failed. Necropsy data indicated that the signal in tumor-bearing lungs was five times higher than in blood within 1.5 hours, increasing to 50 times higher by 24 hours. Peptide uptake in tumor-bearing lungs pretargeted with TF2 was nine times higher than in non-tumor-bearing lungs, while it was only 1.5-fold higher with (18)F-FDG or the peptide alone. Micro-positron emission tomographic (PET) images showed discrete uptake in individual metastatic tumor colonies; autoradiographic data demonstrated selective targeting within the lungs, including metastases less than 0.3 mm in diameter. CONCLUSION Bispecific antibody pretargeting is highly specific for imaging micrometastatic disease and may thus provide a complementary method to (18)F-FDG at clinical examination.
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Affiliation(s)
- Robert M Sharkey
- Center for Molecular Medicine and Immunology, Garden State Cancer Center, 520 Belleville Ave, Belleville, NJ 07109, USA.
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Goldenberg DM, Rossi EA, Sharkey RM, McBride WJ, Chang CH. Multifunctional Antibodies by the Dock-and-Lock Method for Improved Cancer Imaging and Therapy by Pretargeting. J Nucl Med 2007; 49:158-63. [DOI: 10.2967/jnumed.107.046185] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
This article reviews the development of radioimmunoconjugates as a new class of cancer therapeutics. Numerous conjugates involving different antigen targets, antibody forms, radionuclides and methods of radiochemistry have been studied in the half-century since radioactive antibodies were first used in model systems to selectively target radiation to tumors. Whereas directly conjugated antibodies, fragments and subfragments have shown promise preclinically, the same approaches have not gained success in patients except in radiosensitive hematological neoplasms, or in settings involving minimal or locoregional disease. The separation of tumor targeting from the delivery of the therapeutic radionuclide in a multistep process called pretargeting has the potential to overcome many of the limitations of conventional, or one-step, radioimmunotherapy, with initial preclinical and clinical data showing increased sensitivity, specificity and higher radiation doses delivered. Our particular focus in pretargeting is the use of bispecific, trimeric (three Fab's) constructs made by a new antibody engineering method termed 'dock-and-lock.
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Affiliation(s)
- D M Goldenberg
- Garden State Cancer Center, Center for Molecular Medicine and Immunology, Belleville, NJ 07109, USA.
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Tolmachev V, Orlova A, Pehrson R, Galli J, Baastrup B, Andersson K, Sandström M, Rosik D, Carlsson J, Lundqvist H, Wennborg A, Nilsson FY. Radionuclide therapy of HER2-positive microxenografts using a 177Lu-labeled HER2-specific Affibody molecule. Cancer Res 2007; 67:2773-82. [PMID: 17363599 DOI: 10.1158/0008-5472.can-06-1630] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A radiolabeled anti-HER2 Affibody molecule (Z(HER2:342)) targets HER2-expressing xenografts with high selectivity and gives good imaging contrast. However, the small size (approximately 7 kDa) results in rapid glomerular filtration and high renal accumulation of radiometals, thus excluding targeted therapy. Here, we report that reversible binding to albumin efficiently reduces the renal excretion and uptake, enabling radiometal-based nuclide therapy. The dimeric Affibody molecule (Z(HER2:342))(2) was fused with an albumin-binding domain (ABD) conjugated with the isothiocyanate derivative of CHX-A''-DTPA and labeled with the low-energy beta-emitter (177)Lu. The obtained conjugate [CHX-A''-DTPA-ABD-(Z(HER2:342))(2)] had a dissociation constant of 18 pmol/L to HER2 and 8.2 and 31 nmol/L for human and murine albumin, respectively. The radiolabeled conjugate displayed specific binding to HER2-expressing cells and good cellular retention in vitro. In vivo, fusion with ABD enabled a 25-fold reduction of renal uptake in comparison with the nonfused dimer molecule (Z(HER2:342))(2). Furthermore, the biodistribution showed high and specific uptake of the conjugate in HER2-expressing tumors. Treatment of SKOV-3 microxenografts (high HER2 expression) with 17 or 22 MBq (177)Lu-CHX-A''-DTPA-ABD-(Z(HER2:342))(2) completely prevented formation of tumors, in contrast to mice given PBS or 22 MBq of a radiolabeled non-HER2-binding Affibody molecule. In LS174T xenografts (low HER2 expression), this treatment resulted in a small but significant increase of the survival time. Thus, fusion with ABD improved the in vivo biodistribution, and the results highlight (177)Lu-CHX-A''-DTPA-ABD-(Z(HER2:342))(2) as a candidate for treatment of disseminated tumors with a high level of HER2 expression.
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Tolmachev V, Orlova A, Nilsson FY, Feldwisch J, Wennborg A, Abrahmsén L. Affibody molecules: potential for in vivo imaging of molecular targets for cancer therapy. Expert Opin Biol Ther 2007; 7:555-68. [PMID: 17373906 DOI: 10.1517/14712598.7.4.555] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Targeting radionuclide imaging of tumor-associated antigens may help to select patients who will benefit from a particular biological therapy. Affibody molecules are a novel class of small (approximately 7 kDa) phage display-selected affinity proteins, based on the B-domain scaffold of staphylococcal protein A. A large library (3 x 10(9) variants) has enabled selection of high-affinity (up to 22 pM) binders for a variety of tumor-associated antigens. The small size of Affibody molecules provides rapid tumor localization and fast clearance from nonspecific compartments. Preclinical studies have demonstrated the potential of Affibody molecules for specific and high-contrast radionuclide imaging of HER2 in vivo, and pilot clinical data using indium-111 and gallium-68 labeled anti-HER2 Affibody tracer have confirmed its utility for radionuclide imaging in cancer patients.
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Jain M, Venkatraman G, Batra SK. Optimization of radioimmunotherapy of solid tumors: biological impediments and their modulation. Clin Cancer Res 2007; 13:1374-82. [PMID: 17309914 DOI: 10.1158/1078-0432.ccr-06-2436] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In contrast to the overwhelming success of radiolabeled antibodies in treating hematologic malignancies, only modest success has been achieved in the radioimmunotherapy of solid tumors. One of the major limitations in successful application of radioimmunotherapy is the large molecular size of the intact immunoglobulin that results in prolonged serum half-life and poor tumor penetration and uptake. With the advent of antibody engineering, small molecular weight antibody fragments exhibiting improved pharmacokinetics and tumor penetration have been generated. However, their clinical application has been limited by suboptimal tumor uptake and short tumor residence time. There is a greater realization that optimization of the molecular size of the antibodies alone is not sufficient for clinical success of radioimmunotherapy. In addition to their size, radiolabeled antibodies encounter other impediments before reaching their target antigens expressed on the cell surface of solid tumors. Some of the barriers include poor blood flow in large tumors, permeability of vascular endothelium, elevated interstitial fluid pressure of tumor stroma, and heterogeneous antigen expression. Recent research has considerably improved our understanding and appreciation of these forces, and the new wave of optimization strategies involves the use of biological modifiers to modulate the impediments posed by solid tumors. In combination with radiolabeled antibodies, various agents are being used to improve the tumor blood flow, enhance vascular permeability, lower tumor interstitial fluid pressure by modulating stromal cells and extracellular matrix components, up-regulate the expression of target antigens, and improve the penetration and retention of the radiopharmaceuticals. This review outlines ongoing research efforts involving biological modifiers to optimize the uptake and efficacy of radiolabeled antibodies for the treatment of solid tumors.
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Affiliation(s)
- Maneesh Jain
- Department of Biochemistry and Molecular Biology, Department of Pathology and Microbiology, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-5870, USA
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