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Ramogida C, Price E. Transition and Post-Transition Radiometals for PET Imaging and Radiotherapy. Methods Mol Biol 2024; 2729:65-101. [PMID: 38006492 DOI: 10.1007/978-1-0716-3499-8_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Radiometals are an exciting class of radionuclides because of the large number of metallic elements available that have medically useful isotopes. To properly harness radiometals, they must be securely bound by chelators, which must be carefully matched to the radiometal ion to maximize radiolabeling performance and the stability of the resulting complex. This chapter focuses on practical aspects of radiometallation chemistry including chelator selection, radiolabeling procedures and conditions, radiolysis prevention, purification, quality control, requisite equipment and reagents, and useful tips.
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Affiliation(s)
- Caterina Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada.
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.
| | - Eric Price
- Department of Chemistry, College of Arts and Science, University of Saskatchewan, Saskatoon, SK, Canada
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2
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Morgan KA, Rudd SE, Noor A, Donnelly PS. Theranostic Nuclear Medicine with Gallium-68, Lutetium-177, Copper-64/67, Actinium-225, and Lead-212/203 Radionuclides. Chem Rev 2023; 123:12004-12035. [PMID: 37796539 DOI: 10.1021/acs.chemrev.3c00456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
Molecular changes in malignant tissue can lead to an increase in the expression levels of various proteins or receptors that can be used to target the disease. In oncology, diagnostic imaging and radiotherapy of tumors is possible by attaching an appropriate radionuclide to molecules that selectively bind to these target proteins. The term "theranostics" describes the use of a diagnostic tool to predict the efficacy of a therapeutic option. Molecules radiolabeled with γ-emitting or β+-emitting radionuclides can be used for diagnostic imaging using single photon emission computed tomography or positron emission tomography. Radionuclide therapy of disease sites is possible with either α-, β-, or Auger-emitting radionuclides that induce irreversible damage to DNA. This Focus Review centers on the chemistry of theranostic approaches using metal radionuclides for imaging and therapy. The use of tracers that contain β+-emitting gallium-68 and β-emitting lutetium-177 will be discussed in the context of agents in clinical use for the diagnostic imaging and therapy of neuroendocrine tumors and prostate cancer. A particular emphasis is then placed on the chemistry involved in the development of theranostic approaches that use copper-64 for imaging and copper-67 for therapy with functionalized sarcophagine cage amine ligands. Targeted therapy with radionuclides that emit α particles has potential to be of particular use in late-stage disease where there are limited options, and the role of actinium-225 and lead-212 in this area is also discussed. Finally, we highlight the challenges that impede further adoption of radiotheranostic concepts while highlighting exciting opportunities and prospects.
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Affiliation(s)
- Katherine A Morgan
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
| | - Stacey E Rudd
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
| | - Asif Noor
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
| | - Paul S Donnelly
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne 3010, Australia
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3
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Kauffman N, Singh SK, Morrison J, Zinn KR. Effective therapy with Bismuth-212 labeled macroaggregated albumin in orthotopic mouse breast tumor models. Front Chem 2023; 11:1204872. [PMID: 37234203 PMCID: PMC10206259 DOI: 10.3389/fchem.2023.1204872] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023] Open
Abstract
Intravascularly administered radiation therapy using beta (β-)-emitting radioisotopes has relied on either intravenously injected radiolabeled peptides that target cancer or radiolabeled microspheres that are trapped in the tumor following intra-arterial delivery. More recently, targeted intravenous radiopeptide therapies have explored the use of alpha (α)-particle emitting radioisotopes, but microspheres radiolabeled with α-particle emitters have not yet been studied. Here, FDA-approved macroaggregated albumin (MAA) particles were radiolabeled with Bismuth-212 (Bi-212-MAA) and evaluated using clonogenic and survival assays in vitro and using immune-competent mouse models of breast cancer. The in vivo biodistribution of Bi-212-MAA was investigated in Balb/c and C57BL/6 mice with 4T1 and EO771 orthotopic breast tumors, respectively. The same orthotopic breast cancer models were used to evaluate the treatment efficacy of Bi-212-MAA. Our results showed that macroaggregated albumin can be stably radiolabeled with Bi-212 and that Bi-212-MAA can deliver significant radiation therapy to reduce the growth and clonogenic potential of 4T1 and EO771 cells in vitro. Additionally, Bi-212-MAA treatment upregulated γH2AX and cleaved Caspase-3 expression in 4T1 cells. Biodistribution analyses showed 87-93% of the Bi-212-MAA remained in 4T1 and EO771 tumors 2 and 4 h after injection. Following single-tumor treatments with Bi-212-MAA there was a significant reduction in the growth of both 4T1 and EO771 breast tumors over the 18-day monitoring period. Overall, these findings showed that Bi-212-MAA was stably radiolabeled and inhibited breast cancer growth. Bi-212-MAA is an exciting platform to study α-particle therapy and will be easily translatable to larger animal models and human clinical trials.
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Affiliation(s)
- Nathan Kauffman
- Comparative Medicine and Integrative Biology, Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Satyendra Kumar Singh
- Department of Biomedical Engineering, Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - James Morrison
- Advanced Radiology Services, Grand Rapids, MI, United States
| | - Kurt R. Zinn
- Departments of Radiology, Biomedical Engineering, Small Animal Clinical Sciences, Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States
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4
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Li J, Huang T, Hua J, Wang Q, Su Y, Chen P, Bidlingmaier S, Li A, Xie Z, Bidkar AP, Shen S, Shi W, Seo Y, Flavell RR, Gioeli D, Dreicer R, Li H, Liu B, He J. CD46 targeted 212Pb alpha particle radioimmunotherapy for prostate cancer treatment. J Exp Clin Cancer Res 2023; 42:61. [PMID: 36906664 PMCID: PMC10007843 DOI: 10.1186/s13046-023-02636-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/01/2023] [Indexed: 03/13/2023] Open
Abstract
We recently identified CD46 as a novel prostate cancer cell surface antigen that shows lineage independent expression in both adenocarcinoma and small cell neuroendocrine subtypes of metastatic castration resistant prostate cancer (mCRPC), discovered an internalizing human monoclonal antibody YS5 that binds to a tumor selective CD46 epitope, and developed a microtubule inhibitor-based antibody drug conjugate that is in a multi-center phase I trial for mCRPC (NCT03575819). Here we report the development of a novel CD46-targeted alpha therapy based on YS5. We conjugated 212Pb, an in vivo generator of alpha-emitting 212Bi and 212Po, to YS5 through the chelator TCMC to create the radioimmunoconjugate, 212Pb-TCMC-YS5. We characterized 212Pb-TCMC-YS5 in vitro and established a safe dose in vivo. We next studied therapeutic efficacy of a single dose of 212Pb-TCMC-YS5 using three prostate cancer small animal models: a subcutaneous mCRPC cell line-derived xenograft (CDX) model (subcu-CDX), an orthotopically grafted mCRPC CDX model (ortho-CDX), and a prostate cancer patient-derived xenograft model (PDX). In all three models, a single dose of 0.74 MBq (20 µCi) 212Pb-TCMC-YS5 was well tolerated and caused potent and sustained inhibition of established tumors, with significant increases of survival in treated animals. A lower dose (0.37 MBq or 10 µCi 212Pb-TCMC-YS5) was also studied on the PDX model, which also showed a significant effect on tumor growth inhibition and prolongation of animal survival. These results demonstrate that 212Pb-TCMC-YS5 has an excellent therapeutic window in preclinical models including PDXs, opening a direct path for clinical translation of this novel CD46-targeted alpha radioimmunotherapy for mCRPC treatment.
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Affiliation(s)
- Jun Li
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22903, USA
- Department of Nuclear Medicine, Peking University Shenzhen Hospital, Guangdong, 518036, China
| | - Tao Huang
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22903, USA
| | - Jun Hua
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22903, USA
- Department of Nuclear Medicine, Chongqing Cancer Hospital, Chongqing University, Chongqing, China
| | - Qiong Wang
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Department of Pathology, University of Virginia, Charlottesville, VA, 22903, USA
| | - Yang Su
- Department of Anesthesia, University of California, San Francisco, CA, 94110, USA
| | - Ping Chen
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22903, USA
- Department of Nuclear Medicine, Peking University Shenzhen Hospital, Guangdong, 518036, China
| | - Scott Bidlingmaier
- Department of Anesthesia, University of California, San Francisco, CA, 94110, USA
| | - Allan Li
- Department of Anesthesia, University of California, San Francisco, CA, 94110, USA
| | - Zhongqiu Xie
- Department of Pathology, University of Virginia, Charlottesville, VA, 22903, USA
| | - Anil P Bidkar
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, 94110, USA
| | - Sui Shen
- Department of Radiation Oncology, University of Alabama, Birmingham, AL, 35233, USA
| | - Weibin Shi
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22903, USA
| | - Youngho Seo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, 94110, USA
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, 94110, USA
| | - Robert R Flavell
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, 94110, USA
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, 94110, USA
| | - Daniel Gioeli
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA, 22903, USA
- UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, VA, 22903, USA
| | - Robert Dreicer
- UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, VA, 22903, USA
- Department of Medicine, University of Virginia, Charlottesville, VA, 22903, USA
| | - Hui Li
- Department of Pathology, University of Virginia, Charlottesville, VA, 22903, USA
- UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, VA, 22903, USA
| | - Bin Liu
- Department of Anesthesia, University of California, San Francisco, CA, 94110, USA.
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, 94110, USA.
| | - Jiang He
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22903, USA.
- UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, VA, 22903, USA.
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5
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Liatsou I, Josefsson A, Yu J, Cortez A, Bastiaannet R, Velarde E, Davis K, Brayton C, Wang H, Torgue J, Hobbs RF, Sgouros G. Bone Marrow Relative Biological Effectiveness for a 212Pb-labeled Anti-HER2/neu Antibody. Int J Radiat Oncol Biol Phys 2023; 115:518-528. [PMID: 35926719 DOI: 10.1016/j.ijrobp.2022.07.1842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 07/25/2022] [Accepted: 07/28/2022] [Indexed: 01/11/2023]
Abstract
PURPOSE We have determined the in vivo relative biological effectiveness (RBE) of an alpha-particle-emitting radiopharmaceutical therapeutic agent (212Pb-labeled anti-HER2/neu antibody) for the bone marrow, a potentially dose-limiting normal tissue. METHODS AND MATERIALS The RBE was measured in mice using femur marrow cellularity as the biological endpoint. External beam radiation therapy (EBRT), delivered by a small-animal radiation research platform was used as the reference radiation. Alpha-particle emissions were delivered by 212Bi after the decay of its parent nuclide 212Pb, which was conjugated onto an anti-HER2/neu antibody. The alpha-particle absorbed dose to the marrow after an intravenous administration (tail vein) of 122.1 to 921.3 kBq 212Pb-TCMC-7.16.4 was calculated. The mice were sacrificed at 0 to 7 days after treatment and the radioactivity from the femur bone marrow was measured. Changes in marrow cellularity were assessed by histopathology. RESULTS The dose response for EBRT and 212Pb-anti-HER2/neu antibody were linear-quadratic and linear, respectively. On transforming the EBRT dose-response relationship into a linear relationship using the equivalent dose in 2-Gy fractions of external beam radiation formalism, we obtained an RBE (denoted RBE2) of 6.4, which is independent of cellularity and absorbed dose. CONCLUSIONS Because hematologic toxicity is dose limiting in almost all antibody-based RPT, in vivo measurements of RBE are important in helping identify an initial administered activity in phase 1 escalation trials. Applying the RBE2 and assuming typical antibody clearance kinetics (biological half-life of 48 hours), using a modified blood-based dosimetry method, an average administered activity of approximately 185.5 MBq (5.0 mCi) per patient could be administered before hematologic toxicity is anticipated.
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Affiliation(s)
- Ioanna Liatsou
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| | - Anders Josefsson
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jing Yu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Angel Cortez
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Remco Bastiaannet
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Esteban Velarde
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Kaori Davis
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Cory Brayton
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Hao Wang
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Robert F Hobbs
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - George Sgouros
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
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6
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Li RG, Stenberg VY, Larsen RH. An Experimental Generator for Production of High-Purity 212Pb for Use in Radiopharmaceuticals. J Nucl Med 2023; 64:173-176. [PMID: 35798556 PMCID: PMC9841245 DOI: 10.2967/jnumed.122.264009] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 01/28/2023] Open
Abstract
The feasibility, performance, and radiation safety of an experimental generator were evaluated to efficiently produce 212Pb intended for radiopharmaceuticals. Methods: The generator consisted of a flask with a removable cap containing a source of 224Ra or 228Th absorbed on quartz wool. Gaseous 220Rn emanated from the decaying source, which subsequently decayed to 212Pb, which was adsorbed on the flask's interior surface. The 212Pb was collected by washing the flask with 0.5-1 mL of 0.1 M HCl. Results: The generator collector flask trapped 62%-68% of the 212Pb, of which more than 87% (tested up to 26 MBq) could be harvested. The obtained 212Pb solution had a high purity (>99.98%) and could be used for the preparation of radioconjugates with more than 97% radiochemical purity. Future designs of the generator should aim to further reduce the risk of radon and γ-energy exposure to operators. Conclusion: The presented technology is a promising method for easy and convenient 212Pb production.
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Affiliation(s)
- Ruth Gong Li
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway; .,Department of Radiation Biology, Institute of Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Oncoinvent AS, Oslo, Norway
| | - Vilde Yuli Stenberg
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway;,Department of Radiation Biology, Institute of Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway;,ArtBio AS, Oslo, Norway; and
| | - Roy Hartvig Larsen
- Oncoinvent AS, Oslo, Norway;,ArtBio AS, Oslo, Norway; and,Sciencons AS, Oslo, Norway
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7
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Core-shell structured gold nanoparticles as carrier for 166Dy/ 166Ho in vivo generator. EJNMMI Radiopharm Chem 2022; 7:16. [PMID: 35852733 PMCID: PMC9296738 DOI: 10.1186/s41181-022-00170-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/04/2022] [Indexed: 12/24/2022] Open
Abstract
Background Radionuclide therapy (RNT) has become a very important treatment modality for cancer nowadays. Comparing with other cancer treatment options, sufficient efficacy could be achieved in RNT with lower toxicity. β− emitters are frequently used in RNT due to the long tissue penetration depth of the β− particles. The dysprosium-166/holmium-166 (166Dy/166Ho) in vivo generator shows great potential for treating large malignancies due to the long half-life time of the mother nuclide 166Dy and the emission of high energy β− from the daughter nuclide 166Ho. However, the internal conversion occurring after β− decay from 166Dy to 166Ho could cause the release of about 72% of 166Ho when 166Dy is bound to conventional chelators. The aim of this study is to develop a nanoparticle based carrier for 166Dy/166Ho in vivo generator such that the loss of the daughter nuclide 166Ho induced by internal conversion is prevented. To achieve this goal, we radiolabelled platinum-gold bimetallic nanoparticles (PtAuNPs) and core–shell structured gold nanoparticles (AuNPs) with 166Dy and studied the retention of both 166Dy and 166Ho under various conditions. Results The 166Dy was co-reduced with gold and platinum precursor to form the 166DyAu@AuNPs and 166DyPtAuNPs. The 166Dy radiolabelling efficiency was determined to be 60% and 70% for the two types of nanoparticles respectively. The retention of 166Dy and 166Ho were tested in MiliQ water or 2.5 mM DTPA for a period of 72 h. In both cases, more than 90% of both 166Dy and 166Ho was retained. The results show that the incorporation of 166Dy in AuNPs can prevent the escape of 166Ho released due to internal conversion. Conclusion We developed a chelator-free radiolabelling method for 166Dy with good radiolabelling efficiency and very high stability and retention of the daughter nuclide 166Ho. The results from this study indicate that to avoid the loss of the daughter radionuclides by internal conversion, carriers composed of electron-rich materials should be used. Supplementary Information The online version contains supplementary material available at 10.1186/s41181-022-00170-3.
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Holik HA, Ibrahim FM, Elaine AA, Putra BD, Achmad A, Kartamihardja AHS. The Chemical Scaffold of Theranostic Radiopharmaceuticals: Radionuclide, Bifunctional Chelator, and Pharmacokinetics Modifying Linker. Molecules 2022; 27:molecules27103062. [PMID: 35630536 PMCID: PMC9143622 DOI: 10.3390/molecules27103062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/27/2022] [Accepted: 05/05/2022] [Indexed: 11/16/2022] Open
Abstract
Therapeutic radiopharmaceuticals have been researched extensively in the last decade as a result of the growing research interest in personalized medicine to improve diagnostic accuracy and intensify intensive therapy while limiting side effects. Radiometal-based drugs are of substantial interest because of their greater versatility for clinical translation compared to non-metal radionuclides. This paper comprehensively discusses various components commonly used as chemical scaffolds to build radiopharmaceutical agents, i.e., radionuclides, pharmacokinetic-modifying linkers, and chelators, whose characteristics are explained and can be used as a guide for the researcher.
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Affiliation(s)
- Holis Abdul Holik
- Department of Pharmaceutical Analysis and Medicinal Chemistry, Faculty of Pharmacy, Universitas Padjadjaran, Sumedang 45363, Indonesia; (F.M.I.); (A.A.E.); (B.D.P.)
- Correspondence:
| | - Faisal Maulana Ibrahim
- Department of Pharmaceutical Analysis and Medicinal Chemistry, Faculty of Pharmacy, Universitas Padjadjaran, Sumedang 45363, Indonesia; (F.M.I.); (A.A.E.); (B.D.P.)
| | - Angela Alysia Elaine
- Department of Pharmaceutical Analysis and Medicinal Chemistry, Faculty of Pharmacy, Universitas Padjadjaran, Sumedang 45363, Indonesia; (F.M.I.); (A.A.E.); (B.D.P.)
| | - Bernap Dwi Putra
- Department of Pharmaceutical Analysis and Medicinal Chemistry, Faculty of Pharmacy, Universitas Padjadjaran, Sumedang 45363, Indonesia; (F.M.I.); (A.A.E.); (B.D.P.)
| | - Arifudin Achmad
- Department of Nuclear Medicine and Molecular Theranostics, Faculty of Medicine, Universitas Padjadjaran/Hasan Sadikin General Hospital, Bandung 40161, Indonesia; (A.A.); (A.H.S.K.)
- Oncology and Stem Cell Working Group, Faculty of Medicine, Universitas Padjadjaran, Bandung 40161, Indonesia
| | - Achmad Hussein Sundawa Kartamihardja
- Department of Nuclear Medicine and Molecular Theranostics, Faculty of Medicine, Universitas Padjadjaran/Hasan Sadikin General Hospital, Bandung 40161, Indonesia; (A.A.); (A.H.S.K.)
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Kokov KV, Egorova BV, German MN, Klabukov ID, Krasheninnikov ME, Larkin-Kondrov AA, Makoveeva KA, Ovchinnikov MV, Sidorova MV, Chuvilin DY. 212Pb: Production Approaches and Targeted Therapy Applications. Pharmaceutics 2022; 14:pharmaceutics14010189. [PMID: 35057083 PMCID: PMC8777968 DOI: 10.3390/pharmaceutics14010189] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/30/2021] [Accepted: 12/30/2021] [Indexed: 01/18/2023] Open
Abstract
Over the last decade, targeted alpha therapy has demonstrated its high effectiveness in treating various oncological diseases. Lead-212, with a convenient half-life of 10.64 h, and daughter alpha-emitter short-lived 212Bi (T1/2 = 1 h), provides the possibility for the synthesis and purification of complex radiopharmaceuticals with minimum loss of radioactivity during preparation. As a benefit for clinical implementation, it can be milked from a radionuclide generator in different ways. The main approaches applied for these purposes are considered and described in this review, including chromatographic, solution, and other techniques to isolate 212Pb from its parent radionuclide. Furthermore, molecules used for lead’s binding and radiochemical features of preparation and stability of compounds labeled with 212Pb are discussed. The results of preclinical studies with an estimation of therapeutic and tolerant doses as well as recently initiated clinical trials of targeted radiopharmaceuticals are presented.
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Affiliation(s)
- Konstantin V. Kokov
- Physical and Chemical Technology Center, National Research Center Kurchatov Institute, 123182 Moscow, Russia; (K.V.K.); (M.N.G.); (A.A.L.-K.); (K.A.M.); (D.Y.C.)
| | - Bayirta V. Egorova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Correspondence: or
| | - Marina N. German
- Physical and Chemical Technology Center, National Research Center Kurchatov Institute, 123182 Moscow, Russia; (K.V.K.); (M.N.G.); (A.A.L.-K.); (K.A.M.); (D.Y.C.)
| | - Ilya D. Klabukov
- Department of Regenerative Medicine, National Medical Research Radiological Center, 249036 Obninsk, Russia;
| | - Michael E. Krasheninnikov
- Research and Educational Resource Center for Cellular Technologies, Peoples’ Friendship University of Russia, 117198 Moscow, Russia;
| | - Antonius A. Larkin-Kondrov
- Physical and Chemical Technology Center, National Research Center Kurchatov Institute, 123182 Moscow, Russia; (K.V.K.); (M.N.G.); (A.A.L.-K.); (K.A.M.); (D.Y.C.)
| | - Kseniya A. Makoveeva
- Physical and Chemical Technology Center, National Research Center Kurchatov Institute, 123182 Moscow, Russia; (K.V.K.); (M.N.G.); (A.A.L.-K.); (K.A.M.); (D.Y.C.)
| | - Michael V. Ovchinnikov
- Laboratory of Peptide Synthesis, National Medical Research Center of Cardiology, 121552 Moscow, Russia; (M.V.O.); (M.V.S.)
| | - Maria V. Sidorova
- Laboratory of Peptide Synthesis, National Medical Research Center of Cardiology, 121552 Moscow, Russia; (M.V.O.); (M.V.S.)
| | - Dmitry Y. Chuvilin
- Physical and Chemical Technology Center, National Research Center Kurchatov Institute, 123182 Moscow, Russia; (K.V.K.); (M.N.G.); (A.A.L.-K.); (K.A.M.); (D.Y.C.)
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10
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Liatsou I, Yu J, Bastiaannet R, Li Z, Hobbs RF, Torgue J, Sgouros G. 212Pb-conjugated anti-rat HER2/ neu antibody against a neu-N derived murine mammary carcinoma cell line: cell kill and RBE in vitro. Int J Radiat Biol 2022; 98:1452-1461. [PMID: 35073214 PMCID: PMC9673603 DOI: 10.1080/09553002.2022.2033341] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE In the current work, the RBE of a 212Pb-conjugated anti-HER2/neu antibody construct has been evaluated, in vitro, by colony formation assay. The RBE was estimated by comparing two absorbed dose-survival curves: the first obtained from the conjugated 212Pb experiments (test radiation), the second obtained by parallel experiments of single bolus irradiation of external beam (reference radiation). MATERIALS AND METHODS Mammary carcinoma NT2.5 cells were treated with (0-3.70) kBq/ml of radiolabeled antibody. Nonspecific binding was assessed with addition of excess amount of unlabeled antibody. The colony formation curves were converted from activity concentration to cell nucleus absorbed dose by simulating the decay and transport of all daughter and secondary particles of 212Pb, using the Monte Carlo code GEANT 4. RESULTS The radiolabeled antibody yielded an RBE of 8.3 at 37% survival and a survival independent RBE (i.e. RBE2) of 9.9. Unbound/untargeted 212Pb-labeled antibody, as obtained in blocking experiments yielded minimal alpha-particle radiation to cells. Conclusions: These results further highlight the importance of specific targeting toward achieving tumor cell kill and low toxicity to normal tissue.
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Affiliation(s)
- Ioanna Liatsou
- Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, USA
| | - Jing Yu
- Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, USA
| | - Remco Bastiaannet
- Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, USA
| | - Zhi Li
- Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, USA
| | - Robert F. Hobbs
- Department of Radiation Oncology, School of Medicine, Johns Hopkins University, Baltimore, USA
| | | | - George Sgouros
- Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, USA
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11
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A Novel Single-Step-Labeled 212Pb-CaCO 3 Microparticle for Internal Alpha Therapy: Preparation, Stability, and Preclinical Data from Mice. MATERIALS 2021; 14:ma14237130. [PMID: 34885283 PMCID: PMC8658347 DOI: 10.3390/ma14237130] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 02/06/2023]
Abstract
Lead-212 is recognized as a promising radionuclide for targeted alpha therapy for tumors. Many studies of 212Pb-labeling of various biomolecules through bifunctional chelators have been conducted. Another approach to exploiting the cytotoxic effect is coupling the radionuclide to a microparticle acting as a carrier vehicle, which could be used for treating disseminated cancers in body cavities. Calcium carbonate may represent a suitable material, as it is biocompatible, biodegradable, and easy to synthesize. In this work, we explored 212Pb-labeling of various CaCO3 microparticles and developed a protocol that can be straightforwardly implemented by clinicians. Vaterite microparticles stabilized by pamidronate were effective as 212Pb carriers; labeling yields of ≥98% were achieved, and 212Pb was strongly retained by the particles in an in vitro stability assessment. Moreover, the amounts of 212Pb reaching the kidneys, liver, spleen, and skeleton of mice following intraperitoneal (i.p.) administration were very low compared to i.p. injection of unbound 212Pb2+, indicating that CaCO3-bound 212Pb exhibited stability when administered intraperitoneally. Therapeutic efficacy was observed in a model of i.p. ovarian cancer for all the tested doses, ranging from 63 to 430 kBq per mouse. Lead-212-labeled CaCO3 microparticles represent a promising candidate for treating intracavitary cancers.
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Trujillo-Nolasco M, Morales-Avila E, Cruz-Nova P, Katti KV, Ocampo-García B. Nanoradiopharmaceuticals Based on Alpha Emitters: Recent Developments for Medical Applications. Pharmaceutics 2021; 13:1123. [PMID: 34452084 PMCID: PMC8398190 DOI: 10.3390/pharmaceutics13081123] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 12/02/2022] Open
Abstract
The application of nanotechnology in nuclear medicine offers attractive therapeutic opportunities for the treatment of various diseases, including cancer. Indeed, nanoparticles-conjugated targeted alpha-particle therapy (TAT) would be ideal for localized cell killing due to high linear energy transfer and short ranges of alpha emitters. New approaches in radiolabeling are necessary because chemical radiolabeling techniques are rendered sub-optimal due to the presence of recoil energy generated by alpha decay, which causes chemical bonds to break. This review attempts to cover, in a concise fashion, various aspects of physics, radiobiology, and production of alpha emitters, as well as highlight the main problems they present, with possible new approaches to mitigate those problems. Special emphasis is placed on the strategies proposed for managing recoil energy. We will also provide an account of the recent studies in vitro and in vivo preclinical investigations of α-particle therapy delivered by various nanosystems from different materials, including inorganic nanoparticles, liposomes, and polymersomes, and some carbon-based systems are also summarized.
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Affiliation(s)
- Maydelid Trujillo-Nolasco
- Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, Ocoyoacac 52750, Mexico; (M.T.-N.); (P.C.-N.)
- Facultad de Química, Universidad Autónoma del Estado de México, Paseo Tollocan S/N, Toluca 50120, Mexico;
| | - Enrique Morales-Avila
- Facultad de Química, Universidad Autónoma del Estado de México, Paseo Tollocan S/N, Toluca 50120, Mexico;
| | - Pedro Cruz-Nova
- Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, Ocoyoacac 52750, Mexico; (M.T.-N.); (P.C.-N.)
| | - Kattesh V. Katti
- Department of Radiology, Institute of Green Nanotechnology, University of Missouri, Columbia, MO 65212, USA;
| | - Blanca Ocampo-García
- Departamento de Materiales Radiactivos, Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, Ocoyoacac 52750, Mexico; (M.T.-N.); (P.C.-N.)
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Eychenne R, Chérel M, Haddad F, Guérard F, Gestin JF. Overview of the Most Promising Radionuclides for Targeted Alpha Therapy: The "Hopeful Eight". Pharmaceutics 2021; 13:pharmaceutics13060906. [PMID: 34207408 PMCID: PMC8234975 DOI: 10.3390/pharmaceutics13060906] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/02/2021] [Accepted: 06/08/2021] [Indexed: 12/11/2022] Open
Abstract
Among all existing radionuclides, only a few are of interest for therapeutic applications and more specifically for targeted alpha therapy (TAT). From this selection, actinium-225, astatine-211, bismuth-212, bismuth-213, lead-212, radium-223, terbium-149 and thorium-227 are considered as the most suitable. Despite common general features, they all have their own physical characteristics that make them singular and so promising for TAT. These radionuclides were largely studied over the last two decades, leading to a better knowledge of their production process and chemical behavior, allowing for an increasing number of biological evaluations. The aim of this review is to summarize the main properties of these eight chosen radionuclides. An overview from their availability to the resulting clinical studies, by way of chemical design and preclinical studies is discussed.
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Affiliation(s)
- Romain Eychenne
- Groupement d’Intérêt Public ARRONAX, 1 Rue Aronnax, F-44817 Saint-Herblain, France;
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Cancérologie et Immunologie Nantes—Angers (CRCINA)—UMR 1232, ERL 6001, F-44000 Nantes, France; (M.C.); (F.G.)
- Correspondence: (R.E.); (J.-F.G.)
| | - Michel Chérel
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Cancérologie et Immunologie Nantes—Angers (CRCINA)—UMR 1232, ERL 6001, F-44000 Nantes, France; (M.C.); (F.G.)
| | - Férid Haddad
- Groupement d’Intérêt Public ARRONAX, 1 Rue Aronnax, F-44817 Saint-Herblain, France;
- Laboratoire Subatech, UMR 6457, Université de Nantes, IMT Atlantique, CNRS, Subatech, F-44000 Nantes, France
| | - François Guérard
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Cancérologie et Immunologie Nantes—Angers (CRCINA)—UMR 1232, ERL 6001, F-44000 Nantes, France; (M.C.); (F.G.)
| | - Jean-François Gestin
- Université de Nantes, Inserm, CNRS, Centre de Recherche en Cancérologie et Immunologie Nantes—Angers (CRCINA)—UMR 1232, ERL 6001, F-44000 Nantes, France; (M.C.); (F.G.)
- Correspondence: (R.E.); (J.-F.G.)
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14
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Stenberg VY, Juzeniene A, Bruland ØS, Larsen RH. In situ Generated <sup>212</sup>Pb-PSMA Ligand in a <sup>224</sup>Ra-Solution for Dual Targeting of Prostate Cancer Sclerotic Stroma and PSMA-positive Cells. Curr Radiopharm 2021; 13:130-141. [PMID: 32389119 PMCID: PMC7527546 DOI: 10.2174/1874471013666200511000532] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/18/2020] [Accepted: 02/23/2020] [Indexed: 12/31/2022]
Abstract
Background: New treatments combating bone and extraskeletal metastases are needed for patients with metastatic castration-resistant prostate cancer. The majority of metastases overexpress prostate-specific membrane antigen (PSMA), making it an ideal candidate for targeted radionuclide therapy. Objective: The aim of this study was to test a novel liquid 224Ra/212Pb-generator for the rapid preparation of a dual-alpha targeting solution. Here, PSMA-targeting ligands are labelled with 212Pb in the 224Ra-solution in transient equilibrium with daughter nuclides. Thus, natural bone-seeking 224Ra targeting sclerotic bone metastases and 212Pb-chelated PSMA ligands targeting PSMA-expressing tumour cells are obtained. Methods: Two PSMA-targeting ligands, the p-SCN-Bn-TCMC-PSMA ligand (NG001), specifically developed for chelating 212Pb, and the most clinically used DOTA-based PSMA-617 were labelled with 212Pb. Radiolabelling and targeting potential were investigated in situ, in vitro (PSMA-positive C4-2 human prostate cancer cells) and in vivo (athymic mice bearing C4-2 xenografts). Results: NG001 was rapidly labelled with 212Pb (radiochemical purity >94% at concentrations of ≥15 µg/ml) using the liquid 224Ra/212Pb-generator. The high radiochemical purity and stability of [212Pb]Pb-NG001 were demonstrated over 48 hours in the presence of ascorbic acid and albumin. Similar binding abilities of the 212Pb-labelled ligands were observed in C4-2 cells. The PSMA ligands displayed comparable tumour uptake after 2 hours, but NG001 showed a 3.5-fold lower kidney uptake than PSMA-617. Radium-224 was not chelated and, hence, showed high uptake in bones. Conclusion: A fast method for the labelling of PSMA ligands with 212Pb in the 224Ra/212Pb-solution was developed. Thus, further in vivo studies with dual tumour targeting by alpha-particles are warranted.
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Affiliation(s)
- Vilde Y Stenberg
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway,Nucligen AS, Oslo, Norway,Institute for Clinical Medicine, University of Oslo, Oslo, Norway
| | - Asta Juzeniene
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Øyvind S Bruland
- Institute for Clinical Medicine, University of Oslo, Oslo, Norway,Department of Oncology, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
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15
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McNeil BL, Robertson AKH, Fu W, Yang H, Hoehr C, Ramogida CF, Schaffer P. Production, purification, and radiolabeling of the 203Pb/ 212Pb theranostic pair. EJNMMI Radiopharm Chem 2021; 6:6. [PMID: 33527221 PMCID: PMC7851237 DOI: 10.1186/s41181-021-00121-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/11/2021] [Indexed: 11/26/2022] Open
Abstract
Background Lead-212 (212Pb, t1/2 = 10.6 h) and lead-203 (203Pb, t1/2 = 51.9 h) are an element-equivalent, or a matched theranostic radioisotope pair that show great potential for application in targeted radionuclide therapy (TRT) and single-photon emission computed tomography (SPECT), respectively. At TRIUMF we have produced both 203Pb and 212Pb using TRIUMF’s TR13 (13 MeV) and 500 MeV cyclotrons, and subsequently purified and evaluated both radioisotopes using a series of pyridine-modified DOTA analogues in comparison to the commercially available chelates DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and TCMC (1,4,7,10-tetraaza-1,4,7,10-tetra(2-carbamoylmethyl)cyclododecane). Results Proton irradiation (12.8 MeV) of natural and enriched thallium-203 (203Tl) targets gave 203Pb saturation yields of 134 ± 25 and 483 ± 3 MBq/μA, respectively. Thorium-228 (228Th, t1/2 = 1.9 y), a by-product of 232Th proton spallation on TRIUMF’s main 500 MeV beamline (beamline 1A, BL1A), was recovered to build a 228Th/212Pb generator with the ability to deliver up to 9–10 MBq of 212Pb daily. Both lead isotopes were purified via solid phase extraction chromatography (Pb resin), and isolated in an acetate form ([203/212Pb]Pb(OAc)2) suitable for direct radiolabeling of chelators and bioconjugates. A series of cyclen-based chelators (herein referred to as DOTA-1Py, -2Py, and -3Py) along with established chelates DOTA and TCMC were evaluated for their ability to complex both 203Pb and 212Pb. All chelates incorporated 212Pb/203Pb efficiently, with higher radiolabeling yields observed for the 212Pb-complexes. Conclusion The production of 203Pb and 212Pb was established using TRIUMF 13 MeV and 500 MeV cyclotrons, respectively. Both production methods provided radiometals suitable for subsequent radiolabeling reactions using known and novel chelates. Furthermore, the novel chelate DOTA-3Py may be a good candidate for biomolecule conjugation and further theranostic 212Pb/203Pb studies. Supplementary Information The online version contains supplementary material available at 10.1186/s41181-021-00121-4.
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Affiliation(s)
- Brooke L McNeil
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.,Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Andrew K H Robertson
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.,Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Winnie Fu
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | | | - Caterina F Ramogida
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada. .,Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada.
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada. .,Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada. .,Department of Radiology, University of British Columbia, Vancouver, BC, Canada.
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16
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Grieve ML, Paterson BM. The Evolving Coordination Chemistry of Radiometals for Targeted Alpha Therapy. Aust J Chem 2021. [DOI: 10.1071/ch21184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Targeted Alpha Therapy: Progress in Radionuclide Production, Radiochemistry, and Applications. Pharmaceutics 2020; 13:pharmaceutics13010049. [PMID: 33396374 PMCID: PMC7824049 DOI: 10.3390/pharmaceutics13010049] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/15/2020] [Accepted: 12/23/2020] [Indexed: 12/17/2022] Open
Abstract
This review outlines the accomplishments and potential developments of targeted alpha (α) particle therapy (TAT). It discusses the therapeutic advantages of the short and highly ionizing path of α-particle emissions; the ability of TAT to complement and provide superior efficacy over existing forms of radiotherapy; the physical decay properties and radiochemistry of common α-emitters, including 225Ac, 213Bi, 224Ra, 212Pb, 227Th, 223Ra, 211At, and 149Tb; the production techniques and proper handling of α-emitters in a radiopharmacy; recent preclinical developments; ongoing and completed clinical trials; and an outlook on the future of TAT.
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18
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Stenberg VY, Juzeniene A, Chen Q, Yang X, Bruland ØS, Larsen RH. Preparation of the alpha-emitting prostate-specific membrane antigen targeted radioligand [ 212 Pb]Pb-NG001 for prostate cancer. J Labelled Comp Radiopharm 2020; 63:129-143. [PMID: 31919866 DOI: 10.1002/jlcr.3825] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/17/2019] [Accepted: 01/06/2020] [Indexed: 12/26/2022]
Abstract
Prostate-specific membrane antigen (PSMA) is the most promising target for radioligand therapy of prostate cancer. The aim of this study was to prepare a small molecular ligand p-SCN-Bn-TCMC-PSMA (NG001) and compare it with the commonly used DOTA-based PSMA-617. The PSMA-targeting ability of the 212 Pb-labelled ligands was evaluated using PSMA-positive C4-2 human prostate cancer cells. Lead-212 is an in vivo generator of alpha particles by its daughter nuclides 212 Bi and 212 Po. NG001 was synthesized by conjugating the isothiocyanato group of p-SCN-Bn-TCMC to the amino group of a glutamate-urea-based PSMA-binding entity. Molecular size, chelator unit and chelator linking method are different in NG001 and PSMA-617. Both ligands were efficiently labelled with 212 Pb using a 224 Ra/212 Pb-solution generator in transient equilibrium with progeny. Lead-212-labelled NG001 was purified with a yield of 85.9±4.7% and with 0.7±0.2% of 224 Ra. Compared with [212 Pb]Pb-PSMA-617, [212 Pb]Pb-NG001 displayed a similar binding and internalization in C4-2 cells, with comparable tumour uptake in mice bearing C4-2 tumours, but almost a 2.5-fold lower kidney uptake. Due to the rapid normal tissue clearance and tumour cell internalization, any significant translocalization of 212 Bi was not detected in mice. In conclusion, the obtained results warrant further preclinical studies to evaluate the therapeutic efficacy of [212 Pb]Pb-NG001.
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Affiliation(s)
- Vilde Yuli Stenberg
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Department of Research and Development, Nucligen AS, Oslo, Norway.,Institute for Clinical Medicine, University of Oslo, Oslo, Norway
| | - Asta Juzeniene
- Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Qingqi Chen
- Department of Drug Synthesis, MedKoo Biosciences, Morrisville, North Carolina
| | - Xiaoming Yang
- Department of Drug Synthesis, MedKoo Biosciences, Morrisville, North Carolina
| | - Øyvind Sverre Bruland
- Institute for Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Oncology, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
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19
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Tafreshi NK, Doligalski ML, Tichacek CJ, Pandya DN, Budzevich MM, El-Haddad G, Khushalani NI, Moros EG, McLaughlin ML, Wadas TJ, Morse DL. Development of Targeted Alpha Particle Therapy for Solid Tumors. Molecules 2019; 24:molecules24234314. [PMID: 31779154 PMCID: PMC6930656 DOI: 10.3390/molecules24234314] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/11/2022] Open
Abstract
Targeted alpha-particle therapy (TAT) aims to selectively deliver radionuclides emitting α-particles (cytotoxic payload) to tumors by chelation to monoclonal antibodies, peptides or small molecules that recognize tumor-associated antigens or cell-surface receptors. Because of the high linear energy transfer (LET) and short range of alpha (α) particles in tissue, cancer cells can be significantly damaged while causing minimal toxicity to surrounding healthy cells. Recent clinical studies have demonstrated the remarkable efficacy of TAT in the treatment of metastatic, castration-resistant prostate cancer. In this comprehensive review, we discuss the current consensus regarding the properties of the α-particle-emitting radionuclides that are potentially relevant for use in the clinic; the TAT-mediated mechanisms responsible for cell death; the different classes of targeting moieties and radiometal chelators available for TAT development; current approaches to calculating radiation dosimetry for TATs; and lead optimization via medicinal chemistry to improve the TAT radiopharmaceutical properties. We have also summarized the use of TATs in pre-clinical and clinical studies to date.
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Affiliation(s)
- Narges K. Tafreshi
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
| | - Michael L. Doligalski
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
| | - Christopher J. Tichacek
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
| | - Darpan N. Pandya
- Department of Cancer Biology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA; (D.N.P.); (T.J.W.)
| | - Mikalai M. Budzevich
- Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
| | - Ghassan El-Haddad
- Depts. of Diagnostic Imaging and Interventional Radiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
| | - Nikhil I. Khushalani
- Department of Cutaneous Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
| | - Eduardo G. Moros
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Department of Physics, University of South Florida, Tampa, FL 33612, USA
- Department of Oncologic Sciences, University of South Florida, Tampa, FL 33612, USA
| | - Mark L. McLaughlin
- Department of Pharmaceutical Sciences, West Virginia University, Health Sciences Center, Morgantown, WV & Modulation Therapeutics Inc., 64 Medical Center Drive, Morgantown, WV 26506, USA;
| | - Thaddeus J. Wadas
- Department of Cancer Biology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA; (D.N.P.); (T.J.W.)
| | - David L. Morse
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA; (N.K.T.); (M.L.D.); (C.J.T.); (E.G.M.)
- Department of Physics, University of South Florida, Tampa, FL 33612, USA
- Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA;
- Department of Oncologic Sciences, University of South Florida, Tampa, FL 33612, USA
- Correspondence: ; Tel.: +1-813-745-8948; Fax: +1-813-745-8375
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20
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Egorova BV, Fedorova OA, Kalmykov SN. Cationic radionuclides and ligands for targeted therapeutic radiopharmaceuticals. RUSSIAN CHEMICAL REVIEWS 2019. [DOI: 10.1070/rcr4890] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This review considers the already used and potential α- and β-emitting cationic radionuclides for targeted radionuclide therapy. Recent results of laboratory, preclinical and clinical applications of these radionuclides are discussed. As opposed to β-emitters, which are already used in nuclear medicine, α-emitters involved in targeted radiopharmaceuticals were subjected to clinical trials only recently and were found to be therapeutically effective. The review summarizes recent trends in the development of ligands as components of radiopharmaceuticals addressing specific features of short-lived cationic radionuclides applied in medicine. Despite a steadily growing number of chelating ligands, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and diethylenetriaminepentaacetic acid (DTPA) remain the most widely used agents in nuclear medicine. The drawbacks of these compounds restrict the application of radionuclides in medicine. Variations in the macrocycle size, the introduction and modification of substituents can significantly improve the chelating ability of ligands, enhance stability of radionuclide complexes with these ligands and eliminate the influence of ligands on the affinity of biological targeting vectors.
The bibliography includes 189 references.
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21
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Ramogida CF, Robertson AKH, Jermilova U, Zhang C, Yang H, Kunz P, Lassen J, Bratanovic I, Brown V, Southcott L, Rodríguez-Rodríguez C, Radchenko V, Bénard F, Orvig C, Schaffer P. Evaluation of polydentate picolinic acid chelating ligands and an α-melanocyte-stimulating hormone derivative for targeted alpha therapy using ISOL-produced 225Ac. EJNMMI Radiopharm Chem 2019; 4:21. [PMID: 31659557 PMCID: PMC6684685 DOI: 10.1186/s41181-019-0072-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/18/2019] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Actinium-225 (225Ac, t1/2 = 9.9 d) is a promising candidate radionuclide for use in targeted alpha therapy (TAT), though the currently limited global supply has hindered the development of a suitable Ac-chelating ligand and 225Ac-radiopharmaceuticals towards the clinic. We at TRIUMF have leveraged our Isotope Separation On-Line (ISOL) facility to produce 225Ac and use the resulting radioactivity to screen a number of potential 225Ac-radiopharmaceutical compounds. RESULTS MBq quantities of 225Ac and parent radium-225 (225Ra, t1/2 = 14.8 d) were produced and separated using solid phase extraction DGA resin, resulting in a radiochemically pure 225Ac product in > 98% yield and in an amenable form for radiolabeling of ligands and bioconjugates. Of the many polydentate picolinic acid ("pa") containing ligands evaluated (H4octapa [N4O4], H4CHXoctapa [N4O4], p-NO2-Bn-H4neunpa [N5O4], and H6phospa [N4O4]), all out-performed the current gold standard, DOTA for 225Ac radiolabeling ability at ambient temperature. Moreover, a melanocortin 1 receptor-targeting peptide conjugate, DOTA-modified cyclized α-melanocyte-stimulating hormone (DOTA-CycMSH), was radiolabeled with 225Ac and proof-of-principle biodistribution studies using B16F10 tumour-bearing mice were conducted. At 2 h post-injection, tumour-to-blood ratios of 20.4 ± 3.4 and 4.8 ± 2.4 were obtained for the non-blocking (molar activity [M.A.] > 200 kBq/nmol) and blocking (M.A. = 1.6 kBq/nmol) experiment, respectively. CONCLUSION TRIUMF's ISOL facility is able to provide 225Ac suitable for preclinical screening of radiopharmaceutical compounds; [225Ac(octapa)]-, [225Ac(CHXoctapa)]-, and [225Ac(DOTA-CycMSH)] may be good candidates for further targeted alpha therapy studies.
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Affiliation(s)
- Caterina F Ramogida
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada. .,Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC, V5A 1S6, Canada.
| | - Andrew K H Robertson
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.,Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1, Canada
| | - Una Jermilova
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Chengcheng Zhang
- Department of Molecular Oncology, BC Cancer Research Centre, 675 West 10th Ave, Vancouver, BC, V5Z 1L3, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Peter Kunz
- Accelerator Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Jens Lassen
- Accelerator Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Ivica Bratanovic
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Victoria Brown
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Lily Southcott
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Cristina Rodríguez-Rodríguez
- Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1, Canada.,Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.,Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer Research Centre, 675 West 10th Ave, Vancouver, BC, V5Z 1L3, Canada.,Department of Functional Imaging, BC Cancer, 600 West 10th Ave, Vancouver, BC, V5Z 4E6, Canada.,Department of Radiology, University of British Columbia, 2775 Laurel St, Vancouver, BC, V5Z 1M9, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada. .,Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC, V5A 1S6, Canada. .,Department of Radiology, University of British Columbia, 2775 Laurel St, Vancouver, BC, V5Z 1M9, Canada.
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22
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Banerjee SR, Minn I, Kumar V, Josefsson A, Lisok A, Brummet M, Chen J, Kiess AP, Baidoo K, Brayton C, Mease RC, Brechbiel M, Sgouros G, Hobbs RF, Pomper MG. Preclinical Evaluation of 203/212Pb-Labeled Low-Molecular-Weight Compounds for Targeted Radiopharmaceutical Therapy of Prostate Cancer. J Nucl Med 2019; 61:80-88. [PMID: 31253744 DOI: 10.2967/jnumed.119.229393] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/18/2019] [Indexed: 12/16/2022] Open
Abstract
Targeted radiopharmaceutical therapy (TRT) using α-particle radiation is a promising approach for treating both large and micrometastatic lesions. We developed prostate-specific membrane antigen (PSMA)-targeted low-molecular-weight agents for 212Pb-based TRT of patients with prostate cancer (PC) by evaluating the matching γ-emitting surrogate, 203Pb. Methods: Five rationally designed low-molecular-weight ligands (L1-L5) were synthesized using the lysine-urea-glutamate scaffold, and PSMA inhibition constants were determined. Tissue biodistribution and SPECT/CT imaging of 203Pb-L1-203Pb-L5 were performed on mice bearing PSMA(+) PC3 PIP and PSMA(-) PC3 flu flank xenografts. The absorbed radiation dose of the corresponding 212Pb-labeled analogs was determined using the biodistribution data. Antitumor efficacy of 212Pb-L2 was evaluated in PSMA(+) PC3 PIP and PSMA(-) PC3 flu tumor models and in the PSMA(+) luciferase-expressing micrometastatic model. 212Pb-L2 was also evaluated for dose-escalated, long-term toxicity. Results: All new ligands were obtained in high yield and purity. PSMA inhibitory activities ranged from 0.10 to 17 nM. 203Pb-L1-203Pb-L5 were synthesized in high radiochemical yield and specific activity. Whole-body clearance of 203Pb-L1-203Pb-L5 was fast. The absorbed dose coefficients (mGy/kBq) of the tumor and kidneys were highest for 203Pb-L5 (31.0, 15.2) and lowest for 203Pb-L2 (8.0, 4.2). The tumor-to-kidney absorbed dose ratio was higher for 203Pb-L3 (3.2) and 203Pb-L4 (3.6) than for the other agents, but with lower tumor-to-blood ratios. PSMA(+) tumor lesions were visualized through SPECT/CT as early as 0.5 h after injection. A proof-of-concept therapy study with a single administration of 212Pb-L2 demonstrated dose-dependent inhibition of tumor growth in the PSMA(+) flank tumor model. 212Pb-L2 also demonstrated an increased survival benefit in the micrometastatic model compared with 177Lu-PSMA-617. Long-term toxicity studies in healthy, immunocompetent CD-1 mice revealed kidney as the dose-limiting organ. Conclusion: 203Pb-L1-203Pb-L5 demonstrated favorable pharmacokinetics for 212Pb-based TRT. The antitumor efficacy of 212Pb-L2 supports the corresponding 203Pb/212Pb theranostic pair for PSMA-based α-particle TRT in advanced PC.
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Affiliation(s)
- Sangeeta Ray Banerjee
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland .,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Vivek Kumar
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Anders Josefsson
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ala Lisok
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mary Brummet
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jian Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ana P Kiess
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Cory Brayton
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ronnie C Mease
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - George Sgouros
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Robert F Hobbs
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Martin G Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
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23
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Milenic DE, Kim YS, Baidoo KE, Wong KJ, Barkley R, Delgado J, Brechbiel MW. Exploration of a F(ab') 2 Fragment as the Targeting Agent of α-Radiation Therapy: A Comparison of the Therapeutic Benefit of Intraperitoneal and Intravenous Administered Radioimmunotherapy. Cancer Biother Radiopharm 2018; 33:182-193. [PMID: 29916748 DOI: 10.1089/cbr.2018.2434] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Refinement of treatment regimens enlisting targeted α-radiation therapy (TAT) is an ongoing effort. Among the variables to consider are the target molecule, radionuclide, dosage, and administration route. The panitumumab F(ab')2 fragment targeting epidermal growth factor receptor tolerated modification with the TCMC chelate as well as radiolabeling with 203Pb or 212Pb. Good specific activity was attained when the immunoconjugate was labeled with 212Pb (9.6 ± 1.4 mCi/mg). Targeting of LS-174T tumor xenografts with the 203Pb-panitumumab F(ab')2 demonstrated comparable amounts of uptake to the similarly radiolabeled panitumumab IgG. A dose escalation study was performed to determine an effective working dose for both intraperitoneal (i.p.) and intravenous (i.v.) injections of 212Pb-panitumumab F(ab')2. Therapeutic efficacy, with modest toxicity, was observed with 30 μCi given i.p. Results for the i.v. administration were not as definitive and the experiment was repeated with a higher dose range. From this study, 20 μCi given i.v. was selected as the effective working dose. A subsequent therapy study combined gemcitabine or paclitaxel with i.v. 212Pb-panitumumab F(ab')2, which increased the median survival (MS) of LS-174T tumor-bearing mice to 208 and 239 d, respectively. Meanwhile, the MS of mice treated with i.v. 212Pb-panitumumab F(ab')2 alone was 61 and 11 d for the untreated group of mice. In conclusion, the panitumumab F(ab')2 fragment whether given by i.p. or i.v. injection, is a viable candidate as a delivery vector for TAT of disseminated i.p. disease.
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Affiliation(s)
- Diane E Milenic
- 1 Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Young-Seung Kim
- 1 Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Kwamena E Baidoo
- 1 Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Karen J Wong
- 2 Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Rachel Barkley
- 1 Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Jose Delgado
- 1 Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Martin W Brechbiel
- 1 Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
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24
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Kasten BB, Oliver PG, Kim H, Fan J, Ferrone S, Zinn KR, Buchsbaum DJ. 212Pb-Labeled Antibody 225.28 Targeted to Chondroitin Sulfate Proteoglycan 4 for Triple-Negative Breast Cancer Therapy in Mouse Models. Int J Mol Sci 2018; 19:ijms19040925. [PMID: 29561763 PMCID: PMC5979285 DOI: 10.3390/ijms19040925] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 03/11/2018] [Accepted: 03/15/2018] [Indexed: 01/16/2023] Open
Abstract
Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with a poor prognosis. There is a clinical need for effective, targeted therapy strategies that destroy both differentiated TNBC cells and TNBC cancer initiating cells (CICs), as the latter are implicated in the metastasis and recurrence of TNBC. Chondroitin sulfate proteoglycan 4 (CSPG4) is overexpressed on differentiated tumor cells and CICs obtained from TNBC patient specimens, suggesting that CSPG4 may be a clinically relevant target for the imaging and therapy of TNBC. The purpose of this study was to determine whether α-particle radioimmunotherapy (RIT) targeting TNBC cells using the CSPG4-specific monoclonal antibody (mAb) 225.28 as a carrier was effective at eliminating TNBC tumors in preclinical models. To this end, mAb 225.28 labeled with 212Pb (212Pb-225.28) as a source of α-particles for RIT was used for in vitro Scatchard assays and clonogenic survival assays with human TNBC cells (SUM159 and 2LMP) grown as adherent cells or non-adherent CIC-enriched mammospheres. Immune-deficient mice bearing orthotopic SUM159 or 2LMP xenografts were injected i.v. with the targeted (225.28) or irrelevant isotype-matched control (F3-C25) mAbs, labeled with 99mTc, 125I, or 212Pb for in vivo imaging, biodistribution, or tumor growth inhibition studies. 212Pb-225.28 bound to adherent SUM159 and 2LMP cells and to CICs from SUM159 and 2LMP mammospheres with a mean affinity of 0.5 nM. Nearly ten times more binding sites per cell were present on SUM159 cells and CICs compared with 2LMP cells. 212Pb-225.28 was six to seven times more effective than 212Pb-F3-C25 at inhibiting SUM159 cell and CIC clonogenic survival (p < 0.05). Radiolabeled mAb 225.28 showed significantly higher uptake than radiolabeled mAb F3-C25 in SUM159 and 2LMP xenografts (p < 0.05), and the uptake of 212Pb-225.28 in TNBC xenografts was correlated with target epitope expression. 212Pb-225.28 caused dose-dependent growth inhibition of SUM159 xenografts; 0.30 MBq 212Pb-225.28 was significantly more effective than 0.33 MBq 212Pb-F3-C25 at inhibiting tumor growth (p < 0.01). These results suggest that CSPG4-specific 212Pb-225.28 is a useful reagent for RIT of CSPG4-expressing tumors, including metastatic TNBC.
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Affiliation(s)
- Benjamin B Kasten
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Patsy G Oliver
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Harrison Kim
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Jinda Fan
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Soldano Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
| | - Kurt R Zinn
- Institute for Quantitative Health Science and Engineering, Department of Radiology, Michigan State University, East Lansing, MI 48824, USA.
| | - Donald J Buchsbaum
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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25
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Poty S, Francesconi LC, McDevitt MR, Morris MJ, Lewis JS. α-Emitters for Radiotherapy: From Basic Radiochemistry to Clinical Studies-Part 1. J Nucl Med 2018; 59:878-884. [PMID: 29545378 DOI: 10.2967/jnumed.116.186338] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 02/03/2018] [Indexed: 12/11/2022] Open
Abstract
With a short particle range and high linear energy transfer, α-emitting radionuclides demonstrate high cell-killing efficiencies. Even with the existence of numerous radionuclides that decay by α-particle emission, only a few of these can reasonably be exploited for therapeutic purposes. Factors including radioisotope availability and physical characteristics (e.g., half-life) can limit their widespread dissemination. The first part of this review will explore the diversity, basic radiochemistry, restrictions, and hurdles of α-emitters.
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Affiliation(s)
- Sophie Poty
- Department of Radiology and Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Lynn C Francesconi
- Department of Chemistry, Hunter College, New York, New York.,Graduate Center of City University of New York, New York, New York
| | - Michael R McDevitt
- Department of Radiology and Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, New York.,Department of Radiology, Weill Cornell Medical College, New York, New York
| | - Michael J Morris
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Jason S Lewis
- Department of Radiology and Program in Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, New York .,Departments of Radiology and Pharmacology, Weill Cornell Medical College, New York, New York
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26
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Westrøm S, Malenge M, Jorstad IS, Napoli E, Bruland ØS, Bønsdorff TB, Larsen RH. Ra-224 labeling of calcium carbonate microparticles for internal α-therapy: Preparation, stability, and biodistribution in mice. J Labelled Comp Radiopharm 2018; 61:472-486. [PMID: 29380410 PMCID: PMC6001669 DOI: 10.1002/jlcr.3610] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 12/16/2017] [Accepted: 01/17/2018] [Indexed: 12/19/2022]
Abstract
Internal therapy with α‐emitters should be well suited for micrometastatic disease. Radium‐224 emits multiple α‐particles through its decay and has a convenient 3.6 days of half‐life. Despite its attractive properties, the use of 224Ra has been limited to bone‐seeking applications because it cannot be stably bound to a targeting molecule. Alternative delivery systems for 224Ra are therefore of considerable interest. In this study, calcium carbonate microparticles are proposed as carriers for 224Ra, designed for local therapy of disseminated cancers in cavitary regions, such as peritoneal carcinomatosis. Calcium carbonate microparticles were radiolabeled by precipitation of 224Ra on the particle surface, resulting in high labeling efficiencies for both 224Ra and daughter 212Pb and retention of more than 95% of these nuclides for up to 1 week in vitro. The biodistribution after intraperitoneal administration of the 224Ra‐labeled CaCO3 microparticles in immunodeficient mice revealed that the radioactivity mainly remained in the peritoneal cavity. In addition, the systemic distribution of 224Ra was found to be strongly dependent on the amount of administered microparticles, with a reduced skeletal uptake of 224Ra with increasing dose. The results altogether suggest that the 224Ra‐labeled CaCO3 microparticles have promising properties for use as a localized internal α‐therapy of cavitary cancers.
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Affiliation(s)
- Sara Westrøm
- Oncoinvent AS, Oslo, Norway.,Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital,, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | | | | | - Elisa Napoli
- Oncoinvent AS, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Øyvind S Bruland
- Oncoinvent AS, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
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27
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Falzone N, Ackerman NL, Rosales LDLF, Bernal MA, Liu X, Peeters SGJA, Soto MS, Corroyer-Dulmont A, Bernaudin M, Grimoin E, Touzani O, Sibson NR, Vallis KA. Dosimetric evaluation of radionuclides for VCAM-1-targeted radionuclide therapy of early brain metastases. Theranostics 2018; 8:292-303. [PMID: 29290808 PMCID: PMC5743475 DOI: 10.7150/thno.22217] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/02/2017] [Indexed: 11/13/2022] Open
Abstract
Brain metastases develop frequently in patients with breast cancer, and present a pressing therapeutic challenge. Expression of vascular cell adhesion molecule 1 (VCAM-1) is upregulated on brain endothelial cells during the early stages of metastasis and provides a target for the detection and treatment of early brain metastases. The aim of this study was to use a model of early brain metastasis to evaluate the efficacy of α-emitting radionuclides, 149Tb, 211At, 212Pb, 213Bi and 225Ac; β-emitting radionuclides, 90Y, 161Tb and 177Lu; and Auger electron (AE)-emitters 67Ga, 89Zr, 111In and 124I, for targeted radionuclide therapy (TRT). METHODS Histologic sections and two photon microscopy of mouse brain parenchyma were used to inform a cylindrical vessel geometry using the Geant4 general purpose Monte Carlo (MC) toolkit with the Geant4-DNA low energy physics models. Energy deposition was evaluated as a radial function and the resulting phase spaces were superimposed on a DNA model to estimate double-strand break (DSB) yields for representative β- and α-emitters, 177Lu and 212Pb. Relative biological effectiveness (RBE) values were determined by only evaluating DNA damage due to physical interactions. RESULTS 177Lu produced 2.69 ± 0.08 DSB per GbpGy, without significant variation from the lumen of the vessel to a radius of 100 µm. The DSB yield of 212Pb included two local maxima produced by the 6.1 MeV and 8.8 MeV α-emissions from decay products, 212Bi and 212Po, with yields of 7.64 ± 0.12 and 9.15 ± 0.24 per GbpGy, respectively. Given its higher DSB yield 212Pb may be more effective for short range targeting of early micrometastatic lesions than 177Lu. CONCLUSION MC simulation of a model of early brain metastases provides invaluable insight into the potential efficacy of α-, β- and AE-emitting radionuclides for TRT. 212Pb, which has the attributes of a theranostic radionuclide since it can be used for SPECT imaging, showed a favorable dose profile and RBE.
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Affiliation(s)
- Nadia Falzone
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Nicole L. Ackerman
- Department of Physics and Astronomy, Agnes Scott College, Decatur, GA, United States of America
| | | | - Mario A. Bernal
- Departamento de Física Aplicada, Instituto de Física "Gleb Wataghin", UNICAMP, Campinas, Brazil
| | - Xiaoxuan Liu
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Sarah GJA Peeters
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Manuel Sarmiento Soto
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Aurélien Corroyer-Dulmont
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy group, Caen, France
| | - Myriam Bernaudin
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy group, Caen, France
| | - Elisa Grimoin
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy group, Caen, France
| | - Omar Touzani
- Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy group, Caen, France
| | - Nicola R. Sibson
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Katherine A. Vallis
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
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28
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Kasten BB, Gangrade A, Kim H, Fan J, Ferrone S, Ferrone CR, Zinn KR, Buchsbaum DJ. 212Pb-labeled B7-H3-targeting antibody for pancreatic cancer therapy in mouse models. Nucl Med Biol 2017; 58:67-73. [PMID: 29413459 DOI: 10.1016/j.nucmedbio.2017.12.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/02/2017] [Accepted: 12/13/2017] [Indexed: 12/14/2022]
Abstract
INTRODUCTION We recently validated monoclonal antibody (mAb) 376.96 as an effective carrier for targeted α-particle radioimmunotherapy (RIT) with 212Pb in ovarian cancer mouse models. In this study, we tested the binding of radiolabeled mAb 376.96 to human pancreatic ductal adenocarcinoma (PDAC) cells and localization in xenografts in immune-deficient mice and evaluated 212Pb-labeled 376.96 (212Pb-376.96) for PDAC therapy. METHODS In vitro Scatchard assays assessed the specific binding of 212Pb-376.96 to human PDAC3 adherent differentiated cells and non-adherent cancer initiating cells (CICs) dissociated from tumorspheres. In vitro clonogenic assays were used to measure the proliferation of adherent PDAC3 cells and CIC-enriched tumorspheres treated with 212Pb-376.96 or the irrelevant isotype-matched 212Pb-F3-C25. Mice bearing patient derived pancreatic cancer Panc039 xenografts were i.v. injected with 0.17-0.70 MBq 212Pb-376.96 or isotype control 212Pb-F3-C25, and used for biodistribution and tumor growth inhibition studies. Mice bearing orthotopic PDAC3 xenografts were i.v. co-injected with 99mTc-376.96 and 125I-F3-C25 and used for biodistribution studies. RESULTS 212Pb-376.96 specifically bound to PDAC3 adherent and dissociated tumorsphere CICs; Kd values averaged 9.0 and 21.7 nM, respectively, with 104-105 binding sites/cell. 212Pb-376.96 inhibited the clonogenic survival of PDAC3 cells or CICs dissociated from tumorspheres 3-6 times more effectively than isotype-matched control 212Pb-F3-C25. Panc039 s.c. tumors showed significantly higher uptake of 212Pb-376.96 (14.0 ± 2.1% ID/g) compared to 212Pb-F3-C25 (6.5 ± 0.9% ID/g, p < .001) at 24 h after dosing. Orthotopic PDAC3 tumors showed significantly higher uptake of 99mTc-376.96 (6.4 ± 1.8% ID/g) compared to 125I-F3-C25 (3.9 ± 0.9% ID/g, p < .05) at 24 h after dosing. Panc039 tumor growth was significantly inhibited by 212Pb-376.96 compared to 212Pb-F3-C25 or non-treated control tumors (p < .05). CONCLUSION Our results provide evidence for the efficacy of B7-H3 targeted RIT against preclinical models of pancreatic ductal adenocarcinoma (PDAC) and support future studies with 212Pb-376.96 in combination with chemotherapy to potentiate efficacy against PDAC.
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Affiliation(s)
- Benjamin B Kasten
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States.
| | - Abhishek Gangrade
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Harrison Kim
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jinda Fan
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Soldano Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Cristina R Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Kurt R Zinn
- Institute for Quantitative Health Science and Engineering, Department of Radiology, Michigan State University, East Lansing, MI, United States
| | - Donald J Buchsbaum
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, United States
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29
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Milenic DE, Baidoo KE, Kim YS, Barkley R, Brechbiel MW. Comparative studies on the therapeutic benefit of targeted α-particle radiation therapy for the treatment of disseminated intraperitoneal disease. Dalton Trans 2017; 46:14591-14601. [PMID: 28675216 PMCID: PMC5664163 DOI: 10.1039/c7dt01819c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Identification of the appropriate combination of radionuclide, target and targeting vehicle is critical for successful radioimmunotherapy. For the treatment of disseminated peritoneal diseases such as pancreatic or ovarian cancer, α-emitting radionuclides have been proposed for targeted radiation therapy. This laboratory has taken a systematic approach investigating targeted α-radiation therapy, allowing comparisons to now be made between 211At, 227Th, 213Bi and 212Pb. Herein, trastuzumab radiolabeled with 211At and 227Th was evaluated for therapeutic efficacy in the LS-174T i.p. tumor model. A dose escalation study was conducted with each radioimmunoconjugate (RIC). Therapeutic benefit was realized with 211At-trastuzumab with doses of 20, 30 and 40 μCi. At doses >40 μCi, toxicity was observed with greater weight loss and 2-fold higher decrease in the platelet counts. Following a second study comparing the effect of 20, 30 and 40 μCi of 211At-trastuzumab, 30 μCi was selected as the dose for future studies. A parallel study was performed evaluating 0.25, 0.5, 1.0, 2.0 and 5.0 μCi of 227Th-trastuzumab. The 0.5 and 1.0 μCi injected dose resulted in a therapeutic response; a lower degree of weight loss was experienced by the mice in the 0.5 μCi cohort. When the data is normalized for comparing 211At, 227Th, 213Bi and 212Pb, the choice of radionuclide for RIT is perhaps not entirely based on simple therapeutic efficacy, other factors may play a role in choosing the "right" radionuclide.
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Affiliation(s)
- Diane E Milenic
- Radioimmune & Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda MD, USA.
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30
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Li M, Zhang X, Quinn TP, Lee D, Liu D, Kunkel F, Zimmerman BE, McAlister D, Olewein K, Menda Y, Mirzadeh S, Copping R, Johnson FL, Schultz MK. Automated cassette-based production of high specific activity [ 203/212Pb]peptide-based theranostic radiopharmaceuticals for image-guided radionuclide therapy for cancer. Appl Radiat Isot 2017; 127:52-60. [PMID: 28521118 PMCID: PMC6295910 DOI: 10.1016/j.apradiso.2017.05.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/29/2017] [Accepted: 05/06/2017] [Indexed: 01/28/2023]
Abstract
A method for preparation of Pb-212 and Pb-203 labeled chelator-modified peptide-based radiopharmaceuticals for cancer imaging and radionuclide therapy has been developed and adapted for automated clinical production. Pre-concentration and isolation of radioactive Pb2+ from interfering metals in dilute hydrochloric acid was optimized using a commercially-available Pb-specific chromatography resin packed in disposable plastic columns. The pre-concentrated radioactive Pb2+ is eluted in NaOAc buffer directly to the reaction vessel containing chelator-modified peptides. Radiolabeling was found to proceed efficiently at 85°C (45min; pH 5.5). The specific activity of radiolabeled conjugates was optimized by separation of radiolabeled conjugates from unlabeled peptide via HPLC. Preservation of bioactivity was confirmed by in vivo biodistribution of Pb-203 and Pb-212 labeled peptides in melanoma-tumor-bearing mice. The approach has been found to be robustly adaptable to automation and a cassette-based fluid-handling system (Modular Lab Pharm Tracer) has been customized for clinical radiopharmaceutical production. Our findings demonstrate that the Pb-203/Pb-212 combination is a promising elementally-matched radionuclide pair for image-guided radionuclide therapy for melanoma, neuroendocrine tumors, and potentially other cancers.
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Affiliation(s)
- Mengshi Li
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, USA.
| | - Xiuli Zhang
- Department of Biochemistry, University of Missouri, Columbia, MO USA
| | - Thomas P Quinn
- Department of Biochemistry, University of Missouri, Columbia, MO USA
| | - Dongyoul Lee
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, USA
| | - Dijie Liu
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA, USA
| | - Falk Kunkel
- Eckert & Ziegler Radiopharma GmbH, Berlin, Germany
| | - Brian E Zimmerman
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | | | - Yusuf Menda
- Department of Radiology, The University of Iowa, Iowa City, IA, USA
| | - Saed Mirzadeh
- Oak Ridge National Laboratory, The US Department of Energy, Oak Ridge, TN, USA
| | - Roy Copping
- Oak Ridge National Laboratory, The US Department of Energy, Oak Ridge, TN, USA
| | - Frances L Johnson
- Viewpoint Molecular Targeting, LLC, Coralville, IA, USA; Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Michael K Schultz
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, USA; Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA, USA; Department of Radiology, The University of Iowa, Iowa City, IA, USA; Viewpoint Molecular Targeting, LLC, Coralville, IA, USA; Department of Radiation Oncology (Free Radical and Radiation Biology Program), Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Department of Chemistry, University of Iowa, Iowa City, IA, USA.
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Targeted α-Particle Radiation Therapy of HER1-Positive Disseminated Intraperitoneal Disease: An Investigation of the Human Anti-EGFR Monoclonal Antibody, Panitumumab. Transl Oncol 2017; 10:535-545. [PMID: 28577439 PMCID: PMC5458064 DOI: 10.1016/j.tranon.2017.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/13/2017] [Accepted: 04/17/2017] [Indexed: 11/29/2022] Open
Abstract
Identifying molecular targets and an appropriate targeting vehicle, i.e., monoclonal antibodies (mAb) and their various forms, for radioimmunotherapy (RIT) remains an active area of research. Panitumumab, a fully human and less immunogenic mAb that binds to the epidermal growth factor receptor (Erb1; HER1), was evaluated for targeted α-particle radiation therapy using 212Pb, an in vivo α generator. A single dose of 212Pb-panitumumab administered to athymic mice bearing LS-174T intraperitoneal (i.p.) tumor xenografts was found to have greater therapeutic efficacy when directly compared with 212Pb-trastuzumab, which binds to HER2. A dose escalation study determined a maximum effective working dose of 212Pb-panitumumab to be 20 μCi with a median survival of 35 days versus 25 days for the untreated controls. Pretreatment of tumor-bearing mice with paclitaxel and gemcitabine 24 hours prior to injection of 212Pb-pantiumumab at 10 or 20 μCi resulted in the greatest enhanced therapeutic response at the higher dose with median survivals of 106 versus 192 days, respectively. The greatest therapeutic impact, however, was observed in the animals that were treated with topotecan 24 hours prior to RIT and then again 24 hours after RIT; the best response from this combination was also obtained with the lower 10-μCi dose of 212Pb-panitumumab (median survival >280 days). In summary, 212Pb-panitumumab is an excellent candidate for the treatment of HER1-positive disseminated i.p. disease. Furthermore, the potentiation of the therapeutic impact of 212Pb-pantiumumab by chemotherapeutics confirms and validates the importance of developing a multimodal therapy regimen.
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Westrøm S, Generalov R, Bønsdorff TB, Larsen RH. Preparation of 212Pb-labeled monoclonal antibody using a novel 224Ra-based generator solution. Nucl Med Biol 2017; 51:1-9. [PMID: 28486098 DOI: 10.1016/j.nucmedbio.2017.04.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/06/2017] [Accepted: 04/15/2017] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Alpha-emitting radionuclides have gained considerable attention as payloads for cancer targeting molecules due to their high cytotoxicity. One attractive radionuclide for this purpose is 212Pb, which by itself is a β-emitter, but acts as an in vivo generator for its short-lived α-emitting daughters. The standard method of preparing 212Pb-labeled antibodies requires handling and evaporation of strong acids containing high radioactivity levels by the end user. An operationally easier and more rapid process could be useful since the 10.6h half-life of 212Pb puts time constraints on the preparation protocol. In this study, an in situ procedure for antibody labeling with 212Pb, using a solution of the generator nuclide 224Ra, is proposed as an alternative protocol for preparing 212Pb-radioimmunoconjugates. METHODS Radium-224, the generator radionuclide of 212Pb, was extracted from its parent nuclide, 228Th. Lead-212-labeling of the TCMC-chelator conjugated monoclonal antibody trastuzumab was carried out in a solution containing 224Ra in equilibrium with progeny. Subsequently, the efficiency of separating the 212Pb-radioimmunoconjugate from 224Ra and other unconjugated daughter nuclides in the solution using either centrifugal separation or a PD-10 desalting size exclusion column was evaluated and compared. RESULTS Radiolabeling with 212Pb in 224Ra-solutions was more than 90% efficient after only 30min reaction time at TCMC-trastuzumab concentrations from 0.15mg/mL and higher. Separation of 212Pb-labeled trastuzumab from 224Ra using a PD-10 column was clearly superior to centrifugal separation. This method allowed recovery of approximately 75% of the 212Pb-antibody-conjugate in the eluate, and the remaining amount of 224Ra was only 0.9±0.8% (n=7). CONCLUSIONS The current work demonstrates a novel method of producing 212Pb-based radioimmunoconjugates from a 224Ra-solution, which may be simpler and less time-consuming for the end user compared with the method established for use in clinical trials of 212Pb-TCMC-trastuzumab.
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Affiliation(s)
- Sara Westrøm
- Oncoinvent AS, Oslo, Norway; Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | | | | | - Roy H Larsen
- Oncoinvent AS, Oslo, Norway; Sciencons AS, Oslo, Norway.
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Kasten BB, Arend RC, Katre AA, Kim H, Fan J, Ferrone S, Zinn KR, Buchsbaum DJ. B7-H3-targeted 212Pb radioimmunotherapy of ovarian cancer in preclinical models. Nucl Med Biol 2017; 47:23-30. [PMID: 28104527 DOI: 10.1016/j.nucmedbio.2017.01.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/06/2017] [Accepted: 01/06/2017] [Indexed: 01/30/2023]
Abstract
INTRODUCTION Novel therapies that effectively kill both differentiated cancer cells and cancer initiating cells (CICs), which are implicated in causing chemotherapy-resistance and disease recurrence, are needed to reduce the morbidity and mortality of ovarian cancer. These studies used monoclonal antibody (mAb) 376.96, which recognizes a B7-H3 epitope expressed on ovarian cancer cells and CICs, as a carrier molecule for targeted α-particle radioimmunotherapy (RIT) in preclinical models of human ovarian cancer. METHODS mAb 376.96 was conjugated to the chelate 2-(4-isothiocyanotobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoylmethyl)-cyclododecane (TCMC) and radiolabeled with 212Pb, a source of α-particles. In vitro Scatchard assays determined the specific binding of 212Pb-376.96 to adherent differentiated or non-adherent CIC-enriched ES-2 and A2780cp20 ovarian cancer cells. Adherent ovarian cancer cells and non-adherent CIC-enriched tumorspheres treated in vitro with 212Pb-376.96 or the irrelevant isotype-matched 212Pb-F3-C25 were assessed for clonogenic survival. Mice bearing i.p. ES-2 or A2780cp20 xenografts were injected i.p. with 0.17-0.70MBq 212Pb-376.96 or 212Pb-F3-C25 and were used for in vivo imaging, ex vivo biodistribution, and therapeutic survival studies. RESULTS 212Pb-376.96 was obtained in high yield and purity (>98%); Kd values ranged from 10.6-26.6nM for ovarian cancer cells, with 104-105 binding sites/cell. 212Pb-376.96 inhibited the clonogenic survival of ovarian cancer cells up to 40 times more effectively than isotype-matched control 212Pb-F3-C25; combining 212Pb-376.96 with carboplatin significantly decreased clonogenic survival compared to either agent alone. In vivo imaging and biodistribution analysis 24h after i.p. injection of 212Pb-376.96 showed high peritoneal retention and tumor tissue accumulation (28.7% ID/g in ES-2 ascites, 73.1% ID/g in A2780cp20 tumors); normal tissues showed lower and comparable uptake for 212Pb-376.96 and 212Pb-F3-C25. Tumor-bearing mice treated with 212Pb-376.96 alone or combined with carboplatin survived 2-3 times longer than mice treated with 212Pb-F3-C25 or non-treated controls. CONCLUSION These results support additional RIT studies with 212Pb-376.96 for future evaluation in patients with ovarian cancer.
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Affiliation(s)
- Benjamin B Kasten
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL.
| | - Rebecca C Arend
- Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL
| | - Ashwini A Katre
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL
| | - Harrison Kim
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL
| | - Jinda Fan
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL
| | - Soldano Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Kurt R Zinn
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL
| | - Donald J Buchsbaum
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL
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Máthé D, Szigeti K, Hegedűs N, Horváth I, Veres DS, Kovács B, Szűcs Z. Production and in vivo imaging of (203)Pb as a surrogate isotope for in vivo (212)Pb internal absorbed dose studies. Appl Radiat Isot 2016; 114:1-6. [PMID: 27156049 DOI: 10.1016/j.apradiso.2016.04.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/29/2016] [Accepted: 04/20/2016] [Indexed: 11/18/2022]
Abstract
(212)Pb is a clinically relevant therapeutic alpha emitter isotope. A surrogate, (203)Pb, if prepared with sufficiently high specific activity could be used to estimate (212)Pb in vivo absorbed doses. An improved production procedure of (203)Pb with a simple, new separation method and high specific radioactivity for imaging is reported. We determined the in-vivo biodistribution of (203)Pb in mice by SPECT/CT. This highlights application possibilities of (203)Pb for further in vivo and clinical uses (radiolabeled (212)Pb-peptide co-injection, dosimetry calculation).
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Affiliation(s)
- Domokos Máthé
- CROmed Research Centers Ltd., Baross utca 91-95, H-1047 Budapest, Hungary.
| | - Krisztián Szigeti
- Dept. of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó utca 37-47, H-1094 Budapest, Hungary.
| | - Nikolett Hegedűs
- Dept. of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó utca 37-47, H-1094 Budapest, Hungary.
| | - Ildikó Horváth
- Dept. of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó utca 37-47, H-1094 Budapest, Hungary.
| | - Dániel S Veres
- Dept. of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó utca 37-47, H-1094 Budapest, Hungary.
| | - Béla Kovács
- Institute of Food Science, University of Debrecen, Böszörményi út 138, H-4032 Debrecen, Hungary.
| | - Zoltán Szűcs
- Dept. of Cyclotron Application, MTA Atomki, Bem tér 18/c, H-4026 Debrecen, Hungary.
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Imaging, biodistribution, and toxicology evaluation of (212)Pb-TCMC-trastuzumab in nonhuman primates. Nucl Med Biol 2016; 43:391-6. [PMID: 27179247 DOI: 10.1016/j.nucmedbio.2016.04.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/01/2016] [Accepted: 04/06/2016] [Indexed: 02/07/2023]
Abstract
INTRODUCTION The biodistribution and toxicology of a radiotherapeutic (212)Pb-trastuzumab conjugate were evaluated in nonhuman primates to meet the investigational new drug requirements prior to a phase I clinical trial in human subjects. METHODS Male cynomolgus monkeys (n=3/group) were injected intraperitoneally with the (212)Pb-trastuzumab conjugate and terminated at 8h, 10d, and 90d post-injection. Quantitative imaging studies in phantoms and monkeys were conducted using a planar gamma camera and a high purity germanium (HPGe) detector out to 48h following injection. Biodistribution analyses were conducted at 8h; all tissues and time points were evaluated for macroscopic and microscopic pathology. Blood samples were taken throughout the 90d study period for assessment of hematology parameters and serum chemistry parameters. RESULTS Quantitative gamma camera imaging and region-of-interest analyses of phantoms and monkeys indicated that 95.5±5.0% of the decay-corrected (212)Pb activity was retained in the peritoneal region up to 48h following administration of the (212)Pb-trastuzumab. Gamma-ray spectroscopy analyses confirmed that 87.6±4.5% of the decay-corrected (212)Bi activity was also retained in the peritoneal cavity during this time. Serum chemistry parameters for all groups always fell within normal ranges. Gross and histopathology evaluations showed no radiation-related toxicity in any tissue at any time. CONCLUSION In vivo imaging and biodistribution analyses showed that about 90% of both (212)Pb and decay product (212)Bi remained in the monkey peritoneal cavity. The imaging methods could also be applied to human subjects. The lack of toxicity observed in monkeys following intraperitoneal injection of the (212)Pb-trastuzumab conjugate supports its clinical assessment in humans.
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Palm S, Bäck T, Haraldsson B, Jacobsson L, Lindegren S, Albertsson P. Biokinetic Modeling and Dosimetry for Optimizing Intraperitoneal Radioimmunotherapy of Ovarian Cancer Microtumors. J Nucl Med 2016; 57:594-600. [PMID: 26769860 DOI: 10.2967/jnumed.115.167825] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/24/2015] [Indexed: 01/19/2023] Open
Abstract
UNLABELLED A biokinetic model was constructed to evaluate and optimize various intraperitoneal radioimmunotherapies for micrometastatic tumors. The model was used to calculate the absorbed dose to both anticipated microtumors and critical healthy organs and demonstrated how intraperitoneal targeted radiotherapy can be optimized to maximize the ratio between them. METHODS The various transport mechanisms responsible for the biokinetics of intraperitoneally infused radiolabeled monoclonal antibodies (mAbs) were modeled using a software package. Data from the literature were complemented by pharmacokinetic data derived from our clinical phase I study to set parameter values. Results using the β-emitters (188)Re, (177)Lu, and (90)Y and the α-emitters (211)At, (213)Bi, and (212)Pb were compared. The effects of improving the specific activity, prolonging residence time by introducing an osmotic agent, and varying the activity concentration of the infused agent were investigated. RESULTS According to the model, a 1.7-L infused saline volume will decrease by 0.3 mL/min because of lymphatic drainage and by 0.7 mL/min because of the transcapillary convective component. The addition of an osmotic agent serves to lower the radiation dose to the bone marrow. Clinically relevant radioactivity concentrations of α- and β-emitters bound to mAbs were compared. For α-emitters, microtumors receive high doses (>20 Gy or 100 Sv [relative biological effect = 5]). Since most of the tumor dose originates from cell-bound radionuclides, an increase in the specific activity would further increase the tumor dose without affecting the dose to peritoneal fluid or bone marrow. For β-emitters, tumors will receive almost entirely nonspecific irradiation. The dose from cell-bound radiolabeled mAbs will be negligible by comparison. For the long-lived (90)Y, tumor doses are expected to be low at the maximum activity concentration delivered in clinical studies. CONCLUSION According to the presented model, α-emitters are needed to achieve radiation doses high enough to eradicate microscopic tumors.
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Affiliation(s)
- Stig Palm
- Department of Radiation Physics, Institute for Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Tom Bäck
- Department of Radiation Physics, Institute for Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Börje Haraldsson
- Department of Clinical and Molecular Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; and
| | - Lars Jacobsson
- Department of Radiation Physics, Institute for Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Sture Lindegren
- Department of Radiation Physics, Institute for Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Per Albertsson
- Department of Oncology, Institute for Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
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Milenic DE, Baidoo KE, Kim YS, Brechbiel MW. Evaluation of cetuximab as a candidate for targeted α-particle radiation therapy of HER1-positive disseminated intraperitoneal disease. MAbs 2015; 7:255-64. [PMID: 25587678 DOI: 10.4161/19420862.2014.985160] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although the epidermal growth factor receptor (EGFR), also known as HER1, has been studied for over a decade, it continues to be a molecule of great interest and focus of investigators for development of targeted therapies. The marketed monoclonal antibody cetuximab binds to HER1, and thus might serve as the basis for creation of imaging or therapies that target this receptor. The potential of cetuximab as a vehicle for the delivery of α-particle radiation was investigated in an intraperitoneal tumor mouse model. The effective working dose of 10 μCi of (212)Pb-cetuximab was determined from a dose (10-50 μCi) escalation study. Toxicity, as indicated by the lack of animal weight loss, was not evident at the 10 μCi dose of (212)Pb-cetuximab. A subsequent study demonstrated (212)Pb-cetuximab had a therapeutic efficacy similar to that of (212)Pb-trastuzumab (p = 0.588). Gemcitabine given 24 h prior to (212)Pb-cetuximab increased the median survival from 174 d to 283 d, but carboplatin suppressed the effectiveness of (212)Pb-cetuximab. Notably, concurrent treatment of tumor-bearing mice with (212)Pb-labeled cetuximab and trastuzumab provided therapeutic benefit that was greater than either antibody alone. In conclusion, cetuximab proved to be an effective vehicle for targeting HER1-expressing tumors with α-radiation for the treatment of disseminated intraperitoneal disease. These studies provide further evidence that the multimodality therapy regimens may have greater efficacy and benefit in the treatment of cancer patients.
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Key Words
- %ID/g, percent injected dose per gram
- 212Pb
- BSA, bovine serum albumin
- EGFR, epidermal growth factor receptor
- HER1
- HulgG, human immunoglobulin
- MS, median survival
- PBS, phosphate-buffered saline
- PET, positron emission tomography
- RIT, radioimmunotherapy
- TCMC, 1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoyl methyl)-cyclododecane
- cetuximab
- i.p., intraperitoneal
- mAb, monoclonal antibody
- radioimmunotherapy
- s.c, subcutaneous
- α-particle
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Affiliation(s)
- Diane E Milenic
- a Radioimmune & Inorganic Chemistry Section; Radiation Oncology Branch; Center for Cancer Research; National Cancer Institute; National Institutes of Health ; Bethesda MD USA
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Yong K, Brechbiel M. Application of 212Pb for Targeted α-particle Therapy (TAT): Pre-clinical and Mechanistic Understanding through to Clinical Translation. AIMS MEDICAL SCIENCE 2015; 2:228-245. [PMID: 26858987 DOI: 10.3934/medsci.2015.3.228] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Targeted α-particle therapy (TAT), in which an α-particle emitting radionuclide is specifically directed to a biological target, is gaining more attention to treat cancers as new targets are validated. Bio-vectors such as monoclonal antibodies are able to selectively transport α-particles to destroy targeted cancer cells. TAT has the potential for an improved therapeutic ratio over β-particle targeted conjugate therapy. The short path length and the intense ionization path generated render α-emitters suitable for treatment and management of minimal disease such as micrometastases or residual tumor after surgical debulking. 212Pb is the longer-lived parent radionuclide of 212Bi and serves as an in vivo generator of 212Bi. 212Pb has demonstrated significant utility in both in vitro and in vivo models. Recent evaluation of 212Pb-TCMC-trastuzumab in a Phase I clinical trial has demonstrated the feasibility of 212Pb in TAT for the treatment of ovarian cancer patients. This review highlights progress in radionuclide production, radiolabeling chemistry, molecular mechanisms, and application of 212Pb to targeted pre-clinical and clinical radiation therapy for the management and treatment of cancer.
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Affiliation(s)
- Kwon Yong
- Radioimmune & Inorganic Chemistry Section, Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda MD, USA
| | - Martin Brechbiel
- Radioimmune & Inorganic Chemistry Section, Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda MD, USA
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Bench to Bedside: Stability Studies of GMP Produced Trastuzumab-TCMC in Support of a Clinical Trial. Pharmaceuticals (Basel) 2015; 8:435-54. [PMID: 26230702 PMCID: PMC4588176 DOI: 10.3390/ph8030435] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 07/23/2015] [Accepted: 07/23/2015] [Indexed: 02/06/2023] Open
Abstract
The first-in-human phase 1 clinical radioimmunotherapy (RIT) trial with 212Pb-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoylmethyl)-cyclododecane-trastuzumab (212Pb-TCMC-trastuzumab) was completed in October 2014 as a joint effort at the University of Alabama (UAB) and the University of California San Diego Moores Cancer Center. The preliminary reports indicate that after five dose-levels of intraperitoneally administered 212Pb-TCMC-trastuzumab, patients with carcinomatosis experienced minimal agent-related toxicity. This report presents the data accumulated to date on the stability of the clinical grade, produced according to current good manufacturing practices (cGMP), TCMC-trastuzumab conducted in support of that clinical trial. Of the eleven tests performed with the cGMP TCMC-trastuzumab all but one remained within specifications throughout the 5 year testing period. The protein concentration varied by 0.01 mg/mL at 48 months. Two other assays, ion-exchange high performance liquid chromatography (IEX-HPLC) and a competitive radioimmunoassay (RIA) indicated that the cGMP TCMC-trastuzumab integrity may be changing, although the change thus far is within specifications. Subsequent stability testing will confirm if a trend has truly developed. The cGMP TCMC-trastuzumab was also evaluated for tolerance to higher temperatures and the potential of storage at −80 °C. The immunoconjugate proved stable when subjected to the lower temperatures and to multiple freeze-thaw cycles. The size exclusion (SE) HPLC analysis of the 203Pb-TCMC-trastuzumab was the only indicator that cGMP TCMC-trastuzumab may be sensitive to storage at 37 °C for 3 months.
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Lima LMP, Beyler M, Delgado R, Platas-Iglesias C, Tripier R. Investigating the Complexation of the Pb(2+)/Bi(3+) Pair with Dipicolinate Cyclen Ligands. Inorg Chem 2015; 54:7045-57. [PMID: 26146022 DOI: 10.1021/acs.inorgchem.5b01079] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The complexation properties toward Pb(2+) and Bi(3+) of the macrocyclic ligands 6,6'-((1,4,7,10-tetraazacyclododecane-1,7-diyl)bis(methylene))dipicolinic acid (H2do2pa) and 6,6'-((4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diyl)bis(methylene))dipicolinic acid (H2Me-do2pa) have been investigated. A new three-step synthesis of H2do2pa following the bisaminal methodology has also been developed. The X-ray structures of [Pb(Me-do2pa)]·6H2O and [Bi(Me-do2pa)](NO3)·H2O show that the two metal ions are eight-coordinated by the ligand. The two complexes exist as the racemic Δ(δδδδ)/Λ(λλλλ) mixture both in the solid state and in solution, as indicated by NMR and DFT studies. The stability constants of the lead(II) and bismuth(III) complexes of the two ligands were determined in 0.5 M KCl using potentiometric and spectrophotometric techniques. The stability constants determined for the complexes of Pb(2+) are relatively high (log KML = 16.44 and 18.44 for H2do2pa and H2Me-do2pa, respectively) and exceptionally high for the complexes of Bi(3+) (log KML = 32.0 and 34.2 for H2do2pa and H2Me-do2pa, respectively). The [Pb(Me-do2pa)] complex presents rather fast formation and very good kinetic inertness toward transchelation. Additionally, the [Bi(Me-do2pa)](+) complex was found to present a remarkably fast complexation rate (full complexation in ∼2 min at pH 5.0, acetate buffer) and a very good kinetic inertness with respect to metal ion dissociation (half-life of 23.9 min in 1 M HCl), showing promise for potential applications in α-radioimmunotherapy.
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Affiliation(s)
- Luís M P Lima
- †Université de Bretagne Occidentale, UMR-CNRS 6521, UFR des Sciences et Techniques, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 BREST Cedex 3, France.,‡Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Maryline Beyler
- †Université de Bretagne Occidentale, UMR-CNRS 6521, UFR des Sciences et Techniques, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 BREST Cedex 3, France
| | - Rita Delgado
- ‡Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Carlos Platas-Iglesias
- §Departamento de Química Fundamental, Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
| | - Raphaël Tripier
- †Université de Bretagne Occidentale, UMR-CNRS 6521, UFR des Sciences et Techniques, 6 avenue Victor le Gorgeu, C.S. 93837, 29238 BREST Cedex 3, France
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41
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Abstract
Radioisotopes of elements from all parts of the periodic table find both clinical and research applications in radionuclide molecular imaging and therapy (nuclear medicine). This article provides an overview of these applications in relation to both the radiological properties of the radionuclides and the chemical properties of the elements, indicating past successes, current applications and future opportunities and challenges for inorganic chemistry.
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Affiliation(s)
- Philip J Blower
- King's College London, Division of Imaging Sciences and Biomedical Engineering, 4th Floor Lambeth Wing, St Thomas' Hospital, London SE1 7EH, UK.
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42
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Abstract
α-particle-emitting radionuclides are highly cytotoxic and are thus promising candidates for use in targeted radioimmunotherapy of cancer. Due to their high linear energy transfer (LET) combined with a short path length in tissue, α-particles cause severe DNA double-strand breaks that are repaired inaccurately and finally trigger cell death. For radioimmunotherapy, α-emitters such as 225Ac, 211At, 212Bi/212Pb, 213Bi and 227Th are coupled to antibodies via appropriate chelating agents. The α-emitter immunoconjugates preferably target proteins that are overexpressed or exclusively expressed on cancer cells. Application of α-emitter immunoconjugates seems particularly promising in treatment of disseminated cancer cells and small tumor cell clusters that are released during the resection of a primary tumor. α-emitter immunoconjugates have been successfully administered in numerous experimental studies for therapy of ovarian, colon, gastric, blood, breast and bladder cancer. Initial clinical trials evaluating α-emitter immunoconjugates in terms of toxicity and therapeutic efficacy have also shown positive results in patients with melanoma, ovarian cancer, acute myeloid lymphoma and glioma. The present problems in terms of availability of therapeutically effiective α-emitters will presumably be solved by use of alternative production routes and installation of additional production facilities in the near future. Therefore, clinical establishment of targeted α-emitter radioimmunotherapy as one part of a multimodal concept for therapy of cancer is a promising, middle-term concept.
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Affiliation(s)
- Christof Seidl
- Technische Universität München, Department of Nuclear Medicine, Ismaninger Strasse 22, 81675 Munich, Germany
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43
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Abstract
Radiometals comprise many useful radioactive isotopes of various metallic elements. When properly harnessed, these have valuable emission properties that can be used for diagnostic imaging techniques, such as single photon emission computed tomography (SPECT, e.g.(67)Ga, (99m)Tc, (111)In, (177)Lu) and positron emission tomography (PET, e.g.(68)Ga, (64)Cu, (44)Sc, (86)Y, (89)Zr), as well as therapeutic applications (e.g.(47)Sc, (114m)In, (177)Lu, (90)Y, (212/213)Bi, (212)Pb, (225)Ac, (186/188)Re). A fundamental critical component of a radiometal-based radiopharmaceutical is the chelator, the ligand system that binds the radiometal ion in a tight stable coordination complex so that it can be properly directed to a desirable molecular target in vivo. This article is a guide for selecting the optimal match between chelator and radiometal for use in these systems. The article briefly introduces a selection of relevant and high impact radiometals, and their potential utility to the fields of radiochemistry, nuclear medicine, and molecular imaging. A description of radiometal-based radiopharmaceuticals is provided, and several key design considerations are discussed. The experimental methods by which chelators are assessed for their suitability with a variety of radiometal ions is explained, and a large selection of the most common and most promising chelators are evaluated and discussed for their potential use with a variety of radiometals. Comprehensive tables have been assembled to provide a convenient and accessible overview of the field of radiometal chelating agents.
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Affiliation(s)
- Eric W Price
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, CanadaV6T 1Z1.
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