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Liu Y, Oroujeni M, Liao Y, Vorobyeva A, Bodenko V, Orlova A, Konijnenberg M, Carlqvist M, Wahlberg E, Loftenius A, Frejd FY, Tolmachev V. Evaluation of a novel 177Lu-labelled therapeutic Affibody molecule with a deimmunized ABD domain and improved biodistribution profile. Eur J Nucl Med Mol Imaging 2024:10.1007/s00259-024-06840-5. [PMID: 39008065 DOI: 10.1007/s00259-024-06840-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024]
Abstract
PURPOSE Fusion of Affibody molecules with an albumin-binding domain (ABD) provides targeting agents, which are suitable for radionuclide therapy. To facilitate clinical translation, the low immunogenic potential of such constructs with targeting properties conserved is required. METHODS The HER2-targeting Affibody molecule ZHER2:2891 was fused with a deimmunized ABD variant and DOTA was conjugated to a unique C-terminal cysteine. The novel construct, PEP49989, was labelled with 177Lu. Affinity, specificity, and in vivo targeting properties of [177Lu]Lu-PEP49989 were characterised. Experimental therapy in mice with human HER2-expressing xenografts was evaluated. RESULTS The maximum molar activity of 52 GBq/µmol [177Lu]Lu-PEP49989 was obtained. [177Lu]Lu-PEP49989 bound specifically to HER2-expressing cells in vitro and in vivo. The HER2 binding affinity of [177Lu]Lu-PEP49989 was similar to the affinity of [177Lu]Lu-ABY-027 containing the parental ABD035 variant. The renal uptake of [177Lu]Lu-PEP49989 was 1.4-fold higher, but hepatic and splenic uptake was 1.7-2-fold lower than the uptake of [177Lu]Lu-ABY-027. The median survival of xenograft-bearing mice treated with 21 MBq [177Lu]Lu-PEP49989 (> 90 days) was significantly longer than the survival of mice treated with vehicle (38 days) or trastuzumab (45 days). Treatment using a combination of [177Lu]Lu-PEP49989 and trastuzumab increased the number of complete tumour remissions. The renal and hepatic toxicity was minimal to mild. CONCLUSION In preclinical studies, [177Lu]Lu-PEP49989 demonstrated favourable biodistribution and a strong antitumour effect, which was further enhanced by co-treatment with trastuzumab.
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Affiliation(s)
- Yongsheng Liu
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
| | - Maryam Oroujeni
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
- Affibody AB, Solna, 171 65, Sweden
| | - Yunqi Liao
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
| | - Anzhelika Vorobyeva
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
| | - Vitalina Bodenko
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
| | - Anna Orlova
- Department of Medicinal Chemistry, Uppsala University, Uppsala, 751 23, Sweden
| | - Mark Konijnenberg
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | | | | | | | - Fredrik Y Frejd
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden
- Affibody AB, Solna, 171 65, Sweden
| | - Vladimir Tolmachev
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, 751 85, Sweden.
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2
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Westerlund K, Oroujeni M, Gestin M, Clinton J, Hani Rosly A, Tano H, Vorobyeva A, Orlova A, Eriksson Karlström A, Tolmachev V. Shorter Peptide Nucleic Acid Probes Improve Affibody-Mediated Peptide Nucleic Acid-Based Pretargeting. ACS Pharmacol Transl Sci 2024; 7:1595-1611. [PMID: 38751640 PMCID: PMC11091976 DOI: 10.1021/acsptsci.4c00106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/28/2024] [Accepted: 04/10/2024] [Indexed: 05/18/2024]
Abstract
Affibody-mediated PNA-based pretargeting shows promise for HER2-expressing tumor radiotherapy. In our recent study, a 15-mer ZHER2:342-HP15 affibody-PNA conjugate, in combination with a shorter 9-mer [177Lu]Lu-HP16 effector probe, emerged as the most effective pretargeting strategy. It offered a superior tumor-to-kidney uptake ratio and more efficient tumor targeting compared to longer radiolabeled effector probes containing 12 or 15 complementary PNA bases. To enhance the production efficiency of our pretargeting system, we here introduce even shorter 6-, 7-, and 8-mer secondary probes, designated as HP19, HP21, and HP20, respectively. We also explore the replacement of the original 15-mer Z-HP15 primary probe with shorter 12-mer Z-HP12 and 9-mer Z-HP9 alternatives. This extended panel of shorter PNA-based probes was synthesized using automated microwave-assisted methods and biophysically screened in vitro to identify shorter probe combinations with the most effective binding properties. In a mouse xenograft model, we evaluated the biodistribution of these probes, comparing them to the Z-HP15:[177Lu]Lu-HP16 combination. Tumor-to-kidney ratios at 4 and 144 h postinjection of the secondary probe showed no significant differences among the Z-HP9:[177Lu]Lu-HP16, Z-HP9:[177Lu]Lu-HP20, and the Z-HP15:[177Lu]Lu-HP16 pairs. Importantly, tumor uptake significantly exceeded, by several hundred-fold, that of most normal tissues, with kidney uptake being the critical organ for radiation therapy. This suggests that using a shorter 9-mer primary probe, Z-HP9, in combination with 9-mer HP16 or 8-mer HP20 secondary probes effectively targets tumors while minimizing the dose-limiting kidney uptake of radionuclide. In conclusion, the Z-HP9:HP16 and Z-HP9:HP20 probe combinations offer good prospects for both cost-effective production and efficient in vivo pretargeting of HER2-expressing tumors.
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Affiliation(s)
- Kristina Westerlund
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Maryam Oroujeni
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
- Affibody
AB, Solna 171
65, Sweden
| | - Maxime Gestin
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Jacob Clinton
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Alia Hani Rosly
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
| | - Hanna Tano
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Anzhelika Vorobyeva
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
| | - Anna Orlova
- Department
of Medicinal Chemistry, Uppsala University, Uppsala 751 23, Sweden
| | - Amelie Eriksson Karlström
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Vladimir Tolmachev
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
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3
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Zhang M, Kang F, Xing T, Wang J, Ma T, Li G, Quan Z, Yang W, Chen X, Wang J. First-in-human validation of enzymolysis clearance strategy for decreasing renal radioactivity using modified [ 68Ga]Ga-HER2 Affibody. Eur J Nucl Med Mol Imaging 2024; 51:1713-1724. [PMID: 38216779 DOI: 10.1007/s00259-023-06584-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 12/11/2023] [Indexed: 01/14/2024]
Abstract
PURPOSE Enzymolysis clearance strategy, characterized by releasing the non-reabsorbable radioactive fragment under the specific cleavage of enzymes, is confirmed to be a safe and effective way to reduce the renal radioactivity accumulation in mice. However, the effectiveness of this strategy in humans remains unknown. Human epidermal growth factor receptor 2 (HER2) is overexpressed in various types of tumors, and radiolabeled HER2 Affibody is believed to be an attractive tool for HER2-targeted theranostics. However, its wide application is limited by the high and persistent renal uptake. In this study, we intend to validate the effectiveness of enzymolysis clearance strategy in reducing renal accumulation by using a modified HER2 Affibody. MATERIALS AND METHODS A new HER2 Affibody ligand, NOTA-MVK-ZHER2:2891, containing a cleavable Met-Val-Lys (MVK) linker was synthesized and labeled with 68Ga. The microPET imaging study was performed in SKOV-3 tumor mice to assess the uptakes of the control ligand and the MVK one in tumors and kidneys. Seven healthy volunteers were included for biodistribution and dosimetric studies with both the control and MVK ligands performed 1 week apart. Urine and blood samples from healthy volunteers were collected for in vivo metabolism study of the two ligands. Four HER2-positive and two HER2-negative patients were recruited for [68Ga]Ga-NOTA-MVK-ZHER2:2891 PET/CT imaging at 2 and 4 h post-injection (p.i.). RESULTS [68Ga]Ga-NOTA-MVK-ZHER2:2891 was stable both in PBS and in mouse serum. MicroPET images showed that the tumor uptake of [68Ga]Ga-NOTA-MVK-ZHER2:2891 was comparable to that of [68Ga]Ga-NOTA-ZHER2:2891 at all the time points, while the kidney uptake was significantly reduced 40 min p.i. (P < 0.05). The biodistribution study in healthy volunteers showed that the kidney uptake of MVK ligand was significantly lower than that of the control ligand at 1 h p.i. (P < 0.05), with the SUVmean of 34.3 and 45.8, respectively, while the uptakes of the two ligands in the other organs showed negligible difference. The effective doses of the MVK ligand and the control one were 26.1 and 28.7 µSv/MBq, respectively. The enzymolysis fragment of [68Ga]Ga-NOTA-Met-OH was observed in the urine samples of healthy volunteers injected with the MVK ligand, indicating that the enzymolysis clearance strategy worked in humans. The PET/CT study of patients showed that the range of SUVmax of HER2-positive lesions was 9.4-21, while that of HER2-negative lesions was 2.7-6.2, which suggested that the MVK modification did not affect the ability of ZHER2:2891 structure to bind with HER2. CONCLUSION We for the first time demonstrated that enzymolysis clearance strategy can effectively reduce renal radioactivity accumulation in humans. This strategy is expected to decrease renal radiation dose of peptide and small protein-based radiotracers, especially in the field of radionuclide therapy.
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Affiliation(s)
- Mingru Zhang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Fei Kang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Tong Xing
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Junling Wang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Taoqi Ma
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Guiyu Li
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Zhiyong Quan
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Weidong Yang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China
| | - Xiaoyuan Chen
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore.
- Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore.
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.
| | - Jing Wang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shannxi, China.
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4
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Zhang T, Lei H, Chen X, Dou Z, Yu B, Su W, Wang W, Jin X, Katsube T, Wang B, Zhang H, Li Q, Di C. Carrier systems of radiopharmaceuticals and the application in cancer therapy. Cell Death Discov 2024; 10:16. [PMID: 38195680 PMCID: PMC10776600 DOI: 10.1038/s41420-023-01778-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/04/2023] [Accepted: 12/13/2023] [Indexed: 01/11/2024] Open
Abstract
Radiopharmaceuticals play a vital role in cancer therapy. The carrier of radiopharmaceuticals can precisely locate and guide radionuclides to the target, where radionuclides kill surrounding tumor cells. Effective application of radiopharmaceuticals depends on the selection of an appropriate carrier. Herein, different types of carriers of radiopharmaceuticals and the characteristics are briefly described. Subsequently, we review radiolabeled monoclonal antibodies (mAbs) and their derivatives, and novel strategies of radiolabeled mAbs and their derivatives in the treatment of lymphoma and colorectal cancer. Furthermore, this review outlines radiolabeled peptides, and novel strategies of radiolabeled peptides in the treatment of neuroendocrine neoplasms, prostate cancer, and gliomas. The emphasis is given to heterodimers, bicyclic peptides, and peptide-modified nanoparticles. Last, the latest developments and applications of radiolabeled nucleic acids and small molecules in cancer therapy are discussed. Thus, this review will contribute to a better understanding of the carrier of radiopharmaceuticals and the application in cancer therapy.
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Affiliation(s)
- Taotao Zhang
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
| | - Huiwen Lei
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
| | - Xiaohua Chen
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
- Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, 516029, China
| | - Zhihui Dou
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
| | - Boyi Yu
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
| | - Wei Su
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
| | - Wei Wang
- College of Life Science, Northwest Normal University, Lanzhou, 730000, China
| | - Xiaodong Jin
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China
- Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, 516029, China
| | - Takanori Katsube
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, 263-8555, Japan
| | - Bing Wang
- National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, 263-8555, Japan
| | - Hong Zhang
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China.
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China.
- Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, 516029, China.
| | - Qiang Li
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China.
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China.
- Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, 516029, China.
| | - Cuixia Di
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
- Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.
- College of Life Sciences, University of Chinese Academy of Sciences, 101408, Beijing, China.
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China.
- Advanced Energy Science and Technology Guangdong Laboratory, Huizhou, 516029, China.
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5
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Bragina O, Chernov V, Larkina M, Rybina A, Zelchan R, Garbukov E, Oroujeni M, Loftenius A, Orlova A, Sörensen J, Frejd FY, Tolmachev V. Phase I clinical evaluation of 99mTc-labeled Affibody molecule for imaging HER2 expression in breast cancer. Theranostics 2023; 13:4858-4871. [PMID: 37771776 PMCID: PMC10526658 DOI: 10.7150/thno.86770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 08/27/2023] [Indexed: 09/30/2023] Open
Abstract
The determination of tumor human epidermal growth factor receptor type 2 (HER2) status is of increasing importance with the recent approval of more efficacious HER2-targeted treatments. There is a lack of suitable methods for clinical in vivo HER2 expression assessment. Affibody molecules are small affinity proteins ideal for imaging detection of receptors, which are engineered using a small (molecular weight 6.5 kDa) nonimmunoglobulin scaffold. Labeling of Affibody molecules with positron emitters enabled the development of sensitive and specific agents for molecular imaging. The development of probes for SPECT would permit the use of Affibody-based imaging in regions where PET is not available. In this first-in-human study, we evaluated the safety, biodistribution, and dosimetry of the 99mTc-ZHER2:41071 Affibody molecule developed for SPECT/CT imaging of HER2 expression. Methods: Thirty-one patients with primary breast cancer were enrolled and divided into three cohorts (injected with 500, 1000, or 1500 µg ZHER2:41071) comprising at least five patients with high (positive) HER2 tumor expression (IHC score 3+ or 2+ and ISH positive) and five patients with low (IHC score 2+ or 1+ and ISH negative) or absent HER2 tumor expression. Patients were injected with 451 ± 71 MBq 99mTc-ZHER2:4107. Planar scintigraphy was performed after 2, 4, 6 and 24 h, and SPECT/CT imaging followed planar imaging 2, 4 and 6 h after injection. Results: Injections of 99mTc-ZHER2:41071 were well tolerated and not associated with adverse events. Normal organs with the highest accumulation were the kidney and liver. The effective dose was 0.019 ± 0.004 mSv/MBq. Injection of 1000 µg provided the best standard discrimination between HER2-positive and HER2-low or HER2-negative tumors 2 h after injection (SUVmax 16.9 ± 7.6 vs. 3.6 ± 1.4, p < 0.005). The 99mTc-ZHER2:41071 uptake in HER2-positive lymph node metastases (SUVmax 6.9 ± 2.4, n = 5) was significantly (p < 0.05) higher than that in HER2-low/negative lymph nodes (SUVmax 3.5 ± 1.2, n = 4). 99mTc-ZHER2:41071 visualized hepatic metastases in a patient with liver involvement. Conclusions: Injections of 99mTc-ZHER2:41071 appear safe and exhibit favorable dosimetry. The protein dose of 1000 µg provides the best discrimination between HER2-positive and HER2-low/negative expression of HER2 according to the definition used for current HER2-targeting drugs.
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Affiliation(s)
- Olga Bragina
- Department of Nuclear Therapy and Diagnostic, Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, Tomsk, Russia
| | - Vladimir Chernov
- Department of Nuclear Therapy and Diagnostic, Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, Tomsk, Russia
| | - Mariia Larkina
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, Tomsk, Russia
- Department of Pharmaceutical Analysis, Siberian State Medical University, 634050 Tomsk, Russia
| | - Anstasiya Rybina
- Department of Nuclear Therapy and Diagnostic, Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia
| | - Roman Zelchan
- Department of Nuclear Therapy and Diagnostic, Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, Tomsk, Russia
| | - Eugeniy Garbukov
- Department of Nuclear Therapy and Diagnostic, Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia
| | - Maryam Oroujeni
- Department of Immunology, Genetics and Pathology, Uppsala University, 752 37 Uppsala, Sweden
- Affibody AB, Solna, Sweden
| | | | - Anna Orlova
- Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Jens Sörensen
- Radiology and Nuclear Medicine, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Fredrik Y. Frejd
- Department of Immunology, Genetics and Pathology, Uppsala University, 752 37 Uppsala, Sweden
- Affibody AB, Solna, Sweden
| | - Vladimir Tolmachev
- Department of Immunology, Genetics and Pathology, Uppsala University, 752 37 Uppsala, Sweden
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6
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Chung SK, Vargas DB, Chandler CS, Katugampola S, Veach DR, McDevitt MR, Seo SH, Vaughn BA, Rinne SS, Punzalan B, Patel M, Xu H, Guo HF, Zanzonico PB, Monette S, Yang G, Ouerfelli O, Nash GM, Cercek A, Fung EK, Howell RW, Larson SM, Cheal SM, Cheung NKV. Efficacy of HER2-Targeted Intraperitoneal 225Ac α-Pretargeted Radioimmunotherapy for Small-Volume Ovarian Peritoneal Carcinomatosis. J Nucl Med 2023; 64:1439-1445. [PMID: 37348919 PMCID: PMC10478816 DOI: 10.2967/jnumed.122.265095] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 04/14/2023] [Indexed: 06/24/2023] Open
Abstract
Epithelial ovarian cancer (EOC) is often asymptomatic and presents clinically in an advanced stage as widespread peritoneal microscopic disease that is generally considered to be surgically incurable. Targeted α-therapy with the α-particle-emitting radionuclide 225Ac (half-life, 9.92 d) is a high-linear-energy-transfer treatment approach effective for small-volume disease and even single cells. Here, we report the use of human epidermal growth factor receptor 2 (HER2) 225Ac-pretargeted radioimmunotherapy (PRIT) to treat a mouse model of human EOC SKOV3 xenografts growing as peritoneal carcinomatosis (PC). Methods: On day 0, 105 SKOV3 cells transduced with a luciferase reporter gene were implanted intraperitoneally in nude mice, and tumor engraftment was verified by bioluminescent imaging (BLI). On day 15, treatment was started using 1 or 2 cycles of 3-step anti-HER2 225Ac-PRIT (37 kBq/cycle as 225Ac-Proteus DOTA), separated by a 1-wk interval. Efficacy and toxicity were monitored for up to 154 d. Results: Untreated PC-tumor-bearing nude mice showed a median survival of 112 d. We used 2 independent measures of response to evaluate the efficacy of 225Ac-PRIT. First, a greater proportion of the treated mice (9/10 1-cycle and 8/10 2-cycle; total, 17/20; 85%) survived long-term compared with controls (9/27, 33%), and significantly prolonged survival was documented (log-rank [Mantel-Cox] P = 0.0042). Second, using BLI, a significant difference in the integrated BLI signal area to 98 d was noted between controls and treated groups (P = 0.0354). Of a total of 8 mice from the 2-cycle treatment group (74 kBq total) that were evaluated by necropsy, kidney radiotoxicity was mild and did not manifest itself clinically (normal serum blood urea nitrogen and creatinine). Dosimetry estimates (relative biological effectiveness-weighted dose, where relative biological effectiveness = 5) per 37 kBq administered for tumors and kidneys were 56.9 and 16.1 Gy, respectively. One-cycle and 2-cycle treatments were equally effective. With immunohistology, mild tubular changes attributable to α-toxicity were observed in both therapeutic groups. Conclusion: Treatment of EOC PC-tumor-bearing mice with anti-HER2 225Ac-PRIT resulted in histologic cures and prolonged survival with minimal toxicity. Targeted α-therapy using the anti-HER2 225Ac-PRIT system is a potential treatment for otherwise incurable EOC.
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Affiliation(s)
- Sebastian K Chung
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | | | | | - Sumudu Katugampola
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Darren R Veach
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Michael R McDevitt
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Shin H Seo
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Brett A Vaughn
- Department of Radiology, Weill Cornell Medicine, New York, New York
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sara S Rinne
- Department of Radiology, Weill Cornell Medicine, New York, New York
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Blesida Punzalan
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Mitesh Patel
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Hong Xu
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Hong-Fen Guo
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Pat B Zanzonico
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sébastien Monette
- Laboratory of Comparative Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and Rockefeller University, New York, New York; and
| | - Guangbin Yang
- Organic Synthesis Core Facility, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ouathek Ouerfelli
- Organic Synthesis Core Facility, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Garrett M Nash
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Andrea Cercek
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Edward K Fung
- Department of Radiology, Weill Cornell Medicine, New York, New York
| | - Roger W Howell
- Division of Radiation Research, Department of Radiology and Center for Cell Signaling, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Steven M Larson
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Radiology, Weill Cornell Medicine, New York, New York
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sarah M Cheal
- Department of Radiology, Weill Cornell Medicine, New York, New York;
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York
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7
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Xu K, Han J, Yang L, Cao L, Li S, Hong Z. Tumor Site-Specific Cleavage Improves the Antitumor Efficacy of Antibody-Drug Conjugates. Int J Mol Sci 2023; 24:11011. [PMID: 37446189 DOI: 10.3390/ijms241311011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
Antibody-drug conjugates (ADCs) play important roles in tumor therapy. However, traditional ADCs are limited by the extremely large molecular weight of the antibody molecules, which results in low permeability into solid tumors. The use of small ADCs may be expected to alleviate this problem, but this switch brings the new limitation of a greatly shortened blood circulation half-life. Here, we propose a new cleavable ADC design with excellent tumor tissue permeability and a long circulation half-life by fusing the small ADC ZHER2-MMAE with the Fc domain of the antibody for circulation half-life extension, and inserting a digestion sequence between them to release the small ADC inside tumors for better tumor penetration. The experimental results showed that the designed molecule Fc-U-ZHER2-MMAE has a significantly increased blood circulation half-life (7.1 h, 59-fold longer) compared to the small ADC ZHER2-MMAE, and significantly improved drug accumulation ability at tumor sites compared to the conventional full-length antibody-coupled ADC Herceptin-MMAE. These combined effects led to Fc-U-ZHER2-MMAE having significantly enhanced tumor treatment ability, as shown in mouse models of NCI-N87 gastric cancer and SK-OV-3 ovarian cancer, where Fc-U-ZHER2-MMAE treatment achieved complete regression of tumors in all or a portion of animals with no obvious side effects and an MTD exceeding 90 mg/kg. These data demonstrate the therapeutic advantages of this cleavable ADC strategy, which could provide a new approach for ADC design.
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Affiliation(s)
- Keyuan Xu
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jiani Han
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Liu Yang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Li Cao
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Shuang Li
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Zhangyong Hong
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
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8
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Li R, He H, Li X, Zheng X, Li Z, Zhang H, Ye J, Zhang W, Yu C, Feng G, Fan W. EDB-FN targeted probes for the surgical navigation, radionuclide imaging, and therapy of thyroid cancer. Eur J Nucl Med Mol Imaging 2023; 50:2100-2113. [PMID: 36807768 DOI: 10.1007/s00259-023-06147-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/08/2023] [Indexed: 02/20/2023]
Abstract
PURPOSE Extradomain B of fibronectin (EDB-FN) is a promising diagnostic and therapeutic biomarker for thyroid cancer (TC). Here, we identified a high-affinity EDB-FN targeted peptide named EDBp (AVRTSAD) and developed three EDBp-based probes, Cy5-PEG4-EDBp(Cy5-EDBp), [18F]-NOTA-PEG4-EDBp([18F]-EDBp), and [177Lu]-DOTA-PEG4-EDBp ([177Lu]-EDBp), for the surgical navigation, radionuclide imaging, and therapy of TC. METHODS Based on the previously identified EDB-FN targeted peptide ZD2, the optimized EDB-FN targeted peptide EDBp was identified by using the alanine scan strategy. Three EDBp-based probes, Cy5-EDBp, [18F]-EDBp, and [177Lu]-EDBp, were developed for fluorescence imaging, positron emission tomography (PET) imaging, and radiotherapy in TC tumor-bearing mice, respectively. Additionally, [18F]-EDBp was evaluated in two TC patients. RESULTS The binding affinity of EDBp to the EDB fragment protein (Kd = 14.4 ± 1.4 nM, n = 3) was approximately 336-fold greater than that of the ZD2 (Kd = 4839.7 ± 361.7 nM, n = 3). Fluorescence imaging with Cy5-EDBp facilitated the complete removal of TC tumors. [18F]-EDBp PET imaging clearly delineated TC tumors, with high tumor uptake (16.43 ± 1.008%ID/g, n = 6, at 1-h postinjection). Radiotherapy with [177Lu]-EDBp inhibited tumor growth and prolonged survival in TC tumor-bearing mice (survival time of different treatment groups: saline vs. EDBp vs. ABRAXANE vs. [177Lu]-EDBp = 8.00 d vs. 8.00 d vs. 11.67 d vs. 22.33 d, ***p < 0.001). Importantly, the first-in-human evaluation of [18F]-EDBp demonstrated that it had specific targeting properties (SUVmax value of 3.6) and safety. CONCLUSION Cy5-EDBp, [18F]-EDBp, and [177Lu]-EDBp are promising candidates for the surgical navigation, radionuclide imaging, and radionuclide therapy of TC, respectively.
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Affiliation(s)
- Ruping Li
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China
| | - Huihui He
- Department of Nuclear Medicine, Affiliated Hospital of Jiangnan University, Wuxi, 214000, China
| | - Xinling Li
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China
| | - Xiaobin Zheng
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China
| | - Zhijian Li
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China
| | - Hu Zhang
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China
| | - Jiacong Ye
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China
| | - Weiguang Zhang
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China
| | - Chunjing Yu
- Department of Nuclear Medicine, Affiliated Hospital of Jiangnan University, Wuxi, 214000, China.
| | - Guokai Feng
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China.
| | - Wei Fan
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou , 510060, Guangdong, People's Republic of China.
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Liu Y, Xu T, Vorobyeva A, Loftenius A, Bodenko V, Orlova A, Frejd FY, Tolmachev V. Radionuclide Therapy of HER2-Expressing Xenografts Using [ 177Lu]Lu-ABY-027 Affibody Molecule Alone and in Combination with Trastuzumab. Cancers (Basel) 2023; 15:cancers15092409. [PMID: 37173878 PMCID: PMC10177614 DOI: 10.3390/cancers15092409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/16/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023] Open
Abstract
ABY-027 is a scaffold-protein-based cancer-targeting agent. ABY-027 includes the second-generation Affibody molecule ZHER2:2891, which binds to human epidermal growth factor receptor type 2 (HER2). An engineered albumin-binding domain is fused to ZHER2:2891 to reduce renal uptake and increase bioavailability. The agent can be site-specifically labeled with a beta-emitting radionuclide 177Lu using a DOTA chelator. The goals of this study were to test the hypotheses that a targeted radionuclide therapy using [177Lu]Lu-ABY-027 could extend the survival of mice with HER2-expressing human xenografts and that co-treatment with [177Lu]Lu-ABY-027 and the HER2-targeting antibody trastuzumab could enhance this effect. Balb/C nu/nu mice bearing HER2-expressing SKOV-3 xenografts were used as in vivo models. A pre-injection of trastuzumab did not reduce the uptake of [177Lu]Lu-ABY-027 in tumors. Mice were treated with [177Lu]Lu-ABY-027 or trastuzumab as monotherapies and a combination of these therapies. Mice treated with vehicle or unlabeled ABY-027 were used as controls. Targeted monotherapy using [177Lu]Lu-ABY-027 improved the survival of mice and was more efficient than trastuzumab monotherapy. A combination of therapies utilizing [177Lu]Lu-ABY-027 and trastuzumab improved the treatment outcome in comparison with monotherapies using these agents. In conclusion, [177Lu]Lu-ABY-027 alone or in combination with trastuzumab could be a new potential agent for the treatment of HER2-expressing tumors.
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Affiliation(s)
- Yongsheng Liu
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Tianqi Xu
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Anzhelika Vorobyeva
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | | | - Vitalina Bodenko
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, 634050 Tomsk, Russia
| | - Anna Orlova
- Department of Medicinal Chemistry, Uppsala University, 751 23 Uppsala, Sweden
| | - Fredrik Y Frejd
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
- Affibody AB, 171 65 Solna, Sweden
| | - Vladimir Tolmachev
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, 634050 Tomsk, Russia
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Jia D, Liu H, Zheng S, Yuan D, Sun R, Wang F, Li Y, Li H, Yuan F, Fan Q, Zhao Z. ICG-Dimeric Her2-Specific Affibody Conjugates for Tumor Imaging and Photothermal Therapy for Her2-Positive Tumors. Mol Pharm 2023; 20:427-437. [PMID: 36315025 DOI: 10.1021/acs.molpharmaceut.2c00708] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Human epidermal growth factor receptor 2 (Her2) is abundantly expressed in various solid tumors. The Her2-specific Affibody (ZHer2:2891) has been clinically tested in patients with Her2-positive breast cancer and is regarded as an ideal drug carrier for tumor diagnosis and targeted treatment. Indocyanine green (ICG) can be used as a photosensitizer for photothermal therapy (PTT), in addition to fluorescent dyes for tumor imaging. In this study, a dimeric Her2-specific Affibody (ZHer2) based on ZHer2:2891 was prepared using the E. coli expression system and then coupled to ICG through an N-hydroxysuccinimide (NHS) ester reactive group to construct a novel bifunctional protein drug (named ICG-ZHer2) for tumor diagnosis and PTT. In vitro, ICG-ZHer2-mediated PTT selectively and efficiently killed Her2-positive BT-474 and SKOV-3 tumor cells rather than Her2-negative HeLa tumor cells. In vivo, ICG-ZHer2 specifically accumulated in Her2-positive SKOV-3 tumor grafts rather than Her2-negative HeLa tumor grafts; high-contrast tumor optical images were obtained. However, Her2-negative HeLa tumor grafts were not detected. More importantly, ICG-ZHer2-mediated PTT exhibited a significantly enhanced antitumor effect in mice bearing SKOV-3 tumor grafts owing to the good photothermal properties of ICG-ZHer2. Of note, ICG-ZHer2 did not exhibit acute toxicity in mice during short-term treatment. Overall, our findings indicate that ICG-ZHer2 is a promising bifunctional drug for Her2-positive tumor diagnosis and PTT.
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Affiliation(s)
- Dianlong Jia
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng, Shandong 252000, China
| | - Huimin Liu
- Department of Pharmacy, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Shuhui Zheng
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng, Shandong 252000, China
| | - Dandan Yuan
- Department of Pharmacy, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Ruohan Sun
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng, Shandong 252000, China
| | - Fei Wang
- Department of Pharmacy, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Yang Li
- Department of Pharmacy, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Hui Li
- Department of Pharmacy, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Fengjiao Yuan
- Joint Laboratory for Translational Medicine Research, Liaocheng People's Hospital, Liaocheng, Shandong 252000, China
| | - Qing Fan
- Department of Pharmacy, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Zhenxiong Zhao
- Taizhou Central Hospital (Taizhou University Hospital), Taizhou, Zhejiang 317700, China
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18F- or 177Lu-labeled bivalent ligand of fibroblast activation protein with high tumor uptake and retention. Eur J Nucl Med Mol Imaging 2022; 49:2705-2715. [PMID: 35290473 DOI: 10.1007/s00259-022-05757-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/03/2022] [Indexed: 11/04/2022]
Abstract
PURPOSE Fibroblast activation protein (FAP) has become a promising cancer-related target for diagnosis and therapy. The aim of this study was to develop a bivalent FAP ligand for both diagnostic PET imaging and endoradiotherapy. METHODS We synthesized a bivalent FAP ligand (ND-bisFAP) and labeled it with 18F or 177Lu. FAP-positive A549-FAP cells were used to study competitive binding to FAP, cellular internalization, and efflux properties in vitro. Micro-PET imaging with [18F]AlF-ND-bisFAPI was conducted in mice bearing A549-FAP or U87MG tumors. Biodistribution and therapeutic efficacy of [177Lu]Lu-ND-bisFAPI were conducted in mice bearing A549-FAP tumors. RESULTS The FAP binding affinity of ND-bisFAPI is 0.25 ± 0.05 nM, eightfold higher in potency than the monomeric DOTA-FAPI-04 (IC50 = 2.0 ± 0.18 nM). In A549-FAP cells, ND-bisFAPI showed specific uptake, a high internalized fraction, and slow cellular efflux. Compared to the monomeric [18F]AlF-FAPI-42, micro-PET imaging with [18F]AlF-ND-bisFAPI showed higher specific tumor uptake and retention for at least 6 h. Biodistribution studies showed that [177Lu]Lu-ND-bisFAPI had higher tumor uptake than [177Lu]Lu-FAPI-04 at the 24, 72, 120, and 168 h time points (all P < 0.01). [177Lu]Lu-ND-bisFAPI delivered fourfold higher radiation than [177Lu]Lu-FAPI-04 to A549-FAP tumors. For the endoradiotherapy study, 37 MBq of [177Lu]Lu-ND-bisFAPI significantly reduced tumor growth compared to the same dose of [177Lu]Lu-FAPI-04. Half of the dose of [177Lu]Lu-ND-bisFAPI (18.5 MBq) has comparable median survival as 37 MBq of [177Lu]Lu-FAPI-04 (37 vs 36 days). CONCLUSION The novel bivalent FAP ligand was developed as a theranostic radiopharmaceutical and showed promising properties including higher tumor uptake and retention compared to the established radioligands [18F]AlF-FAPI-42 and [177Lu]Lu-FAPI-04. Preliminary experiments with 18F- or 177Lu-labeled ND-bisFAPI showed promising imaging properties and favorable anti-tumor responses.
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