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Śmiłowicz D, Schlyer D, Boros E, Meimetis L. Evaluation of a Radio-IMmunoStimulant (RIMS) in a Syngeneic Model of Murine Prostate Cancer and ImmunoPET Analysis of T-cell Distribution. Mol Pharm 2022; 19:3217-3227. [PMID: 35895995 DOI: 10.1021/acs.molpharmaceut.2c00361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An immunosuppressive tumor microenvironment and tumor heterogeneity have led to the resilience of metastatic castrate resistant prostate cancer (mCRPC) to current treatments. To address these challenges, we developed and evaluated a new drug paradigm, Radio-IMmunostimulant (RIMS), in a syngeneic model of murine prostate cancer. RIMS-1 was generated using a convergent synthesis employing solid phase peptide and solution chemistries. The prostate-specific membrane antigen (PSMA) inhibitory constant for natLu-RIMS-1 was determined, and radiolabeling with 177Lu generated 177Lu-RIMS-1. The TLR 7/8 agonist payload release from natLu-RIMS-1 was determined using a cathepsin B assay. The biodistribution of 177Lu-RIMS-1 was evaluated in a bilateral xenograft model in NCru nude mice bearing PSMA(+) (PC3-PiP) and PSMA(-) (PC3-Flu) tumors at 2, 24, and 72 h. The therapeutic effect of 177Lu-RIMS-1 was evaluated in C57BL/6J mice bearing RM1-PGLS (PSMA-positive, green fluorescent protein-positive, and luciferase-positive) tumors and compared to that of 177Lu-PSMA-617 at the same total administered radioactivity of 57 MBq and molar activity of 5.18 MBq/nmol. natLu-RIMS-1 and vehicle were evaluated as the controls. Immuno-positron emission tomography (PET) using 89Zr-DFO-anti-CD3 was used to visualize T-cell distribution during treatment. 177Lu-RIMS-1 was quantitatively radiolabeled at >99% radiochemical purity and maintained a high affinity toward PSMA (Ki = 3.77 ± 0.5 nM). Cathepsin B efficiently released the entire immunostimulant payload in 17.6 h. 177Lu-RIMS-1 displayed a sustained uptake in PSMA(+) tumor tissue up to 72 h (2.65 ± 1.03% ID/g) and was not statistically different (P = 0.1936) compared to 177Lu-PSMA-617 (3.65 ± 0.59% ID/g). All animals treated with 177Lu-RIMS-1 displayed tumor growth suppression and provided a median survival of 30 days (P = 0.0007) while 177Lu-PSMA-617 provided a median survival of 15 days, which was not statistically significant (P = 0.3548) compared to the vehicle group (14 days). ImmunoPET analysis revealed 2-fold more tumor infiltrating T-cells in 177Lu-RIMS-1-treated animals compared to 177Lu-PSMA-617-treated animals; 177Lu-RIMS-1 improves therapeutic outcomes in a syngeneic model of mouse prostate cancer and elicits greater T-cell infiltration to the tumor compared to 177Lu-PSMA-617. These results support further investigation of the RIMS paradigm as the first example of a single molecular entity combining radiotherapy and immunostimulation.
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Affiliation(s)
- Dariusz Śmiłowicz
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - David Schlyer
- Department of Radiology, Stony Brook University, Stony Brook, New York 11794, United States.,Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Eszter Boros
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Labros Meimetis
- Department of Radiology, Stony Brook University, Stony Brook, New York 11794, United States
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Elvborn M, Shubbar E, Forssell-Aronsson E. Hyperfractionated Treatment with 177Lu-Octreotate Increases Tumor Response in Human Small-Intestine Neuroendocrine GOT1 Tumor Model. Cancers (Basel) 2022; 14:cancers14010235. [PMID: 35008397 PMCID: PMC8750112 DOI: 10.3390/cancers14010235] [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: 11/10/2021] [Revised: 12/29/2021] [Accepted: 12/29/2021] [Indexed: 02/01/2023] Open
Abstract
Simple Summary Neuroendocrine tumors are slow growing and initially associated with vague symptoms and, therefore, often spread in the patient’s body at diagnosis, leading to a poor prognosis without means of curation through surgery. Although tumor-targeting treatments exist and are used in clinics, they are not fully optimized. The aim of this study was to test different dosages and time intervals of the radioactive pharmaceutical 177Lu-octreotate. We found that dividing a dosage into several portions and administering it at short time intervals resulted in a stronger tumor reduction and/or prolonged time for regrowth in mice than if given as a single dose. The biggest differences were seen in the lower dosage levels of the study. The findings indicate that there is clear room for improvements in the treatment of neuroendocrine tumors with 177Lu-octreotate. Abstract Radionuclide treatment of patients with neuroendocrine tumors has advanced in the last decades with favorable results using 177Lu-octreotate. However, the gap between the high cure rate in animal studies vs. patient studies indicates a potential to increase the curation of patients. The aim of this study was to investigate the tumor response for different fractionation schemes with 177Lu-octreotate. BALB/c mice bearing a human small-intestine neuroendocrine GOT1 tumor were either mock treated with saline or injected intravenously with a total of 30–120 MBq of 177Lu-octreotate: 1 × 30, 2 × 15, 1 × 60, 2 × 30, 1 × 120, 2 × 60, or 3 × 40 MBq. The tumor volume was measured twice per week until the end of the experiment. The mean tumor volume for mice that received 2 × 15 = 30 and 1 × 30 MBq 177Lu-octreotate was reduced by 61% and 52%, respectively. The mean tumor volume was reduced by 91% and 44% for mice that received 2 × 30 = 60 and 1 × 60 MBq 177Lu-octreotate, respectively. After 120 MBq 177Lu-octreotate, given as 1–3 fractions, the mean tumor volume was reduced by 91–97%. Multiple fractions resulted in delayed regrowth and prolonged overall survival by 20–25% for the 120 MBq groups and by 45% for lower total activities, relative to one fraction. The results indicate that fractionation and hyperfractionation of 177Lu-octreotate are beneficial for tumor reduction and prolongs the time to regrowth.
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Affiliation(s)
- Mikael Elvborn
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden; (E.S.); (E.F.-A.)
- Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden
- Correspondence: ; Tel.: +46-(0)-31-342-95-99
| | - Emman Shubbar
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden; (E.S.); (E.F.-A.)
- Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Eva Forssell-Aronsson
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden; (E.S.); (E.F.-A.)
- Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
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Romiani A, Spetz J, Shubbar E, Lind DE, Hallberg B, Palmer RH, Forssell-Aronsson E. Neuroblastoma xenograft models demonstrate the therapeutic potential of 177Lu-octreotate. BMC Cancer 2021; 21:950. [PMID: 34433438 PMCID: PMC8386073 DOI: 10.1186/s12885-021-08551-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 06/14/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Neuroblastoma (NB) is one of the most frequently diagnosed tumors in infants. NB is a neuroendocrine tumor type with various characteristics and features, and with diverse outcome. The most malignant NBs have a 5-year survival rate of only 40-50%, indicating the need for novel and improved treatment options. 177Lu-octreotate is routinely administered for treatment of neuroendocrine tumors overexpressing somatostatin receptors (SSTR). The aim of this study was to examine the biodistribution of 177Lu-octreotate in mice bearing aggressive human NB cell lines, in order to evaluate the potential usefulness of 177Lu-octreotate for treatment of NB. METHODS BALB/c nude mice bearing CLB-BAR, CLB-GE or IMR-32 tumor xenografts (n = 5-7/group) were i.v. injected with 0.15 MBq, 1.5 MBq or 15 MBq 177Lu-octreotate and sacrificed 1 h, 24 h, 48 h and 168 h after administration. The radioactivity concentration was determined for collected tissue samples, tumor-to-normal-tissue activity concentration ratios (T/N) and mean absorbed dose for each tissue were calculated. Immunohistochemical (IHC) staining for SSTR1-5, and Ki67 were carried out for tumor xenografts from the three cell lines. RESULTS High 177Lu concentration levels and T/N values were observed in all NB tumors, with the highest for CLB-GE tumor xenografts (72%IA/g 24 h p.i.; 1.5 MBq 177Lu-octreotate). The mean absorbed dose to the tumor was 6.8 Gy, 54 Gy and 29 Gy for CLB-BAR, CLB-GE and IMR-32, respectively, p.i. of 15 MBq 177Lu-octreotate. Receptor saturation was clearly observed in CLB-BAR, resulting in higher concentration levels in the tumor when lower activity levels where administered. IHC staining demonstrated highest expression of SSTR2 in CLB-GE, followed by CLB-BAR and IMR-32. CONCLUSION T/N values for all three human NB tumor xenograft types investigated were high relative to previously investigated neuroendocrine tumor types. The results indicate a clear potential of 177Lu-octreotate as a therapeutic alternative for metastatic NB.
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Affiliation(s)
- Arman Romiani
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
- Department of Medical Physics, Sahlgrenska University Hospital, SE-41345, Gothenburg, Sweden.
| | - Johan Spetz
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Emman Shubbar
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Dan E Lind
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Bengt Hallberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ruth H Palmer
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Eva Forssell-Aronsson
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Center for Cancer Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
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Andersson CK, Shubbar E, Schüler E, Åkerström B, Gram M, Forssell-Aronsson EB. Recombinant α 1-Microglobulin Is a Potential Kidney Protector in 177Lu-Octreotate Treatment of Neuroendocrine Tumors. J Nucl Med 2019; 60:1600-1604. [PMID: 30926650 DOI: 10.2967/jnumed.118.225243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/19/2019] [Indexed: 12/30/2022] Open
Abstract
Treatment of neuroendocrine tumors with 177Lu-octreotate results in prolonged survival and improved quality of life for the patient. However, the treatment is today limited by side effects on kidney and bone marrow, and complete tumor remission is rarely seen. A possible way to minimize dose-limiting toxicity and to optimize this treatment method is to use radioprotectors in conjunction with radiotherapy. A recombinant form of α1-microglobulin (rA1M) was recently shown to preserve kidney structure and function after 177Lu-octreotate injection in mice and was suggested as a radioprotector in peptide receptor radionuclide therapy. The aims of this work were to investigate the influence of rA1M on the in vivo biokinetics of 177Lu-octreotate, with a focus on tumor tissue, and to study the impact of rA1M on the therapeutic response in tumor tissue subjected to 177Lu-octreotate treatment. Methods: The biodistribution of 177Lu-octreotate was examined in BALB/c nude mice with GOT2 tumors 1-168 h after injection with either 177Lu-octreotate or coadministration of 177Lu-octreotate and rA1M. The effects of rA1M on the tumor response after 177Lu-octreotate treatment were studied in BALB/c nude mice with GOT1 tumors. Three groups of mice were administered rA1M, 177Lu-octreotate, or both. Another group served as untreated controls. Tumor volume was measured to follow the treatment effects. Results: No statistically significant difference in biodistribution of 177Lu was observed between the groups receiving 177Lu-octreotate or coinjection of 177Lu-octreotate and rA1M. The therapy study showed a decrease in mean tumor volume during the first 2 wk for both the 177Lu-octreotate group and the coadministration group, followed by tumor regrowth. No statistically significant difference between the groups was found. Conclusion: rA1M did not negatively impact absorbed dose to tumor or therapeutic response in combination with 177Lu-octreotate and may be a promising kidney protector during 177Lu-octreotate treatment of patients with neuroendocrine tumors.
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Affiliation(s)
- Charlotte K Andersson
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Cancer Center, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Emman Shubbar
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Cancer Center, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Emil Schüler
- Department of Radiation Oncology, Stanford School of Medicine, Stanford University, Stanford, California
| | - Bo Åkerström
- Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden; and
| | - Magnus Gram
- Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden; and.,A1M Pharma AB, Lund, Sweden
| | - Eva B Forssell-Aronsson
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Cancer Center, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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Mellhammar E, Dahlbom M, Evans-Axelsson S, Strand SE. Preserving Preclinical PET Quality During Intratherapeutic Imaging in Radionuclide Therapy with Rose Metal Shielding Reducing Photon Flux. J Nucl Med 2018; 60:710-715. [PMID: 30389819 DOI: 10.2967/jnumed.118.217117] [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: 07/03/2018] [Accepted: 10/05/2018] [Indexed: 11/16/2022] Open
Abstract
Performing PET imaging during ongoing radionuclide therapy can be a promising method to follow tumor response in vivo. However, the high therapeutic activity can interfere with the PET camera performance and degrade both image quality and quantitative capabilities. As a solution, low-energy photon emissions from the therapeutic radionuclide can be highly attenuated, still allowing sufficient detection of annihilation photons in coincidence. Methods: Hollow Rose metal cylinders with walls 2-4 mm thick were used to shield a 22Na point source and a uniform phantom filled with 18F as they were imaged on a preclinical PET camera with increasing activities of 177Lu. A mouse with a subcutaneous tumor was injected with 18F-FDG and imaged with an additional 120 MBq of 177Lu and repeated with shields surrounding the animal. Results: The addition of 177Lu to the volume imaged continuously degraded the image quality with increasing activity. The image quality was improved when shielding was introduced. The shields showed a high ability to produce stable and reproducible results for both spatial resolution and quantification of up to 120 MBq of 177Lu activity (maximum activity tested). Conclusion: Without shielding, the activity quantification will be inaccurate for time points at which therapeutic activities are high. The suggested method shows that the shields reduce the noise induced by the 177Lu and therefore enable longitudinal quantitative intratherapeutic imaging studies.
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Affiliation(s)
- Emma Mellhammar
- Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Magnus Dahlbom
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California; and
| | - Susan Evans-Axelsson
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California; and
| | - Sven-Erik Strand
- Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden.,Division of Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
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Kletting P, Schuchardt C, Kulkarni HR, Shahinfar M, Singh A, Glatting G, Baum RP, Beer AJ. Investigating the Effect of Ligand Amount and Injected Therapeutic Activity: A Simulation Study for 177Lu-Labeled PSMA-Targeting Peptides. PLoS One 2016; 11:e0162303. [PMID: 27611841 PMCID: PMC5017739 DOI: 10.1371/journal.pone.0162303] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/19/2016] [Indexed: 11/19/2022] Open
Abstract
In molecular radiotherapy with 177Lu-labeled prostate specific membrane antigen (PSMA) peptides, kidney and/or salivary glands doses limit the activity which can be administered. The aim of this work was to investigate the effect of the ligand amount and injected activity on the tumor-to-normal tissue biologically effective dose (BED) ratio for 177Lu-labeled PSMA peptides. For this retrospective study, a recently developed physiologically based pharmacokinetic model was adapted for PSMA targeting peptides. General physiological parameters were taken from the literature. Individual parameters were fitted to planar gamma camera measurements (177Lu-PSMA I&T) of five patients with metastasizing prostate cancer. Based on the estimated parameters, the pharmacokinetics of tumor, salivary glands, kidneys, total body and red marrow was simulated and time-integrated activity coefficients were calculated for different peptide amounts. Based on these simulations, the absorbed doses and BEDs for normal tissue and tumor were calculated for all activities leading to a maximal tolerable kidney BED of 10 Gy2.5/cycle, a maximal salivary gland absorbed dose of 7.5 Gy/cycle and a maximal red marrow BED of 0.25 Gy15/cycle. The fits yielded coefficients of determination > 0.85, acceptable relative standard errors and low parameter correlations. All estimated parameters were in a physiologically reasonable range. The amounts (for 25−29 nmol) and pertaining activities leading to a maximal tumor dose, considering the defined maximal tolerable doses to organs of risk, were calculated to be 272±253 nmol (452±420 μg) and 7.3±5.1 GBq. Using the actually injected amount (235±155 μg) and the same maximal tolerable doses, the potential improvement for the tumor BED was 1–3 fold. The results suggest that currently given amounts for therapy are in the appropriate order of magnitude for many lesions. However, for lesions with high binding site density or lower perfusion, optimizing the peptide amount and activity might improve the tumor-to-kidney and tumor-to-salivary glands BED ratio considerably.
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Affiliation(s)
- Peter Kletting
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
- * E-mail:
| | - Christiane Schuchardt
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Harshad R. Kulkarni
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Mostafa Shahinfar
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Aviral Singh
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Richard P. Baum
- THERANOSTICS Center for Molecular Radiotherapy and Molecular Imaging (PET/CT), Zentralklinik Bad Berka, Bad Berka, Germany
| | - Ambros J. Beer
- Department of Nuclear Medicine, Ulm University, Ulm, Germany
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Potential Biomarkers for Radiation-Induced Renal Toxicity following 177Lu-Octreotate Administration in Mice. PLoS One 2015; 10:e0136204. [PMID: 26287527 PMCID: PMC4546116 DOI: 10.1371/journal.pone.0136204] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 07/30/2015] [Indexed: 12/14/2022] Open
Abstract
The kidneys are one of the main dose-limiting organs in peptide receptor radionuclide therapy and due to large inter-individual variations in renal toxicity, biomarkers are urgently needed in order to optimize therapy and reduce renal tissue damage. The aim of this study was to investigate the transcriptional, functional, and morphological effects on renal tissue after 177Lu-octreotate administration in normal mice, and to identify biomarkers for radiation induced renal toxicity.
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