1
|
K Nazar A, Basu S. Radiolabeled Somatostatin Analogs for Cancer Imaging. Semin Nucl Med 2024:S0001-2998(24)00058-8. [PMID: 39122608 DOI: 10.1053/j.semnuclmed.2024.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Accepted: 07/01/2024] [Indexed: 08/12/2024]
Abstract
Somatostatin receptors (SSTR) are expressed by many tumours especially those related to neuro-endocrine origin and molecular functional imaging of SSTR expression using radiolabelled somatostatin analogs have revolutionized imaging of patients with these group of malignancies. Coming a long way from the first radiolabelled somatostatin analog 123I-Tyr-3-octreotide, there has been significant developments in terms of radionuclides used, the ligands and somatostatin derivatives. 111In-Pentetreotide extensively employed for imaging NETs at the beginning has now been replaced by 68Ga-SSA based PET-CT. SSA-PET/CT performs superior to conventional imaging modalities and has evolved in the mainframe for NET imaging. The advantages were multiple: (i) superior spatial resolution of PET versus SPECT, (ii) quantitative capabilities of PET aiding in disease activity and treatment response monitoring with better precision, (iii) shorter scan time and (iv) less patient exposure to radiation. The modality is indicated for staging, detecting the primary in CUP-NETs, restaging, treatment planning (along with FDG: the concept of dual-tracer PET-CT) as well as treatment response evaluation and follow-up of NETs. SSA PET/CT has also been incorporated in the guidelines for imaging of Pheochromocytoma-Paraganglioma, Medullary carcinoma thyroid, Meningioma and Tumor induced osteomalacia. At present, there is rising interest on (a) 18F-labelled SSA, (b) 64Cu-labelled SSA, and (c) somatostatin antagonists. 18F offers excellent imaging properties, 64Cu makes delayed imaging feasible which has implications in dosimetry and SSTR antagonists bind with the SST receptors with high affinity and specificity, providing high contrast images with less background, which can be translated to theranostics effectively. SSTR have been demonstrated in non-neuroendocrine tumours as well in the peer-reviewed literature, with studies demonstrating the potential of SSA PET/CT in Neuroblastoma, Nasopharyngeal carcinoma, carcinoma prostate (neuroendocrine differentiation) and lymphoma. This review will focus on the currently available SSAs and their history, different SPECT/PET agents, SSTR antagonists, comparison between the various imaging tracers, and their utility in both neuroendocrine and non-neuroendocrine tumors.
Collapse
Affiliation(s)
- Aamir K Nazar
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Centre Annexe, Mumbai; Homi Bhabha National Institute, Mumbai
| | - Sandip Basu
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Centre Annexe, Mumbai; Homi Bhabha National Institute, Mumbai.
| |
Collapse
|
2
|
Novak D, Janota B, Hörmann AA, Sawicka A, Kroselj M, Hubalewska-Dydejczyk A, Fani M, Mikolajczak R, Kolenc P, Decristoforo C, Garnuszek P. Development of the 99mTc-Labelled SST2 Antagonist TECANT-1 for a First-in-Man Multicentre Clinical Study. Pharmaceutics 2023; 15:pharmaceutics15030885. [PMID: 36986746 PMCID: PMC10053408 DOI: 10.3390/pharmaceutics15030885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/24/2023] [Accepted: 03/05/2023] [Indexed: 03/12/2023] Open
Abstract
Broad availability and cost-effectiveness of 99Mo/99mTc generators worldwide support the use, and thus the development, of novel 99mTc-labelled radiopharmaceuticals. In recent years, preclinical and clinical developments for neuroendocrine neoplasms patient management focused on somatostatin receptor subtype 2 (SST2) antagonists, mainly due to their superiority in SST2-tumour targeting and improved diagnostic sensitivity over agonists. The goal of this work was to provide a reliable method for facile preparation of a 99mTc-labelled SST2 antagonist, [99mTc]Tc-TECANT-1, in a hospital radiopharmacy setting, suitable for a multi-centre clinical trial. To ensure successful and reproducible on-site preparation of the radiopharmaceutical for human use shortly before administration, a freeze-dried three-vial kit was developed. The final composition of the kit was established based on the radiolabelling results obtained during the optimisation process, in which variables such as precursor content, pH and buffer, as well as kit formulations, were tested. Finally, the prepared GMP-grade batches met all predefined specification parameters together with long-term kit stability and stability of the product [99mTc]Tc-TECANT-1. Furthermore, the selected precursor content complies with micro-dosing, based on an extended single-dose toxicity study, where histopathology NOEL was established at 0.5 mg/kg BW, being more than 1000 times higher than the planned human dose of 20 µg. In conclusion, [99mTc]Tc-TECANT-1 is suitable to be advanced into a first-in-human clinical trial.
Collapse
Affiliation(s)
- Doroteja Novak
- The Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Barbara Janota
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland
| | - Anton Amadeus Hörmann
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Agnieszka Sawicka
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland
| | - Marko Kroselj
- Department of Nuclear Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
- The Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | | | - Melpomeni Fani
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, 4031 Basel, Switzerland
| | - Renata Mikolajczak
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland
| | - Petra Kolenc
- The Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
- Department of Nuclear Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria
- Correspondence: ; Tel.: +43-512-504-80951
| | - Piotr Garnuszek
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland
| |
Collapse
|
3
|
Makris G, Li Y, Gallazzi F, Kuchuk M, Wang J, Lewis MR, Jurisson SS, Hennkens HM. Evaluation of Re/ 99mTc-labeled somatostatin receptor-targeting peptide complexes synthesized via direct metal cyclization. RADIOCHIM ACTA 2023. [DOI: 10.1515/ract-2022-0097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Abstract
With interest in the development of somatostatin receptor (SSTR) targeting agents for potential application in diagnostic SPECT imaging (99mTc) or Peptide Radionuclide Receptor Therapy (PRRT, 186Re or 188Re) of neuroendocrine tumors, we present herein 99mTc/Re (radio)complexes synthesized by the integrated (radio)labeling approach of peptide cyclization via metal complexation. In particular, we utilized the potent SSTR2 peptide antagonist sequence DOTA-4-NO2-Phe-c(DCys-Tyr-DTrp-Lys-Thr-Cys)-DTyr-NH2 (DOTA-sst2-ANT) and report the syntheses and in vitro evaluations of its respective [99mTc]Tc/Re-cyclized peptides ([99mTc]Tc/Re-cyc-DOTA-sst2-ANT). The Re-cyc-DOTA-sst2-ANT complex was synthesized via an on-resin Re(V)-cyclization reaction using the ReOCl3(PPh3)2 precursor and consisted of three isomers characterized by LC–ESI-MS. The [99mTc]Tc-cyclized analogue was prepared via a ligand exchange reaction of the [99mTc][TcO]3+ core through a [99mTc]Tc-glucoheptonate intermediate with linear DOTA-sst2-ANT and was characterized by comparative HPLC studies against Re-cyc-DOTA-sst2-ANT. Good in vitro binding affinity was demonstrated in SSTR-expressing cells (AR42J) by the Re-cyc-DOTA-sst2-ANT major isomer, similar to the potent binder Lu-DOTA-sst2-ANT, in which the Lu metal was complexed by the bifunctional chelator DOTA versus via peptide cyclization. [99mTc]Tc-cyc-DOTA-sst2-ANT was obtained in high radiochemical yield, also with an elution pattern of three isomers observed by HPLC analysis, which were comparable yet not identical to those of Re-cyc-DOTA-sst2-ANT. The [99mTc]Tc-tracer complex was shown to be hydrophilic, and stability studies at 4 h demonstrated that it remained intact in both PBS and in rat serum, with low non-specific rat serum protein binding, while exhibiting more moderate stability in 1 mM cysteine. These findings demonstrate that direct Re/[99mTc]Tc-cyclization of DOTA-sst2-ANT is feasible and may be used as an alternative approach to the bifunctional chelate labeling strategy. However, given that the non-radioactive (Re) and radiotracer (99mTc) analogues are not identical and both form isomeric products in equilibrium, additional design modifications will be necessary prior to in vivo application of [99mTc]Tc/Re-cyc-DOTA-sst2-ANT.
Collapse
Affiliation(s)
- George Makris
- Research Reactor Center, University of Missouri , Columbia , MO 65211 , USA
| | - Yawen Li
- Department of Chemistry , University of Missouri , Columbia , MO 65211 , USA
| | - Fabio Gallazzi
- Department of Chemistry , University of Missouri , Columbia , MO 65211 , USA
- Molecular Interactions Core, University of Missouri , Columbia , MO 65211 , USA
| | - Marina Kuchuk
- Research Reactor Center, University of Missouri , Columbia , MO 65211 , USA
| | - Jing Wang
- Research Reactor Center, University of Missouri , Columbia , MO 65211 , USA
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics , Mianyang , Sichuan 621900 , P. R. China
| | - Michael R. Lewis
- Department of Veterinary Medicine and Surgery , University of Missouri , Columbia , MO 65211 , USA
- Research Service, Harry S. Truman Memorial Veterans’ Hospital , Columbia , MO 65201 , USA
| | - Silvia S. Jurisson
- Department of Chemistry , University of Missouri , Columbia , MO 65211 , USA
| | - Heather M. Hennkens
- Research Reactor Center, University of Missouri , Columbia , MO 65211 , USA
- Department of Chemistry , University of Missouri , Columbia , MO 65211 , USA
| |
Collapse
|
4
|
Kunert JP, Müller M, Günther T, Stopper L, Urtz-Urban N, Beck R, Wester HJ. Synthesis and preclinical evaluation of novel 99mTc-labeled PSMA ligands for radioguided surgery of prostate cancer. EJNMMI Res 2023; 13:2. [PMID: 36645586 PMCID: PMC9842843 DOI: 10.1186/s13550-022-00942-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/15/2022] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Radioguided surgery (RGS) has recently emerged as a valuable new tool in the management of recurrent prostate cancer (PCa). After preoperative injection of a 99mTc-labeled prostate-specific membrane antigen (PSMA) inhibitor, radioguided intraoperative identification and resection of lesions is facilitated by means of suitable γ-probes. First clinical experiences show the feasibility of RGS and suggest superiority over conventional lymph node dissection in recurrent PCa. However, commonly used [99mTc]Tc-PSMA-I&S exhibits slow whole-body clearance, thus hampering optimal tumor-to-background ratios (TBR) during surgery. We therefore aimed to develop novel 99mTc-labeled, PSMA-targeted radioligands with optimized pharmacokinetic profile to increase TBR at the time of surgery. METHODS Three 99mTc-labeled N4-PSMA ligands were preclinically evaluated and compared to [99mTc]Tc-PSMA-I&S. PSMA affinity (IC50) and internalization were determined on LNCaP cells. Lipophilicity was assessed by means of the distribution coefficient logD7.4 and an ultrafiltration method was used to determine binding to human plasma proteins. Biodistribution studies and static µSPECT/CT-imaging were performed at 6 h p.i. on LNCaP tumor-bearing CB17-SCID mice. RESULTS The novel N4-PSMA tracers were readily labeled with [99mTc]TcO4- with RCP > 95%. Comparable and high PSMA affinity was observed for all [99mTc]Tc-N4-PSMA-ligands. The ligands showed variable binding to human plasma and medium to low lipophilicity (logD7.4 - 2.6 to - 3.4), both consistently decreased compared to [99mTc]Tc-PSMA-I&S. Biodistribution studies revealed comparable tumor uptake among all [99mTc]Tc-N4-PSMA-ligands and [99mTc]Tc-PSMA-I&S, while clearance from most organs was superior for the novel tracers. Accordingly, increased TBR were achieved. [99mTc]Tc-N4-PSMA-12 showed higher TBR than [99mTc]Tc-PSMA-I&S for blood and all evaluated tissue. In addition, a procedure suitable for routine clinical production of [99mTc]Tc-N4-PSMA-12 was established. Labeling with 553 ± 187 MBq was achieved with RCP of 98.5 ± 0.6% (n = 10). CONCLUSION High tumor accumulation and favorable clearance from blood and non-target tissue make [99mTc]Tc-N4-PSMA-12 an attractive tracer for RGS, possibly superior to currently established [99mTc]Tc-PSMA-I&S. Its GMP-production according to a method presented here and first clinical investigations with this novel radioligand is highly recommended.
Collapse
Affiliation(s)
- Jan-Philip Kunert
- Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748, Garching, Germany.
| | - Max Müller
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Thomas Günther
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - León Stopper
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Nicole Urtz-Urban
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Roswitha Beck
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| | - Hans-Jürgen Wester
- grid.6936.a0000000123222966Chair of Pharmaceutical Radiochemistry, Department of Chemistry, Technical University of Munich (TUM), Walther-Meißner-Str 3, 85748 Garching, Germany
| |
Collapse
|
5
|
Günther T, Konrad M, Stopper L, Kunert JP, Fischer S, Beck R, Casini A, Wester HJ. Optimization of the Pharmacokinetic Profile of [ 99mTc]Tc-N 4-Bombesin Derivatives by Modification of the Pharmacophoric Gln-Trp Sequence. Pharmaceuticals (Basel) 2022; 15:ph15091133. [PMID: 36145354 PMCID: PMC9500665 DOI: 10.3390/ph15091133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/06/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Current radiolabeled gastrin-releasing peptide receptor (GRPR) ligands usually suffer from high accumulation in GRPR-positive organs (pancreas, stomach), limiting tumor-to-background contrast in the abdomen. In novel N4-bombesin derivatives this was addressed by substitutions at the Gln7-Trp8 site within the MJ9 peptide (H-Pip5-phe6-Gln7-Trp8-Ala9-Val10-Gly11-His12-Sta13-Leu14-NH2) either by homoserine (Hse7), β-(3-benzothienyl) alanine (Bta8) or α-methyl tryptophan (α-Me-Trp8), with the aim of optimizing pharmacokinetics. We prepared and characterized the peptide conjugates 6-carboxy-1,4,8,11-tetraazaundecane (N4)-asp-MJ9, N4-asp-[Bta8]MJ9, N4-[Hse7]MJ9 and N4-[α-Me-Trp8]MJ9, and evaluated these compounds in vitro (GRPR affinity via IC50,inverse; internalization; lipophilicity via logD7.4) and in vivo (biodistribution and μSPECT/CT studies at 1 h post injection (p.i.) in PC-3 tumor-bearing CB17-SCID mice). 99mTc-labeling resulted in radiochemical yields (RCYs) > 95%. All 99mTc-labeled MJ9 analogues showed comparable or higher GRPR affinity than the external reference [99mTc]Tc-Demobesin 4. Receptor-bound fractions were noticeably higher than that of the reference. Despite a slightly enhanced lipophilicity, all novel MJ9 derivatives revealed improved in vivo pharmacokinetics compared to the reference. The Bta8-modified ligand revealed the most favorable tumor-to-abdomen contrast at 1 h p.i. Substitutions at the Gln7-Trp8 site within GRPR ligands hold great potential to modify pharmacokinetics for improved imaging.
Collapse
|
6
|
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: 18] [Impact Index Per Article: 9.0] [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.
Collapse
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.)
| |
Collapse
|
7
|
Crișan G, Moldovean-Cioroianu NS, Timaru DG, Andrieș G, Căinap C, Chiș V. Radiopharmaceuticals for PET and SPECT Imaging: A Literature Review over the Last Decade. Int J Mol Sci 2022; 23:ijms23095023. [PMID: 35563414 PMCID: PMC9103893 DOI: 10.3390/ijms23095023] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/23/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [18F]-FDG and NA [18F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of 11C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
Collapse
Affiliation(s)
- George Crișan
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | | | - Diana-Gabriela Timaru
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
| | - Gabriel Andrieș
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | - Călin Căinap
- The Oncology Institute “Prof. Dr. Ion Chiricuţă”, Republicii 34-36, 400015 Cluj-Napoca, Romania;
| | - Vasile Chiș
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Institute for Research, Development and Innovation in Applied Natural Sciences, Babeș-Bolyai University, Str. Fântânele 30, 400327 Cluj-Napoca, Romania
- Correspondence:
| |
Collapse
|
8
|
Fani M, Mansi R, Nicolas GP, Wild D. Radiolabeled Somatostatin Analogs-A Continuously Evolving Class of Radiopharmaceuticals. Cancers (Basel) 2022; 14:cancers14051172. [PMID: 35267479 PMCID: PMC8909681 DOI: 10.3390/cancers14051172] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022] Open
Abstract
Somatostatin receptors (SSTs) are recognized as favorable molecular targets in neuroendocrine tumors (NETs) and neuroendocrine neoplasms (NENs), with subtype 2 (SST2) being the predominantly and most frequently expressed. PET/CT imaging with 68Ga-labeled SST agonists, e.g., 68Ga-DOTA-TOC (SomaKit TOC®) or 68Ga-DOTA-TATE (NETSPOT®), plays an important role in staging and restaging these tumors and can identify patients who qualify and would potentially benefit from peptide receptor radionuclide therapy (PRRT) with the therapeutic counterparts 177Lu-DOTA-TOC or 177Lu-DOTA-TATE (Lutathera®). This is an important feature of SST targeting, as it allows a personalized treatment approach (theranostic approach). Today, new developments hold promise for enhancing diagnostic accuracy and therapeutic efficacy. Among them, the use of SST2 antagonists, such as JR11 and LM3, has shown certain advantages in improving image sensitivity and tumor radiation dose, and there is evidence that they may find application in other oncological indications beyond NETs and NENs. In addition, PRRT performed with more cytotoxic α-emitters, such as 225Ac, or β- and Auger electrons, such as 161Tb, presents higher efficacy. It remains to be seen if any of these new developments will overpower the established radiolabeled SST analogs and PRRT with β--emitters.
Collapse
Affiliation(s)
- Melpomeni Fani
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, 4031 Basel, Switzerland;
- Correspondence:
| | - Rosalba Mansi
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, 4031 Basel, Switzerland;
| | - Guillaume P. Nicolas
- Division of Nuclear Medicine, University Hospital Basel, 4031 Basel, Switzerland; (G.P.N.); (D.W.)
- ENETS Center of Excellence for Neuroendocrine and Endocrine Tumors, University Hospital Basel, 4031 Basel, Switzerland
| | - Damian Wild
- Division of Nuclear Medicine, University Hospital Basel, 4031 Basel, Switzerland; (G.P.N.); (D.W.)
- ENETS Center of Excellence for Neuroendocrine and Endocrine Tumors, University Hospital Basel, 4031 Basel, Switzerland
| |
Collapse
|
9
|
SPECT Imaging of SST2-Expressing Tumors with 99mTc-Based Somatostatin Receptor Antagonists: The Role of Tetraamine, HYNIC, and Spacers. Pharmaceuticals (Basel) 2021; 14:ph14040300. [PMID: 33800582 PMCID: PMC8065591 DOI: 10.3390/ph14040300] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/24/2022] Open
Abstract
[99mTc]Tc-HYNIC-TOC is the most widely used 99mTc-labeled somatostatin receptor (SST) agonist for the SPECT imaging of SST-expressing tumors, such as neuroendocrine tumors. Recently, radiolabeled SST antagonists have shown improved diagnostic efficacy over agonists. 99mTc-labeled SST antagonists are lacking in clinical practice. Surprisingly, when [99mTc]Tc-HYNIC was conjugated to the SST2 antagonist SS01, SST2 imaging was not feasible. This was not the case when [99mTc]Tc-N4 was conjugated to SS01. Here, we assessed the introduction of different spacers (X: β-Ala, Ahx, Aun and PEG4) among HYNIC and SS01 with the aim of restoring the affinity of HYNIC conjugates. In addition, we used the alternative antagonist JR11 for determining the suitability of HYNIC with 99mTc-labeled SST2 antagonists. We performed a head-to-head comparison of the N4 conjugates of SS01 and JR11. [99mTc]Tc-HYNIC-TOC was used as a reference, and HEK-SST2 cells were used for in vitro and in vivo evaluation. EDDA was used as a co-ligand for all [99mTc]Tc-HYNIC conjugates. The introduction of Ahx restored, to a great extent, the SST2-mediated cellular uptake of the [99mTc]Tc-HYNIC-X conjugates (X: spacer), albeit lower than the corresponding [99mTc]Tc-N4-conjugates. SPECT/CT images showed that all 99mTc-labeled conjugates accumulated in the tumor and kidneys with [99mTc]Tc-HYNIC-PEG4-SS01, [99mTc]Tc-N4-SS01 and [99mTc]Tc-N4-JR11 having notably higher kidney uptake. Biodistribution studies showed similar or better tumor-to-non-tumor ratios for the [99mTc]Tc-HYNIC-Ahx conjugates, compared to the [99mTc]Tc-N4 counterparts. The [99mTc]Tc-HYNIC-Ahx conjugates of SS01 and JR11 were comparable to [99mTc]Tc-HYNIC-TOC as imaging agents. HYNIC is a suitable chelator for the development of 99mTc-labeled SST2 antagonists when a spacer of appropriate length, such as Ahx, is used.
Collapse
|
10
|
Mikulová MB, Mikuš P. Advances in Development of Radiometal Labeled Amino Acid-Based Compounds for Cancer Imaging and Diagnostics. Pharmaceuticals (Basel) 2021; 14:167. [PMID: 33669938 PMCID: PMC7924883 DOI: 10.3390/ph14020167] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/13/2021] [Accepted: 02/18/2021] [Indexed: 02/08/2023] Open
Abstract
Radiolabeled biomolecules targeted at tumor-specific enzymes, receptors, and transporters in cancer cells represent an intensively investigated and promising class of molecular tools for the cancer diagnosis and therapy. High specificity of such biomolecules is a prerequisite for the treatment with a lower burden to normal cells and for the effective and targeted imaging and diagnosis. Undoubtedly, early detection is a key factor in efficient dealing with many severe tumor types. This review provides an overview and critical evaluation of novel approaches in the designing of target-specific probes labeled with metal radionuclides for the diagnosis of most common death-causing cancers, published mainly within the last three years. Advances are discussed such traditional peptide radiolabeling approaches, and click and nanoparticle chemistry. The progress of radiolabeled peptide based ligands as potential radiopharmaceuticals is illustrated via novel structure and application studies, showing how the molecular modifications reflect their binding selectivity to significant onco-receptors, toxicity, and, by that, practical utilization. The most impressive outputs in categories of newly developed structures, as well as imaging and diagnosis approaches, and the most intensively studied oncological diseases in this context, are emphasized in order to show future perspectives of radiometal labeled amino acid-based compounds in nuclear medicine.
Collapse
Affiliation(s)
- Mária Bodnár Mikulová
- Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University in Bratislava, Odbojarov 10, 832 32 Bratislava, Slovakia;
| | - Peter Mikuš
- Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University in Bratislava, Odbojarov 10, 832 32 Bratislava, Slovakia;
- Toxicological and Antidoping Center (TAC), Faculty of Pharmacy, Comenius University in Bratislava, Odbojarov 10, 832 32 Bratislava, Slovakia
| |
Collapse
|
11
|
Maina T, Thakur M. SPECT Radiochemistry. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00023-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
12
|
Duatti A. Review on 99mTc radiopharmaceuticals with emphasis on new advancements. Nucl Med Biol 2021; 92:202-216. [PMID: 32475681 DOI: 10.1016/j.nucmedbio.2020.05.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/07/2020] [Accepted: 05/18/2020] [Indexed: 02/06/2023]
Abstract
Rapid imaging acquisition, high spatial resolution and sensitivity, powered by advancements in solid-state detector technology, are significantly changing the perspective of single photon emission tomography (SPECT). In particular, this evolutionary step is fueling a rediscovery of technetium-99m, a still unique radionuclide within the nuclear medicine scenario because of its ideal nuclear properties and easy preparation of its radiopharmaceuticals that does not require a costly infrastructure and complex procedures. Scope of this review is to show that the arsenal of technetium-99m radiopharmaceuticals is already equipped with imaging agents that may complement and integrate the role played by analogous tracers developed for positron emission tomography (PET). These include, in particular, somatostatin (SST) and prostate-specific membrane antigen (PSMA) receptor targeting agents, and a number of peptide-derived radiopharmaceuticals. Additionally, these recent technological developments, combined with new myocardial perfusion tracers having more favorable biodistribution and pharmacokinetic properties as compared to current commercial agents, may also reinvigorate the prevailing position still hold by technetium-99m radiopharmaceuticals in nuclear cardiology.
Collapse
Affiliation(s)
- Adriano Duatti
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy.
| |
Collapse
|
13
|
Fani M, Weingaertner V, Kolenc Peitl P, Mansi R, Gaonkar RH, Garnuszek P, Mikolajczak R, Novak D, Simoncic U, Hubalewska-Dydejczyk A, Rangger C, Kaeopookum P, Decristoforo C. Selection of the First 99mTc-Labelled Somatostatin Receptor Subtype 2 Antagonist for Clinical Translation-Preclinical Assessment of Two Optimized Candidates. Pharmaceuticals (Basel) 2020; 14:19. [PMID: 33379299 PMCID: PMC7824897 DOI: 10.3390/ph14010019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/01/2023] Open
Abstract
Recently, radiolabelled antagonists targeting somatostatin receptors subtype 2 (SST2) in neuroendocrine neoplasms demonstrated certain superior properties over agonists. Within the ERA-PerMED project "TECANT" two 99mTc-Tetramine (N4)-derivatized SST2 antagonists (TECANT-1 and TECANT-2) were studied for the selection of the best candidate for clinical translation. Receptor-affinity, internalization and dissociation studies were performed in human embryonic kidney-293 (HEK293) cells transfected with the human SST2 (HEK-SST2). Log D, protein binding and stability in human serum were assessed. Biodistribution and SPECT/CT studies were carried out in nude mice bearing HEK-SST2 xenografts, together with dosimetric estimations from mouse-to-man. [99mTc]Tc-TECANT-1 showed higher hydrophilicity and lower protein binding than [99mTc]-TECANT-2, while stability was comparable. Both radiotracers revealed similar binding affinity, while [99mTc]Tc-TECANT-1 had higher cellular uptake (>50%, at 2 h/37 °C) and lower dissociation rate (<30%, at 2 h/37 °C). In vivo, [99mTc]Tc-TECANT-1 showed lower blood values, kidney and muscles uptake, whereas tumour uptake was comparable to [99mTc]Tc-TECANT-2. SPECT/CT imaging confirmed the biodistribution results, providing the best tumour-to-background image contrast for [99mTc]Tc-TECANT-1 at 4 h post-injection (p.i.). The estimated radiation dose amounted to approximately 6 µSv/MBq for both radiotracers. This preclinical study provided the basis of selection of [99mTc]Tc-TECANT-1 for clinical translation of the first 99mTc-based SST2 antagonist.
Collapse
Affiliation(s)
- Melpomeni Fani
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, Universitätsspital Basel, CH-4031 Basel, Switzerland; (M.F.); (R.M.); (R.H.G.)
| | - Viktoria Weingaertner
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
| | - Petra Kolenc Peitl
- Department of Nuclear Medicine, University Medical Centre Ljubljana, University of Ljubljana, 1000 Ljubljana, Slovenia; (P.K.P.); (D.N.)
| | - Rosalba Mansi
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, Universitätsspital Basel, CH-4031 Basel, Switzerland; (M.F.); (R.M.); (R.H.G.)
| | - Raghuvir H. Gaonkar
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, Universitätsspital Basel, CH-4031 Basel, Switzerland; (M.F.); (R.M.); (R.H.G.)
| | - Piotr Garnuszek
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland; (P.G.); (R.M.)
| | - Renata Mikolajczak
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland; (P.G.); (R.M.)
| | - Doroteja Novak
- Department of Nuclear Medicine, University Medical Centre Ljubljana, University of Ljubljana, 1000 Ljubljana, Slovenia; (P.K.P.); (D.N.)
| | - Urban Simoncic
- Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | | | - Christine Rangger
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
| | - Piriya Kaeopookum
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
| |
Collapse
|
14
|
Eychenne R, Bouvry C, Bourgeois M, Loyer P, Benoist E, Lepareur N. Overview of Radiolabeled Somatostatin Analogs for Cancer Imaging and Therapy. Molecules 2020; 25:E4012. [PMID: 32887456 PMCID: PMC7504749 DOI: 10.3390/molecules25174012] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 12/19/2022] Open
Abstract
Identified in 1973, somatostatin (SST) is a cyclic hormone peptide with a short biological half-life. Somatostatin receptors (SSTRs) are widely expressed in the whole body, with five subtypes described. The interaction between SST and its receptors leads to the internalization of the ligand-receptor complex and triggers different cellular signaling pathways. Interestingly, the expression of SSTRs is significantly enhanced in many solid tumors, especially gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). Thus, somatostatin analogs (SSAs) have been developed to improve the stability of the endogenous ligand and so extend its half-life. Radiolabeled analogs have been developed with several radioelements such as indium-111, technetium-99 m, and recently gallium-68, fluorine-18, and copper-64, to visualize the distribution of receptor overexpression in tumors. Internal metabolic radiotherapy is also used as a therapeutic strategy (e.g., using yttrium-90, lutetium-177, and actinium-225). With some radiopharmaceuticals now used in clinical practice, somatostatin analogs developed for imaging and therapy are an example of the concept of personalized medicine with a theranostic approach. Here, we review the development of these analogs, from the well-established and authorized ones to the most recently developed radiotracers, which have better pharmacokinetic properties and demonstrate increased efficacy and safety, as well as the search for new clinical indications.
Collapse
Affiliation(s)
- Romain Eychenne
- UPS, CNRS, SPCMIB (Laboratoire de Synthèse et Physico-Chimie de Molécules d’Intérêt Biologique)—UMR 5068, Université de Toulouse, F-31062 Toulouse, France; (R.E.); (E.B.)
- Groupement d’Intérêt Public ARRONAX, 1 Rue Aronnax, F-44817 Saint Herblain, France;
- CNRS, CRCINA (Centre de Recherche en Cancérologie et Immunologie Nantes—Angers)—UMR 1232, ERL 6001, Inserm, Université de Nantes, F-44000 Nantes, France
| | - Christelle Bouvry
- Comprehensive Cancer Center Eugène Marquis, Rennes, F-35000, France;
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)—UMR 6226, Univ Rennes, F-35000 Rennes, France
| | - Mickael Bourgeois
- Groupement d’Intérêt Public ARRONAX, 1 Rue Aronnax, F-44817 Saint Herblain, France;
- CNRS, CRCINA (Centre de Recherche en Cancérologie et Immunologie Nantes—Angers)—UMR 1232, ERL 6001, Inserm, Université de Nantes, F-44000 Nantes, France
| | - Pascal Loyer
- INRAE, Institut NUMECAN (Nutrition, Métabolismes et Cancer)—UMR_A 1341, UMR_S 1241, Inserm, Univ Rennes, F-35000 Rennes, France;
| | - Eric Benoist
- UPS, CNRS, SPCMIB (Laboratoire de Synthèse et Physico-Chimie de Molécules d’Intérêt Biologique)—UMR 5068, Université de Toulouse, F-31062 Toulouse, France; (R.E.); (E.B.)
| | - Nicolas Lepareur
- Comprehensive Cancer Center Eugène Marquis, Rennes, F-35000, France;
- INRAE, Institut NUMECAN (Nutrition, Métabolismes et Cancer)—UMR_A 1341, UMR_S 1241, Inserm, Univ Rennes, F-35000 Rennes, France;
| |
Collapse
|
15
|
Preclinical Evaluation of [ 68Ga]Ga-DFO-ZEGFR:2377: A Promising Affibody-Based Probe for Noninvasive PET Imaging of EGFR Expression in Tumors. Cells 2018; 7:cells7090141. [PMID: 30231504 PMCID: PMC6162391 DOI: 10.3390/cells7090141] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 09/13/2018] [Accepted: 09/15/2018] [Indexed: 01/10/2023] Open
Abstract
Radionuclide imaging of epidermal growth factor receptor (EGFR) expression in tumors may stratify patients for EGFR-targeting therapies and predict response or resistance to certain treatments. Affibody molecules, which are nonimmunoglobulin scaffold proteins, have a high potential as probes for molecular imaging. In this study, maleimido derivative of desferrioxamine B (DFO) chelator was site-specifically coupled to the C-terminal cysteine of the anti-EGFR affibody molecule ZEGFR:2377, and the DFO-ZEGFR:2377 conjugate was labeled with the generator-produced positron-emitting radionuclide 68Ga. Stability, specificity of binding to EGFR-expressing cells, and processing of [68Ga]Ga-DFO-ZEGFR:2377 by cancer cells after binding were evaluated in vitro. In vivo studies were performed in nude mice bearing human EGFR-expressing A431 epidermoid cancer xenografts. The biodistribution of [68Ga]Ga-DFO-ZEGFR:2377 was directly compared with the biodistribution of [89Zr]Zr-DFO-ZEGFR:2377. DFO-ZEGFR:2377 was efficiently (isolated yield of 73 ± 3%) and stably labeled with 68Ga. Binding of [68Ga]Ga-DFO-ZEGFR:2377 to EGFR-expressing cells in vitro was receptor-specific and proportional to the EGFR expression level. In vivo saturation experiment demonstrated EGFR-specific accumulation of [68Ga]Ga-DFO-ZEGFR:2377 in A431 xenografts. Compared to [89Zr]Zr-DFO-ZEGFR:2377, [68Ga]Ga-DFO-ZEGFR:2377 demonstrated significantly (p < 0.05) higher uptake in tumors and lower uptake in spleen and bones. This resulted in significantly higher tumor-to-organ ratios for [68Ga]Ga-DFO-ZEGFR:2377. In conclusion, [68Ga]Ga-DFO-ZEGFR:2377 is a promising probe for imaging of EGFR expression.
Collapse
|