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Miederer M, Benešová-Schäfer M, Mamat C, Kästner D, Pretze M, Michler E, Brogsitter C, Kotzerke J, Kopka K, Scheinberg DA, McDevitt MR. Alpha-Emitting Radionuclides: Current Status and Future Perspectives. Pharmaceuticals (Basel) 2024; 17:76. [PMID: 38256909 PMCID: PMC10821197 DOI: 10.3390/ph17010076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/24/2024] Open
Abstract
The use of radionuclides for targeted endoradiotherapy is a rapidly growing field in oncology. In particular, the focus on the biological effects of different radiation qualities is an important factor in understanding and implementing new therapies. Together with the combined approach of imaging and therapy, therapeutic nuclear medicine has recently made great progress. A particular area of research is the use of alpha-emitting radionuclides, which have unique physical properties associated with outstanding advantages, e.g., for single tumor cell targeting. Here, recent results and open questions regarding the production of alpha-emitting isotopes as well as their chemical combination with carrier molecules and clinical experience from compassionate use reports and clinical trials are discussed.
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Kurtz K, Eibler L, Dacek MM, Carter LM, Veach DR, Lovibond S, Reynaud E, Qureshy S, McDevitt MR, Bourne C, Monette S, Punzalan B, Khayat S, Verma S, Kesner AL, Cheung NKV, Schöder H, Gajecki L, Cheal SM, Larson SM, Scheinberg DA, Krebs S. Engineering CAR-T cells for radiohapten capture in imaging and radioimmunotherapy applications. Theranostics 2023; 13:5469-5482. [PMID: 37908719 PMCID: PMC10614694 DOI: 10.7150/thno.87489] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/29/2023] [Indexed: 11/02/2023] Open
Abstract
Rationale: The in vivo dynamics of CAR-T cells remain incompletely understood. Novel methods are urgently needed to longitudinally monitor transferred cells non-invasively for biodistribution, functionality, proliferation, and persistence in vivo and for improving their cytotoxic potency in case of treatment failure. Methods: Here we engineered CD19 CAR-T cells ("Thor"-cells) to express a membrane-bound scFv, huC825, that binds DOTA-haptens with picomolar affinity suitable for labeling with imaging or therapeutic radionuclides. We assess its versatile utility for serial tracking studies with PET and delivery of α-radionuclides to enhance anti-tumor killing efficacy in sub-optimal adoptive cell transfer in vivo using Thor-cells in lymphoma models. Results: We show that this reporter gene/probe platform enables repeated, sensitive, and specific assessment of the infused Thor-cells in the whole-body using PET/CT imaging with exceptionally high contrast. The uptake on PET correlates with the Thor-cells on a cellular and functional level. Furthermore, we report the ability of Thor-cells to accumulate cytotoxic alpha-emitting radionuclides preferentially at tumor sites, thus increasing therapeutic potency. Conclusion: Thor-cells are a new theranostic agent that may provide crucial information for better and safer clinical protocols of adoptive T cell therapies, as well as accelerated development strategies.
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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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Storey CM, Altai M, Bicak M, Veach DR, Lückerath K, Adrian G, McDevitt MR, Kalidindi T, Park JE, Herrmann K, Abou D, Zedan W, Peekhaus N, Klein RJ, Damoiseaux R, Larson SM, Lilja H, Thorek D, Ulmert D. Quantitative In Vivo Imaging of the Androgen Receptor Axis Reveals Degree of Prostate Cancer Radiotherapy Response. Mol Cancer Res 2023; 21:307-315. [PMID: 36608299 PMCID: PMC10355285 DOI: 10.1158/1541-7786.mcr-22-0736] [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: 09/16/2022] [Revised: 12/13/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023]
Abstract
Noninvasive biomarkers for androgen receptor (AR) pathway activation are urgently needed to better monitor patient response to prostate cancer therapies. AR is a critical driver and mediator of resistance of prostate cancer but currently available noninvasive prostate cancer biomarkers to monitor AR activity are discordant with downstream AR pathway activity. External beam radiotherapy (EBRT) remains a common treatment for all stages of prostate cancer, and DNA damage induced by EBRT upregulates AR pathway activity to promote therapeutic resistance. [89Zr]11B6-PET is a novel modality targeting prostate-specific protein human kallikrein 2 (hK2), which is a surrogate biomarker for AR activity. Here, we studied whether [89Zr]11B6-PET can accurately assess EBRT-induced AR activity.Genetic and human prostate cancer mouse models received EBRT (2-50 Gy) and treatment response was monitored by [89Zr]11B6-PET/CT. Radiotracer uptake and expression of AR and AR target genes was quantified in resected tissue.EBRT increased AR pathway activity and [89Zr]11B6 uptake in LNCaP-AR and 22RV1 tumors. EBRT increased prostate-specific [89Zr]11B6 uptake in prostate cancer-bearing mice (Hi-Myc x Pb_KLK2) with no significant changes in uptake in healthy (Pb_KLK2) mice, and this correlated with hK2 protein levels. IMPLICATIONS hK2 expression in prostate cancer tissue is a proxy of EBRT-induced AR activity that can noninvasively be detected using [89Zr]11B6-PET; further clinical evaluation of hK2-PET for monitoring response and development of resistance to EBRT in real time is warranted.
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Zhang H, Abou D, Lu P, Hasson AM, Villmer A, Benabdallah N, Jiang W, Ulmert D, Carlin S, Rogers BE, Turtle NF, McDevitt MR, Baumann B, Simons BW, Dehdashti F, Zhou D, Thorek DLJ. [ 18F]-Labeled PARP-1 PET imaging of PSMA targeted alpha particle radiotherapy response. Sci Rep 2022; 12:13034. [PMID: 35906379 PMCID: PMC9338249 DOI: 10.1038/s41598-022-17460-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/26/2022] [Indexed: 11/15/2022] Open
Abstract
The growing interest and clinical translation of alpha particle (α) therapies brings with it new challenges to assess target cell engagement and to monitor therapeutic effect. Noninvasive imaging has great potential to guide α-treatment and to harness the potential of these agents in the complex environment of disseminated disease. Poly(ADP) ribose polymerase 1 (PARP-1) is among the most abundantly expressed DNA repair enzymes with key roles in multiple repair pathways-such as those induced by irradiation. Here, we used a third-generation PARP1-specific radiotracer, [18F]-PARPZ, to delineate castrate resistant prostate cancer xenografts. Following treatment with the clinically applied [225Ac]-PSMA-617, positron emission tomography was performed and correlative autoradiography and histology acquired. [18F]-PARPZ was able to distinguish treated from control (saline) xenografts by increased uptake. Kinetic analysis of tracer accumulation also suggests that the localization of the agent to sites of increased PARP-1 expression is a consequence of DNA damage response. Together, these data support expanded investigation of [18F]-PARPZ to facilitate clinical translation in the ⍺-therapy space.
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Krebs S, Grommes C, McDevitt MR, Carlin SD, O'Donoghue JA, Graham MS, Young RJ, Schöder H, Gutin PH, Bander NH, Osborne JR. Correction to: [ 89Zr]Zr‑huJ591 immuno‑PET targeting PSMA in IDH mutant anaplastic oligodendroglioma. Eur J Nucl Med Mol Imaging 2022; 49:2102. [PMID: 35266033 DOI: 10.1007/s00259-022-05736-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rosenblat TL, McDevitt MR, Carrasquillo JA, Pandit-Taskar N, Frattini MG, Maslak PG, Park JH, Douer D, Cicic D, Larson SM, Scheinberg DA, Jurcic JG. Treatment of Patients with Acute Myeloid Leukemia with the Targeted Alpha-Particle Nano-Generator Actinium-225-Lintuzumab. Clin Cancer Res 2022; 28:2030-2037. [PMID: 35247915 DOI: 10.1158/1078-0432.ccr-21-3712] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/13/2022] [Accepted: 02/28/2022] [Indexed: 11/16/2022]
Abstract
PURPOSE The anti-CD33 antibody lintuzumab has modest activity against acute myeloid leukemia (AML). To increase its potency, lintuzumab was conjugated to actinium-225 (225Ac), a radionuclide yielding 4 α-particles. This first-in-human, phase I trial was conducted to determine the safety, pharmacology, and biological activity of 225Ac-lintuzumab. PATIENTS AND METHODS Eighteen patients (median age, 64 years; range, 45-80) with relapsed or refractory AML received a single infusion of 225Ac-lintuzumab at activities of 18.5-148 kBq/kg. RESULTS The maximum tolerated dose was 111 kBq/kg. Dose-limiting toxicities included myelosuppression lasting > 35 days in one patient receiving 148 kBq/kg and death from sepsis in two patients treated with 111 and 148 kBq/kg. Myelosuppression was the most common toxicity. Significant extramedullary toxicities were limited to transient grade 3 liver function abnormalities. Pharmacokinetics were determined by gamma counting serial whole blood, plasma, and urine samples at energy windows for the 225Ac daughters, francium-221 and bismuth-213. Two-phase elimination kinetics were seen with mean plasma t1/2-α and t1/2-β of 1.9 and 38 hours, respectively. Peripheral blood blasts were eliminated in 10 of 16 evaluable patients (63%) but only at doses of {greater than or equal to} 37 kBq/kg. Bone marrow blasts were reduced in 10 of 15 evaluable patients (67%), including 3 patients with marrow blasts {less than or equal to} 5% and 1 patient with a morphologic leukemia-free state. CONCLUSIONS Therapy for AML with the targeted α-particle generator 225Ac-lintuzumab was feasible with an acceptable safety profile. Elimination of circulating blasts or reductions in marrow blasts were observed across all dose levels.
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Krebs S, Grommes C, McDevitt MR, Carlin SD, O'Donoghue JA, Graham MS, Young RJ, Schöder H, Gutin PH, Bander NH, Osborne JR. [ 89Zr]Zr-huJ591 immuno-PET targeting PSMA in IDH mutant anaplastic oligodendroglioma. Eur J Nucl Med Mol Imaging 2022; 49:783-785. [PMID: 34498111 DOI: 10.1007/s00259-021-05543-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 08/24/2021] [Indexed: 10/20/2022]
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Chung SK, Chandler CS, Vargas DB, Seo SH, McDevitt MR, Veach D, Punzalan B, Hong X, Guo HF, Nash GM, Cercek A, Cheung NKV, Larson SM, Cheal SM. Abstract P168: Pretargeted radioimmunotherapy using 225Ac for intraperitoneal Her2-expressing epithelial ovarian carcinoma xenografts. Mol Cancer Ther 2021. [DOI: 10.1158/1535-7163.targ-21-p168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Objectives Epithelial ovarian carcinoma (EOC) is a common and lethal gynecologic malignancy that frequently presents as advanced staged disease, such as peritoneal carcinomatosis (PC). We previously reported cures in BT-474 murine xenografts with Pretargeted Radioimmunotherapy (PRIT) using 177Lu radiohaptens targeting Her2 via a bispecific antibody (BsAb). Here-in we report the use of PRIT with alpha emitter 225Ac labelled PrDOTA to treat a PC model of SKOV3, a Her2+ cell line of EOC. Methods 6 wk old female athymic nude mice inoculated IP with 1E5 luciferase/GFP-transfected SKOV3 cells were separated into 5 groups (n=10). Treatment mice received 1 or 2 cycles of Anti-Her2-C825 BsAb + [225Ac]PrDOTA (Her2-Targeted), at 14 and 21 days after inoculation, respectively. Control groups received Anti-Her2 BsAb only, Anti-GPA33 BsAb + [225Ac]PrDOTA (Off-Targeted) or no treatment. On cycle day 1, the mice were injected IP with 0.25mg (1.19nmol) BsAb. On cycle day 2, 25µg (2.76nmol) CCA16-DOTAY clearing agent (CA) was given IV 22h from BsAb. Mice in therapy groups were injected IP with 1µCi (0.74-0.79nmol) [225Ac]PrDOTA-Bn 4h after CA. Weekly weights and BLIs with IP cavity ROIs were obtained and normalized to the respective values for each mouse at week 0 pre-treatment. End points: weight loss >20% baseline, moribund, or severe abdominal distension. At 154 days, 15 surviving treatment and 1 untreated control mice were submitted for hematology and histopathology. Results Histologic cures and prolonged survival were demonstrated in treatment mice (17/20 at 133 days) as compared to control mice (12/27 at 133 d, Logrank p<0.04). 3 mice from control groups were excluded due to BLI values <50% background in the first 3 weeks, suggesting no tumor burden. Tumors, as measured by normalized BLI values (nBLI), regressed in treatment mice when compared to control mice (2-way ANOVA p<0.01). nBLI values between treatment mice (1 and 2 cycles) and control mice (BsAb only, Off-target, no treatment) diverged at week 10 (Tukey’s test p<0.01). There was no difference in nBLI values between mice treated with 1 or 2 cycles of targeted PRIT (Tukey’s test p>0.05; all weeks). BLI of mice treated with 1 and 2 cycle of Her2 PRIT decreased 47% when compared to baseline within 1 week (T test p=0.04), suggesting treatment effects as early as 1 week. There were no differences in weights when compared to baseline (2-way ANOVA p>0.05). While the untreated mouse had high peritoneal adenocarcinoma tumor burden, there was no histologic evidence of viable neoplasia in 15/15 submitted treatment mice. Treatment mice had moderate renal tubular degenerative lesions on histology, but this did not affect renal function based on serum BUN or Cr. All hematologic parameters were within normal limits for treated mice. Conclusions 1 and 2 cycles of [225Ac]PrDOTA-PRIT against Her2 resulted in histologic cures and prolonged survival in IP SKOV3 xenografts with minimal toxicity. The anti-Her2 PrDOTA-PRIT system is a promising theranostic approach for otherwise incurable PC.
Citation Format: Sebastian K. Chung, Christopher S. Chandler, Daniela Burnes Vargas, Shin H. Seo, Michael R. McDevitt, Darren Veach, Blesida Punzalan, Xu Hong, Hong-fen Guo, Garrett M. Nash, Andrea Cercek, Nai-Kong V. Cheung, Steven M. Larson, Sarah M. Cheal. Pretargeted radioimmunotherapy using 225Ac for intraperitoneal Her2-expressing epithelial ovarian carcinoma xenografts [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P168.
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Serencsits B, Chu B, Pandit-Taskar N, McDevitt MR, Dauer LT. Radiation Safety Considerations and Clinical Advantages of Alpha-Emitting Therapy Radionuclides. J Nucl Med Technol 2021; 50:10-16. [PMID: 34750237 DOI: 10.2967/jnmt.121.262294] [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: 04/19/2021] [Revised: 09/26/2021] [Indexed: 11/16/2022] Open
Abstract
Alpha-emitting radionuclides provide an effective means of delivering large radiation doses to targeted treatment locations. Radium-223 dichloride (223RaCl2) is FDA approved for treatment of metastatic castration-resistant prostate cancer (mCRPC) and Actinium-225 (225Ac-Lintuzumab) radiolabeled antibodies have been shown to be beneficial for patients with acute myeloid leukemia. In recent years, there is an increasing use of alpha emitters in theranostic agents with both small and large molecule constructs. The proper precautionary means for their use and surveying documentation of these isotopes in a clinical setting are an essential accompaniment to these treatments. Methods: Patient treatment data collected over a three-year period, as well as regulatory requirements and safety practices, are described. Commonly used radiation instrumentation was evaluated for their ability to identify potential radioactive material spills and contamination events during a clinical administration of 225Ac. These instruments were placed at 0.32 cm from a 1.0 cm 225Ac disk source for measurement purposes. Radiation background values, efficiencies, and minimal detectable activities were measured and calculated for each type of detector. Results: The median external measured patient dose rate from 223RaCl2 patients (n = 611) was 2.5 µSv hr-1 on contact and 0.2 µSv hr-1 at 1 meter immediately after administration. Similarly, 225Ac-Lintuzumab (n = 19) patients had median external dose rates of 2.0 µSv hr-1 on contact and 0.3 µSv hr-1 at 1 meter. For the measurement of 225Ac samples, a liquid scintillation counter was found to have the highest overall efficiency (97%), while a zinc sulfide (ZnS) alpha probe offered the lowest minimal detectable activity at 3 counts per minute. Conclusion: In this study, we report data from 630 patients who were undergoing treatment with alpha-emitting isotopes 223Ra and 225Ac. While alpha emitters have ability to deliver higher internal radiation dose to the tissues exposed as compared with other unsealed radionuclides, they typically present minimal external dose rate concerns. Additionally, alpha radiation can be efficiently detected with appropriate radiation instrumentation, such as a liquid scintillation counter or ZnS probe, that should be prioritized when surveying for spills of alpha-emitters.
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Dacek MM, Veach DR, Cheal SM, Carter LM, McDevitt MR, Punzalan B, Burnes Vargas D, Kubik TZ, Monette S, Santich BH, Yang G, Ouerfelli O, Kesner AL, Cheung NKV, Scheinberg DA, Larson SM, Krebs S. Engineered Cells as a Test Platform for Radiohaptens in Pretargeted Imaging and Radioimmunotherapy Applications. Bioconjug Chem 2021; 32:649-654. [PMID: 33819023 DOI: 10.1021/acs.bioconjchem.0c00595] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pretargeted imaging and radioimmunotherapy approaches are designed to have superior targeting properties over directly targeted antibodies but impose more complex pharmacology, which hinders efforts to optimize the ligands prior to human applications. Human embryonic kidney 293T cells expressing the humanized single-chain variable fragment (scFv) C825 (huC825) with high-affinity for DOTA-haptens (293T-huC825) in a transmembrane-anchored format eliminated the requirement to use other pretargeting reagents and provided a simplified, accelerated assay of radiohapten capture while offering normalized cell surface expression of the molecular target of interest. Using binding assays, ex vivo biodistribution, and in vivo imaging, we demonstrated that radiohaptens based on benzyl-DOTA and a second generation "Proteus" DOTA-platform effectively and specifically engaged membrane-bound huC825, achieving favorable tumor-to-normal tissue uptake ratios in mice. Furthermore, [86Y]Y-DOTA-Bn predicted absorbed dose to critical organs with reasonable accuracy for both [177Lu]Lu-DOTA-Bn and [225Ac]Ac-Pr, which highlights the benefit of a dosimetry-based treatment approach.
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Veach DR, Storey CM, Lückerath K, Braun K, von Bodman C, Lamminmäki U, Kalidindi T, Strand SE, Strand J, Altai M, Damoiseaux R, Zanzonico P, Benabdallah N, Pankov D, Scher HI, Scardino P, Larson SM, Lilja H, McDevitt MR, Thorek DLJ, Ulmert D. PSA-Targeted Alpha-, Beta-, and Positron-Emitting Immunotheranostics in Murine Prostate Cancer Models and Nonhuman Primates. Clin Cancer Res 2021; 27:2050-2060. [PMID: 33441295 DOI: 10.1158/1078-0432.ccr-20-3614] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/13/2020] [Accepted: 01/07/2021] [Indexed: 12/22/2022]
Abstract
PURPOSE Most patients with prostate cancer treated with androgen receptor (AR) signaling inhibitors develop therapeutic resistance due to restoration of AR functionality. Thus, there is a critical need for novel treatment approaches. Here we investigate the theranostic potential of hu5A10, a humanized mAb specifically targeting free PSA (KLK3). EXPERIMENTAL DESIGN LNCaP-AR (LNCaP with overexpression of wildtype AR) xenografts (NSG mice) and KLK3_Hi-Myc transgenic mice were imaged with 89Zr- or treated with 90Y- or 225Ac-labeled hu5A10; biodistribution and subcellular localization were analyzed by gamma counting, PET, autoradiography, and microscopy. Therapeutic efficacy of [225Ac]hu5A10 and [90Y]hu5A10 in LNCaP-AR tumors was assessed by tumor volume measurements, time to nadir (TTN), time to progression (TTP), and survival. Pharmacokinetics of [89Zr]hu5A10 in nonhuman primates (NHP) were determined using PET. RESULTS Biodistribution of radiolabeled hu5A10 constructs was comparable in different mouse models. Specific tumor uptake increased over time and correlated with PSA expression. Treatment with [90Y]/[225Ac]hu5A10 effectively reduced tumor burden and prolonged survival (P ≤ 0.0054). Effects of [90Y]hu5A10 were more immediate than [225Ac]hu5A10 (TTN, P < 0.0001) but less sustained (TTP, P < 0.0001). Complete responses were observed in 7 of 18 [225Ac]hu5A10 and 1 of 9 mice [90Y]hu5A10. Pharmacokinetics of [89Zr]hu5A10 were consistent between NHPs and comparable with those in mice. [89Zr]hu5A10-PET visualized the NHP-prostate over the 2-week observation period. CONCLUSIONS We present a complete preclinical evaluation of radiolabeled hu5A10 in mouse prostate cancer models and NHPs, and establish hu5A10 as a new theranostic agent that allows highly specific and effective downstream targeting of AR in PSA-expressing tissue. Our data support the clinical translation of radiolabeled hu5A10 for treating prostate cancer.
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Sgouros G, Bodei L, McDevitt MR, Nedrow JR. Author Correction: Radiopharmaceutical therapy in cancer: clinical advances and challenges. Nat Rev Drug Discov 2020; 19:819. [PMID: 32895501 PMCID: PMC7962575 DOI: 10.1038/s41573-020-0085-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Santich BH, Cheal SM, Ahmed M, McDevitt MR, Ouerfelli O, Yang G, Veach DR, Fung EK, Patel M, Burnes Vargas D, Malik AA, Guo HF, Zanzonico PB, Monette S, Michel AO, Rudin CM, Larson SM, Cheung NK. A Self-Assembling and Disassembling (SADA) Bispecific Antibody (BsAb) Platform for Curative Two-step Pretargeted Radioimmunotherapy. Clin Cancer Res 2020; 27:532-541. [PMID: 32958698 DOI: 10.1158/1078-0432.ccr-20-2150] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/22/2020] [Accepted: 09/15/2020] [Indexed: 11/16/2022]
Abstract
PURPOSE Many cancer treatments suffer from dose-limiting toxicities to vital organs due to poor therapeutic indices. To overcome these challenges we developed a novel multimerization platform that rapidly removes tumor-targeting proteins from the blood to substantially improve therapeutic index. EXPERIMENTAL DESIGN The platform was designed as a fusion of a self-assembling and disassembling (SADA) domain to a tandem single-chain bispecific antibody (BsAb, anti-ganglioside GD2 × anti-DOTA). SADA-BsAbs were assessed with multiple in vivo tumor models using two-step pretargeted radioimmunotherapy (PRIT) to evaluate tumor uptake, dosimetry, and antitumor responses. RESULTS SADA-BsAbs self-assembled into stable tetramers (220 kDa), but could also disassemble into dimers or monomers (55 kDa) that rapidly cleared via renal filtration and substantially reduced immunogenicity in mice. When used with rapidly clearing DOTA-caged PET isotopes, SADA-BsAbs demonstrated accurate tumor localization, dosimetry, and improved imaging contrast by PET/CT. When combined with therapeutic isotopes, two-step SADA-PRIT safely delivered massive doses of alpha-emitting (225Ac, 1.48 MBq/kg) or beta-emitting (177Lu, 6,660 MBq/kg) S-2-(4-aminobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid (DOTA) payloads to tumors, ablating them without any short-term or long-term toxicities to the bone marrow, kidneys, or liver. CONCLUSIONS The SADA-BsAb platform safely delivered large doses of radioisotopes to tumors and demonstrated no toxicities to the bone marrow, kidneys, or liver. Because of its modularity, SADA-BsAbs can be easily adapted to most tumor antigens, tumor types, or drug delivery approaches to improve therapeutic index and maximize the delivered dose.See related commentary by Capala and Kunos, p. 377.
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Cheal SM, McDevitt MR, Santich BH, Patel M, Yang G, Fung EK, Veach DR, Bell M, Ahad A, Vargas DB, Punzalan B, Pillarsetty NVK, Xu H, Guo HF, Monette S, Michel AO, Piersigilli A, Scheinberg DA, Ouerfelli O, Cheung NKV, Larson SM. Alpha radioimmunotherapy using 225Ac-proteus-DOTA for solid tumors - safety at curative doses. Theranostics 2020; 10:11359-11375. [PMID: 33052220 PMCID: PMC7546012 DOI: 10.7150/thno.48810] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/29/2020] [Indexed: 02/07/2023] Open
Abstract
This is the initial report of an α-based pre-targeted radioimmunotherapy (PRIT) using 225Ac and its theranostic pair, 111In. We call our novel tumor-targeting DOTA-hapten PRIT system "proteus-DOTA" or "Pr." Herein we report the first results of radiochemistry development, radiopharmacology, and stoichiometry of tumor antigen binding, including the role of specific activity, anti-tumor efficacy, and normal tissue toxicity with the Pr-PRIT approach (as α-DOTA-PRIT). A series of α-DOTA-PRIT therapy studies were performed in three solid human cancer xenograft models of colorectal cancer (GPA33), breast cancer (HER2), and neuroblastoma (GD2), including evaluation of chronic toxicity at ~20 weeks of select survivors. Methods: Preliminary biodistribution experiments in SW1222 tumor-bearing mice revealed that 225Ac could not be efficiently pretargeted with current DOTA-Bn hapten utilized for 177Lu or 90Y, leading to poor tumor uptake in vivo. Therefore, we synthesized Pr consisting of an empty DOTA-chelate for 225Ac, tethered via a short polyethylene glycol linker to a lutetium-complexed DOTA for picomolar anti-DOTA chelate single-chain variable fragment (scFv) binding. Pr was radiolabeled with 225Ac and its imaging surrogate, 111In. In vitro studies verified anti-DOTA scFv recognition of [225Ac]Pr, and in vivo biodistribution and clearance studies were performed to evaluate hapten suitability and in vivo targeting efficiency. Results: Intravenously (i.v.) administered 225Ac- or 111In-radiolabeled Pr in mice showed rapid renal clearance and minimal normal tissue retention. In vivo pretargeting studies show high tumor accumulation of Pr (16.71 ± 5.11 %IA/g or 13.19 ± 3.88 %IA/g at 24 h p.i. for [225Ac]Pr and [111In]Pr, respectively) and relatively low uptake in normal tissues (all average ≤ 1.4 %IA/g at 24 h p.i.). Maximum tolerated dose (MTD) was not reached for either [225Ac]Pr alone or pretargeted [225Ac]Pr at administered activities up to 296 kBq/mouse. Single-cycle treatment consisting of α-DOTA-PRIT with either huA33-C825 bispecific anti-tumor/anti-DOTA-hapten antibody (BsAb), anti-HER2-C825 BsAb, or hu3F8-C825 BsAb for targeting GPA33, HER2, or GD2, respectively, was highly effective. In the GPA33 model, no complete responses (CRs) were observed but prolonged overall survival of treated animals was 42 d for α-DOTA-PRIT vs. 25 d for [225Ac]Pr only (P < 0.0001); for GD2, CRs (7/7, 100%) and histologic cures (4/7, 57%); and for HER2, CRs (7/19, 37%) and histologic cures (10/19, 56%) with no acute or chronic toxicity. Conclusions: [225Ac]Pr and its imaging biomarker [111In]Pr demonstrate optimal radiopharmacologic behavior for theranostic applications of α-DOTA-PRIT. For this initial evaluation of efficacy and toxicity, single-cycle treatment regimens were performed in all three systems. Histologic toxicity was not observed, so MTD was not observed. Prolonged overall survival, CRs, and histologic cures were observed in treated animals. In comparison to RIT with anti-tumor IgG antibodies, [225Ac]Pr has a much improved safety profile. Ultimately, these data will be used to guide clinical development of toxicity and efficacy studies of [225Ac]Pr, with the goal of delivering massive lethal doses of radiation to achieve a high probability of cure without toxicity.
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Sgouros G, Bodei L, McDevitt MR, Nedrow JR. Radiopharmaceutical therapy in cancer: clinical advances and challenges. Nat Rev Drug Discov 2020; 19:589-608. [PMID: 32728208 PMCID: PMC7390460 DOI: 10.1038/s41573-020-0073-9] [Citation(s) in RCA: 363] [Impact Index Per Article: 90.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2020] [Indexed: 12/25/2022]
Abstract
Radiopharmaceutical therapy (RPT) is emerging as a safe and effective targeted approach to treating many types of cancer. In RPT, radiation is systemically or locally delivered using pharmaceuticals that either bind preferentially to cancer cells or accumulate by physiological mechanisms. Almost all radionuclides used in RPT emit photons that can be imaged, enabling non-invasive visualization of the biodistribution of the therapeutic agent. Compared with almost all other systemic cancer treatment options, RPT has shown efficacy with minimal toxicity. With the recent FDA approval of several RPT agents, the remarkable potential of this treatment is now being recognized. This Review covers the fundamental properties, clinical development and associated challenges of RPT.
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Urbanska AM, Khanin R, Alidori S, Wong S, Mello BP, Almeida BA, Chen F, Ma K, Turker MZ, Korontsvit T, Scheinberg DA, Zanzonico PB, Wiesner U, Bradbury MS, Quinn TP, McDevitt MR. A Genomic Profile of Local Immunity in the Melanoma Microenvironment Following Treatment with α Particle-Emitting Ultrasmall Silica Nanoparticles. Cancer Biother Radiopharm 2020; 35:459-473. [PMID: 32013538 PMCID: PMC7462037 DOI: 10.1089/cbr.2019.3150] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
An α particle-emitting nanodrug that is a potent and specific antitumor agent and also prompts significant remodeling of local immunity in the tumor microenvironment (TME) has been developed and may impact the treatment of melanoma. Biocompatible ultrasmall fluorescent core-shell silica nanoparticles (C' dots, diameter ∼6.0 nm) have been engineered to target the melanocortin-1 receptor expressed on melanoma through α melanocyte-stimulating hormone peptides attached to the C' dot surface. Actinium-225 is also bound to the nanoparticle to deliver a densely ionizing dose of high-energy α particles to cancer. Nanodrug pharmacokinetic properties are optimal for targeted radionuclide therapy as they exhibit rapid blood clearance, tumor-specific accumulation, minimal off-target localization, and renal elimination. Potent and specific tumor control, arising from the α particles, was observed in a syngeneic animal model of melanoma. Surprisingly, the C' dot component of this drug initiates a favorable pseudopathogenic response in the TME generating distinct changes in the fractions of naive and activated CD8 T cells, Th1 and regulatory T cells, immature dendritic cells, monocytes, MΦ and M1 macrophages, and activated natural killer cells. Concomitant upregulation of the inflammatory cytokine genome and adaptive immune pathways each describes a macrophage-initiated pseudoresponse to a viral-shaped pathogen. This study suggests that therapeutic α-particle irradiation of melanoma using ultrasmall functionalized core-shell silica nanoparticles potently kills tumor cells, and at the same time initiates a distinct immune response in the TME.
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MESH Headings
- Actinium/administration & dosage
- Actinium/pharmacokinetics
- Alpha Particles/therapeutic use
- Animals
- Cell Line, Tumor/transplantation
- Computational Biology
- Disease Models, Animal
- Dose-Response Relationship, Radiation
- Drug Carriers/chemistry
- Female
- Gene Expression Regulation, Neoplastic/immunology
- Gene Expression Regulation, Neoplastic/radiation effects
- Humans
- Immunity, Cellular/genetics
- Immunity, Cellular/radiation effects
- Male
- Maximum Tolerated Dose
- Melanoma, Experimental/genetics
- Melanoma, Experimental/immunology
- Melanoma, Experimental/pathology
- Melanoma, Experimental/radiotherapy
- Mice
- Molecular Targeted Therapy/methods
- Nanoparticles/chemistry
- RNA-Seq
- Radiopharmaceuticals/administration & dosage
- Radiopharmaceuticals/pharmacokinetics
- Receptor, Melanocortin, Type 1/antagonists & inhibitors
- Receptor, Melanocortin, Type 1/metabolism
- Silicon Dioxide/chemistry
- Skin Neoplasms/genetics
- Skin Neoplasms/immunology
- Skin Neoplasms/pathology
- Skin Neoplasms/radiotherapy
- Tissue Distribution
- Tumor Microenvironment/genetics
- Tumor Microenvironment/immunology
- Tumor Microenvironment/radiation effects
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18
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Bicak M, Lückerath K, Kalidindi T, Phelps ME, Strand SE, Morris MJ, Radu CG, Damoiseaux R, Peltola MT, Peekhaus N, Ho A, Veach D, Malmborg Hager AC, Larson SM, Lilja H, McDevitt MR, Klein RJ, Ulmert D. Genetic signature of prostate cancer mouse models resistant to optimized hK2 targeted α-particle therapy. Proc Natl Acad Sci U S A 2020; 117:15172-15181. [PMID: 32532924 PMCID: PMC7334567 DOI: 10.1073/pnas.1918744117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hu11B6 is a monoclonal antibody that internalizes in cells expressing androgen receptor (AR)-regulated prostate-specific enzyme human kallikrein-related peptidase 2 (hK2; KLK2). In multiple rodent models, Actinium-225-labeled hu11B6-IgG1 ([225Ac]hu11B6-IgG1) has shown promising treatment efficacy. In the present study, we investigated options to enhance and optimize [225Ac]hu11B6 treatment. First, we evaluated the possibility of exploiting IgG3, the IgG subclass with superior activation of complement and ability to mediate FC-γ-receptor binding, for immunotherapeutically enhanced hK2 targeted α-radioimmunotherapy. Second, we compared the therapeutic efficacy of a single high activity vs. fractionated activity. Finally, we used RNA sequencing to analyze the genomic signatures of prostate cancer that progressed after targeted α-therapy. [225Ac]hu11B6-IgG3 was a functionally enhanced alternative to [225Ac]hu11B6-IgG1 but offered no improvement of therapeutic efficacy. Progression-free survival was slightly increased with a single high activity compared to fractionated activity. Tumor-free animals succumbing after treatment revealed no evidence of treatment-associated toxicity. In addition to up-regulation of canonical aggressive prostate cancer genes, such as MMP7, ETV1, NTS, and SCHLAP1, we also noted a significant decrease in both KLK3 (prostate-specific antigen ) and FOLH1 (prostate-specific membrane antigen) but not in AR and KLK2, demonstrating efficacy of sequential [225Ac]hu11B6 in a mouse model.
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Zhang X, Chen F, Turker MZ, Ma K, Zanzonico P, Gallazzi F, Shah MA, Prater AR, Wiesner U, Bradbury MS, McDevitt MR, Quinn TP. Targeted melanoma radiotherapy using ultrasmall 177Lu-labeled α-melanocyte stimulating hormone-functionalized core-shell silica nanoparticles. Biomaterials 2020; 241:119858. [PMID: 32120314 DOI: 10.1016/j.biomaterials.2020.119858] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/27/2020] [Accepted: 02/10/2020] [Indexed: 02/07/2023]
Abstract
Lutetium-177 (177Lu) radiolabeled ultrasmall (~6 nm dia.) fluorescent core-shell silica nanoparticles (Cornell prime dots or C' dots) were developed for improving efficacy of targeted radiotherapy in melanoma models. PEGylated C' dots were surface engineered to display 10-15 alpha melanocyte stimulating hormone (αMSH) cyclic peptide analogs for targeting the melanocortin-1 receptor (MC1-R) over-expressed on melanoma tumor cells. The 177Lu-DOTA-αMSH-PEG-C' dot product was radiochemically stable, biologically active, and exhibited high affinity cellular binding properties and internalization. Selective tumor uptake and favorable biodistribution properties were also demonstrated, in addition to bulk renal clearance, in syngeneic B16F10 and human M21 xenografted models. Prolonged survival was observed in the treated cohorts relative to controls. Dosimetric analysis showed no excessively high absorbed dose among normal organs. Correlative histopathology of ex vivo treated tumor specimens revealed expected necrotic changes; no acute pathologic findings were noted in the liver or kidneys. Collectively, these results demonstrated that 177Lu-DOTA-αMSH-PEG-C' dot targeted melanoma therapy overcame the unfavorable biological properties and dose-limiting toxicities associated with existing mono-molecular treatments. The unique and tunable surface chemistries of this targeted ultrasmall radiotherapeutic, coupled with its favorable pharmacokinetic properties, substantially improved treatment efficacy and demonstrated a clear survival benefit in melanoma models, which supports its further clinical translation.
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Thorek DLJ, Ku AT, Mitsiades N, Veach D, Watson PA, Metha D, Strand SE, Sharma SK, Lewis JS, Abou DS, Lilja HG, Larson SM, McDevitt MR, Ulmert D. Harnessing Androgen Receptor Pathway Activation for Targeted Alpha Particle Radioimmunotherapy of Breast Cancer. Clin Cancer Res 2018; 25:881-891. [PMID: 30254080 DOI: 10.1158/1078-0432.ccr-18-1521] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/30/2018] [Accepted: 09/17/2018] [Indexed: 01/26/2023]
Abstract
PURPOSE The impact of androgen receptor (AR) activity in breast cancer biology is unclear. We characterized and tested a novel therapy to an AR-governed target in breast cancer.Experimental Design: We evaluated the expression of prototypical AR gene products human kallikrein 2 (hK2) and PSA in breast cancer models. We screened 13 well-characterized breast cancer cell lines for hK2 and PSA production upon in vitro hormone stimulation by testosterone [dihydrotestosterone (DHT)]. AR-positive lines were further evaluated by exposure to estrogen (17β-Estradiol) and the synthetic progestin D-Norgestrel. We then evaluated an anti-hK2-targeted radiotherapy platform (hu11B6), labeled with alpha (α)-particle emitting Actinium-225, to specifically treat AR-expressing breast cancer xenografts under hormone stimulation. RESULTS D-Norgestrel and DHT activated the AR pathway, while 17β-Estradiol did not. Competitive binding for AR protein showed similar affinity between DHT and D-Norgestrel, indicating direct AR-ligand interaction. In vivo production of hK2 was sufficient to achieve site-specific delivery of therapeutic radionuclide to tumor tissue at >20-fold over background muscle uptake; effecting long-term local tumor control. CONCLUSIONS [225Ac]hu11B6 targeted radiotherapy was potentiated by DHT and by D-Norgestrel in murine xenograft models of breast cancer. AR activity in breast cancer correlates with kallikrein-related peptidase-2 and can be activated by D-Norgestrel, a common contraceptive, and AR induction can be harnessed for hK2-targeted breast cancer α-emitter radiotherapy.
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21
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Mulvey JJ, Littmann ER, Ling L, McDevitt MR, Pamer EG, Scheinberg DA. The effects of amine-modified single-walled carbon nanotubes on the mouse microbiota. Int J Nanomedicine 2018; 13:5275-5286. [PMID: 30237714 PMCID: PMC6136419 DOI: 10.2147/ijn.s168554] [Citation(s) in RCA: 2] [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] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Amine-modified carbon nanotubes are drug delivery platforms with great potential that have not yet been applied in human clinical trials. Although modified nanotube vectors have the ability to carry multiple effectors, targeting agents, and even wrapped RNA, reports on unmodified, insoluble carbon nanotubes have highlighted inflammation in organs, including the intestine, with disruption of its resident microbiota. Disruption of the microbiota may allow for colonization by pathogenic bacteria, such as Clostridoidies difficile, stimulate immunoinfiltrates into the lamina propria or alter the absorption of therapeutics. Most proposed nanotube drugs are soluble, modified structures that are administered parenterally, and the majority of these soluble macromolecules are renally excreted; however, some are released into the bile, gaining access to the gastrointestinal tract. METHODS Using environmentally isolated BALB/C mice in oral and intraperitoneal dosing models, high dose (3.80 or 4.25 mg/week), we administered amine-modified, soluble carbon nanotubes for 7 or 8 weeks. The general health and weight of the mice were monitored weekly, and upon killing, the diversity and content of their colonic, cecal, and ileal microbiota were assessed using shotgun 16S DNA sequencing. RESULTS AND CONCLUSION We show that while oral administration at suprapharmacological doses modestly altered the α- and β-diversity of the mouse microbiome, these changes did not result in observed changes in clinical end points. Intraperitoneally-dosed mice exhibited none of the toxicities assessed.
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Abstract
α-Particle irradiation of cancerous tissue is increasingly recognized as a potent therapeutic option. We briefly review the physics, radiobiology, and dosimetry of α-particle emitters, as well as the distinguishing features that make them unique for radiopharmaceutical therapy. We also review the emerging clinical role of α-particle therapy in managing cancer and recent studies on in vitro and preclinical α-particle therapy delivered by antibodies, other small molecules, and nanometer-sized particles. In addition to their unique radiopharmaceutical characteristics, the increased availability and improved radiochemistry of α-particle radionuclides have contributed to the growing recent interest in α-particle radiotherapy. Targeted therapy strategies have presented novel possibilities for the use of α-particles in the treatment of cancer. Clinical experience has already demonstrated the safe and effective use of α-particle emitters as potent tumor-selective drugs for the treatment of leukemia and metastatic disease.
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McDevitt MR, Thorek DLJ, Hashimoto T, Gondo T, Veach DR, Sharma SK, Kalidindi TM, Abou DS, Watson PA, Beattie BJ, Timmermand OV, Strand SE, Lewis JS, Scardino PT, Scher HI, Lilja H, Larson SM, Ulmert D. Feed-forward alpha particle radiotherapy ablates androgen receptor-addicted prostate cancer. Nat Commun 2018; 9:1629. [PMID: 29691406 PMCID: PMC5915579 DOI: 10.1038/s41467-018-04107-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 03/02/2018] [Indexed: 11/09/2022] Open
Abstract
Human kallikrein peptidase 2 (hK2) is a prostate specific enzyme whose expression is governed by the androgen receptor (AR). AR is the central oncogenic driver of prostate cancer (PCa) and is also a key regulator of DNA repair in cancer. We report an innovative therapeutic strategy that exploits the hormone-DNA repair circuit to enable molecularly-specific alpha particle irradiation of PCa. Alpha-particle irradiation of PCa is prompted by molecularly specific-targeting and internalization of the humanized monoclonal antibody hu11B6 targeting hK2 and further accelerated by inherent DNA-repair that up-regulate hK2 (KLK2) expression in vivo. hu11B6 demonstrates exquisite targeting specificity for KLK2. A single administration of actinium-225 labeled hu11B6 eradicates disease and significantly prolongs survival in animal models. DNA damage arising from alpha particle irradiation induces AR and subsequently KLK2, generating a unique feed-forward mechanism, which increases binding of hu11B6. Imaging data in nonhuman primates support the possibility of utilizing hu11B6 in man.
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Poty S, Francesconi LC, McDevitt MR, Morris MJ, Lewis JS. α-Emitters for Radiotherapy: From Basic Radiochemistry to Clinical Studies-Part 1. J Nucl Med 2018; 59:878-884. [PMID: 29545378 DOI: 10.2967/jnumed.116.186338] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 02/03/2018] [Indexed: 12/11/2022] Open
Abstract
With a short particle range and high linear energy transfer, α-emitting radionuclides demonstrate high cell-killing efficiencies. Even with the existence of numerous radionuclides that decay by α-particle emission, only a few of these can reasonably be exploited for therapeutic purposes. Factors including radioisotope availability and physical characteristics (e.g., half-life) can limit their widespread dissemination. The first part of this review will explore the diversity, basic radiochemistry, restrictions, and hurdles of α-emitters.
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Poty S, Francesconi LC, McDevitt MR, Morris MJ, Lewis JS. α-Emitters for Radiotherapy: From Basic Radiochemistry to Clinical Studies-Part 2. J Nucl Med 2018; 59:1020-1027. [PMID: 29496984 DOI: 10.2967/jnumed.117.204651] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/03/2018] [Indexed: 12/30/2022] Open
Abstract
The use of radioactive sources to deliver cytotoxic ionizing radiation to disease sites dates back to the early 20th century, with the discovery of radium and its physiologic effects. α-emitters are of particular interest in the field of clinical oncology for radiotherapy applications. The first part of this review explored the basic radiochemistry, high cell-killing potency, and availability of α-emitting radionuclides, together with hurdles such as radiolabeling methods and daughter redistribution. The second part of this review will give an overview of the most promising and current uses of α-emitters in preclinical and clinical studies.
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