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Daniels VA, Luo J, Paller CJ, Kanayama M. Therapeutic Approaches to Targeting Androgen Receptor Splice Variants. Cells 2024; 13:104. [PMID: 38201308 PMCID: PMC10778271 DOI: 10.3390/cells13010104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/31/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
Therapeutic options for advanced prostate cancer have vastly expanded over the last decade and will continue to expand in the future. Drugs targeting the androgen receptor (AR) signaling pathway, i.e., androgen receptor targeting agents (ARTAs), remain the mainstream treatments that are increasingly transforming the disease into one that can be controlled for an extended period of time. Prostate cancer is inherently addicted to AR. Under the treatment pressure of ARTA, molecular alterations occur, leading to the clonal expansion of resistant cells in a disease state broadly categorized as castration-resistant prostate cancer (CRPC). One castration resistance mechanism involves AR splice variants (AR-Vs) lacking the ligand-binding domain. Some AR-Vs have been identified as constitutively active, capable of activating AR signaling pathways without androgenic ligands. Among these variants, AR-V7 is the most extensively studied and may be measured non-invasively using validated circulating tumor cell (CTC) tests. In the context of the evolving prostate cancer treatment landscape, novel agents are developed and evaluated for their efficacy in targeting AR-V7. In patients with metastatic CRPC (mCRPC), the availability of the AR-V7 tests will make it possible to determine whether the treatments are effective for CTC AR-V7-positive disease, even though the treatments may not be specifically designed to target AR-V7. In this review, we will first outline the current prostate cancer treatment landscape, followed by an in-depth review of relatively newer prostate cancer therapeutics, focusing on AR-targeting agents under clinical development. These drugs are categorized from the standpoint of their activities against AR-V7 through direct or indirect mechanisms.
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Affiliation(s)
- Violet A. Daniels
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (V.A.D.); (J.L.)
| | - Jun Luo
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (V.A.D.); (J.L.)
- Departments of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Channing J. Paller
- Departments of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Mayuko Kanayama
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (V.A.D.); (J.L.)
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Khan S, Baligar P, Tandon C, Nayyar J, Tandon S. Molecular heterogeneity in prostate cancer and the role of targeted therapy. Life Sci 2024; 336:122270. [PMID: 37979833 DOI: 10.1016/j.lfs.2023.122270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/03/2023] [Accepted: 11/12/2023] [Indexed: 11/20/2023]
Abstract
Data collected from large-scale studies has shown that the incidence of prostate cancer globally is on the rise, which could be attributed to an overall increase in lifespan. So, the question is how has modern science with all its new technologies and clinical breakthroughs mitigated or managed this disease? The answer is not a simple one as prostate cancer exhibits various subtypes, each with its unique characteristics or signatures which creates challenges in treatment. To understand the complexity of prostate cancer these signatures must be deciphered. Molecular studies of prostate cancer samples have identified certain genetic and epigenetic alterations, which are instrumental in tumorigenesis. Some of these candidates include the androgen receptor (AR), various oncogenes, tumor suppressor genes, and the tumor microenvironment, which serve as major drivers that lead to cancer progression. These aberrant genes and their products can give an insight into prostate cancer development and progression by acting as potent markers to guide future therapeutic approaches. Thus, understanding the complexity of prostate cancer is crucial for targeting specific markers and tailoring treatments accordingly.
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Affiliation(s)
- Sabiha Khan
- Amity Institute of Molecular Medicine, Amity University Uttar Pradesh, India
| | - Prakash Baligar
- Amity Institute of Molecular Medicine, Amity University Uttar Pradesh, India
| | - Chanderdeep Tandon
- Amity School of Biological Sciences, Amity University Punjab, Mohali, India
| | - Jasamrit Nayyar
- Department of Chemistry, Goswami Ganesh Dutt Sanatan Dharam College, Chandigarh, India
| | - Simran Tandon
- Amity School of Health Sciences, Amity University Punjab, Mohali, India.
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Gebrael G, Fortuna GG, Sayegh N, Swami U, Agarwal N. Advances in the treatment of metastatic prostate cancer. Trends Cancer 2023; 9:840-854. [PMID: 37442702 PMCID: PMC10527423 DOI: 10.1016/j.trecan.2023.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/18/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023]
Abstract
The field of metastatic prostate cancer (mPCa) has seen unprecedented therapeutic advances in the past decade. In the past 2 years, recent approvals include the triplet therapy regimens of androgen deprivation therapy (ADT), docetaxel, and an androgen receptor (AR) pathway inhibitor (ARPI) in the castration-sensitive setting and lutetium-177 vipivotide tetraxetan (177Lu-PSMA-617) and the combination of poly(ADP) ribose polymerase (PARP) inhibitors (PARPis) and ARPIs in the castration-resistant setting. With many agents currently undergoing investigation in registration trials, the therapeutic armamentarium will expand rapidly, making treatment selection and sequencing challenging. Herein, we review the landmark clinical trials ongoing or reported in the past 2 years, discuss the optimal approach to treatment selection, and provide insight into future directions.
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Affiliation(s)
- Georges Gebrael
- Division of Medical Oncology, Department of Internal Medicine, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | - Gliceida Galarza Fortuna
- Division of Medical Oncology, Department of Internal Medicine, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | - Nicolas Sayegh
- Division of Medical Oncology, Department of Internal Medicine, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | - Umang Swami
- Division of Medical Oncology, Department of Internal Medicine, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | - Neeraj Agarwal
- Division of Medical Oncology, Department of Internal Medicine, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
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Dai C, Dehm SM, Sharifi N. Targeting the Androgen Signaling Axis in Prostate Cancer. J Clin Oncol 2023; 41:4267-4278. [PMID: 37429011 PMCID: PMC10852396 DOI: 10.1200/jco.23.00433] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/14/2023] [Accepted: 05/30/2023] [Indexed: 07/12/2023] Open
Abstract
Activation of the androgen receptor (AR) and AR-driven transcriptional programs is central to the pathophysiology of prostate cancer. Despite successful translational efforts in targeting AR, therapeutic resistance often occurs as a result of molecular alterations in the androgen signaling axis. The efficacy of next-generation AR-directed therapies for castration-resistant prostate cancer has provided crucial clinical validation for the continued dependence on AR signaling and introduced a range of new treatment options for men with both castration-resistant and castration-sensitive disease. Despite this, however, metastatic prostate cancer largely remains an incurable disease, highlighting the need to better understand the diverse mechanisms by which tumors thwart AR-directed therapies, which may inform new therapeutic avenues. In this review, we revisit concepts in AR signaling and current understandings of AR signaling-dependent resistance mechanisms as well as the next frontier of AR targeting in prostate cancer.
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Affiliation(s)
- Charles Dai
- Massachusetts General Hospital Cancer Center, Boston, MA
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
- Dana-Farber Cancer Institute, Boston, MA
| | - Scott M. Dehm
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN
- Department of Urology, University of Minnesota, Minneapolis, MN
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN
| | - Nima Sharifi
- Genitourinary Malignancies Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
- Department of Urology, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH
- Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH
- Desai Sethi Urology Institute, University of Miami Miller School of Medicine, Miami, FL
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL
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Zhang B, Liu C, Yang Z, Zhang S, Hu X, Li B, Mao M, Wang X, Li Z, Ma S, Zhang S, Qin C. Discovery of BWA-522, a First-in-Class and Orally Bioavailable PROTAC Degrader of the Androgen Receptor Targeting N-Terminal Domain for the Treatment of Prostate Cancer. J Med Chem 2023; 66:11158-11186. [PMID: 37556600 DOI: 10.1021/acs.jmedchem.3c00585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
We report small molecular PROTAC compounds targeting the androgen receptor N-terminal domain (AR-NTD), which were obtained by tethering AR-NTD antagonists and different classes of E3 ligase ligands through chemical linkers. A representative compound, BWA-522, effectively induces degradation of both AR-FL and AR-V7 and is more potent than the corresponding antagonist against prostate cancer (PC) cells in vitro. We have shown that the degradation of AR-FL and AR-V7 proteins by BWA-522 can suppress the expression of AR downstream proteins and induce PC cell apoptosis. BWA-522 achieves 40.5% oral bioavailability in mice and 69.3% in beagle dogs. In a LNCaP xenograft model study, BWA-522 was also proved to be an efficacious PROTAC degrader, resulting in 76% tumor growth inhibition after oral administration of a dose of 60 mg/kg. This study indicates that BWA-522 is a promising AR-NTD PROTAC for the treatment of AR-FL- and AR-V7-dependent tumors.
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Affiliation(s)
- Bowen Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
| | - Chang Liu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
| | - Zhenqian Yang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
| | - Sai Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
- Center for Targeted Protein Degradation and Drug Discovery, Ocean University of China, Qingdao, Shandong 266003, China
| | - Xiaolin Hu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
| | - Baohu Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
| | - Mei Mao
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
| | - Xiao Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
- Center for Targeted Protein Degradation and Drug Discovery, Ocean University of China, Qingdao, Shandong 266003, China
| | - Zhuoyue Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
- Center for Targeted Protein Degradation and Drug Discovery, Ocean University of China, Qingdao, Shandong 266003, China
| | - Shumin Ma
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
- Center for Targeted Protein Degradation and Drug Discovery, Ocean University of China, Qingdao, Shandong 266003, China
| | - Siqi Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
- Center for Targeted Protein Degradation and Drug Discovery, Ocean University of China, Qingdao, Shandong 266003, China
| | - Chong Qin
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, China
- Center for Targeted Protein Degradation and Drug Discovery, Ocean University of China, Qingdao, Shandong 266003, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology, Qingdao, Shandong 266137, China
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Yi Q, Liu W, Seo JH, Su J, Alaoui-Jamali MA, Luo J, Lin R, Wu JH. Discovery of a Small-Molecule Inhibitor Targeting the Androgen Receptor N-Terminal Domain for Castration-Resistant Prostate Cancer. Mol Cancer Ther 2023; 22:570-582. [PMID: 37139712 DOI: 10.1158/1535-7163.mct-22-0237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 08/11/2022] [Accepted: 01/30/2023] [Indexed: 05/05/2023]
Abstract
The current mainstay therapeutic strategy for advanced prostate cancer is to suppress androgen receptor (AR) signaling. However, castration-resistant prostate cancer (CRPC) invariably arises with restored AR signaling activity. To date, the AR ligand-binding domain (LBD) is the only targeted region for all clinically available AR signaling antagonists, such as enzalutamide (ENZ). Major resistance mechanisms have been uncovered to sustain the AR signaling in CRPC despite these treatments, including AR amplification, AR LBD mutants, and the emergence of AR splice variants (AR-Vs) such as AR-V7. AR-V7 is a constitutively active truncated form of AR that lacks the LBD; thus, it can not be inhibited by AR LBD-targeting drugs. Therefore, an approach to inhibit AR through the regions outside of LBD is urgently needed. In this study, we have discovered a novel small molecule SC428, which directly binds to the AR N-terminal domain (NTD) and exhibits pan-AR inhibitory effect. SC428 potently decreased the transactivation of AR-V7, ARv567es, as well as full-length AR (AR-FL) and its LBD mutants. SC428 substantially suppressed androgen-stimulated AR-FL nuclear translocation, chromatin binding, and AR-regulated gene transcription. Moreover, SC428 also significantly attenuated AR-V7-mediated AR signaling that does not rely on androgen, hampered AR-V7 nuclear localization, and disrupted AR-V7 homodimerization. SC428 inhibited in vitro proliferation and in vivo tumor growth of cells that expressed a high level of AR-V7 and were unresponsive to ENZ treatment. Together, these results indicated the potential therapeutic benefits of AR-NTD targeting for overcoming drug resistance in CRPC.
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Affiliation(s)
- Qianhui Yi
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Québec, Canada
- Departments of Oncology and Medicine, Faculty of Medicine, McGill University, Montreal, Québec, Canada
| | - Weiguo Liu
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Québec, Canada
| | - Jung Hwa Seo
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Québec, Canada
| | - Jie Su
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Québec, Canada
| | - Moulay A Alaoui-Jamali
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Québec, Canada
- Departments of Oncology and Medicine, Faculty of Medicine, McGill University, Montreal, Québec, Canada
| | - Jun Luo
- Urology, Johns Hopkins University, Baltimore, Maryland
| | - Rongtuan Lin
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Québec, Canada
- Departments of Oncology and Medicine, Faculty of Medicine, McGill University, Montreal, Québec, Canada
| | - Jian Hui Wu
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, McGill University, Montreal, Québec, Canada
- Departments of Oncology and Medicine, Faculty of Medicine, McGill University, Montreal, Québec, Canada
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Huang J, Lin B, Li B. Anti-Androgen Receptor Therapies in Prostate Cancer: A Brief Update and Perspective. Front Oncol 2022; 12:865350. [PMID: 35372068 PMCID: PMC8965587 DOI: 10.3389/fonc.2022.865350] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 02/17/2022] [Indexed: 12/28/2022] Open
Abstract
Prostate cancer is a major health issue in western countries and is the second leading cause of cancer death in American men. Prostate cancer depends on the androgen receptor (AR), a transcriptional factor critical for prostate cancer growth and progression. Castration by surgery or medical treatment reduces androgen levels, resulting in prostatic atrophy and prostate cancer regression. Thus, metastatic prostate cancers are initially managed with androgen deprivation therapy. Unfortunately, prostate cancers rapidly relapse after castration therapy and progress to a disease stage called castration-resistant prostate cancer (CRPC). Currently, clinical treatment for CRPCs is focused on suppressing AR activity with antagonists like Enzalutamide or by reducing androgen production with Abiraterone. In clinical practice, these treatments fail to yield a curative benefit in CRPC patients in part due to AR gene mutations or splicing variations, resulting in AR reactivation. It is conceivable that eliminating the AR protein in prostate cancer cells is a promising solution to provide a potential curative outcome. Multiple strategies have emerged, and several potent agents that reduce AR protein levels were reported to eliminate xenograft tumor growth in preclinical models via distinct mechanisms, including proteasome-mediated degradation, heat-shock protein inhibition, AR splicing suppression, blockage of AR nuclear localization, AR N-terminal suppression. A few small chemical compounds are undergoing clinical trials combined with existing AR antagonists. AR protein elimination by enhanced protein or mRNA degradation is a realistic solution for avoiding AR reactivation during androgen deprivation therapy in prostate cancers.
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Affiliation(s)
- Jian Huang
- Pathological Diagnosis and Research Center, The Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Biyun Lin
- Pathological Diagnosis and Research Center, The Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Benyi Li
- Department of Urology, The University of Kansas Medical Center, Kansas City, KS, United States
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Sadar MD. Drugging the Undruggable: Targeting the N-Terminal Domain of Nuclear Hormone Receptors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1390:311-326. [PMID: 36107327 DOI: 10.1007/978-3-031-11836-4_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This chapter focuses on the development of drugs targeting the N-terminal domain of nuclear hormone receptors, using progress with the androgen receptor as an example. Historically, development of therapies targeting nuclear hormone receptors has focused on the folded C-terminal ligand-binding domain. Therapies were traditionally not developed to target the intrinsically disordered N-terminal domain as it was considered "undruggable". Recent developments have now shown it is possible to direct therapies to the N-terminal domain. This chapter will provide an introduction of the structure and function of the domains of nuclear hormone receptors, followed by a discussion of the rationale supporting the development of N-terminal domain inhibitors. Chemistry and mechanisms of action of small molecule inhibitors will be described with emphasis on N-terminal domain inhibitors developed to the androgen receptor including those in clinical trials.
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Affiliation(s)
- Marianne D Sadar
- Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer, Vancouver, BC, Canada.
- Department of Pathology and Laboratory Science, University of British Columbia, Vancouver, BC, Canada.
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A phase 1 study to assess the safety, pharmacokinetics, and anti-tumor activity of the androgen receptor n-terminal domain inhibitor epi-506 in patients with metastatic castration-resistant prostate cancer. Invest New Drugs 2021; 40:322-329. [PMID: 34843005 DOI: 10.1007/s10637-021-01202-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/22/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND EPI-506 is the first of a new class of drugs targeting the N-terminal domain (NTD) of the androgen receptor (AR), potentially overcoming known resistance mechanisms to androgen receptor pathway inhibitors (ARPIs) among men with metastatic castration resistant prostate cancer (mCRPC). METHODS Patients with mCRPC who had progressed on prior ARPI were enrolled in this phase 1 open-label, adaptive 3 + 3 dose escalation study. The primary outcome was safety and tolerability of oral EPI-506. Secondary objectives included determination of the maximal tolerated dose (MTD), pharmacokinetic profile, and antitumor efficacy. RESULTS 28 mCRPC patients were enrolled into 7 dose cohorts of EPI-506 ranging from 80-3600 mg given once daily and 1800 mg given twice daily. Six DLTs occurred in 4 patients; Grade 4 elevated amylase; Grade 3 abdominal pain; Grade 3 elevated ALT and Grade 3 elevated AST; Grade 2 nausea and Grade 1 vomiting which resulted in study drug intake of < 75% of the expected dose during the DLT assessment period. The most common drug-related adverse events included diarrhea, nausea and fatigue. Six patients had a PSA decline not meeting PSA response criteria. The study was terminated prior to reaching the MTD due to poor oral bioavailability. CONCLUSIONS This phase 1 trial established the safety of EPI-506 and provides proof of concept for targeting the AR NTD. Next generation compounds with improved bioavailability and potency are in clinical development.
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Kanayama M, Lu C, Luo J, Antonarakis ES. AR Splicing Variants and Resistance to AR Targeting Agents. Cancers (Basel) 2021; 13:2563. [PMID: 34071114 PMCID: PMC8197115 DOI: 10.3390/cancers13112563] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 12/23/2022] Open
Abstract
Over the past decade, advances in prostate cancer research have led to discovery and development of novel biomarkers and effective treatments. As treatment options diversify, it is critical to further develop and use optimal biomarkers for the purpose of maximizing treatment benefit and minimizing unwanted adverse effects. Because most treatments for prostate cancer target androgen receptor (AR) signaling, aberrations affecting this drug target are likely to emerge following the development of castration-resistant prostate cancer (CRPC), and it is conceivable that such aberrations may play a role in drug resistance. Among the many AR aberrations, we and others have been studying androgen receptor splice variants (AR-Vs), especially AR-V7, and have conducted preclinical and clinical studies to develop and validate the clinical utility of AR-V7 as a prognostic and potential predictive biomarker. In this review, we first describe mechanisms of AR-V generation, regulation and their functions from a molecular perspective. We then discuss AR-Vs from a clinical perspective, focusing on the significance of AR-Vs detected in different types of human specimens and AR-Vs as potential therapeutic targets.
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Affiliation(s)
- Mayuko Kanayama
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (M.K.); (C.L.); (J.L.)
| | - Changxue Lu
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (M.K.); (C.L.); (J.L.)
| | - Jun Luo
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (M.K.); (C.L.); (J.L.)
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Emmanuel S. Antonarakis
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; (M.K.); (C.L.); (J.L.)
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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