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Thompson SA, Gala U, Davis DA, Kucera S, Miller D, Williams RO. Can the Oral Bioavailability of the Discontinued Prostate Cancer Drug Galeterone Be Improved by Processing Method? KinetiSol® Outperforms Spray Drying in a Head-to-head Comparison. AAPS PharmSciTech 2023; 24:137. [PMID: 37344629 DOI: 10.1208/s12249-023-02597-6] [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: 03/28/2023] [Accepted: 05/31/2023] [Indexed: 06/23/2023] Open
Abstract
Galeterone, a novel prostate cancer candidate treatment, was discontinued after a Phase III clinical trial due to lack of efficacy. Galeterone is weakly basic and exhibits low solubility in biorelevant media (i.e., ~ 2 µg/mL in fasted simulated intestinal fluid). It was formulated as a 50-50 (w/w) galeterone-hypromellose acetate succinate spray-dried dispersion to increase its bioavailability. Despite this increase, the bioavailability of this formulation may have been insufficient and contributed to its clinical failure. We hypothesized that reformulating galeterone as an amorphous solid dispersion by KinetiSol® compounding could increase its bioavailability. In this study, we examined the effects of composition and manufacturing technology (Kinetisol and spray drying) on the performance of galeterone amorphous solid dispersions. KinetiSol compounding was utilized to create galeterone amorphous solid dispersions containing the complexing agent hydroxypropyl-β-cyclodextrin or hypromellose acetate succinate with lower drug loads that both achieved a ~ 6 × increase in dissolution performance versus the 50-50 spray-dried dispersion. When compared to a spray-dried dispersion with an equivalent drug load, the KinetiSol amorphous solid dispersions formulations exhibited ~ 2 × exposure in an in vivo rat study. Acid-base surface energy analysis showed that the equivalent composition of the KinetiSol amorphous solid dispersion formulation better protected the weakly basic galeterone from premature dissolution in acidic media and thereby reduced precipitation, inhibited recrystallization, and extended the extent of supersaturation during transit into neutral intestinal media.
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Affiliation(s)
- Stephen A Thompson
- Molecular Pharmaceutics and Drug Delivery Division, The University of Texas at Austin College of Pharmacy, 2409 W. University Ave. PHR 4.214, Austin, Texas, 78712, USA.
| | - Urvi Gala
- AustinPx, LLC. 111 W Cooperative Way, Suite 300, Georgetown, Texas, 78626, USA
| | - Daniel A Davis
- AustinPx, LLC. 111 W Cooperative Way, Suite 300, Georgetown, Texas, 78626, USA
| | - Sandra Kucera
- AustinPx, LLC. 111 W Cooperative Way, Suite 300, Georgetown, Texas, 78626, USA
| | - Dave Miller
- AustinPx, LLC. 111 W Cooperative Way, Suite 300, Georgetown, Texas, 78626, USA
| | - Robert O Williams
- Molecular Pharmaceutics and Drug Delivery Division, The University of Texas at Austin College of Pharmacy, 2409 W. University Ave. PHR 4.214, Austin, Texas, 78712, USA
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2
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Aberrant Regulation of RAD51 Promotes Resistance of Neoadjuvant Endocrine Therapy in ER-positive Breast Cancer. Sci Rep 2019; 9:12939. [PMID: 31506496 PMCID: PMC6736845 DOI: 10.1038/s41598-019-49373-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 08/23/2019] [Indexed: 01/02/2023] Open
Abstract
Breast cancer is one of the most common malignant cancers affecting females. Estrogen receptor (ER)-positive breast cancer is responsive to endocrine therapy. Although current therapies offer favorable prospects for improving survival, the development of resistance remains a severe problem. In this study, we explored the resistance mechanisms of ER-positive breast cancer to neoadjuvant endocrine therapy. Microarray data of GSE87411 contained 109 pairs of samples from Z1031 trial, including untreated samples and post-treated samples with neoadjuvant aromatase inhibitor (AI) therapy. The differentially expressed genes (DEGs) were obtained from two different comparisons: untreated samples versus post-treated samples with AIs, and post-treated samples sensitive versus resistant to AIs. Multiple bioinformatic methods were applied to evaluate biological function, protein-protein network and potential binding between target protein and aromatase inhibitor. Then, regulation of gene expression, DNA methylation and clinicopathological factors of breast cancer were further analyzed with TCGA data. From GSE87411 dataset, 30 overlapped DEGs were identified. Cell division was found to be the main function of overlapped DEGs by functional enrichment and gene ontology (GO) analysis. RAD51 recombinase (RAD51), a key protein of homologous recombination, was detected to interact with BReast CAncer genes 2 (BRCA2). Moreover, according to the docking simulation, RAD51 might potentially bind to AIs. Overexpressed RAD51 was associated with hypermethylation of BRCA2, resistance to AIs and poor overall survival of patients with ER-positive breast cancer. Furthermore, RAD51 was found to be a better indicator than MKI67 for predicting resistance in neoadjuvant setting. The results indicated that methylation of BRCA2 led to incomplete suppression on RAD51, which caused an increased expression of RAD51, subsequently AI-resistance and poor prognosis in ER-positive breast cancer. RAD51 could be a new candidate used as a predicative marker and therapeutic target in neoadjuvant endocrine treatment.
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3
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Dhawan M, Ryan CJ. Utility of novel androgen receptor therapies in the real world: A nuanced approach. Urol Oncol 2016; 34:340-7. [PMID: 27450893 DOI: 10.1016/j.urolonc.2016.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 04/28/2016] [Accepted: 05/02/2016] [Indexed: 01/01/2023]
Abstract
Abiraterone and enzalutamide are in widespread clinical use because of their favorable safety and efficacy. Nonetheless, even with newer agents, resistance develops overtime. In this review, we discuss mechanisms of resistance to these newer agents as well as novel therapeutic agents. We also review the literature to help clinicians decide which agent to begin with and when to stop or switch androgen receptor agents.
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Affiliation(s)
- Mallika Dhawan
- Genitourinary Medical Oncology Program, UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, CA
| | - Charles J Ryan
- Genitourinary Medical Oncology Program, UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, CA.
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4
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Saad F, Fizazi K. Androgen Deprivation Therapy and Secondary Hormone Therapy in the Management of Hormone-sensitive and Castration-resistant Prostate Cancer. Urology 2015; 86:852-61. [DOI: 10.1016/j.urology.2015.07.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/30/2015] [Accepted: 07/30/2015] [Indexed: 01/08/2023]
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5
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Crona DJ, Milowsky MI, Whang YE. Androgen receptor targeting drugs in castration-resistant prostate cancer and mechanisms of resistance. Clin Pharmacol Ther 2015; 98:582-9. [PMID: 26331358 DOI: 10.1002/cpt.256] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 08/26/2015] [Indexed: 12/16/2022]
Abstract
Reactivated androgen receptor (AR) signaling drives castration-resistant prostate cancer (CRPC). The novel AR targeting drugs abiraterone and enzalutamide have improved survival of CRPC patients. However, resistance to these agents develops and patients ultimately succumb to CRPC. Potential mechanisms of resistance include the following: 1) Expression of AR splice variants, such as the AR-V7 isoform, which lacks the ligand-binding domain; 2) AR missense mutations in the ligand-binding domain, such as F876L and T877A; and 3) Mutation or overexpression of androgen biosynthetic enzymes or glucocorticoid receptor. Several novel agents may overcome resistance mechanisms. Galeterone acts through multiple mechanisms that include degradation of AR protein and is being evaluated in CRPC patients positive for AR-V7. EPI-001 and related compounds inhibit AR splice variants by targeting the N-terminal transactivation domain of AR. Promising therapies and novel biomarkers, such as AR-V7, may lead to improved outcomes for CRPC patients.
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Affiliation(s)
- D J Crona
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
| | - M I Milowsky
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Y E Whang
- Division of Hematology and Oncology, Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA
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6
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Wyatt AW, Gleave ME. Targeting the adaptive molecular landscape of castration-resistant prostate cancer. EMBO Mol Med 2015; 7:878-94. [PMID: 25896606 PMCID: PMC4520654 DOI: 10.15252/emmm.201303701] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 03/12/2015] [Accepted: 03/26/2015] [Indexed: 12/19/2022] Open
Abstract
Castration and androgen receptor (AR) pathway inhibitors induce profound and sustained responses in advanced prostate cancer. However, the inevitable recurrence is associated with reactivation of the AR and progression to a more aggressive phenotype termed castration-resistant prostate cancer (CRPC). AR reactivation can occur directly through genomic modification of the AR gene, or indirectly via co-factor and co-chaperone deregulation. This mechanistic heterogeneity is further complicated by the stress-driven induction of a myriad of overlapping cellular survival pathways. In this review, we describe the heterogeneous and evolvable molecular landscape of CRPC and explore recent successes and failures of therapeutic strategies designed to target AR reactivation and adaptive survival pathways. We also discuss exciting areas of burgeoning anti-tumour research, and their potential to improve the survival and management of patients with CRPC.
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Affiliation(s)
- Alexander W Wyatt
- Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Martin E Gleave
- Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada
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7
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[New therapies in metastatic castration resistant prostate cancer]. Bull Cancer 2015; 102:501-8. [PMID: 26022286 DOI: 10.1016/j.bulcan.2015.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/02/2015] [Indexed: 02/07/2023]
Abstract
Therapeutic arsenal in prostate cancer widens for several years. New hormonal therapies such as acetate abiraterone or enzalutamide were the first molecules to revolutionize the treatment of metastatic castration resistant prostate cancer. Several other treatments are on trial targeting different pathways: androgene pathway (TAK-007, ARN-509, ODM-201, TOK-001), immune system (sipuleucel, ipilimumab, PROSTVAC-V/F, tasquinimod), but also tumor cell (PARP inhibitor, cabozantinib). The treatment sequencing will therefore soon be problematic, raising the necessity to identify predictive markers of response to the new therapies.
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8
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Njar VCO, Brodie AMH. Discovery and Development of Galeterone (TOK-001 or VN/124-1) for the Treatment of All Stages of Prostate Cancer. J Med Chem 2015; 58:2077-87. [DOI: 10.1021/jm501239f] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Vincent C. O. Njar
- Department of Pharmacology, ‡Center for Biomolecular
Therapeutics, and §Marlene Stewart
Greenebaum Cancer Center, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, Maryland 21201-1559, United States
| | - Angela M. H. Brodie
- Department of Pharmacology, ‡Center for Biomolecular
Therapeutics, and §Marlene Stewart
Greenebaum Cancer Center, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, Maryland 21201-1559, United States
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9
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Gupta E, Guthrie T, Tan W. Changing paradigms in management of metastatic Castration Resistant Prostate Cancer (mCRPC). BMC Urol 2014; 14:55. [PMID: 25062956 PMCID: PMC4167156 DOI: 10.1186/1471-2490-14-55] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 07/17/2014] [Indexed: 11/14/2022] Open
Abstract
Recently, the standard of care for metastatic Castration Resistant Prostate Cancer (mCRPC) has changed considerably. Persistent androgen receptor (AR) signaling has been identified as a target for novel therapies and reengages the fact that AR continues to be the primary target responsible for metastatic prostate cancer. Androgen receptor gene amplification and over expression have been found to result in a higher concentration of androgen receptors on tumor cells, making them extremely sensitive to low levels of circulating androgens. Additionally, prostate cancer cells are able to maintain dihydrotestosterone (DHT) concentration in excess of serum concentrations to support tumor growth. For many years ketoconazole was the only CYP17 inhibitor that was used to treat mCRPC. However, significant toxicities limit its use. Newly approved chemotherapeutic agents such as Abiraterone (an oral selective inhibitor of CYP17A), which blocks androgen biosynthesis both within and outside the prostate cancer cells), and enzalutamide (blocks AR signaling) have improved overall survival. There are also ongoing phase III trials for Orteronel (TAK- 700), ARN- 509 and Galeterone (TOK-001), which targets androgen signaling. In this review, we will present the rationale for the newly approved hormonal treatments, their indications and complications, and we will discuss ongoing trials that are being done to improve the efficacy of the approved agents. Finally, we will talk about the potential upcoming hormonal treatments for mCRPC.
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Affiliation(s)
- Eva Gupta
- Mayo Clinic, 4500 San Pablo Rd S, Jacksonville 32224, FL, USA
| | | | - Winston Tan
- Mayo Clinic, 4500 San Pablo Rd S, Jacksonville 32224, FL, USA
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10
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Stein MN, Patel N, Bershadskiy A, Sokoloff A, Singer EA. Androgen synthesis inhibitors in the treatment of castration-resistant prostate cancer. Asian J Androl 2014; 16:387-400. [PMID: 24759590 PMCID: PMC4023364 DOI: 10.4103/1008-682x.129133] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 03/11/2014] [Accepted: 03/14/2014] [Indexed: 01/01/2023] Open
Abstract
Suppression of gonadal testosterone synthesis represents the standard first line therapy for treatment of metastatic prostate cancer. However, in the majority of patients who develop castration-resistant prostate cancer (CRPC), it is possible to detect persistent activation of the androgen receptor (AR) through androgens produced in the adrenal gland or within the tumor itself. Abiraterone acetate was developed as an irreversible inhibitor of the dual functional cytochrome P450 enzyme CYP17 with activity as a 17α-hydroxylase and 17,20-lyase. CYP17 is necessary for production of nongonadal androgens from cholesterol. Regulatory approval of abiraterone in 2011, based on a phase III trial showing a significant improvement in overall survival (OS) with abiraterone and prednisone versus prednisone, represented proof of principle that targeting AR is essential for improving outcomes in men with CRPC. Inhibition of 17α-hydroxylase by abiraterone results in accumulation of upstream mineralocorticoids due to loss of cortisol-mediated suppression of pituitary adrenocorticotropic hormone (ACTH), providing a rationale for development of CYP17 inhibitors with increased specificity for 17,20-lyase (orteronel, galeterone and VT-464) that can potentially be administered without exogenous corticosteroids. In this article, we review the development of abiraterone and other CYP17 inhibitors; recent studies with abiraterone that inform our understanding of clinical parameters such as drug effects on quality-of-life, potential early predictors of response, and optimal sequencing of abiraterone with respect to other agents; and results of translational studies providing insights into resistance mechanisms to CYP17 inhibitors leading to clinical trials with drug combinations designed to prolong abiraterone benefit or restore abiraterone activity.
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Affiliation(s)
- Mark N Stein
- Rutgers Cancer Institute of New Jersey, USA
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - Neal Patel
- Rutgers Cancer Institute of New Jersey, USA
- Section of Urologic Oncology, Department of Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - Alexander Bershadskiy
- Rutgers Cancer Institute of New Jersey, USA
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - Alisa Sokoloff
- Rutgers Cancer Institute of New Jersey, USA
- Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
| | - Eric A Singer
- Rutgers Cancer Institute of New Jersey, USA
- Section of Urologic Oncology, Department of Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
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11
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Lorente D, De Bono JS. Molecular alterations and emerging targets in castration resistant prostate cancer. Eur J Cancer 2014; 50:753-64. [PMID: 24418724 DOI: 10.1016/j.ejca.2013.12.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Revised: 11/25/2013] [Accepted: 12/03/2013] [Indexed: 02/06/2023]
Abstract
Prostate cancer is the most common malignancy in Western Europe, of which approximately 10-20% presents with advanced or metastatic disease. Initial response with androgen deprivation therapy is almost universal, but progression to castration resistant prostate cancer (CRPC), an incurable disease, occurs in approximately 2-3 years. In recent years, the novel taxane cabazitaxel, the hormonal agents abiraterone and enzalutamide, the immunotherapeutic agent sipuleucel-T and the radiopharmaceutical radium-223 have been shown to prolong survival in large randomised trials, thus widely increasing the therapeutic armamentarium against the disease. Despite these advances, the median survival in the first-line setting of metastatic castration-resistant prostate cancer (mCRPC) is still up to 25 months and in the post-docetaxel setting is about 15-18 months. There is an urgent need for the development of biomarkers of treatment response, and for a deeper understanding of tumour heterogeneity and the molecular biology underlying the disease. In this review, we attempt to provide insight into the novel molecular targets showing promise in clinical trials.
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Affiliation(s)
- D Lorente
- Prostate Cancer Targeted Therapy Group and Drug Development Unit, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Downs Road, SM2 5PT Sutton, Surrey, UK
| | - J S De Bono
- Prostate Cancer Targeted Therapy Group and Drug Development Unit, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Downs Road, SM2 5PT Sutton, Surrey, UK.
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12
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Pezaro C, Omlin A, Lorente D, de Bono J. Management of patients with castration-resistant disease. Hematol Oncol Clin North Am 2013; 27:1243-60, ix. [PMID: 24188261 DOI: 10.1016/j.hoc.2013.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The medical management of men with castration-resistant prostate cancer (CRPC) has changed dramatically in the last decade. Men can now access several agents developed to extend survival, delay morbidity caused by complications, and preserve quality of life. Strategies to extend survival include docetaxel and cabazitaxel, the CYP-inhibitor abiraterone acetate, the second-generation androgen receptor antagonist enzalutamide, sipuleucel-T immunotherapy, and the α-emitting radionuclide (223)radium. These novel therapies have fostered interest in translational science and a deeper understanding of the underlying biology of CRPC. This article summarizes clinical data and unresolved issues in the use of current and emerging CRPC therapies.
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Affiliation(s)
- Carmel Pezaro
- Prostate Cancer Targeted Therapy Group and Drug Development Unit, The Royal Marsden NHS Foundation Trust, The Institute of Cancer Research, Downs Road, Sutton, Surrey SM2 5PT, UK
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13
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Hendrix LN, Hamilton DA, Kyprianou N. Emerging therapeutics targeting castration-resistant prostate cancer: the AR-mageddon of tumor epithelial-mesenchymal transition. Expert Rev Endocrinol Metab 2013; 8:403-416. [PMID: 30736155 DOI: 10.1586/17446651.2013.811914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Advanced prostate cancer will claim nearly 30,000 lives among men in the USA in the year 2013. Most of these will be castration-resistant prostate cancers that are not responsive to traditional therapeutic modalities, and there is no available regimen that fully eradicates metastatic disease. This poses a significant clinical challenge for practitioners and has stimulated the development of novel agents that target these castration-resistant tumor cells. Development of metastatic prostate cancer is orchestrated by multiple signaling pathways that regulate cell survival, apoptosis, anoikis, epithelial-mesenchymal transition (EMT), invasion, the androgen signaling axis and angiogenesis. Disruption of the mechanisms underlying these processes is critical for development of agents that can target otherwise resistant tumor cells. Insights into the mechanisms by which rounds of EMT/mesenchymal-epithelial transition conversions facilitate the progression of localized prostate carcinomas to advanced metastatic and castration-resistant disease emerge as attractive targets for drug development. In this review, the authors discuss the current understanding of therapeutic resistance in castration-resistant prostate cancer with focus on the androgen receptor signaling axis and EMT. Novel therapeutic approaches targeting critical players of both pathways as well as the results from ongoing clinical trials will be discussed in this review.
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Affiliation(s)
- Lauren N Hendrix
- a Division of Urology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - David A Hamilton
- a Division of Urology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Natasha Kyprianou
- b Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, USA
- c Department of Pathology, University of Kentucky College of Medicine, Lexington, KY, USA
- d Division of Urology, University of Kentucky College of Medicine, Lexington, KY, USA.
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Abstract
Androgen receptor (AR)-mediated signaling is critical to the growth and survival of prostate cancer. Although medical castration and antiandrogen therapy can decrease AR activity and lower PSA, castration resistance eventually develops. Recent work exploring the molecular structure and evolution of AR in response to hormonal therapies has revealed novel mechanisms of progression of castration-resistant prostate cancer and yielded new targets for drug development. This review focuses on understanding the mechanisms of persistent AR signaling in the castrate environment, and highlights new therapies either currently available or in clinical trials, including androgen synthesis inhibitors and novel direct AR inhibitors.
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Affiliation(s)
- Terence W Friedlander
- Division of Genitourinary Medical Oncology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94143, USA.
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Schweizer MT, Antonarakis ES. Abiraterone and other novel androgen-directed strategies for the treatment of prostate cancer: a new era of hormonal therapies is born. Ther Adv Urol 2012; 4:167-78. [PMID: 22852027 PMCID: PMC3398601 DOI: 10.1177/1756287212452196] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The number of life-prolonging therapies proven effective in the treatment of metastatic castrate-resistant prostate cancer (CRPC) has been limited until recently. In the past 2 years several such therapies have come to market. In 2010, the autologous immunotherapy sipuleucel-T and the next-generation taxane cabazitaxel were approved in this setting. However, abundant evidence has shown that CRPC growth continues to be driven through androgen-dependent signaling. Both of these drugs fail to take advantage of this targetable oncogenic pathway. Potent specific inhibitors of cytochrome P450-17 have been engineered with the aim of suppressing androgen synthesis beyond that seen with the luteinizing hormone-releasing hormone agonists/antagonists. Abiraterone acetate was developed by rational design based on a pregnenolone parent structure. Its approval by the US Food and Drug Administration (FDA) was granted in 2011 based on phase III data demonstrating an overall survival advantage compared with placebo. More recently, other drugs that act along the androgen signaling pathway, such as orteronel (TAK-700), galeterone (TOK-001), enzalutamide (MDV3100) and ARN-509, have shown promise in clinical trials. Some of these are expected to gain FDA approval in the near future. Here, we review abiraterone and other novel androgen-directed therapeutic strategies for the management of advanced prostate cancer.
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Affiliation(s)
- Michael T Schweizer
- Prostate Cancer Research Program, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, USA
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