Efficacy and safety of gonadotropin-releasing hormone agonists used in the treatment of prostate cancer

Development of a Novel Patient-Reported Outcome Measure to Assess Symptoms and Impacts of Androgen Deprivation Therapy for Advanced Prostate Cancer

INTRODUCTION

This qualitative research study was conducted to develop a novel, comprehensive, patient-reported outcome measure (PRO), the "Symptoms and Impacts of Androgen Deprivation Therapy (ADT) for Prostate Cancer" (SIADT-PC), assessing hormonal therapy-related symptoms and their impacts on men with advanced prostate cancer.

METHODS

Concept elicitation (CE) interviews were conducted among adult men with prostate cancer to evaluate their experiences with ADT. Based on key symptom and impact concepts mentioned, an initial PRO measure was developed. The draft measure was further assessed in cognitive debriefing (CD) interviews with men with prostate cancer, in which participants reviewed items, response options, and recall periods. Initial item-based psychometric analyses were conducted using interview data. The draft questionnaire was revised on the basis of participant feedback, quantitative psychometric results, and consultation with clinical experts.

RESULTS

A total of 21 participants were interviewed (CE concept elicitation, n = 12; CD cognitive debriefing, n = 17; n = 8 completed both). Mean participant age (SD) was 59.7 (8.7) years and 76.2% were white. The de novo SIADT-PC measure consists of 27 items: 11 symptoms (e.g., fatigue, hot flashes, and erectile dysfunction), 2 long-term symptoms (e.g., weight gain), 10 impacts (e.g., impacts on physical activities and relationships), and 4 related to mode of administration (i.e., injection-site reactions). Items were assessed with a 5-point verbal rating scale, with answer choices that capture frequency or severity.

CONCLUSIONS

Once fully validated, this de novo measure may be used in clinical studies and clinical practice to assess hormone therapy-related symptoms and impacts, enabling physicians to identify timely and appropriate interventions.

Phytochemical identification and in silico elucidation of interactions of bioactive compounds from Citrullus lanatus with androgen receptor towards prostate cancer treatment

Androgen receptor (AR) is known to play a crucial role in the development and progression of prostate cancer, and compounds that inhibit its activity are regarded as promising for the development of drugs to treat the disease. This study aimed to investigate the AR-inhibiting potential of Citrullus lanatus fruit compounds for prostate cancer drug development. Following HPLC identification, the binding energies, molecular interactions, and pharmacological potentials of the compounds against AR were elucidated using in silico techniques such as, molecular docking, induced-fit docking, molecular dynamics simulation, and ADMET prediction. Some of the compounds found to be present in Citrullus lanatus fruit included flavonoids such as proanthocyanin, naringin, flavan 3 ol, flavonones, naringenin, epicatechin, citrulline, and catechin. Naringenin exhibited the highest docking score in the molecular docking analysis, followed by resveratrol, ribalinidine, and epicatechin. These compounds share a common AR binding site with the standard ligand, dihydrotestosterone (DHT). Some of the compounds showed favorable ADMET profiles, while others showed at least one toxicity potential. The induced-fit docking of naringenin with AR yielded a higher docking score than the initial score obtained from standard docking while preserving stable molecular contacts with the interacting amino acids. Consistent hydrogen bond interactions of naringenin with PHE 764, ASN 705, and THR 877 of AR, including a persistent pi-pi stacking contact with PHE 764, were observed from the molecular dynamic simulation. The Citrullus lanatus compounds, particularly naringenin, may therefore be considered for further research towards the development of drugs for prostate cancer therapy.

Breast Cancer and Fertility Preservation in Young Female Patients: A Systematic Review of the Literature

INTRODUCTION

Breast cancer affects almost 1.5 million women worldwide below the age of 45 years each year. Many of these women will be advised to undergo adjuvant chemotherapy to minimize the risk of death or recurrence of the tumor. For these patients, chemotherapy is a known cause of infertility, as it can damage primordial follicles, which can lead to early menopause or premature ovarian insufficiency. This systematic review aims to synthesize the current evidence of the most suitable treatments for fertility preservation.

METHODOLOGY

This review was performed following the PRISMA guidelines. The authors conducted an extensive search from the last 15 years. Relevant studies were pursued in PubMed, Embase, and the Cochrane Library up until 31 July 2023. A total of seven eligible studies were identified.

RESULTS

From the reviewed literature, ovarian suppression with gonadotropin-releasing hormone agonists showed promising results in preserving fertility for breast cancer patients undergoing chemotherapy. Additionally, oocyte and embryo cryopreservation demonstrated successful outcomes, with embryo cryopreservation being the most effective option. Notably, the slow-freezing and vitrification methods were both effective in preserving embryos, with vitrification showing superior results in clinical-assisted reproductive technologies. Ovarian tissue cryopreservation emerged as a viable option for prepubertal girls and those unable to undergo conventional ovarian stimulation. The potential of in vitro maturation (IVM) as an alternative method presents a promising avenue for future fertility preservation research.

DISCUSSION

The most suitable treatments for fertility preservation in young patients is the temporary suppression with luteinizing hormone-releasing analogs, while the patient undergoes chemotherapy and cryopreservation. For cryopreservation, the physicians might deem it necessary to either cryopreserve ovarian tissue taken from the patient before any treatment or cryopreserve embryos/oocytes. Cryopreservation of oocytes and/or embryos is the most effective solution for fertility preservation in women of reproductive age, who have a sufficient ovarian reserve and are diagnosed with breast cancer, regardless of the histological type of the tumor. Because approximately 50% of young breast cancer patients are interested in becoming pregnant right after completion of therapy, the evolution and development of fertility preservation techniques promise to be very exciting.

Gonadotropin-Releasing Hormone Receptor (GnRHR) and Hypogonadotropic Hypogonadism

Human sexual and reproductive development is regulated by the hypothalamic-pituitary-gonadal (HPG) axis, which is primarily controlled by the gonadotropin-releasing hormone (GnRH) acting on its receptor (GnRHR). Dysregulation of the axis leads to conditions such as congenital hypogonadotropic hypogonadism (CHH) and delayed puberty. The pathophysiology of GnRHR makes it a potential target for treatments in several reproductive diseases and in congenital adrenal hyperplasia. GnRHR belongs to the G protein-coupled receptor family and its GnRH ligand, when bound, activates several complex and tissue-specific signaling pathways. In the pituitary gonadotrope cells, it triggers the G protein subunit dissociation and initiates a cascade of events that lead to the production and secretion of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) accompanied with the phospholipase C, inositol phosphate production, and protein kinase C activation. Pharmacologically, GnRHR can be modulated by synthetic analogues. Such analogues include the agonists, antagonists, and the pharmacoperones. The agonists stimulate the gonadotropin release and lead to receptor desensitization with prolonged use while the antagonists directly block the GnRHR and rapidly reduce the sex hormone production. Pharmacoperones include the most recent GnRHR therapeutic approaches that directly correct the misfolded GnRHRs, which are caused by genetic mutations and hold serious promise for CHH treatment. Understanding of the GnRHR's genomic and protein structure is crucial for the most appropriate assessing of the mutation impact. Such mutations in the GNRHR are linked to normosmic hypogonadotropic hypogonadism and lead to various clinical symptoms, including delayed puberty, infertility, and impaired sexual development. These mutations vary regarding their mode of inheritance and can be found in the homozygous, compound heterozygous, or in the digenic state. GnRHR expression extends beyond the pituitary gland, and is found in reproductive tissues such as ovaries, uterus, and prostate and non-reproductive tissues such as heart, muscles, liver and melanoma cells. This comprehensive review explores GnRHR's multifaceted role in human reproduction and its clinical implications for reproductive disorders.

Cellular growth factors as prospective therapeutic targets for combination therapy in androgen independent prostate cancer (AIPC)

Cancer is the second leading cause of death worldwide, with prostate cancer, the second most commonly diagnosed cancer among men. Prostate cancer develops in the peripheral zone of the prostate gland, and the initial progression largely depends on androgens, the male reproductive hormone that regulates the growth and development of the prostate gland and testis. The currently available treatments for androgen dependent prostate cancer are, however, effective for a limited period, where the patients show disease relapse, and develop androgen-independent prostate cancer (AIPC). Studies have shown various intricate cellular processes such as, deregulation in multiple biochemical and signaling pathways, intra-tumoral androgen synthesis; AR over-expression and mutations and AR activation via alternative growth pathways are involved in progression of AIPC. The currently approved treatment strategies target a single cellular protein or pathway, where the cells slowly develop resistance and adapt to proliferate via other cellular pathways over a period of time. Therefore, an increased research aims to understand the efficacy of combination therapy, which targets multiple interlinked pathways responsible for acquisition of resistance and survival. The combination therapy is also shown to enhance efficacy as well as reduce toxicity of the drugs. Thus, the present review focuses on the signaling pathways involved in the progression of AIPC, comprising a heterogeneous population of cells and the advantages of combination therapy. Several clinical and pre-clinical studies on a variety of combination treatments have shown beneficial outcomes, yet further research is needed to understand the potential of combination therapy and its diverse strategies.

Peptide-Based Therapeutics for Oncology

The development of peptide-based drugs, which are usually synthetic analogues of endogenous peptides, is currently one of the most topical directions in drug development. Among them, antitumor peptide-based drugs are of great interest. Anticancer peptides can be classified into three main groups based on their mechanism of action: inhibitory, necrosis-inducing and pro-apoptotic peptides. As an antitumor therapy, peptides are considered to have at least the same efficacy as chemotherapy or surgical treatment, but offer advantages in terms of safety and tolerability, given that chemotherapy is usually characterized by severe adverse effects, and surgery carries additional risks for patients. Short peptides have a number of benefits over other molecules. First, compared with full-length proteins and antibodies, short peptides are less immunogenic, more stable ex-vivo (prolonged storage at room temperature), and have better tumor or organ permeability. Moreover, the production of such short peptide-based drugs is more cost effective. Second, in comparison with small organic molecules, peptides have higher efficacy and specificity. Finally, due to the fact that the main products of peptide metabolism are amino acids, these drugs are usually characterized by lower toxicity. Short peptides have a highly selective mechanism of action, thereby demonstrating low toxicity. Furthermore, with the addition of different stabilizing structural modifications, as well as novel drug delivery systems, the peptide-based drugs are proving to be promising therapeutics for cancer mono- or polytherapy. However, challenges remain including that endogenous and synthetic peptide molecules can be oncogenic. Therefore, it is important to investigate whether peptides contribute to tumor growth. In order to answer such questions, numerous preclinical and clinical studies of peptide-based therapeutics are currently being conducted.

NAV3, a Tumor Suppressor Gene, Is Decreased in Uterine Leiomyoma Tissue and Cells

NAV 3 is a tumor suppressor of unknown function in leiomyomas. The objective of this study is to assess NAV3 expression and its potential role in human uterine leiomyomas. NAV3 protein expression was examined in patient leiomyoma and patient-matched myometrial tissue samples by Western blot and immunohistochemistry. NAV3 mRNA and protein expression was assessed in leuprolide acetate- and cetrorelix-treated cell line leiomyoma samples. RNAseq analysis of placebo-treated leiomyoma compared with myometrium demonstrated the presence of transcripts encoding for several neuronal proteins. For NAV3, RNA sequence analysis demonstrated decreased expression in leiomyoma as compared with myometrium (0.86 ± 0.03 fold). Presence of NAV3 mRNA was also decreased in leiomyoma surgical samples (0.43 fold ± 0.05, p = 0.026) compared with patient-matched myometrium. Confirmatory qRT-PCR results on immortalized leiomyoma and myometrial cell lines similarly demonstrated a decrease in expression of NAV3 in leiomyomas (0.28 ± 0.02, p = 0.00075). Immunohistochemical analysis demonstrated a significant decrease in NAV 3 protein in leiomyomas (H-score 154.7 ± 6.2) as compared with myometrium (H-score; 312.5 ± 14.7, p < 0.0001). Leuprolide acetate-treated leiomyoma cells demonstrated an increase in NAV 3 mRNA expression (1.53 ± 0.13, p < 0.0001). Similarly, Western blot analysis on leuprolide-treated leiomyoma cells showed a non-significant increase in NAV 3 protein expression (1.26 ± 0.09, p = 0.063). NAV 3, a tumor suppressor in numerous cancers, is decreased in leiomyoma cells and tissue compared with myometrium, and increased by GnRH analog treatment, suggesting that NAV3 may mediate steroid hormone-independent leiomyoma regulation by GnRH analogs.

Inhibition of RM-1 prostate carcinoma and eliciting robust immune responses in the mouse model by using VEGF-M2-GnRH3-hinge-MVP vaccine

GnRH and VEGF have been investigated as prostate carcinoma enhancers that support tumor spread and progression. Although both have documented roles in prostate carcinoma and many cancer types, the weak immunogenicity of these peptides has remained a major challenge for use in immunotherapy. Here, we describe a novel strategy to inhibit GnRH and VEGF production and assess the effect on the immune responses against these hormones using the RM-1 prostate cancer model. We designed a novel recombinant fusion protein which combined GnRH and VEGF as a vaccine against this tumor. The newly constructed fusion protein hVEGF121-M2-GnRH3-hinge-MVP contains the human vascular endothelial growth factor (hVEGF121) and three copies of GnRH in sequential linear alignment and T helper epitope MVP as an immunogenic vaccine. The effectiveness of the vaccine in eliciting an immune response and attenuating the prostate tumor growth was evaluated. Results showed that administration of a new vaccine effectively elicited humoral and cellular immune responses. We found that, a novel fusion protein, hVEGF121-M2-GnRH3-hinge-MVP, effectively inhibited growth of RM-1 prostate model and effectively promoted immune response. In conclusion, hVEGF121-M2-GnRH3-hinge-MVP is an effective dual mechanism tumor vaccine that limits RM-1 prostate growth. This vaccine may be a promising strategy for the treatment of hormone refractory prostate malignancies.

Treatment costs for advanced prostate cancer using luteinizing hormone-releasing hormone agonists: a solid biodegradable leuprorelin implant versus other formulations

AIM

To compare treatment costs with alternative luteinizing hormone-releasing hormone (LHRH) agonist preparations and determine whether a leuprorelin solid implant is associated with potential cost savings.

PATIENTS & METHODS

A hypothetical population of 1000 prostate cancer patients was apportioned between the three most commonly-prescribed LHRH agonist preparations. Differentiated annual costs for 1- and 3-monthly formulations were calculated for France, Germany, Italy, Spain, the UK (EU5) and Sweden, and compared with the leuprorelin solid implant.

RESULTS

Compared with alternative formulations, leuprorelin solid implants had potential annual cost savings/1000 patients of €353,000 (EU5) and €699,000 (Sweden; 1-month formulations), and €259,000 (EU5) and €300,000 (Sweden; 3-month formulations).

CONCLUSION

The leuprorelin solid implant was associated with potential cost savings compared with the most commonly used LHRH agonist preparations.

Detection of hepatotoxicity potential with metabolite profiling (metabolomics) of rat plasma

While conventional parameters used to detect hepatotoxicity in drug safety assessment studies are generally informative, the need remains for parameters that can detect the potential for hepatotoxicity at lower doses and/or at earlier time points. Previous work has shown that metabolite profiling (metabonomics/metabolomics) can detect signals of potential hepatotoxicity in rats treated with doxorubicin at doses that do not elicit hepatotoxicity as monitored with conventional parameters. The current study extended this observation to the question of whether such signals could be detected in rats treated with compounds that can elicit hepatotoxicity in humans (i.e., drug-induced liver injury, DILI) but have not been reported to do so in rats. Nine compounds were selected on the basis of their known DILI potential, with six other compounds chosen as negative for DILI potential. A database of rat plasma metabolite profiles, MetaMap(®)Tox (developed by metanomics GmbH and BASF SE) was used for both metabolite profiles and mode of action (MoA) metabolite signatures for a number of known toxicities. Eight of the nine compounds with DILI potential elicited metabolite profiles that matched with MoA patterns of various rat liver toxicities, including cholestasis, oxidative stress, acetaminophen-type toxicity and peroxisome proliferation. By contrast, only one of the six non-DILI compounds showed a weak match with rat liver toxicity. These results suggest that metabolite profiling may indeed have promise to detect signals of hepatotoxicity in rats treated with compounds having DILI potential.

Advances in androgen receptor targeted therapy for prostate cancer

Prostate cancer (PCa) is the second leading cause of cancer death in men. Current research findings suggest that the androgen receptor (AR) and its signaling pathway contribute significantly to the progression of metastatic PCa. The AR is a ligand activated transcription factor, where androgens such as testosterone (T) and dihydroxytestosterone (DHT) act as the activating ligands. However in many metastatic PCa, the AR functions promiscuously and is constitutively active through multiple mechanisms. Inhibition of enzymes that take part in androgen synthesis or synthesizing antiandrogens that can inhibit the AR are two popular methods of impeding the androgen receptor signaling axis; however, the inhibition of androgen-independent activated AR function has not yet been fully exploited. This article focuses on the development of emerging novel agents that act at different steps along the androgen-AR signaling pathway to help improve the poor prognosis of PCa patients.

Effect of abiraterone acetate on fatigue in patients with metastatic castration-resistant prostate cancer after docetaxel chemotherapy

BACKGROUND

Fatigue is a common, debilitating side-effect of prostate cancer and its treatment. Patient-reported fatigue was evaluated as part of COU-AA-301, a randomized, placebo-controlled, phase III trial of abiraterone acetate and prednisone versus placebo and prednisone in metastatic castration-resistant prostate cancer (mCRPC) patients after docetaxel chemotherapy. This is the first phase III study in advanced prostate cancer to evaluate fatigue outcomes using a validated fatigue-specific instrument.

PATIENTS AND METHODS

The Brief Fatigue Inventory (BFI) questionnaire was used to measure patient-reported fatigue intensity and fatigue interference with activities of daily life. All analyses were conducted using prespecified responder definitions of clinically meaningful changes.

RESULTS

A total of 797 patients were randomized to abiraterone acetate and prednisone, and 398 were randomized to placebo and prednisone. Compared with prednisone alone, in patients with clinically significant fatigue at baseline, abiraterone acetate and prednisone significantly increased the proportion of patients reporting improvement in fatigue intensity (58.1% versus 40.3%, P = 0.0001), improved fatigue interference (55.0% versus 38.0%, P = 0.0075), and accelerated improvement in fatigue intensity (median 59 days versus 194 days, P = 0.0155).

CONCLUSIONS

In patients with mCRPC progressing after docetaxel chemotherapy, abiraterone acetate and prednisone yielded clinically meaningful improvements in patient-reported fatigue compared with prednisone alone.

New Agonist- and Antagonist-Based Treatment Approaches for Advanced Prostate Cancer

Increased understanding of prostate cancer biology has led to new treatment strategies and promising new agents for treating prostate cancer, in particular peptide-based agonists and antagonists. In this review article, new therapy modalities and potential approaches for the treatment of advanced prostate cancer are discussed, including agonists and antagonists of luteinizing hormone-releasing hormone, antagonists of bombesin/gastrin-releasing peptide, and growth hormone-releasing hormone and somatostatin analogues. Though the prognosis of patients with prostate cancer is much improved by some of these treatment approaches, including combination treatment methods, extensive side-effects are still reported. These include sexual dysfunction, functional lesions of the liver and renal system, osteoporosis, anaemia and diarrhoea. Future studies should focus on new treatment agents and treatment approaches that can eliminate side-effects and improve quality of life in patients with prostate cancer on the basis of potent treatment efficacy.