Aromatase inhibitors for the treatment of endometriosis: a systematic review about efficacy, safety and early clinical development

Effect of a single dose of letrozole on ejaculation time, semen quality, and testicular hemodynamics in goat bucks subjected to heat stress

Letrozole (LTZ) is an aromatase inhibitor that limits estrogen (E2) production and increases testosterone (T) levels. This research aimed to examine the impact of a single dose of LTZ on testicular hemodynamics, ejaculation time, and semen quality in goats under heat stress (HS). Therefore, Doppler examination and semen evaluation were performed on twelve mature bucks for two weeks (W-1, W-2) as pre-heat stress control during winter. Then during summer HS bucks were subjected to Doppler examination, semen evaluation, and hormonal analysis (T, E2, and LH) at 0 h. Afterward, bucks were assigned into two groups and subcutaneously injected with physiological saline (n = 6; CON) or LTZ (0.25 mg/kg BW; n = 6; LTZ). Both groups were subjected to Doppler scanning and hormonal analysis at 2, 4, 24, 48, 72, 96,144, and 168 h. Semen evaluation was performed at 48 and 168 h. The LTZ group showed increasing (P < 0.05) in semen volume, sperm motility, and viability and decreasing (P < 0.05) in ejaculation time and sperm abnormalities compared to CON group at 48 h. Additionally, T concentrations increased (P < 0.01) at 2, 24, and 48 h, E2 decreased (P < 0.01) from 2 to 48 h, and LH raised (P < 0.01) at 2 and 72 h in LTZ group compared to CON one. Doppler indices reduced (P < 0.05) at 96 h in LTZ group. semen pH and scrotal circumference were not affected by LTZ. In conclusion, LTZ administration shortened ejaculation time and enhanced semen quality in bucks during HS.

Structure-Guided Identification of Novel Aromatase Inhibitors Targeting Breast Carcinoma

Aromatase inhibitors play a critical therapeutic role in treating ER+ breast cancer, especially in postmenopausal women. However, their efficacy is often limited by resistance and severe side effects. Identifying new compounds that can disrupt aromatase enzyme function is essential. In this study, structural anomalies in the aromatase enzyme were corrected through energy minimization, and the structure was validated via Ramachandran plot. We screened 170,269 natural compounds from the ASINEX Biodesign library using high-throughput screening algorithms to target the aromatase enzyme. Molecular docking identified three compounds: BDD30170158, BDE33872639, and BDE30177677, all showing stable binding interactions with the aromatase enzyme. Molecular dynamics simulations over 100 ns confirmed the conformational stability of these compounds. Although all three compounds exhibited the desired pharmacokinetic and drug metabolism properties, only one compound (BDE33872639) was identified as a non-blocker, demonstrating a reduced risk of adverse cardiac effects. This compound exhibits significant potential as a novel aromatase inhibitor, warranting further experimental research to develop it as a therapeutic option for ER+ breast cancer.

Hormonal Therapies before in vitro fertilization in women with endometriosis: The Minotaur's Labyrinth and the Ariadne's Thread

Endometriosis-related infertility is one of the most debated topics in reproductive medicine. In recent years, prolonged pre-cycle hormonal regimens gained attention as a mean of improving the assisted reproduction technologies (ART) success rates in endometriosis patients. GnRH agonists, dienogest, medroxyprogesterone acetate, and aromatase inhibitors are the most studied medications. Conflicting results and a high risk of bias exist in almost all of the conducted studies in the field. However, current evidence suggests that pre-cycle treatment with GnRH agonists may be beneficial for patients with stage III/IV endometriosis. Dienogest and medroxyprogesterone acetate-based progestin-primed ovarian stimulation protocol was shown to be comparable to the prolonged GnRH agonists protocol. Finally, aromatase inhibitors seem to be of limited benefit to the assisted reproductive outcomes of endometriosis patients. Although it is challenging to draw any clinical conclusions, pre-cycle hormonal treatments seem to be best indicated in endometriosis patients who had previously failed ART treatment.

Breaking the silence: The role of extracellular vesicles in unraveling the diagnosis and treatment of endometriosis

Cell-to-cell communication is believed to be facilitated by membrane-bound vesicles called extracellular vesicles (EVs), which are released by cells. Protein, lipids, and nucleic acids are major cargo of EVs and are transported in these vesicles. Depending on the parent and recipient cell types, they can affect a wide variety of biological processes in the tissues to which they are delivered. EVs are essential for embryo implantation and endometriosis, and they are located in the uterine cavities of different species, where they promote blastocyst and endometrial preparation for implantation. This review focuses on what is currently understood regarding pathologic and diagnostic characteristics, and the potential therapeutic value of EVs in the context of endometriosis, where they can be used for drug delivery and targeted therapy due to their ability to carry bioactive molecules to specific cells or tissues. The findings of this review highlight the potential for a wide range of clinical applications that involve endometrial EVs in the areas of treatment, such as surgical and pharmacological, diagnostic biomarker development, and drug delivery systems, all with the ultimate goal of improving pregnancy success rates.

Clinical Efficacy, Pharmacokinetics, and Safety of the Available Medical Options in the Treatment of Endometriosis-Related Pelvic Pain: A Scoping Review

BACKGROUND

In this scoping review, we sought to identify published studies evaluating the drugs currently used in the treatment of endometriosis-related pelvic pain, with reflection on their chemical properties, pharmacokinetics, safety profile, and clinical efficacy.

METHODS

A literature search was conducted with the use of the PubMed and EMBASE electronic databases, focusing on identifying articles published in English between January 1990 and 2023.

RESULTS

Based on the included studies, current therapy options for the treatment of endometriosis-related pain identified and reviewed in this article were: (1) non-steroidal anti-inflammatory drugs; (2) combined oral contraceptive (COCs); (3) progestins; (4) gonadotropin-releasing hormone agonists and antagonists; (5) aromatase inhibitors (AIs); (6) selective estrogen and progesterone receptor modulators; and (7) levonorgestrel-intrauterine device.

CONCLUSIONS

Based on the published evidence, clinicians should consider NSAIDs, COCs, and progestins as the first-line medical therapies. Compared with second-line options, such as GnRH agonists/antagonists or AIs, the abovementioned first-line options are well tolerated, efficacious, and exhibit lower overall price. Future research priorities should be to identify novel target therapies and to evaluate the effects of available drugs through different routes of administration.

Aromatase inhibitors in the pharmacotherapy of endometriosis

INTRODUCTION

Endometriosis is a benign chronic inflammatory disease responsible for debilitating pain and decreased quality of life. The traditional treatment is based on estroprogestins, progestins, GnRH analogues and surgery. Recently aromatase inhibitors (AIs) demonstrated good efficacy in controlling symptoms and size of endometriotic implants, mostly because they suppress extraovarian estrogen synthesis, which can enhance the hypoestrogenic state ameliorating symptoms of endometriosis.

AREAS COVERED

Phase I, II, III and IV trials, on the use of AIs used for the treatment of endometriosis have been retrieved. The pharmacokinetics and pharmacodynamics of third generation non-steroidal AIs have also been investigated. a MEDLINE search using the following MeSH keywords: "endometriosis", "aromatase inhibitors", "therapy", "treatment" has been performed. The timeframe was from 2010 up to November 2022 including reviews, systematic reviews, reports, case series, and retrospective or prospective trials.

EXPERT OPINION

AIs have shown good clinical efficacy in combination with hormonal therapy in disease control, and they represent a promising second line therapy in selected patients yet more research is needed on alternative drug delivery systems and better control of adverse effects. In postmenopausal women in which surgery is contraindicated, AIs represent an excellent treatment option. Their application in routine clinical practice remains limited by adverse effects.

A Systematic Review of Systematic Reviews on the Use of Aromatase Inhibitors for the Treatment of Endometriosis: The Evidence to Date

Endometriosis is a chronic gynecologic condition that affects around 6-10% of reproductive age women. This clinical entity is characterized with pelvic pain, dysmenorrhea, dyspareunia, and infertility which are the most often presenting symptoms. Aromatase P450 is the key enzyme for ovarian estrogen biosynthesis and there is evidence that endometriotic lesions express aromatase and are able to synthesize their own estrogens. Aromatase inhibitors (AIs) are potent drugs that suppress the estrogen synthesis via suppression of aromatase. We performed a systematic review of systematic reviews and narrative reviews on the use of aromatase inhibitors in the medical management of endometriosis. We searched: PubMed (1950-2022), Google Scholar (2004-2022), Cochrane Library (2010-2022) and Researchgate (2010-2022). The search included the following medical subject headings (MeSH) or keywords: "Aromatase Inhibitors" AND "Endometriosis" AND "Systematic reviews" OR "Systematic review" AND "Reviews" OR "Reviews" AND "Endometriosis". The electronic database search yielded initially 12,106 studies from the different databases. Further assessment of the studies resulted in exclusion of (n = 12,015) studies due to duplicates and irrelevance; Finally, 24 studies were selected for inclusion, 5 were Systematic reviews and 19 were Narrative reviews. The 5 systematic reviews were assessed by AMSTAR-2 criteria and were found to have low quality. Narrative reviews were assessed with SANRA criteria and were found to have high-quality aromatase inhibitors are potent drugs that can manage the endometriosis-related symptoms in cases where initial medical management has failed to show positive results. However, their use is limited by the adverse effects that are linked with menopausal symptoms. aromatase inhibitors can be administered as an alternative treatment in patients. Future studies with randomized design are required to reach safer conclusions and further investigation. These studies should define the therapeutic dose, new add-back therapy modalities. Future directions should examine the most-appropriate way of administration and the duration of therapy.

Advances in targeting estrogen synthesis and receptors in patients with endometriosis

INTRODUCTION

Endometriosis is an estrogen-dependent disease on the background of progesterone resistance. Increased estrogen production, low estrogen metabolization, and altered estrogen receptors (ERs) expression contribute to the hyperestrogenic milieu within endometriotic lesions. Since estrogens play a crucial role in the pathogenesis of the disease, inhibition of estrogen production is one of the main targets of available and emerging drugs.

AREAS COVERED

Firstly, we described the molecular alterations responsible for estrogen dependence. Secondly, we reviewed available and emerging treatments that interfere, through central (gonadotropin-releasing hormone analogs (GnRH-a), GnRH antagonists) or local mechanisms (aromatase inhibitors (AIs), inhibitors of steroid sulfatase (STS) and hydroxysteroid dehydrogenase type 1 (17β-HSD1)), with estrogen dependence. Finally, we focused on emerging treatments targeting ERs (selective estrogen receptor modulators (SERMs), estrogen receptors agonists, and antagonists).

EXPERT OPINION

Available treatments interfering with estrogen pathways exert a contraceptive effect, have hypoestrogenic side effects, and cannot prevent or definitively treat the disease. Preclinical and animal studies are focusing on emerging drugs targeting ERs in order to overcome limitations of available treatments. These treatments may represent a promising option, as they may produce a more specific inhibition of disease activity within endometriotic implants, avoiding prolonged hypoestrogenic status and limiting systemic side effects.

CTLA4-Linked Autoimmunity in the Pathogenesis of Endometriosis and Related Infertility: A Systematic Review

Several studies, although with conflicting results, have sought to determine the concentration of soluble CTLA4 antigens in peripheral blood plasma and peritoneal fluid in patients with endometriosis-related infertility. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) through a search of the following databases: MEDLINE, EMBASE, Global Health, The Cochrane Library, Health Technology Assessment Database and Web of Science, and Clinical Trials research register. We included observational or prospective human and animal studies with any features related to endometriosis and/or infertility studies involving CTLA4-related pathogenesis published in English. The results of studies in which the size and characteristics of the observed groups were not stated were excluded. From the initial pool of 73 publications identified and screened, we finally included 5 articles to summarize the most recent knowledge about CTLA4-linked autoimmunity in the pathogenesis of endometriosis and related infertility. Evidence from clinical studies shows that CTLA4-based autoimmunity is involved in the maintenance of chronic inflammation in the peritoneal environment, with pre-clinical evidence of anti-CTLA antibodies as a potential novel target therapy for endometriosis. However, CTLA4 gene analyses do not support findings of CTLA4-linked autoimmunity as a primary determinant of the pathogenesis of endometriosis. These findings underlie the role of complex interactions within the family of immune checkpoint molecules involved. Further studies are needed to investigate the clinical relevance of anti-CTLA target therapy, taking into account the potential adverse events and repercussions of novel immunologic therapy modalities. However, with the general scarcity of studies investigating this topic, the clinical importance of CTLA4 autoimmunity still remains unclear.

Uterine leiomyoma is associated with the risk of developing endometriosis: A nationwide cohort study involving 156,195 women

Objective

Evidence for an association between uterine leiomyoma and increased risk of endometriosis is limited by small sample sizes and short follow-up periods. We assessed this association in a large nationwide sample with 14 years of data.

Design

Data were sourced from Taiwan’s Longitudinal Health Insurance Database 2000 (LHID2000).

Materials and methods

We identified 31,239 women aged ≥20 years diagnosed with uterine leiomyoma (International Classification of Disease, Ninth Revision, Clinical Modification [ICD-9-CM] code 218) between Jan 1, 2000 and Dec 31, 2012, who were matched with 124,956 controls (1:4) by 5-year age groups and year of diagnosis. Follow-up was from the date of LHID2000 entry to the first occurrence of endometriosis, loss to follow-up, insurance termination, or until December 31, 2013, whichever was earlier.

Results

In Cox regression analysis, the adjusted hazard ratio (aHR) for endometriosis in women with uterine leiomyoma was 6.44 (95% CI, 6.18, 6.72) compared with controls. The risk of endometriosis was significantly increased in women with uterine leiomyoma and comorbidities of tube-ovarian infection (aHR 2.86; 95% CI, 1.28, 6.36), endometritis (1.14; 1.06, 1.24), infertility (1.26; 1.16, 1.37), or allergic diseases (1.11; 1.05, 1.17). Having both uterine leiomyoma and endometritis significantly increased the risk of endometriosis (aHR 6.73; 95% CI, 6.07, 7.45) versus having only uterine leiomyoma (6.61; 6.33, 6.91) or endometritis (1.49; 1.31, 1.69). Similarly, having both uterine leiomyoma and infertility significantly increased the risk of endometriosis (aHR 6.95; 95% CI, 6.21, 7.78) versus having only uterine leiomyoma (6.66; 6.38, 6.96) or infertility (1.78; 1.57, 2.02).

Conclusions

A diagnosis of uterine leiomyoma appears to increase the risk of endometriosis. Patients presenting with uterine fibroids should be encouraged to give informed consent for possible simultaneous surgical treatment of endometriosis.

Linzagolix: a new GnRH-antagonist under investigation for the treatment of endometriosis and uterine myomas

INTRODUCTION

Uterine myomas and endometriosis are benign hormone-dependent diseases affecting women of reproductive age. Substantial efforts have been made to develop innovative medical options for treating these gynecologic diseases. Elagolix and relugolix have been approved in some countries for treating endometriosis and myomas, respectively; however, linzagolix (OBE 2109, KLH 2109) is a new oral gonadotropin-releasing hormone (GnRH) antagonist in phase II-III trials. Treatment options for women with contraindications for hormonal therapies or who refuse particular options, are the driving force behind the development of new drugs in this area.

AREA COVERED

This drug evaluation highlights definitive and preliminary results from previous and ongoing studies of linzagolix for the treatment of endometriosis and myomas.

EXPERT OPINION

Linzagolix showed a dose-dependent and rapidly reversible action on the pituitary-gonadal axis. In a recent phase II trial (EDELWEISS), linzagolix significantly reduced pain related to endometriosis and improved quality of life at single daily doses of 75-200 mg. The preliminary results of international, double-blind phase III trials (PRIMROSE 1 and 2) reported its efficacy in treating heavy menstrual bleeding related to myomas with a good safety profile. Further studies will determine the necessity of add-back therapy during long-term use of linzagolix.

LigAdvisor: a versatile and user-friendly web-platform for drug design

Although several tools facilitating in silico drug design are available, their results are usually difficult to integrate with publicly available information or require further processing to be fully exploited. The rational design of multi-target ligands (polypharmacology) and the repositioning of known drugs towards unmet therapeutic needs (drug repurposing) have raised increasing attention in drug discovery, although they usually require careful planning of tailored drug design strategies. Computational tools and data-driven approaches can help to reveal novel valuable opportunities in these contexts, as they enable to efficiently mine publicly available chemical, biological, clinical, and disease-related data. Based on these premises, we developed LigAdvisor, a data-driven webserver which integrates information reported in DrugBank, Protein Data Bank, UniProt, Clinical Trials and Therapeutic Target Database into an intuitive platform, to facilitate drug discovery tasks as drug repurposing, polypharmacology, target fishing and profiling. As designed, LigAdvisor enables easy integration of similarity estimation results with clinical data, thereby allowing a more efficient exploitation of information in different drug discovery contexts. Users can also develop customizable drug design tasks on their own molecules, by means of ligand- and target-based search modes, and download their results. LigAdvisor is publicly available at https://ligadvisor.unimore.it/.

The Search for Biomarkers in Endometriosis: a Long and Windy Road

Endometriosis is a complex and chronic estrogen-dependent disease, affecting a significant proportion of women of reproductive age. Despite the long interest and extensive research, the pathogenesis of the disease is still debated. Although available non-invasive diagnostic methods have adequate accuracy, an invasive approach by laparoscopy is often necessary to obtain histological confirmation. In this scenario, the search for an accurate, reliable, cost-effective, clinically applicable non-invasive biomarker plays a crucial role in a potentially early diagnosis and, in this way, shape the future management of the disease. Considering these elements, the current review aims to summarize the most significant and novel results about biomarkers for the diagnosis and follow-up of women affected by endometriosis.

Clinico-pathological assessment of surgically removed abdominal wall endometriomas following cesarean section

BACKGROUND

Over the past few decades, the rate of Cesarean Section (CS) delivery has been rising rapidly and the prevalence of CS-associated complications including Abdominal Wall Endometriomas (AWE) increases with each additional operation. The aim of this study was to evaluate the clinical characteristics, histopathological diagnostic role and surgical management of post-CS AWE through a retrospective case review.

METHODS

We calculated the incidence of AWE and reviewed all the patients underwent surgical removal of Post-CS AWE during the period of 2012-2018 who were diagnosed, treated and followed up for 2-8 years at our tertiary hospital.

RESULTS

Thirty women with AWE were included. The main symptom in 2/3 of cases was cyclic pain and 4 cases (13.3%) had no symptoms. The mean interval between prior CS and appearance of symptoms was 55.2 months and the mean size of the excised mass was 42 mm. Free surgical margin was less than 9 mm in 9 patients (30%) but no recurrence was recorded among all the studied patients. Pre-operative FNAC diagnosis was performed for only 3 patients (10%) which helped in excluding other potential pathologies. The clinical-pathological agreement value for detection of the nature of the abdominal wall mass was 93.4%.

CONCLUSIONS

Patients with suspected AWE should undergo preoperative cytological biopsy to exclude alternative diagnosis. Wide surgical excision with margin of less than 1 cm could be accepted especially in case of weak abdominal wall. More studies on the post-CS complications; risks, prevention, early detection and proper management should be encouraged.