Efficacy of elagolix in the treatment of endometriosis

Post-marketing safety concerns with elagolix: a disproportionality analysis of the FDA adverse event reporting system

OBJECTIVE

Elagolix is approved for the treatment of moderate-to-severe pain associated with endometriosis. However, the long-term safety of elagolix in a large sample of real-world patients is unknown.

METHODS

The U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) reports were collected and analyzed from January 2019 to June 2023. Disproportionality analyses, including the reporting odds ratio (ROR), the proportional reporting ratio (PRR), the Bayesian confidence propagation neural network (BCPNN), and the multi-item gamma Poisson shrinker (MGPS) algorithms, were employed in data mining to quantify the signals of elagolix-related adverse events (AEs).

RESULTS

After removing the non-drug-related AE signals, we detected several AE signals such as hot flushes, bone pain, suicidal ideation, depression, and increased liver enzymes, which were known during the clinical trial phase. In addition to this, we detected several unexpected important AEs that were not mentioned in the drug insert, including cystitis interstitial, parosmia, and epiploic appendagitis. The median onset time of elagolix-associated AEs was 28.5 days.

CONCLUSION

Our study provides a comprehensive picture of the safety of elagolix in the post-marketing setting, while also identifying potential new AE signals. These findings emphasize the importance of continued monitoring of the potential risks of elagolix.

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.

The latest advances in the pharmacological management of endometriosis

INTRODUCTION

Endometriosis is a benign disease, characterized by a wide range of symptoms and different degrees of severity, which is why therapy should be individually adapted to the patient's needs. Over the years, a lot of research has gone into finding new therapeutic approaches for this enigmatic disease.

AREAS COVERED

This review presents the latest advances in pharmacological management of endometriosis and is solely focused on studies published from 2010 to 2021.

EXPERT OPINION

Clinicians and researchers are constantly searching for new therapeutic strategies for endometriosis patients. As there are well-established treatments, however, any new medication should fulfill at least one of the three criteria: increased efficacy, comparable efficacy but a better safety profile, or treatments that have a lack of accompanying contraceptive effects that are seen in most endometriosis treatments. While some new substances show promising results, further studies are needed to demonstrate the fulfillment of one of the above-mentioned criteria.

Ultra-sensitive and selective fluorescence approach for estimation of elagolix in real human plasma and content uniformity using boron-doped carbon quantum dots

Elagolix (ELX) is an orally administered non-peptidic GnRH antagonist that has been approved by the Food and Drug Administration in 2018 for the treatment of endometriosis pain. A sensitive and selective method for estimating elagolix (ELX) in human plasma and content uniformity was developed and validated. The spectrofluorimetric technique was used to investigate ELX utilizing boron-doped carbon quantum dots (B@CQDs). After gradually adding ELX, the quantum dots fluorescence was enhanced with LOQ of 1.74 ng mL⁻¹, the calibration curve between ELX and corresponding fluorescence intensity was found over a range of 4–100 ng mL⁻¹. The method was successfully applied in real human plasma with pharmacokinetic study and content uniformity test. The pharmacokinetic parameters as C_max were found to be 570 ± 5.32 ng. mL⁻¹ after 1 h, t_1/2 was found to be 6.50 h, and AUC was found to be 1290 ± 30.33 ng. h. mL⁻¹. B@CQDs were characterized using variety of instruments. The strategy is simple to implement in clinical labs and therapeutic drug monitoring systems.

Concurrent Benign Metastasizing Leiomyoma in the Abdominal Wall and Pelvic Cavity: A Case Report and Review of the Literature

Benign metastatic leiomyoma (BML) is a histologically benign disease with invasive biological behavior. Most patients are women of childbearing age with a history of uterine leiomyoma. The progress of the disease is relatively slow, the prognosis is good, and most patients can survive for a long time. The lung is the common metastatic site, and BML with metastatic lesions outside the lung is very rare. A 37-year-old woman with multiple BML in the abdominal wall and pelvic cavity after uterine leiomyoma surgery was admitted to our hospital. Combined with the clinical data of this case and reviewing the relevant literature, this paper discusses the pathological characteristics, diagnosis, differential diagnosis, and treatment of BML.

Current approaches to overcome the side effects of GnRH analogs in the treatment of patients with uterine fibroids

Introduction: Uterine fibroids (UFs) are the most prevalent benign neoplastic threat originating from myometria of reproductive age women, with a profound financial load valued in hundreds of billions of dollars. Unfortunately, there is no curative treatment so far except surgery and available pharmacological treatments are restricted for short-term treatment options. Thus, there is a large unmet need in the UF space for noninvasive therapeutics.Areas covered: The authors reviewed the literature available for the utility of gonadotropin-releasing hormone (GnRH) analogs in women with UFs. We also focused on clinical studies exploring the therapeutic benefits of novel oral non-peptide GnRH antagonists that were recently approved by the U.S. Food and Drug Administration (FDA) in combination with estradiol/norethindrone acetate for the management of heavy menstrual bleeding associated with UFs in premenopausal women.Expert opinion: The results regarding the efficacy of new-generation oral GnRH-antagonists, such as elagolix, relugolix and linzagolix, are promising and offer potential prospect for the future therapy of UFs. However, these antagonists must be combined with hormonal add-back therapy to minimize the resultant hypoestrogenic side effects such as bone loss.

Regiodivergent and stereoselective hydroxyazidation of alkenes by biocatalytic cascades

Asymmetric functionalization of alkenes allows the direct synthesis of a wide range of chiral compounds. Vicinal hydroxyazidation of alkenes provides a desirable path to 1,2-azidoalcohols; however, existing methods are limited by the control of stereoselectivity and regioselectivity. Herein, we describe a dual-enzyme cascade strategy for regiodivergent and stereoselective hydroxyazidation of alkenes, affording various enantiomerically pure 1,2-azidoalcohols. The biocatalytic cascade process is designed by combining styrene monooxygenase-catalyzed asymmetric epoxidation of alkenes and halohydrin dehalogenase-catalyzed regioselective ring opening of epoxides with azide. Additionally, a one-pot chemo-enzymatic route to chiral β-hydroxytriazoles from alkenes is developed via combining the biocatalytic cascades and Cu-catalyzed azide-alkyne cycloaddition.

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.

Role of medical treatment of endometriosis

Endometriosis is a chronic benign disease that affects women of reproductive age. Medical therapy is often the first line of management for women with endometriosis in order to ameliorate symptoms or to prevent post-surgical disease recurrence. Currently, there are several medical options for the management of patients with endometriosis and long-term treatments should balance clinical efficacy (controlling pain symptoms and preventing recurrence of disease after surgery) with an acceptable safety-profile. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in the treatment of chronic inflammatory conditions, being efficacious in relieving primary dysmenorrhea. Combined oral contraceptives and progestins, available for multiple routes of administration, are commonly administered as first-line hormonal therapies. Several studies demonstrated that they succeed in improving pain symptoms in the majority of patients; moreover, they are well tolerated and not expensive. Gonadotropin-releasing hormone-agonists are prescribed when first line therapies are ineffective, not tolerated or contraindicated. Even if these drugs are efficacious in treating women not responding to COCs or progestins, they are not orally available and have a less favorable tolerability profile (needing an appropriate add-back therapy). Because few data are available on long-term efficacy and safety of aromatase inhibitors they should be reserved only for women with symptoms who are refractory to other treatments only in a research environment. Almost all of the currently available treatment options for endometriosis suppress ovarian function and are not curative. For this reason, research into new drugs is unsurprisingly demanding. Amongst the drugs currently under investigation, gonadotropin-releasing hormone antagonists have shown most promise, currently in late-stage clinical development. There is a number of potential future therapies currently tested only in vitro, in animal models of endometriosis or in early clinical studies with a small sample size. Further studies are necessary to conclude whether these treatments would be of value for the treatment of endometriosis.

Elagolix in the treatment of heavy menstrual bleeding associated with uterine fibroids in premenopausal women

INTRODUCTION

Uterine fibroids (UFs) are the most common benign tumor arising from myometrium of reproductive age women, with significant financial burden estimated in hundreds of billions of dollars. Unfortunately, there are limitations in available long-term treatment options. Thus, there is a large unmet need in the UF space for noninvasive therapeutics.

AREAS COVERED

Authors reviewed the literature available for elagolix; an orally bioavailable, second-generation, non-peptide gonadotropin-releasing hormone (GnRH) antagonist recently approved by the US Food and Drug Administration (FDA) in combination with estradiol/norethindrone acetate for the management of heavy menstrual bleeding associated with UFs in premenopausal women.

EXPERT OPINION

The utility of new-generation oral GnRH-antagonists, such as elagolix, relugolix and linzagolix, is offering a new potential opportunity for the future therapy of UFs: elagolix has been the most studied drug of this class for treating benign gynecological diseases, including endometriosis and UFs, for which it has been US FDA-approved in 2018 and 2020, respectively.

Structure of the human gonadotropin-releasing hormone receptor GnRH1R reveals an unusual ligand binding mode

Gonadotrophin-releasing hormone (GnRH), also known as luteinizing hormone-releasing hormone, is the main regulator of the reproductive system, acting on gonadotropic cells by binding to the GnRH1 receptor (GnRH1R). The GnRH-GnRH1R system is a promising therapeutic target for maintaining reproductive function; to date, a number of ligands targeting GnRH1R for disease treatment are available on the market. Here, we report the crystal structure of GnRH1R bound to the small-molecule drug elagolix at 2.8 Å resolution. The structure reveals an interesting N-terminus that could co-occupy the enlarged orthosteric binding site together with elagolix. The unusual ligand binding mode was further investigated by structural analyses, functional assays and molecular docking studies. On the other hand, because of the unique characteristic of lacking a cytoplasmic C-terminal helix, GnRH1R exhibits different microswitch structural features from other class A GPCRs. In summary, this study provides insight into the ligand binding mode of GnRH1R and offers an atomic framework for rational drug design.

Medical therapy options for endometriosis related pain, which is better? A systematic review and network meta-analysis of randomized controlled trials

Our objective was to assess and rank different pharmacological interventions for relieving endometriosis-related pain. We conducted an online bibliographic search in different databases from their inception until March 2019. We included randomized controlled trials (RCTs) that assessed different medical therapies in the management of endometriosis-related pain. We applied this network meta-analysis (NMA) based on the frequentist approach using statistical package "netmeta" (version 1.0-1) in R software. Our main outcomes were the change in severity of pelvic pain, dysmenorrhea score, non-menstrual pelvic pain score, and dyspareunia score. Overall, 36 RCTs were included in this study (patients no. = 7942). Dienogest (0.94), combined hormonal contraceptives (CHCs) (0.782), and elagolix (0.38) were the highest-ranked interventions for reducing the severity of pelvic pain at three months, while at six months, gonadotropin-releasing hormone (GnRH) analogues (0.75), levonorgestrel-releasing intrauterine system (LNG-IUS) (0.73), and dienogest (0.65) were linked to more reduction in pelvic pain. The ranking p-score showed that GnRH analogues was the highest-ranked treatment for reducing dysmenorrhea at 3 months (1.00), while CHCs were the highest-ranked treatment at 6 months (0.97), followed by GnRH analogues (0.89). GnRH analogues (0.63) and elagolix (0.54) at three months while desogestrel (0.94) and CHCs (0.91) at six months were the highest-ranked treatment to reduce non-menstrual pelvic pain. GnRH analogues and elagolix were the highest-ranked pharmacologic therapies for reducing dyspareunia. In conclusion, CHCs, GnRH analogues, progesterone, and elagolix were the best approaches in reducing the pain of endometriosis.

Investigational drugs for the treatment of endometriosis, an update on recent developments

INTRODUCTION

Endometriosis is a hormone-dependent benign chronic disease that requires a chronic medical therapy. Although currently available drugs are efficacious in treating endometriosis-related pain, some women experience partial or no improvement. Moreover, the recurrence of symptoms is expected after discontinuation of the therapies. Currently, new drugs are under intense clinical investigation for the treatment of endometriosis.

AREAS COVERED

This review aims to offer the reader a complete and updated overview on new investigational drugs and early molecular targets for the treatment of endometriosis. The authors describe the pre-clinical and clinical development of these agents.

EXPERT OPINION

Among the drugs under investigation, late clinical trials on gonadotropin-releasing hormone antagonists (GnRH-ant) showed the most promising results for the treatment of endometriosis. Aromatase inhibitors (AIs) are efficacious in treating endometriosis related pain symptoms but they cause significant adverse effects that limit their long-term use. New targets have been identified to produce drugs for the treatment of endometriosis, but the majority of these new compounds have only been investigated in laboratory studies or early clinical trials. Thus, further clinical research is required in order to elucidate their efficacy and safety in human.

Alternative Oral Agents in Prophylaxis and Therapy of Uterine Fibroids-An Up-to-Date Review

Uterine fibroids (UFs) are the most common tumors of the female genital tract. The effect of UFs on the quality of life and the overall cost of treatment are significant issues worldwide. Tumor size and location are the two specific factors which influence the occurrence of symptoms, the need for, and method of, treatment (some tumors require surgery while some can be treated with selected drugs). Primary prevention and treatment of early UF disease are worthy goals that might have a great impact on health care systems. Several treatments and prophylactic methods can be used in this endeavor. This publication presents current data about lesser-known substances which may have a beneficial effect on the treatment or prophylaxis of UFs and can be administered orally, serving as an alternative to (or complement of) surgery or selective progesterone receptor modulators (SPRMs). Early prevention and treatment of UFs in women from high-risk groups should be our priority. Innovative forms of UF management are under intensive investigation and may be promising options in the near future. Many of them evaluated vitamin D, paricalcitol, epigallocatechin gallate (EGCG), elagolix, aromatase inhibitors (AIs), and cabergoline and deemed them to be safe and effective. The next step in such projects should be properly constructed randomized control trials (RCTs), carried out by successive phases.