GnRH-antagonists in reproductive medicine

Elagolix treatment in women with heavy menstrual bleeding associated with uterine fibroid: a systematic review and meta-analysis

Background

Elagolix is effective and safe for treating menorrhagia in women with uterine fibroid. However, it is reported to be associated with hypoestrogenism that can be alleviated by adding estradiol/norethindrone acetate. This systematic review and meta-analysis aimed to determine the effectiveness of elagolix treatment in women with heavy menstrual bleeding associated with uterine fibroid by comparing: elagolix versus placebo and elagolix versus estradiol/norethindrone acetate.

Methodology

The Cochrane Central Register of Controlled Trials (CENTRAL 2021, Issue 3 of 12), MEDLINE databases (1980 to December week 1, 2020), and trial registries for relevant randomized clinical trials were used. All randomized clinical trials were reviewed and evaluated. Random effects models were used to estimate the dichotomous outcomes and mean differences with 95% confidence intervals. Data for risk of bias, heterogeneity, sensitivity, reporting bias and quality of evidence were assessed.

Results

Four randomized controlled trials with 1949 premenopausal women from 323 locations were included. Elagolix improved menstrual blood loss of less than 80 ml (RR 4.81, 95% CI 2.45 to 9.45; four trials, 869 participants; moderate quality evidence) or more than 50% reduction from baseline (RR 4.87, 95% CI 2.55 to 9.31; four trials, 869 participants; moderate quality evidence) compared to placebo. There was no difference in menstrual blood loss of less than 80 ml (RR 1.08, 95% CI 1.00 to 1.16; five trials, 1365 participants; moderate quality evidence) or more than 50% reduction from baseline between the elagolix (RR 1.08, 95% CI 1.01 to 1.15; five trials, 1365 participants; high quality evidence) and elagolix with estradiol/norethindrone acetate. In both comparisons, elagolix has reduced the mean percentage change in uterine and fibroid volume, improved symptoms, and health-related quality of life. More patients had hot flush, and bone mineral density loss in the elagolix treatment compared to both placebo and elagolix with estradiol/norethindrone acetate.

Conclusions

Elagolix appeared to be effective in reducing heavy menstrual bleeding caused by uterine fibroid and combination with estradiol/norethindrone acetate was able to alleviate the hypoestrogenism side effects in premenopausal women.

Review registration

PROSPERO CDR 42021233898.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01596-2.

Mild and Expeditious Synthesis of Sulfenyl Enaminones of l-α-Amino Esters and Aryl/Alkyl Amines through NCS-Mediated Sulfenylation

Sulfenylation or selenylation of enaminones of l-α-amino esters requires mild reaction conditions due to the presence of a racemization-prone chiral center and reactive side chains. An N-chlorosuccinimide (NCS)-mediated methodology has been developed for rapid sulfenylation of enaminones of l-α-amino esters and aryl/alkyl amines at room temperature in open air under metal-free conditions. Enaminones of l-α-amino esters bearing aliphatic, aromatic, and heterocyclic side chains react efficiently with diverse aryl/alkyl/heteroaryl thiols (R1SH) in the presence of NCS to afford a library of biologically important sulfenyl enaminones in good-to-excellent yields (71-90%). Under similar reaction conditions, the enaminones also react with benzeneselenol to produce selenyl enaminones in good yield (73-83%). The NCS-mediated pathway generates sulfenyl chloride (R1SCl) as an intermediate which leads to rapid sulfenylation of enaminones through cross-dehydrogenative coupling (CDC) under mild reaction conditions.

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.

A Premature Rise of Luteinizing Hormone Is Associated With a Reduced Cumulative Live Birth Rate in Patients ≥37 Years Old Undergoing GnRH Antagonist In Vitro Fertilization Cycles

This is a retrospective cohort study included 1021 patients underwent a flexible GnRH antagonist IVF protocol from January 2017 to December 2017 to explore the effect of a premature rise in luteinizing hormone (LH) level on the cumulative live birth rate. All patients included received the first ovarian stimulation and finished a follow-up for 3 years. A premature rise in LH was defined as an LH level >10 IU/L or >50% rise from baseline during ovarian stimulation. The cumulative live birth rate was calculated as the number of women who achieved a live birth divided by the total number of women who had either delivered a baby or had used up all their embryos received from the first stimulated cycle. In the advanced patients (≥37 years), the cumulative live birth rate was reduced in patients with a premature rise of LH (β: 0.20; 95% CI: 0.05-0.88; p=0.03), compared to patients (≥37 years) without the premature LH rise. The incidence of premature LH rise is associated with decreased rates of cumulative live birth rate in patients of advanced age (≥37 years) and aggravated the reduced potential of embryos produced by the advanced age, not the number of embryos.

Differential effects of depot formulations of GnRH agonist leuprorelin and antagonist degarelix on the seminiferous epithelium of the rat testis

Despite their pharmacologically opposite actions, long-acting depot formulations of both GnRH agonists and antagonists have been clinically applied for treatment of androgen-sensitive prostate cancer. Sustained treatment with GnRH analogues commonly suppresses both the synthesis and release of gonadotropins, leading to depletion of testicular testosterone. To clarify the underlying differences in the effects of GnRH agonists and antagonists on spermatogenesis, we compared histological changes in the seminiferous epithelium after administration of depot formulations of GnRH agonist leuprorelin and antagonist degarelix to male rats. Testicular weight had markedly declined by 28 days after administration of both GnRH analogues, although the testicular weight was decreased more promptly by leuprorelin compared with degarelix. Shortly after administration, massive exfoliation of premature spermatids and anomalous multinucleated giant cells was observed in seminiferous tubules of leuprorelin-treated rats, probably via the initial hyperstimulatory effects on the hypothalamic-pituitary-testicular axis, whereas no discernible changes were found in those of degarelix-treated rats. Long term treatment with both types of GnRH analogues similarly induced a marked reduction in the height of the epithelium and deformation of apical cytoplasm in Sertoli cells, resulting in premature detachment of spermatids from the epithelium. Lipid droplets had accumulated progressively in Sertoli cells, especially in those of degarelix-treated rats. These findings clearly demonstrate the differences in the effects of GnRH agonists and antagonists on the spermatogenic process. This study suggests that an appropriate choice of GnRH analogues is necessary to minimize their adverse effects on spermatogenesis when reproductive functions should be preserved in patients.

Maintenance of homeostasis in the aging hypothalamus: the central and peripheral roles of succinate

Aging is the phenotype resulting from accumulation of genetic, cellular, and molecular damages. Many factors have been identified as either the cause or consequence of age-related decline in functions and repair mechanisms. The hypothalamus is the source and a target of many of these factors and hormones responsible for the overall homeostasis in the body. With advanced age, the sensitivity of the hypothalamus to various feedback signals begins to decline. In recent years, several aging-related genes have been identified and their signaling pathways elucidated. These gene products include mTOR, IKK-β/NF-κB complex, and HIF-1α, an important cellular survival signal. All of these activators/modulators of the aging process have also been identified in the hypothalamus and shown to play crucial roles in nutrient sensing, metabolic regulation, energy balance, reproductive function, and stress adaptation. This illustrates the central role of the hypothalamus in aging. Inside the mitochondria, succinate is one of the most prominent intermediates of the Krebs cycle. Succinate oxidation in mitochondria provides the most powerful energy output per unit time. Extra-mitochondrial succinate triggers a host of succinate receptor (SUCN1 or GPR91)-mediated signaling pathways in many peripheral tissues including the hypothalamus. One of the actions of succinate is to stabilize the hypoxia and cellular stress conditions by inducing the transcriptional regulator HIF-1α. Through these actions, it is hypothesized that succinate has the potential to restore the gradual but significant loss in functions associated with cellular senescence and systemic aging.

What should be the protocol selection after failure of in-vitro fertilization at normoresponder patients: Agonist or antagonist?

Objective:

Evaluation of the impact of agonist or antagonist protocol selection on pregnancy outcomes after failure of in-vitro fertilization (IVF) treatment cycles which were down regulated with Gonadotropin Releasing Hormone (GnRH) agonist.

Materials and Methods:

This was a retrospective study. Two hundred and sixty nine patients who were treated with GnRH agonist protocol between years 2002-2012 at an IVF unit and underwent a second attempt following one year period after failure of IVF enrolled in the study. Age, basal FSH levels, antral follicle counts, duration of induction, the number of yielded oocytes, the number of transferred embryos and the transfer days, clinical and ongoing pregnancy rates were evaluated for each treatment cycle.

Results:

Normoresponder patients were separated into two groups according to the agonist or antagonist protocol selection at the second attempt and the results of two consequent IVF cycles were compared. There were no statistically significant difference between the groups for the dosage of administered gonadotropin, duration of induction, the count of yielded oocytes, the day and the number of transferred embryos (p>0.05). Furthermore the fertilization rate, clinical and ongoing pregnancy rates were similar in two groups.

Conclusion:

The selection of antagonist treatment is effective as agonist protocols at normoresponder patients after failure of IVF.

Association of controlled ovarian hyperstimulation treatment with down-regulation of key regulators involved in embryonic implantation in mice

The debate exists whether or not gonadotropin-releasing hormone (GnRH) analogs used in controlled ovarian hyperstimulation (COH) impair endometrial receptivity. Homeobox A11 (Hoxa11), Meis homeobox 1 (Meis1), cadherin 1 (Cdh1), and catenin beta 1 (Ctnnb1) are well known to be involved in successful implantation. In this study, the endometrial expression of Hoxa11, Meis1, Cdh1, and Ctnnb1 during the peri-implantation period was investigated in an in vitro fertilization (IVF) mouse model by real-time RT-PCR and Western blot to evaluate the relationship between Hoxa11, Meis1, Cdh1, and Ctnnb1 expression and the impact of the COH on endometrial receptivity. The mimic COH protocols included GnRH agonist plus human menopausal gonadotropin (HMG) (GnRH agonist group), GnRH antagonist plus HMG (GnRH antagonist group), and HMG alone (HMG group). The expression levels of Hoxa11, Meis1, Cdh1, and Ctnnb1 mRNA and protein were decreased in all of the COH groups. The expression levels of Hoxa11 and Ctnnb1 were the lowest in the GnRH agonist group, and those of Meis1 and Cdh1 were lower in the GnRH analog groups than the HMG group. There were positive correlations between the expression of Hoxa11 and Ctnnb1, as well as the expression of Meis1 and Cdh1 among all the groups. In conclusion, the COH protocols, particularly with GnRH analogs, suppressed Hoxa11, Meis1, Ctnnb1 and Cdh1 expression, in mouse endometrium during the peri-implantation period. Our data reveal a novel molecular mechanism by which the COH protocols might impair endometrial receptivity.

Benign prostatic hyperplasia: An overview of existing treatment

Benign prostatic hyperplasia (BPH) is the most common condition in aging men, associated with lower urinary tract symptoms (LUTS). A better understanding of the prostate physiology, function, and pathogenesis has led to the development of promising agents, useful in the management of LUTS in men. The specific approach used to treat BPH depends upon number of factors like age, prostrate size, weight, prostate-specific antigen level, and severity of the symptoms. 5α-reductase inhibitors decrease the production of dihydrotestosterone within the prostate, which results in decreased prostate volume, increased peak urinary flow rate, improvement of symptoms, decreased risk of acute urinary retention, and need for surgical intervention. α(1)-adrenergic receptor (α(1)-AR) antagonists decrease LUTS and increase urinary flow rates in men with symptomatic BPH, but do not reduce the long-term risk of urinary retention or need for surgical intervention. Clinical efficacy of either 5α-reductase inhibitor or α(1)-AR antagonist has been further improved by using combination therapy; however, long-term outcomes are still awaited. Many more potential new therapies are under development that may improve the treatment of BPH. This article gives a brief account of rationale and efficacy of different treatment options presently available in the management of BPH.

Bioanalytical determination of unstable endogenous small peptides: RFRP3 and its metabolites in rat blood

Background: Targeting the gonadotropin-releasing hormone pathway for the treatment of endometriosis leads to an interest in monitoring for endogenous modulators of this pathway (RFRP3 and kisspeptin) as baseline controls for treatment development. Results: Stabilization of RFRP3 was shown to be extremely difficult in a highly enzymatically active matrix, such as rat blood. Sample denaturing with solvent at collection was necessary due to enzyme inhibition being unsuccessful at stabilization leading to difficulties in sample processing. Monitoring multiple fragments formed in blood can aid in profiling these peptides once in-source conversion is controlled. Conclusion: generic high-sensitivity LC–MS/MS assay was developed for RFRP3 and the fragments formed from it in whole blood. Use of 2D chromatography circumvents concentration and retention issues related to small fragments with a normal flow setup, making a more open-access approach feasible.

Management of uterine fibroids in the patient pursuing assisted reproductive technologies

Uterine leiomyomas are present in 30-70% of women of reproductive age. In addition to causing menstrual disorders and pain, uterine fibroids negatively affect fertility and pregnancy outcome for patients pursuing assisted reproduction. The two questions that have to be addressed are: which fibroids should be treated and how should they be treated? Submucosal fibroids are associated with a 70% reduction in delivery rate. Intramural fibroids had a lesser effect and reduced the delivery rate by approximately 30%. By contrast, studies have demonstrated that subserosal fibroids did not negatively impact fertility. Furthermore, both submucosal and intramural fibroids were associated with an increased risk of spontaneous miscarriage. Myomectomy is considered the treatment of choice to alleviate these detrimental effects. Further research is needed before alternative treatments can be recommended.

Comparison of the effects of cetrorelix, a GnRH antagonist, and leuprolide, a GnRH agonist, on experimental endometriosis

AIM

In the present study, we aimed to compare the effects of cetrorelix and leuprolide on endometriosis.

METHODS

This randomized, placebo-controlled, single-blind, experimental study was performed on 45 Wistar adult female rats in the Experimental Surgery Laboratory at Ondokuz Mayis University. After the peritoneal implantation of endometrial tissue, rats were randomized to three equal intervention groups: (i) control group, (ii) leuprolide group, and (iii) cetrorelix group. Six weeks later, following implant volume measurements (volume-1) by performing a second laparotomy, saline (0.1 cc/rat) was administered subcutaneously to the control group once a week, leuprolide (0.075 mg/kg) subcutaneously to the leuprolide group twice at 4-week intervals and cetrorelix (0.001 mg/rat/day) subcutaneously to the cetrorelix group for 8 weeks. At the end of the treatment, by performing a third laparotomy, implant volumes were remeasured (volume-2) and implants were totally excised for histopathological examination. The volume-1 and volume-2 values within the groups, and stromal and glandular tissue scores between the groups were compared.

RESULTS

In both the leuprolide group and the cetrorelix group, volume-2 as compared to volume-1 had significantly reduced (P < 0.01, P < 0.01 respectively), while there was no significant volume change in the control group (P > 0.05). In this group, when compared with the control group, glandular and stromal tissues had significantly lessened (P < 0.01, P < 0.01 respectively).

CONCLUSION

Leuprolide and cetrorelix were found to have similar efficacy in the regression of both the size and the histological structure of experimental endometriotic implants.

Targeting mast cells in endometriosis with janus kinase 3 inhibitor, JANEX-1

Endometriosis (EMS) is a chronic inflammatory disease of multifactorial etiology characterized by implantation and growth of endometrial glands and stroma outside the uterine cavity. EMS is a significant public health issue as it affects 15-20% of women in their reproductive age. Clinical symptoms may include pelvic pain, dysmenorrhea, dyspareunia, pelvic/abdominal masses, and infertility. Symptomatic treatments such as surgical resection and/or hormonal suppression of ovarian function and analgesics are not as effective as desired. Consequently, there is an enormous unmet need to develop effective medical therapy capable of preventing the occurrence and recurrence of EMS without undesirable side-effects. EMS-associated intra-abdominal bleeding episodes, local inflammation, adhesions, and i.p. immunologic dysfunction leads to pelvic nociception and pelvic pain. Increasing evidence supports the involvement of allergic-type inflammation in EMS. Invasion of mast cells, degranulation, and proliferation of interstitial component are observed in endometriotic lesions. Presence of activated and degranulating mast cells within the nerve structures can contribute to the development of pain and hyperalgesia by direct effects on primary nociceptive neurons. Therefore, treatments targeting endometrial mast cells may prove effective in preventing or alleviating EMS-associated symptoms. The Janus kinase 3 (JAK3) is abundantly expressed in mast cells and is required for the full expression of high-affinity IgE receptor-mediated mast cell inflammatory sequelae. JANEX-1/WHI-P131 is a rationally designed novel JAK3 inhibitor with potent anti-inflammatory activity in several cellular and in vivo animal models of inflammation, including mouse models of peritonitis, colitis, cellulitis, sunburn, and airway inflammation with favorable toxicity and pharmacokinetic profile. We hypothesize that JAK3 inhibitors, especially JANEX-1, may prove useful to prevent or alleviate the symptoms of EMS.

Luteinising hormone-releasing hormone antagonists in prostate cancer therapy

The introduction of androgen blockade therapy using luteinising hormone-releasing hormone (LHRH)/gonadotropin-releasing hormone analogues alone or in combination with non-steroidal antiandrogens has a major impact in both survival and quality of life of patients with locally advanced and metastatic prostate cancer. The effect of LHRH agonists is based on the continuous binding to the LHRH receptor (LHRH-R) on the gonadotrope cells of the pituitary, which although initially stimulate LH release, consequently downregulates the LHRH-R, thereby suppressing serum LH, testosterone levels and 5alpha-dihydrotestosterone levels. Because this initial surge of LH and testosterone can cause adverse consequences in these patients (the so-called flare-up symptoms), immediate inhibition of LH release and testosterone production is desirable and this can be achieved with the use of the LHRH antagonists. In addition, there exist data to support a direct anticancer effect of LHRH antagonists on prostate cancer cells. This review summarises the potential clinical use of the LHRH antagonists in prostate cancer patients.

Mechanisms of Disease: the first kiss-a crucial role for kisspeptin-1 and its receptor, G-protein-coupled receptor 54, in puberty and reproduction

Although the hypothalamic secretion of gonadotropin-releasing hormone (GnRH) is the defining hormonal event of puberty, the physiologic mechanisms that drive secretion of GnRH at the time of sexual maturation have been difficult to identify. After puberty is initiated, the factors that modulate the frequency and amplitude of GnRH secretion in rapidly changing sex-steroid environments (i.e. the female menstrual cycle) also remain unknown. The discovery that, in both humans and mouse models, loss-of-function mutations in the gene that encodes G-protein-coupled receptor 54 result in phenotypes of hypogonadotropic hypogonadism with an absence of pubertal development has unearthed a novel pathway regulating GnRH secretion. Ligands for G-protein-coupled receptor 54 (KiSS-1R), including metastin (derived from the parent compound, kisspeptin-1) and metastin's C-terminal peptide fragments, have been shown to be powerful stimulants for GnRH release in vivo via their stimulation of G-protein-coupled receptor 54. This article reviews the discovery of the GPR54 gene, places it into the appropriate biological context, and explores the data from in vitro and in vivo studies that point to this ligand-receptor system as a major driver of GnRH secretion.

Emerging drugs in endometriosis

Endometriosis is a common, estrogen-dependent, gynaecological disease, defined as the presence of endometrial-like tissue outside the uterus. Although several medications are used for treatment of the disease, they are associated with high recurrence rates, considerable side effects and limited duration of application. Due to these limitations and to the impact of endometriosis on the quality of life of affected women, their environment and the society, there is a great need for new drugs able to abolish endometriosis and its symptoms. Studies in recent years investigating the (patho)physiological mechanisms involved in disease aetiology have fostered the development of novel therapeutic concepts for endometriosis, by targeting the hypothalamic-pituitary-gonadal axis, by selective modulation of estrogenic and progestogenic pathways, by inhibiting angiogenesis or by interfering with inflammatory and immunological factors. This article presents a brief summary of the currently available medications and an overview regarding the development of some of the most interesting and/or most promising novel drug candidates for endometriosis.

Medical management of endometriosis

Current approved medical therapies for endometriosis rely on drugs that suppress ovarian steroids and induce a hypoestrogenic state, which determines the atrophy of the ectopic endometrium. Gonadotropin-releasing hormone analogs such as danazol, progestogens and estrogen-progestin combinations have all proven effective in relieving pain and reducing the extent of endometriotic implants. However, symptoms often recur after discontinuation of therapy and hypoestrogenism-related side effects limit the long-term use of most medications. Recently, knowledge of the pathogenesis of endometriosis, particularly at the molecular level, has grown substantially, providing a rational basis for the development of new drugs with precise targets that may be safely administered over the long term.