Selective progesterone receptor modulators: an update

A Phase I Trial of Enzalutamide Plus Selective Glucocorticoid Receptor Modulator Relacorilant in Patients with Metastatic Castration-Resistant Prostate Cancer

PURPOSE

The majority of patients with metastatic prostate cancer who receive androgen-deprivation therapy and androgen receptor (AR) signaling inhibitors (ARSI) progress. Activation of the glucocorticoid receptor (GR) is associated with ARSI resistance. This single-arm phase I trial assessed safety and pharmacokinetic (PK) feasibility of a combined AR antagonist (enzalutamide) and selective GR modulator (relacorilant) in patients with metastatic castration-resistant prostate cancer (mCRPC).

PATIENTS AND METHODS

This was a phase I trial (NCT03674814) of relacorilant and enzalutamide in patients with refractory mCRPC enrolled using a 6+3 design. The enzalutamide dose was kept constant at 120 mg/d with escalating doses of relacorilant based on safety and PK measures in cohorts of ≥6 patients. The primary objective was safety and establishment of pharmacologically active doses. Secondary objectives were related to antitumor activity.

RESULTS

Thirty-five patients with mCRPC were enrolled. Twenty-three were accrued across three dose cohorts in the dose-escalation phase, and 12 enrolled at the recommended phase II dose. The combination was generally well tolerated, safe, and achieved desirable enzalutamide PK. RP2D of 120 + 150 mg/d, respectively, was established. Median time on study was 2.2 months with four patients remaining on study for longer than 11 months. Four of 12 evaluable patients had a prostate-specific antigen (PSA) partial response.

CONCLUSIONS

This is the first prospective trial combining an AR antagonist and a nonsteroidal selective GR modulator. The combination was safe and well tolerated with PSA response and prolonged disease control observed in a limited subset of patients. Further prospective trials are justified to evaluate efficacy and identify predictive biomarkers of response.

Physiological Action of Progesterone in the Nonhuman Primate Oviduct

Therapies that target progesterone action hold potential as contraceptives and in managing gynecological disorders. Recent literature reviews describe the role of steroid hormones in regulating the mammalian oviduct and document that estrogen is required to stimulate epithelial differentiation into a fully functional ciliated and secretory state. However, these reviews do not specifically address progesterone action in nonhuman primates (NHPs). Primates differ from most other mammals in that estrogen levels are >50 pg/mL during the entire menstrual cycle, except for a brief decline immediately preceding menstruation. Progesterone secreted in the luteal phase suppresses oviductal ciliation and secretion; at the end of the menstrual cycle, the drop in progesterone triggers renewed estrogen-driven tubal cell proliferation ciliation secretory activity. Thus, progesterone, not estrogen, drives fallopian tube cycles. Specific receptors mediate these actions of progesterone, and synthetic progesterone receptor modulators (PRMs) disrupt the normal cyclic regulation of the tube, significantly altering steroid receptor expression, cilia abundance, cilia beat frequency, and the tubal secretory milieu. Addressing the role of progesterone in the NHP oviduct is a critical step in advancing PRMs as pharmaceutical therapies.

Phase I/II trial of enzalutamide and mifepristone, a glucocorticoid receptor antagonist, for metastatic castration-resistant prostate cancer

PURPOSE

Although androgen deprivation therapy (ADT) and androgen receptor signaling inhibitors (ARSI) are effective in metastatic prostate cancer (PC), resistance occurs in most patients. This phase I/II trial assessed the safety, pharmacokinetic impact, and efficacy of the glucocorticoid receptor (GR) antagonist mifepristone (Mif) in combination with enzalutamide (Enz) for castration-resistant PC (CRPC).

PATIENTS AND METHODS

106 patients with CRPC were accrued. Phase I subjects were treated with Enz monotherapy at 160 mg per day for 28 days to allow steady-state accumulation. Patients then entered the dose escalation combination portion of the study. In phase II, patients were randomized 1:1 to either receive Enz alone or Enz plus Mif. The primary endpoint was PSA progression free survival (PFS), with radiographic PFS, and PSA response rate (RR) as key secondary endpoints. Circulating tumor cells were collected before randomization for exploratory translational biomarker studies.

RESULTS

We determined a 25% dose reduction in Enz, when added to Mif resulted in equivalent drug levels compared to full dose Enz and was well tolerated. However, the addition of Mif to Enz following a 12-week Enz lead-in did not delay time to PSA, radiographic or clinical PFS. The trial was terminated early due to futility.

CONCLUSION

This is the first prospective trial of dual AR-GR antagonism in CRPC. Enz combined with Mif was safe and well tolerated but did not meet its primary endpoint. The development of more specific GR antagonists combined with AR antagonists, potentially studied in an earlier disease state, should be explored.

Markers of Cellular Proliferation, Apoptosis, Estrogen/Progesterone Receptor Expression and Fibrosis in Selective Progesterone Receptor Modulator (Ulipristal Acetate)-Treated Uterine Fibroids

There appear to be very few data on the exact mechanisms of a selective progesterone receptor modulator action in myomas. The aim of the study was to assess the effects of ulipristal acetate (UPA) on fibroids, especially on estrogen receptor (ER) and progesterone receptor (PR) immunoexpression, proliferation, apoptosis and tissue fibrosis, and to compare the above parameters in untreated (surgical attention only) and UPA-treated leiomyomas. UPA-treated patients were divided into three groups: (1) good response (≥25% reduction in volume of fibroid), (2) weak response (insignificant volume reduction) and (3) no response to treatment (no decrease or increase in fibroid volume). The study observed a significant decrease in the percentage of collagen volume fraction and ER and PR immunoexpression in the good response group, in the percentage of proliferating cell nuclear antigen (PCNA)- and Ki67-positive cells in the groups with good and weak reactions vs. control group; significantly higher apoptotic index (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells) in the good reaction group vs. control group. The results of the study indicate that a good response to UPA, manifested by a volume reduction of myoma, may be associated with a decrease in fibrosis, ER/PR and PCNA and Ki67 immunoexpression and an increase in cell apoptosis within the myoma.

The Biological Impact of Ulipristal Acetate on Cellular Networks Regulating Uterine Leiomyoma Growth

Uterine Fibroids (UFs), or leiomyomas, represent the most frequent pelvic tumor in reproductive-aged women. Although of benign origin, UFs decrease fertility and cause significant reproductive dysfunctions. Compared to normal myometrium, UFs are characterized by a clinical and molecular heterogeneity as demonstrated by the presence of multiple genetic alterations and altered signaling pathways. Recently, selective progesteronereceptor modulators (SPRM), as ulipristal acetate (UPA), have demonstrated their clinical benefits by reducing tumor growth and extracellular matrix deposition. For these reasons, UPA is used in the clinical practice as an intermittent treatment for women symptomatic for UFs or, sometimes, before a myomectomy. However, drug effects on signaling pathways frequently upregulated in UFs remain largely unknown. In fact, the mechanisms of action of the UPA on UFs and on the surrounding areas are not yet understood. To learn more about UPA molecular mechanisms, UF samples were treated ex vivo with UPA and profiled for drug effects on selected markers. During this preliminary ex vivo UPA administration, significant changes were observed in the expression levels of proteins related to cell cycle regulation, cytoskeleton remodeling, and drug resistance. The UPA administration reduced cofilin, Erk and Src phosphorylation, p27 and ezrin protein levels, but not Akt phosphorylation and cyclin D1 and β-catenin levels. This preliminary ex vivo biological analysis provided new insights into the mechanism of action of UPA in the treatment of UFs, which could better explain the biological functioning of the drug on UFs.

Progesterone receptor ligands for the treatment of endometriosis: the mechanisms behind therapeutic success and failure

BACKGROUND

Despite intense research, it remains intriguing why hormonal therapies in general and progestins in particular sometimes fail in endometriosis.

OBJECTIVE AND RATIONALE

We review here the action mechanisms of progesterone receptor ligands in endometriosis, identify critical differences between the effects of progestins on normal endometrium and endometriosis and envisage pathways to escape drug resistance and improve the therapeutic response of endometriotic lesions to such treatments.

SEARCH METHODS

We performed a systematic Pubmed search covering articles published since 1958 about the use of progestins, estro-progestins and selective progesterone receptor modulators, to treat endometriosis and its related symptoms. Two reviewers screened the titles and abstracts to select articles for full-text assessment.

OUTCOMES

Progesterone receptor signalling leads to down-regulation of estrogen receptors and restrains local estradiol production through interference with aromatase and 17 beta-hydroxysteroid dehydrogenase type 1. Progestins inhibit cell proliferation, inflammation, neovascularisation and neurogenesis in endometriosis. However, progesterone receptor expression is reduced and disrupted in endometriotic lesions, with predominance of the less active isoform (PRA) over the full-length, active isoform (PRB), due to epigenetic abnormalities affecting the PGR gene transcription. Oxidative stress is another mechanism involved in progesterone resistance in endometriosis. Among the molecular targets of progesterone in the normal endometrium that resist progestin action in endometriotic cells are the nuclear transcription factor FOXO1, matrix metalloproteinases, the transmembrane gap junction protein connexin 43 and paracrine regulators of estradiol metabolism. Compared to other phenotypes, deep endometriosis appears to be more resistant to size regression upon medical treatments. Individual genetic characteristics can affect the bioavailability and pharmacodynamics of hormonal drugs used to treat endometriosis and, hence, explain part of the variability in the therapeutic response.

WIDER IMPLICATIONS

Medical treatment of endometriosis needs urgent innovation, which should start by deeper understanding of the disease core features and diverse phenotypes and idiosyncrasies, while moving from pure hormonal treatments to drug combinations or novel molecules capable of restoring the various homeostatic mechanisms disrupted by endometriotic lesions.

Ulipristal acetate and pregnancy outcome-an observational study

STUDY QUESTION

Is the failure of the selective progesterone receptor modulator ulipristal acetate (UPA) as emergency contraception (EC; 30 mg, single) or inadvertent exposure for myoma treatment (5 mg/d) in pregnancy associated with a higher risk of birth defects, spontaneous abortion (SAB) or elective termination of pregnancy (ETOP)?

SUMMARY ANSWER

We did not find an increased risk for birth defects, SABs or ETOPs after UPA exposure during implantation and early embryogenesis.

WHAT IS KNOWN ALREADY

Pregnancy outcome data after exposure to UPA are very limited. In cases of EC failure or unplanned pregnancy during myoma treatment, women need well-grounded risk assessment to minimize anxiety and prevent unjustified termination of pregnancy.

STUDY DESIGN, SIZE, DURATION

Observational study of prospectively ascertained pregnancies from the German Embryotox institute with UPA exposure (EC, n = 95; myoma, n = 7). Four retrospectively reported pregnancy outcomes were evaluated separately.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 226 requests on ulipristal were directed to the German Embryotox institute during the study period 2010-2018. Outcomes of pregnancies exposed-(i) precycle, (ii) preconceptional or (iii) first trimester-were ascertained using standardized questionnaires. Descriptive statistics were applied.

MAIN RESULTS AND THE ROLE OF CHANCE

Failed EC with UPA resulted in 95 prospectively ascertained pregnancies, of which 56 had completed follow-up: 37 live births, 7 SABs and 12 ETOPs. There was no major birth defect. Just 34% of women had taken UPA during the fertile window. Seven prospectively enrolled pregnancies were treated for myoma and had known pregnancy outcomes: five healthy live births and two SABs. Among the four retrospectively reported pregnancies after EC, there was one child diagnosed with Beckwith-Wiedemann syndrome (BWS).

LIMITATIONS, REASONS FOR CAUTION

Our limited sample size does not allow concluding safety of UPA use in pregnancy.

WIDER IMPLICATIONS OF THE FINDINGS

We provide a preliminary basis for reassuring women who wish to carry their pregnancy to term after EC or myoma treatment with UPA. However, because of the report of a BWS after UPA exposure, a possible epigenetic effect could not be excluded and requires further evaluation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was performed with financial support from the German Federal Institute for Drugs and Medical Devices (BfArM). All authors declare that they have no conflicts of interest.

TRIAL REGISTRATION NUMBER

Registered with the German Clinical Trial Register (DRKS00015155).

In vivo study on biotransformation of pentacyclic analogs of progesterone: Identification of their metabolites by HPLC-MS method

Progesterone derivatives containing the D' additional cyclohexane ring in the 16α,17α-positions of steroid core (pregna-D'-pentaranes) exhibited high in vitro and in vivo selective progestogenic activity. The assessment of their biotransformation in the body, and the identification of possible metabolites are integral parts of a potential drug studies. Here we describe the results of in vivo metabolic transformation of 6α-methyl-16α,17α-cyclohexanopregn-4-ene-3,20-dione 1 and its 6-demethylated analog 2 and identification of their metabolites in rat urine. We synthesized and fully characterized (1D and 2D NMR, HRMS) 11 possible metabolites as the standards. Then we developed the LC-MS/MS assay including sample preparation and chromatography conditions for identification of the detected metabolites of 1 and 2. The 5α- and 5β-3,20-diketo-, 3β-hydroxy-20-keto-5α-, 3-keto-20(S)-hydroxy-5α-, 3β,20(S)-dihydroxy-5α-metabolites of compounds 1 and 2 were found in rat urine samples. The starting steroids 1 and 2, as well as both 3β,20(R)-dihydroxy metabolites were not detected in the examined biological urine samples. Thus, we demonstrate for the first time that exogenous progestines - pregna-D'-pentaranes - and endogenous progesterone follow similar metabolic pathways. Therefore, despite the presence of an additional ring D' and the methyl group in position 6, the main enzymatic transformations are similar to those of the natural hormone.

Functional genomic analysis of the human receptive endometrium transcriptome upon administration of mifepristone at the time of follicle rupture

The aim of this study was to analyze the effects of progesterone withdrawal on gene transcription in receptive endometrium by the administration of a single dose of 50 mg of the anti-progesterone receptor mifepristone (MFP) at the time of follicle rupture (FR). Six volunteer ovulatory women were studied, taking endometrial biopsies of three control and three MFP-treated women on days LH+2 (C-LH+2) and LH+7 (T-MFP), respectively. The biopsies were prepared for RNA isolation or histological and immunohistochemistry studies. The genomic data from 14 women (C-LH+7) were included as a historical control. The functional genomic analysis of the differentially expressed genes showed that MFP interfered negatively with the bio-functions decidualization of uterus and implantation of blastocyst and embryo. The results of this study confirm but also give new information on how MFP affects endometrial gene expression when administered at the time of FR and the dose used in emergency contraception.

A three-step synthesis of estra-4,9-diene-3,17-dione

Estra-4,9-diene-3,17-dione, an important pharmaceutical intermediate, was synthesized by a three-step sequence from δ-lactone 1 in 23.4% overall yield. Reaction of δ-lactone 1 and Grignard reagent 2 followed by treatment with Jones reagent resulted in precursor 4. The domino cyclization reaction of 4 with piperidinium acetate gave estra-4,9-diene-3,17-dione.

Phase I study of onapristone, a type I antiprogestin, in female patients with previously treated recurrent or metastatic progesterone receptor-expressing cancers

INTRODUCTION

Onapristone is a type I progesterone receptor (PR) antagonist, which prevents PR- mediated DNA transcription. Onapristone is active in multiple preclinical models and two prior studies demonstrated promising activity in patients with breast cancer. We conducted a study of extended release (ER) Onapristone to determine a recommended dose and explore the role of transcriptionally-activated PR (APR), detected as an aggregated subnuclear distribution pattern, as a predictive biomarker.

METHODS

An open-label, multicenter, randomized, parallel-group, phase 1 study (target n = 60; NCT02052128) included female patients ≥18 years with PRpos tumors. APR analysis was performed on archival tumor tissue. Patients were randomized to five cohorts of extended release (ER) onapristone tablets 10, 20, 30, 40 or 50 mg BID, or immediate release 100 mg QD until progressive disease or intolerability. Primary endpoint was to identify the recommended phase 2 dose. Secondary endpoints included safety, clinical benefit and pharmacokinetics.

RESULTS

The phase 1 dose escalation component of the study is complete (n = 52). Tumor diagnosis included: endometrial carcinoma 12; breast cancer 20; ovarian cancer 13; other 7. Median age was 64 (36-84). No dose limiting toxicity was observed with reported liver function test elevation related only to liver metastases. The RP2D was 50 mg ER BID. Median therapy duration was 8 weeks (range 2-44), and 9 patients had clinical benefit ≥24 weeks, including 2 patients with APRpos endometrial carcinoma.

CONCLUSION

Clinical benefit with excellent tolerance was seen in heavily pretreated patients with endometrial, ovarian and breast cancer. The data support the development of Onapristone in endometrial endometrioid cancer. Onapristone should also be evaluated in ovarian and breast cancers along with APR immunohistochemistry validation.

Placenta previa and placental abruption after assisted reproductive technology in patients with endometriosis: a systematic review and meta-analysis

INTRODUCTION

Recent evidence suggests that assisted reproductive technology (ART) increases the risk of adverse pregnancy outcomes, including placental disorders. Similarly, endometriosis resulted detrimental on placenta previa. However, up to 50% of women with endometriosis suffer from infertility, thus requiring ART. The aim of our metanalysis is to compare women with and without endometriosis undergoing ART in terms of placenta disorders events, to establish if ART itself or endometriosis, as an indication to ART, increases the risk of placenta previa.

METHODS

Literature searches were conducted in January 2018 using electronic databases (PubMed, Medline, Scopus, Embase, Science Direct, and the Cochrane Library Scopus). Series comparing pregnancy outcome after ART in women with and without endometriosis were screened and data on placenta previa and placental abruption were extracted.

RESULTS

Five retrospective case-control studies met the inclusion criteria. The meta-analysis revealed that endometriosis is associated with an increased risk of placenta previa in pregnancies achieved through ART (OR 2.96 (95% CI 1.25-7.03); p = 0.01, I²=69%, random-effect model). No differences in placental abruption incidence were found (OR 0.44 (95% CI 0.10-1.87); p = 0.26, I²= 0%, fixed-effect model).

CONCLUSION

Patients with endometriosis undergoing ART may have additional risk of placenta previa. Despite the inability to determine if endometriosis alone or endometriosis plus ART increase the risk, physicians should be aware of the potential additional risk that endometriosis patients undergoing ART harbor.

Prevention of recurrent lower urinary tract infections in postmenopausal women with genitourinary syndrome: outcome after 6 months of treatment with ospemifene

Aim of this study was to evaluate the efficacy of ospemifene in the prevention of recurrent lower urinary tract infections in postmenopausal women with vulvovaginal atrophy. The study have a retrospective design. Thirty-nine patients were enrolled. Patients underwent clinical examination and urine culture. The urinary symptoms and the quality of life were evaluated with UTISA score, PUF and SF-36 questionnaires before and after treatment. All 39 patients received ospemifene 60 mg one tablet/daily for 6 months. Adverse effects and complications were assessed. Thirty-nine patients were enrolled in the study. Two patients experienced one new UTI episode and the mean number of positive urine culture decreased significantly after 6 months (3.65 ± 2.12 vs 0.25 ± 0.17, p < .0001). The mean number of urinary infection symptoms decreased significantly after treatment; dysuria reduced (4.76 ± 2.45 vs 0.89 ± 1.12). PUF score and SF-36 showed a statistically significant change (22.43 ± 5.89 vs 12.14 ± 3.21) and (52.86 ± 9.21 vs 83.43 ± 10.76). No adverse effects were reported and the total success rate was the 92.3% after 6 months at PGI-I. Ospemifene is a valid alternative with excellent tolerability for the UTI_S prevention in postmenopausal patients.

A Comprehensive Review of the Pharmacologic Management of Uterine Leiomyoma

Uterine leiomyomata are the most common benign tumors of the gynecologic tract impacting up to 80% of women by 50 years of age. It is well established that these tumors are the leading cause for hysterectomy with an estimated total financial burden greater than $30 billion per year in the United States. However, for the woman who desires future fertility or is a poor surgical candidate, definitive management with hysterectomy is not an optimal management plan. Typical gynecologic symptoms of leiomyoma include infertility, abnormal uterine bleeding (AUB)/heavy menstrual bleeding (HMB) and/or intermenstrual bleeding (IMB) with resulting iron-deficiency anemia, pelvic pressure and pain, urinary incontinence, and dysmenorrhea. The morbidity caused by these tumors is directly attributable to increases in tumor burden. Interestingly, leiomyoma cells within a tumor do not rapidly proliferate, but rather the increase in tumor size is secondary to production of an excessive, stable, and aberrant extracellular matrix (ECM) made of disorganized collagens and proteoglycans. As a result, medical management should induce leiomyoma cells toward dissolution of the extracellular matrix, as well as halting or inhibiting cellular proliferation. Herein, we review the current literature regarding the medical management of uterine leiomyoma.

Development of N-(4-Phenoxyphenyl)benzenesulfonamide Derivatives as Novel Nonsteroidal Progesterone Receptor Antagonists

We report here development of N-(4-phenoxyphenyl)benzenesulfonamide derivatives as a novel class of nonsteroidal progesterone receptor (PR) antagonists. PR plays key roles in various physiological systems, including the female reproductive system, and PR antagonists are candidates for clinical treatment of multiple diseases, including uterine leiomyoma, endometriosis, breast cancer, and some psychiatric disorders. We found that the benzenesulfonanilide skeleton functions as a novel scaffold for PR antagonists, and we adopted 3-chlorobenzenesulfonyl derivative 20a as a lead compound for structural development. Among the synthesized compounds, 3-trifluoromethyl derivative 32 exhibited the most potent PR-antagonistic activity, with high binding affinity for PR and selectivity over androgen receptor (AR). It is structurally distinct from other nonsteroidal PR antagonists, including cyanopyrrole derivatives, and further modification is expected to afford novel selective PR modulators.

Pharmacologic treatment of the ovarian endometrioma

INTRODUCTION

Treatment of ovarian endometriomas is commonly achieved through laparoscopic surgery and this can be effective in eliminating the disease, although a majority of recent trials documented an adverse effect of surgery on ovarian reserve markers. With the advancement in imaging techniques, ovarian endometriomas are increasingly diagnosed at an earlier stage when the endometrioma may be smaller, less fibrotic and more responsive to medical treatment, making an evaluation of medical options critically important.

AREAS COVERED

The review focuses on currently utilized pharmacologic therapies for endometrioma (oral contraceptives, the levonorgestrel-releasing IUS, the hormone-releasing subdermal implant, Implanon); experimental and future treatments are also mentioned (GnRH antagonists, progesterone receptor modulators, antioestrogens, newer subdermal implants and intracystic administration of pharmacologic agents). Finally, the usefulness of post-operative adjuvant medical treatments is discussed Expert opinion: Today, reliable, non-invasive diagnostic procedures of an ovarian endometrioma are available and should be utilized to identify its presence and type of pathology. In a young patient, classic medical therapies such as oral contraceptives and synthetic progestins should be tried first to alleviate symptoms. Only when these regimens fail, should a minimally invasive surgery be envisaged. Following endoscopic surgery, adjuvant medical treatment may reduce recurrence of both symptoms and the lesion.

Selective progesterone receptor modulators (SPRMs): progesterone receptor action, mode of action on the endometrium and treatment options in gynecological therapies

Introduction: The progesterone receptor plays an essential role in uterine physiology and reproduction. Selective progesterone receptor modulators (SPRMs) have emerged as a valuable treatment option for hormone dependent conditions like uterine fibroids, which have a major impact on women’s quality of life. SPRMs offer potential for longer term medical treatment and thereby patients may avoid surgical intervention.

Areas covered: The authors have reviewed the functional role of the progesterone receptor and its isoforms and their molecular mechanisms of action via genomic and non-genomic pathways. The current knowledge of the interaction of the PR and different SPRMs tested in clinical trials has been reviewed. The authors focused on pharmacological effects of selected SPRMs on the endometrium, their anti-proliferative action, and their suppression of bleeding. Potential underlying molecular mechanisms and the specific histological changes in the endometrium induced by SPRMs (PAEC; Progesterone receptor modulator Associated Endometrial Changes) have been discussed. The clinical potential of this compound class including its impact on quality of life has been covered.

Expert Opinion: Clinical studies indicate SPRMs hold promise for treatment of benign gynecological complaints (fibroids, heavy menstrual bleeding; HMB). There however remains a knowledge gap concerning mechanism of action.

Effects of low doses of mifepristone on human embryo implantation process in a three-dimensional human endometrial in vitro co-culture system

OBJECTIVES

We wanted to explore the effects of two different low doses (0.5μM and 0.05μM) of mifepristone, exposed during the receptive period, on the human embryo implantation process, using a well-established three-dimensional in vitro cell culture model, specifically developed to study this process.

METHODS

An in vitro three-dimensional cell culture model was constructed using human endometrial cells isolated from the endometrium of proven fertile women, collected on cycle day LH+4. After 5 days of culture, supernumerary human embryos were added and cultured for another 5 days with mifepristone 0.5μM (n=8) or 0.05μM (n=10) or vehicle as control (n=10). The cultures were checked for embryo attachment and terminated. We studied the expression of 16 reported endometrial receptivity markers in the endometrial constructs using real-time polymerase chain reaction.

RESULTS

None of the embryos in 0.5μM of mifepristone attached to the endometrial constructs (p=.004), whereas 4 out of 10 in 0.05μM (p=.3698) and 7 out of 10 embryos in the control group attached to the cultures. We found that most of the studied receptivity markers were significantly altered with mifepristone exposure in a similar direction in both treatment groups. Only IL6 was significantly differentially expressed between the treatment groups (p=.017).

CONCLUSION

We report for the first time that exposure to a low concentration (0.5μM) of mifepristone during the receptive period successfully inhibits human embryo implantation process in vitro. Further, we observed a dose-dependent effect of mifepristone on endometrial receptivity at the functional level.

IMPLICATION

This study contributes new knowledge that low dose of mifepristone during the short period of receptive phase can inhibit endometrial receptivity, which further promotes mifepristone as a contraceptive agent. This could give women a treatment choice to avoid unwanted pregnancy with high efficacy and minimal side effects.

Innovations in classical hormonal targets for endometriosis

Endometriosis is a chronic disease of unknown etiology that affects approximately 10% of women in reproductive age. Several evidences show that endometriosis lesions are associated to hormonal imbalance, including estrogen synthesis, metabolism and responsiveness and progesterone resistance. These hormonal alterations influence the ability of endometrial cells to proliferate, migrate and to infiltrate the mesothelium, causing inflammation, pain and infertility. Hormonal imbalance in endometriosis represents also a target for treatment. We provide an overview on therapeutic strategies based on innovations of classical hormonal mechanisms involved in the development of endometriosis lesions. The development phase of new molecules targeting these pathways is also discussed. Endometriosis is a chronic disease involving young women and additional biological targets of estrogen and progesterone pharmacological manipulation (brain, bone and cardiovascular tissue) need to be carefully considered in order to improve and overcome current limits of long-term medical management of endometriosis.

Osteoprotegerin (OPG), The Endogenous Inhibitor of Receptor Activator of NF-κB Ligand (RANKL), is Dysregulated in BRCA Mutation Carriers

Breast cancer development in BRCA1/2 mutation carriers is a net consequence of cell-autonomous and cell nonautonomous factors which may serve as excellent targets for cancer prevention. In light of our previous data we sought to investigate the consequences of the BRCA-mutation carrier state on RANKL/osteoprotegerin (OPG) signalling.

We analysed serum levels of RANKL, OPG, RANKL/OPG complex, oestradiol (E2), and progesterone (P) during menstrual cycle progression in 391 BRCA1/2-mutation carriers and 782 noncarriers. These studies were complemented by analyses of RANKL and OPG in the serum and mammary tissues of female cynomolgus macaques (n = 88) and serum RANKL and OPG in postmenopausal women (n = 150).

BRCA-mutation carriers had lower mean values of free serum OPG in particular in BRCA1-mutation carriers (p = 0.018) compared with controls. Among BRCA1/2 mutation carriers, lower OPG levels were associated with germline mutation locations known to confer an increased breast cancer risk (p = 0.003). P is associated with low OPG levels in serum and tissue, particularly in BRCA-mutation carriers (rho = − 0.216; p = 0.002). Serum OPG levels were inversely correlated (rho = − 0.545, p < 0.001) with mammary epithelial proliferation measured by Ki67 expression and increased (p = 0.01) in postmenopause.

The P–RANKL/OPG system is dysregulated in BRCA-mutation carriers. These and previously published data provide a strong rationale for further investigation of antiprogestogens or an anti-RANKL antibody such as denosumab for breast cancer prevention.

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Osteoprotegerin (OPG) is the endogenous inhibitor of Receptor Activator of NF-κB Ligand (RANKL)

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RANKL has been shown to be crucially important in progesterone-mediated breast carcinogenesis

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Serum OPG is regulated by progesterone and low in BRCA1/2 mutation carriers

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Low serum OPG is associated with increased proliferation in the mammary gland

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Antiprogestogens or anti-RANKL antibody (denosumab) may be new strategies for breast cancer prevention in BRCA1/2 carriers.

Preventing deadly cancers is a high priority of 21st century medicine. To find the most promising cancer causing targets which can be modulated using chemo-preventive drugs remains the biggest challenge. In this paper we show that OPG, which is the physiological antagonist of RANKL (a factor known to be crucially involved in breast carcinogenesis), is low in women who have inherited a gene mutation (i.e. in BRCA1 or 2) which puts them at extremely high risk of developing breast cancer. An antibody which mimics OPG might be a very attractive option in preventing breast cancer.