Vilaprisan in women with uterine fibroids: the randomized phase 2b ASTEROID 1 study

Experimental and new investigational drugs for the treatment of uterine fibroids

INTRODUCTION

Uterine fibroids, the most prevalent benign tumors among reproductive-age women, pose treatment challenges that range from surgical interventions to medical therapies for symptom control. Progestins and estroprogestins effectively manage uterine bleeding by suppressing dysfunctional endometrium over fibroids. While GnRH agonists represent a crucial milestone in symptom treatment, their prolonged use results in menopausal-like symptoms and irreversible bone mineral density loss. Advancements in understanding fibroid pathophysiology have prompted the exploration of new compounds to overcome current therapy limitations.

AREAS COVERED

This manuscript offers an updated overview of investigational drugs for symptomatic uterine fibroids.

EXPERT OPINION

Despite ulipristal acetate's well-established efficacy as a selective progesterone receptor modulator (SPRM) in fibroid treatment, its prescription has declined due to the rare but severe risk of liver damage. Oral GnRH antagonists, like elagolix, relugolix, and linzagolix, with their novel pharmacodynamic properties, are gaining traction in fibroid management, inducing a dose-dependent reduction in circulating sex hormone levels. Ongoing research on natural compounds, such as vitamin D and epigallocatechin gallate (EGCG), presents emerging options for treating uterine fibroids. This evolving landscape reflects the ongoing efforts to improve therapeutic outcomes for individuals with symptomatic uterine fibroids.

Current and Emerging Treatment Options for Uterine Fibroids

Uterine fibroids are the most common benign neoplasm of the female reproductive tract in reproductive age women. Their prevalence is age dependent and can be detected in up to 80% of women by the age of 50 years. Patients affected by uterine fibroids may experience a significant physical, emotional, social, and financial toll as well as losses in their quality of life. Unfortunately, curative hysterectomy abolishes future pregnancy potential, while uterine-sparing surgical and radiologic alternatives are variously associated with reduced long-term reproductive function and/or high tumor recurrence rates. Recently, pharmacological treatment against uterine fibroids have been widely considered by patients to limit uterine fibroid-associated symptoms such as heavy menstrual bleeding. This hormonal therapy seemed effective through blocking the stimulatory effects of gonadal steroid hormones on uterine fibroid growth. However, they are contraindicated in women actively pursuing pregnancy and otherwise effective only during use, which is limited because of long-term safety and other concerns. Accordingly, there is an urgent unmet need for safe, durable, and fertility-compatible non-surgical treatment options for uterine fibroids. In this review article, we cover the current pharmacological treatments for uterine fibroids including their comparable efficacy and side effects as well as emerging safe natural compounds with promising anti-uterine fibroid effects.

Efficacy and safety of vilaprisan in women with uterine fibroids: data from the ASTEROID 3 randomized controlled trial

OBJECTIVE

Vilaprisan is a highly potent selective progesterone receptor modulator shown to reduce heavy menstrual bleeding, induce amenorrhea, and diminish uterine fibroid volume in phase 2 studies. The objective of ASTEROID 3 was to demonstrate the superiority of vilaprisan compared with placebo in the treatment of heavy menstrual bleeding in women with uterine fibroids.

DESIGN

Randomized, double-blind, placebo-controlled, multicenter phase 3 study.

SETTING

Hospitals and medical centers.

PATIENT(S)

Women with ≥1 uterine fibroid of ≥3 cm and heavy menstrual bleeding of >80 mL/cycle.

INTERVENTION(S)

Women were randomly assigned to 1 of 4 treatment arms, which were planned to comprise 2 treatment periods of 12 weeks, each with vilaprisan (2 mg/d) or placebo that were continuous or separated by a break of one bleed.

MAIN OUTCOME MEASURE(S)

Amenorrhea (primary end point; <2 mL in the last 28 days of treatment) and heavy menstrual bleeding response (key secondary end point; <80 mL/cycle and >50% reduction in bleeding from baseline) were measured with the alkaline hematin method. Change in volume of the 3 largest fibroids from baseline to end of treatment was assessed by ultrasound. Safety was monitored throughout the study.

RESULT(S)

Overall, 75 women completed the first 12 weeks of treatment. Statistically significant and clinically meaningful differences were observed between the vilaprisan- and placebo-treated groups in both the full analysis and per-protocol sets. In the per-protocol set (n = 36 and n = 12 for the vilaprisan and placebo groups, respectively), amenorrhea was observed more frequently in women treated with vilaprisan than in those who received placebo (83.3% vs. 0%, P<.0001), with a median time to onset of 3 days in the vilaprisan group. Similarly, more vilaprisan- than placebo-treated women achieved a response in heavy menstrual bleeding (91.7% vs. 25.0%, P<.0001). Serious adverse events were reported for 22 (27.8%) of 79 women and were evenly distributed among the 4 groups receiving vilaprisan and/or placebo. None of these events led to study discontinuation or were related to the liver, and no new safety findings were identified compared with the earlier phase 2 ASTEROID studies.

CONCLUSION(S)

Vilaprisan is efficacious and well tolerated over 12 weeks in the treatment of heavy menstrual bleeding associated with uterine fibroids. Further investigations of the long-term efficacy and safety of vilaprisan are warranted.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03400943 (ClinicalTrials.gov).

Contemporary approaches in the management of uterine leiomyomas

BACKGROUND

Leiomyomas (fibroids), the most common benign solid tumours in females, originate from the myometrium and are associated with poor quality of life for patients. The current management of uterine leiomyomas mainly includes surgical interventions such as hysterectomy and myomectomy, either by laparoscopy or laparotomy, which have several complications and are not ideal for preserving fertility. Therefore, there is a need to develop or repurpose medical treatments that do not require surgical intervention.

OBJECTIVE

Many drugs are used to treat the symptoms associated with uterine fibroids. The main objective of this systematic review is to give an up-to-date account of potential pharmacological agents (non-surgical methods) for the management of uterine leiomyomas.

SEARCH STRATEGY

PubMed was searched for scientific and clinical literature using the keyword 'uterine fibroids' along with the drug names described in each section. For example, 'uterine fibroids' and 'ulipristal acetate' were the keywords used to search for literature on ulipristal acetate (UPA).

RESULTS

Various preclinical and clinical studies have shown that some drugs and herbal formulations exhibit activity in the management of uterine leiomyomas. Recent studies found that drugs such as UPA, elagolix, EC313, asoprisnol, nutritional supplements and herbal preparations were helpful in treating the symptoms associated with uterine leiomyomas.

CONCLUSION

Many drugs show efficacy in patients with symptomatic uterine fibroids. UPA is one of the most studied and prescribed medicines for uterine fibroids; however, its usage has been restricted due to a few recent incidences of hepatic toxicity. Herbal drugs and natural supplements have also shown promising effects on uterine fibroids. The synergistic effects of nutritional and herbal supplements have been reported in certain cases, and should be studied in detail. Further research is warranted to identify the mode of action of the drugs, and to determine the precise conditions that would explain the causes of toxicity in some patients.

Progesterone Signaling and Uterine Fibroid Pathogenesis; Molecular Mechanisms and Potential Therapeutics

Uterine fibroids (UFs) are the most important benign neoplastic threat to women's health worldwide, with a prevalence of up to 80% in premenopausal women, and can cause heavy menstrual bleeding, pain, and infertility. Progesterone signaling plays a crucial role in the development and growth of UFs. Progesterone promotes the proliferation of UF cells by activating several signaling pathways genetically and epigenetically. In this review article, we reviewed the literature covering progesterone signaling in UF pathogenesis and further discussed the therapeutic potential of compounds that modulate progesterone signaling against UFs, including selective progesterone receptor modulator (SPRM) drugs and natural compounds. Further studies are needed to confirm the safety of SPRMs as well as their exact molecular mechanisms. The consumption of natural compounds as a potential anti-UFs treatment seems promising, since these compounds can be used on a long-term basis-especially for women pursuing concurrent pregnancy, unlike SPRMs. However, further clinical trials are needed to confirm their effectiveness.

Selective Progesterone Receptor Modulators (SPRMs) and Androgen Receptor Modulators (SARMs) as Treatment for Benign Gynecologic Diseases

Common benign gynecologic conditions such as uterine fibroids and endometriosis are linked to chronic pelvic pain, abnormal and heavy uterine bleeding, and infertility. Effective medical management of these diseases is an unmet need. The steroid hormones progesterone (P4), estrogen (E2), and testosterone play a major role in reproductive physiology and uterine pathologies. Notably, selective progesterone receptor modulators have shown considerable promise as treatment options for some hormone-dependent conditions. More limited data are available regarding the safety and efficacy of selective androgen receptor modulators. In this report we review current evidence for selective progesterone receptor modulators and selective androgen receptor modulators as treatment options for benign gynecologic conditions.

Clinical Pharmacokinetics and Pharmacodynamics of the Selective Progesterone Receptor Modulator Vilaprisan: A Comprehensive Overview

Vilaprisan is a highly potent selective progesterone receptor modulator in development for the treatment of symptomatic uterine fibroids and endometriosis. Its pharmacokinetics are characterized by rapid absorption, almost complete bioavailability, and dose-proportional exposure. The intrinsic factors of age, bodyweight, and race have no clinically relevant effect on the pharmacokinetics and pharmacodynamics of vilaprisan and do not warrant a dose adjustment. Similarly, vilaprisan can be used in patients with mild or moderate renal or hepatic impairment without dose adjustment, but its use is not recommended in patients with severe organ impairment. Vilaprisan has no perpetrator potential on cytochrome P450 (CYP) enzymes or transporters and therefore restrictions in the concomitant use of their substrates are not required. Nonetheless, because it is a sensitive CYP3A4 substrate itself, concomitant use of vilaprisan with strong CYP3A inhibitors or inducers is not recommended. However, there is no risk for QTc prolongation when vilaprisan and a strong CYP3A inhibitor are administered concomitantly, as indicated by a vilaprisan concentration–QTc response analysis across all studies with triplicate electrocardiogram measurements. Furthermore, due to its mode of action, vilaprisan is also not recommended to be used together with progestin-containing oral contraceptives. Vilaprisan shows a steep exposure–response relationship for inducing amenorrhea in patients with uterine fibroids experiencing heavy menstrual bleeding. Based on simulations, a dose of 2 mg/day is expected to induce a maximum bleeding reduction and was thus selected for phase III.

Assessment of the safe and efficacious dose of the selective progesterone receptor modulator vilaprisan for the treatment of patients with uterine fibroids by exposure-response modelling and simulation

AIMS

We report population pharmacokinetic (popPK) and exposure-response (E-R) analyses for efficacy (induced amenorrhoea [IA]) and safety (unbound oestradiol [E2] concentrations) of the selective progesterone receptor modulator vilaprisan. Results were used to inform the dose for the Phase 3 programme in patients with uterine fibroids.

METHODS

A popPK model was developed using data from Phase 1 and 2 studies (including ASTEROID 1 and 2). The relationship between vilaprisan exposure (steady-state AUC) and IA after oral administration of 0.5, 1, 2 or 4 mg/day over 3 months was analysed in ASTEROID 1 using logistic regression and qualified in ASTEROID 2 by comparing simulated and observed probability for IA after 2 mg/day. The exposure-E2 relationship was analysed visually.

RESULTS

Vilaprisan clearance was 22.7% lower in obese vs non-obese patients. The E-R relationship for IA in ASTEROID 1 was steep and consistent with ASTEROID 2, with a maximum probability (P_max ) of 59% (95% CI: 49-68%). The exposure at which 50% of P_max is obtained was 36.9 μg*h/L (95% CI: 27.7-48.7 μg*h/L). Simulations showed that 36% of the patients will be below 90% of P_max for IA after 1 mg/day compared to 2% after 2 mg/day. E2 levels tended to decrease with increasing exposure. While E2 levels remained largely within the physiologic follicular phase range, the clinical relevance of this decrease will be evaluated in long-term studies.

CONCLUSIONS

A 2 mg/day dose was selected for Phase 3 as E-R analyses show this dose results in a close to maximum probability for IA, without any safety concerns noted.

elaborator: A Novel App for Insights into Laboratory Data of Clinical Trials

In clinical studies there are huge numbers of laboratory parameters available that are measured at several visits for several treatment groups. The status quo for presenting laboratory data in clinical trials consists in generating large numbers of tables and data listings. Such tables and listings are required for submissions to health authorities. However, reviewing laboratory data presented in the form of tables and listings is a lengthy and tedious process. Thus, to enable efficient exploration of laboratory data we developed elaborator, a comprehensive and easy-to-use interactive browser-based application. The elaborator app comprises three analyses types for addressing different questions, for example about changes in laboratory values that frequently occur, treatment-related changes and changes beyond the normal ranges. In this way, the app can be used by study teams for identifying safety signals in a clinical trial as well as for generating hypotheses that are further inspected with detailed analyses and possibly data from other sources. The elaborator app is implemented in the statistical software R. The R package elaborator can be obtained from https://cran.r-project.org/package=elaborator . Patients' laboratory data need to be extracted from the clinical database and pre-processed locally for feeding into the app. For exploring data by means of the elaborator, the user needs some familiarity with R but no programming knowledge is required.

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.

Validation of a menstrual pictogram and a daily bleeding diary for assessment of uterine fibroid treatment efficacy in clinical studies

BACKGROUND

To evaluate the psychometric and measurement properties of two patient-reported outcome instruments, the menstrual pictogram superabsorbent polymer-containing version 3 (MP SAP-c v3) and Uterine Fibroid Daily Bleeding Diary (UF-DBD). Test-retest reliability, criterion, construct validity, responsiveness, missingness and comparability of the MP SAP-c v3 and UF-DBD versus the alkaline hematin (AH) method and a patient global impression of severity (PGI-S) were analyzed in post hoc trial analyses.

RESULTS

Analyses were based on data from up to 756 patients. The full range of MP SAP-c v3 and UF-DBD response options were used, with score distributions reflecting the cyclic character of the disease. Test-retest reliability of MP SAP-c v3 and UF-DBD scores was supported by acceptable intraclass correlation coefficients when stability was defined by the AH method and Patient Global Impression of Severity (PGI-S) scores (0.80-0.96 and 0.42-0.94, respectively). MP SAP-c v3 and UF-DBD scores demonstrated strong and moderate-to-strong correlations with menstrual blood loss assessed by the AH method. Scores increased in monotonic fashion, with greater disease severities, defined by the AH method and PGI-S scores; differences between groups were mostly statistically significant (P < 0.05). MP SAP-c v3 and UF-DBD were sensitive to changes in disease severity, defined by the AH method and PGI-S. MP SAP-c v3 and UF-DBD showed a lower frequency of missing patient data versus the AH method, and good agreement with the AH method.

CONCLUSIONS

This evidence supports the use of the MP SAP-c v3 and UF-DBD to assess clinical efficacy endpoints in UF phase III studies replacing the AH method.

Vilaprisan, a New Selective Progesterone Receptor Modulator in Uterine Fibroid Pharmacotherapy-Will it Really be a Breakthrough?

BACKGROUND

Vilaprisan (VPR) is a new orally available selective progesterone receptor modulator (SPRM), with anti-proliferative activity against uterine fibroids (UFs). It definitively causes suppression of ovulation and inhibition of proliferation of endometrial, myometrial and UF cells.

PURPOSE

This review aims to summarize current knowledge on VPR from all studies, including clinical trials, conducted to date and to contextualize the potential role of VPR in future medical regimens for the treatment of UFs.

METHODS

We performed a literature search in PubMed US National Library of Medicine and Google Scholar databases. Both databases were extensively searched for all original and review articles/book chapters as well as congress abstracts published in English until July 2019. The use of VPR for UF therapy was identified by using the keywords: "uterine fibroids" and "vilaprisan".

RESULTS

In phase I and II clinical trials, VPR was shown to be effective in ameliorating UF-related clinical symptoms, especially abnormal or excessive uterine bleeding and in shrinking UFs. The tolerability of VPR is roughly similar to that of ulipristal acetate (UPA) and it tends to be more favorable than that of GnRH-agonists.

CONCLUSION

Presently, all trials examining the utility of VPR for the treatment of UF are halted; likely, due to the recently reported cases of hepato-toxicity with UPA, in addition to non reassuring toxicology results from preclinical long-term testing on rodents, carried out in parallel with late stage testing on humans. An accurate summary of robust data related to the safety of VPR is urgently needed to draw definitive conclusions on the future clinical development of this drug for UF therapy.

Combined experimental and quantum mechanical elucidation of the synthetically accessible stereoisomers of Hydroxyestradienone (HED), the starting material for vilaprisan synthesis

Selective progesterone receptor modulators are promising therapeutic options for the treatment of uterine fibroids. Vilaprisan, a new chemical entity that was discovered at Bayer is currently in clinical development. In this study we provide a combined experimental and quantum chemical approach providing the data that allowed to present hydroxyestradienone as an acceptable starting material for drug substance synthesis. Hydroxyestradienone has four stereogenic centers leading to 8 diastereomers and 16 enantiomers of which only six diastereomers were synthetically accessible but two not. A computational multistep protocol resulting in density functional P2PLYP-D3(BJ)/dev2-TZVPP Gibbs free energies and SMD solvation free energies led to a clear separation between the existing and the synthetically not accessible enantiomers, whereas multiple geometry-based and cheminformatic descriptors were not able to explain experimental findings.

Effect of Food Intake on the Pharmacokinetics of the Selective Progesterone Receptor Modulator Vilaprisan: A Randomized Clinical Study in Healthy Postmenopausal Women

This exploratory, open-label, randomized, 3-period crossover study in 12 healthy postmenopausal women investigated the effects of food intake on the pharmacokinetics of vilaprisan. Single doses of vilaprisan (2 mg) were administered under fasting conditions, after intake of a high-fat, high-calorie meal, and after intake of a moderate-fat, moderate-calorie meal. The intake of food had only a marginal impact on the oral bioavailability of vilaprisan. The mean exposure of vilaprisan (area under the plasma concentration-time curve [AUC]) was increased by approximately 20% when the drug was taken after a meal and not on an empty stomach (point estimate for AUC ratios [%] and 90% confidence interval: high-fat and -calorie meal/fasting 121 [114-128]; moderate-fat and -calorie meal/fasting 118 [111-125]). The rate of absorption was slightly decreased when the drug was taken after a meal as indicated by approximately 10% lower mean maximum concentrations (C_max ) of vilaprisan in plasma (C_max ratios: high-fat and -calorie meal/fasting 87.9 [75.6-102]; moderate-fat and -calorie meal/fasting 89.4 [76.9-104]) and a prolonged time to C_max (fasting: 1.5 hours; fed conditions; ∼4 hours). Overall, the results of this study indicate that vilaprisan can be administered equally well with or without food.

Selective Progesterone Receptor Modulators-Mechanisms and Therapeutic Utility

Selective progesterone receptor modulators (SPRMs) are a new class of compounds developed to target the progesterone receptor (PR) with a mix of agonist and antagonist properties. These compounds have been introduced for the treatment of several gynecological conditions based on the critical role of progesterone in reproduction and reproductive tissues. In patients with uterine fibroids, mifepristone and ulipristal acetate have consistently demonstrated efficacy, and vilaprisan is currently under investigation, while studies of asoprisnil and telapristone were halted for safety concerns. Mifepristone demonstrated utility for the management of endometriosis, while data are limited regarding the efficacy of asoprisnil, ulipristal acetate, telapristone, and vilaprisan for this condition. Currently, none of the SPRMs have shown therapeutic success in treating endometrial cancer. Multiple SPRMs have been assessed for efficacy in treating PR-positive recurrent breast cancer, with in vivo studies suggesting a benefit of mifepristone, and multiple in vitro models suggesting the efficacy of ulipristal acetate and telapristone. Mifepristone, ulipristal acetate, vilaprisan, and asoprisnil effectively treated heavy menstrual bleeding (HBM) in patients with uterine fibroids, but limited data exist regarding the efficacy of SPRMs for HMB outside this context. A notable class effect of SPRMs are benign, PR modulator-associated endometrial changes (PAECs) due to the actions of the compounds on the endometrium. Both mifepristone and ulipristal acetate are effective for emergency contraception, and mifepristone was approved by the US Food and Drug Administration (FDA) in 2012 for the treatment of Cushing's syndrome due to its additional antiglucocorticoid effect. Based on current evidence, SPRMs show considerable promise for treatment of several gynecologic conditions.

Pharmacokinetics and Safety of the Novel Selective Progesterone Receptor Modulator Vilaprisan in Participants With Renal Impairment

This open label, parallel-group study investigated the pharmacokinetics and safety of a single oral 2-mg dose of the novel selective progesterone receptor modulator vilaprisan in participants with impaired renal function compared with age, weight, sex, and race matched controls with normal renal function. Systemic exposure (area under the plasma concentration-time curve [AUC]) and maximum observed concentrations (Cmax ) were compared among 9 participants with moderate renal impairment and matched controls by ANOVA. An additional 4 participants, each with severe renal impairment or normal renal function, contributed to a linear regression analysis exploring any monotone relationship between individual variables and the estimated glomerular filtration rate. The geometric mean AUC was increased by a factor of 1.35 in renally impaired participants compared to normal controls (not statistically significant: least squares mean, 1.346; 90% confidence interval, 0.918-1.973). Cmax was similar in participants with moderate renal impairment and normal renal function (least squares mean, 1.026; 90% confidence interval, 0.779-1.351). Considering the overall variability, there was no correlation between renal function (estimated glomerular filtration rate) and Cmax or AUC of vilaprisan. Single oral administration of vilaprisan 2 mg was well tolerated by all participants, both men and women and irrespective of renal function. The incidence of treatment-emergent adverse events was similar across all groups. Results from this study do not indicate that a dose adjustment will be necessary for vilaprisan when treating patients up to moderate renal impairment.

Pharmacokinetics and Safety of the Selective Progesterone Receptor Modulator Vilaprisan in Chinese Healthy Postmenopausal Women

Vilaprisan is a novel selective progesterone receptor modulator for the long-term treatment of uterine fibroids and endometriosis. This study investigated the pharmacokinetics, safety, and tolerability of vilaprisan in healthy Chinese postmenopausal women. Twelve participants received multiple doses of vilaprisan once daily over 14 days as a 2-mg tablet. Plasma vilaprisan concentrations were determined using liquid chromatography-tandem mass spectrometry. The main pharmacokinetic parameters of vilaprisan were assessed with noncompartmental analysis, including maximum observed concentration (C_max ), systemic exposure (area under the plasma concentration-time curve), time to reach C_max and terminal half-life. Safety assessments include the documentation of adverse events, measurement of clinical/anthropometric parameters and vital signs, electrocardiogram, and physical and gynecologic examination. The participants had a mean age of 53.3 (± 4.2) years and a body mass index of 23.8 ± 2.8 kg/m² . Median time to reach C_max was 1.5 hours after both single and multiple vilaprisan administration. Mean C_max values obtained after multiple dosing (23.3 μg/L [standard deviation (SD) = 6.73]) were 1.92-fold (SD = 0.554) higher compared to single dosing (12.5 μg/L [SD = 3.04]). Mean area under the plasma concentration-time curve in the dosing interval increased with an accumulation factor of 2.98 (SD = 0.767) between single (91.3 μg · h/L [SD = 20.4]) and multiple dosing (276 μg · h/L [SD = 109]). The mean terminal half-life of vilaprisan was 44.5 hours (SD = 10.3) after multiple dosing. Mild to moderate adverse events were observed similar to previous studies. Overall, daily oral administration of the therapeutic dose of 2 mg of vilaprisan over 14 days was safe and well tolerated by all participants.

The effects of vilaprisan on the pharmacodynamics and pharmacokinetics of a combined oral contraceptive-A randomized controlled trial

AIMS

The primary objective was to explore whether the suppression of ovarian activity induced by a combined oral contraceptive (COC) is influenced by the simultaneous intake of the selective progesterone receptor modulator (SPRM) vilaprisan (VPR).

METHODS

In this exploratory randomized, double-blind, parallel-group study, 71 healthy premenopausal women were randomized (1:1) to receive either 2 mg/d VPR or placebo for 3 months. Concomitantly, a COC (0.15 mg levonorgestrel, 0.03 mg ethinyloestradiol) was administered in a cyclic regimen. Ovarian activity (Hoogland score based on follicle size and hormone concentrations), cervical function (Insler score), bleeding pattern and endometrial thickness/histology were assessed before treatment, in treatment cycle 3 and during follow-up.

RESULTS

The known COC-driven suppression of ovarian activity was mildly affected by VPR. COC+VPR group: 22, 0 and 6% of the subjects had Hoogland scores of 4 (active follicle-like structures), 5 or 6 (ovulation). COC+placebo group: 14% of the subjects had a score of 4 and none a score of 5 or 6 (Bayesian analysis for Hoogland score = 4, median difference in response rate: 7.5%; 90% credible interval [-8.5; 23.5%]). COC effects on cervical function were moderately affected (mucus more sperm permeable under COC+VPR). COC withdrawal bleeding, in contrast, was absent in 81% of the subjects receiving COC+VPR vs 0% receiving COC+placebo.

CONCLUSION

The SPRM VPR interfered with the pharmacodynamic effects of the COC. Therefore, full contraceptive effectiveness cannot be assumed without final judgement by a Pearl index study. Women on SPRMs should be advised to use nonhormonal contraception methods.

Effects of the levonorgestrel intrauterine system on the endometrium after long-term exposure to mifepristone: Secondary outcomes of a randomized controlled trial

OBJECTIVE

Long-term treatment with progesterone receptor modulators (PRM) is associated with a distinct histological entity termed progesterone receptor modulator associated endometrial changes (PAEC). While accumulating evidence implies that these changes are benign and reversible after cessation of treatment, there are currently no data underpinning their development. Consequently, as a precaution, endometrial shedding is recommended after long-term PRM intake. Avoiding endometrial shedding after treatment with a PRM and prior to the start of a progestin treatment would be beneficial for women in reproductive age to avoid pregnancy and bleeding. However, the endometrial morphology with such a treatment regimen is unknown. The aim of this study was to delineate the endometrial morphology following continuous long-term treatment with the PRM mifepristone and subsequent placement of a levonorgestrel intrauterine system (LNG-IUS) without prior shedding of the endometrium.

STUDY DESIGN

This study reports the secondary outcome from a double-blinded randomized controlled trial conducted at Karolinska University Hospital, Sweden, November 2009 to January 2015. Healthy women aged 18-43 years with regular menstrual cycles were included. Eligible women were randomized to receive either 50 mg of mifepristone (n = 29) or a comparator (n = 29), every other day for two months followed by insertion of an LNG-IUS 52 mg. Endometrial biopsies were obtained at baseline and three months after placement of the device. The samples were histologically assessed. The main outcome measure of this sub-study was the endometrial morphology including presence of PAEC three months after LNG-IUS insertion.

RESULTS

Nine and eight paired biopsies from the mifepristone and comparator group, respectively, were included in the histological analysis. There were no differences in baseline characteristics between the groups and all baseline endometrial biopsies were physiological. Three months after LNG-IUS placement the endometrial morphology was still benign without PAEC in all samples treated with either mifepristone or comparator. A progestin effect on the endometrium was seen in all samples.

CONCLUSIONS

Placement of an LNG-IUS immediately following two months' treatment with the PRM mifepristone, without any prior shedding of the endometrium, may represent a feasible approach in terms of endometrial safety. However, larger studies are needed to confirm our results.

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.

NAMS 2018 Utian Translational Science Symposium, October 2018, San Diego, California New therapies for leiomyomas: when surgery may not be the best option

The North American Menopause Society (NAMS) held the 2018 Utian Translational Science Symposium on October 2, 2018, in San Diego, California, to discuss new therapeutic approaches to uterine leiomyomas when surgery is not the optimal choice.Uterine leiomyomas arise from a single clonal cell and are the most common gynecologic disorder affecting reproductive and perimenopausal women worldwide. The prevalence of this disorder is approximately 40% to 70% in white women and 60% to 80% in black women. Recent research suggests that both estrogen and progesterone modulate the growth of leiomyomas, with progesterone being a major stimulator of leiomyoma growth.Women with symptomatic uterine leiomyomas experience heavy uterine bleeding, bulk symptoms, miscarriages, and pregnancy complications. Surgical therapies such as myomectomy or hysterectomy are highly effective; however, medical therapy with progestin-predominant contraceptives or gonadotropin-releasing hormone (GnRH) agonists are in many ways inadequate to address the unmet need for better, noninvasive, and cost-effective treatments.Recent advances in medical treatment, such as selective progesterone receptor modulators, new oral GnRH analogs, and clinical trials that provide new therapeutic approaches, were presented by speakers at the symposium. Research on why there is a prevalence of leiomyomas in black women, the racial and genetic effects on leiomyoma growth, and potential molecular mechanisms also were discussed.

Effect of hepatic impairment on the pharmacokinetics of vilaprisan: An open-label, single-dose, parallel-group study

Aims

The study objective was to evaluate the pharmacokinetics of the selective progesterone receptor modulator vilaprisan in participants with hepatic impairment. Additionally, the safety and tolerability of vilaprisan were investigated.

Methods

In this phase 1, open‐label, nonrandomised, parallel‐group, pharmacokinetic study, men and women with mild or moderate hepatic impairment (Child–Pugh grade A or B) and control participants with normal hepatic function matched by age, weight and sex received a single oral 2 mg dose of vilaprisan. Key pharmacokinetic parameters, relationships between parameters and safety outcomes were measured.

Results

Thirty‐six participants completed the study: 9 with mild hepatic impairment, 9 with moderate hepatic impairment and 18 matched control participants with normal hepatic function. Vilaprisan reached maximum plasma concentrations after 1–2 hours. Unbound vilaprisan exposure was 1.44‐fold higher for participants with mild hepatic impairment vs controls (90% confidence interval: 0.91–2.26), and 1.74‐fold higher for participants with moderate impairment vs controls (90% confidence interval: 1.09–2.78). The maximum observed unbound peak concentrations were similar for participants with hepatic impairment and matched controls. Vilaprisan 2 mg was well tolerated and the incidence of treatment‐emergent adverse events was similar across cohorts.

Conclusion

Only mild increases of <1.75‐fold in exposure were observed in participants with mild or moderate hepatic impairment compared with control participants. No safety concern was identified. These data, alongside the excellent safety profile observed in phase 1 and 2 studies, do not indicate that a dose adjustment would be required in patients with mild or moderate hepatic impairment.