Exposure-Safety Analyses Identify Predictors of Change in Bone Mineral Density and Support Elagolix Labeling for Endometriosis-Associated Pain

The short- and mid-term efficacy and safety of elagolix in the management of pain associated with endometriosis: A systematic review and meta-analysis

BACKGROUND

Elagolix, an approved non-peptide GnRH antagonist, shows promise in relieving endometriosis-related pain, but its short- and mid-term efficacy and potential side effects are still under investigation.

OBJECTIVE

The aim is to provide data for therapeutic applications by methodically evaluating elagolix's safety and effectiveness in treating endometriosis-related pain.

METHODS

Databases such as PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and others were thoroughly searched. The search time was from the establishment date to September 2023. The study included randomized controlled trials (RCTs) that compared the efficacy of elagolix versus placebo in treating endometriosis-associated pain. After data extraction and literature scanning, quality assessment was carried out using Quality evaluation was carried out using the bias risk assessment tool suggested by the Cochrane Reviewers' Handbook 5.1.0 after literature screening and data extraction. Stata 15.0 was used to do the meta-analysis.

RESULTS

In total, five RCTs involving 2056 patients were included in the analysis. The meta-analysis demonstrated a significant superiority of elagolix over placebo in the management of endometriosis-related pain, specifically in endometriosis pain [WMD=-0.77, 95% CI (-1.00, -0.53), P<0.001], as well as in non-menstrual pelvic pain, daily assessment of dysmenorrhea (DYS), and dyspareunia (DYSP), all of which are associated with endometriosis. Regarding safety, no discernible variation was observed in the incidence of serious adverse responses between the elagolix and placebo groups [RR=0.90, 95% CI (0.58, 1.40), P=0.643]. Conversely, the elagolix group exhibited a significantly higher incidence rate of general adverse responses [RR = 1.34, 95% CI (1.18, 1.52), P<0.001] compared to the control group.

CONCLUSIONS

The efficacy of elagolix in reducing pain in premenopausal women with endometriosis has been demonstrated over the short- to mid-term. However, careful monitoring for potential adverse effects is essential throughout the treatment duration.

Low-Dose Elagolix for the Treatment of Heavy Menstrual Bleeding in Patients With Uterine Leiomyomas: A Randomized Controlled Trial

OBJECTIVE

To evaluate the safety and efficacy of elagolix 150 mg once-daily monotherapy in patients with heavy menstrual bleeding associated with uterine leiomyomas.

METHODS

A phase 4, randomized, double-blind, placebo-controlled, 6-month treatment study was conducted in premenopausal patients aged 18-51 years with heavy menstrual bleeding (defined as menstrual blood loss greater than 80 mL during one menstrual cycle) associated with uterine leiomyomas. Patients were randomized 2:1 to receive elagolix 150 mg once daily or placebo. The primary endpoint was reduction in menstrual blood loss volume to less than 80 mL at the final month and at least a 50% reduction in menstrual blood loss volume from baseline to the final month.

RESULTS

Of 82 randomized patients, 54 received elagolix 150 mg and 28 received placebo. With elagolix, 49.4% (95% CI 35.1-63.8%) of patients met the primary endpoint, compared with 23.3% (95% CI 7.2-39.5%) of patients who received placebo ( P =.035). Statistically significant differences between elagolix and placebo in mean reduction of menstrual blood loss from baseline were seen as early as month 1 ( P <.05 for months 1-3 and 5). Significantly more patients receiving elagolix experienced suppression of bleeding compared with placebo ( P =.036). Greater improvements were observed in the elagolix group (vs placebo) in the proportion of patients with amenorrhea, in hemoglobin concentrations, and in health-related quality of life. No serious or severe adverse events were reported for elagolix, compared with 7.1% of participants in the placebo group having serious adverse events (coronavirus disease 2019 [COVID-19] n=1, enlarged uvula n=1). Three patients (5.6%) discontinued elagolix due to adverse events.

CONCLUSION

Elagolix 150 mg once-daily monotherapy significantly improved heavy menstrual bleeding associated with uterine leiomyomas compared with placebo in premenopausal patients. Treatment with elagolix 150 mg once daily was generally well-tolerated in this study, with no new safety signals.

FUNDING SOURCE

AbbVie Inc.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT03886220.

Interdisciplinary model-informed drug development for extending duration of elagolix treatment in patients with uterine fibroids

AIM

Elagolix, a gonadotropin-releasing hormone receptor antagonist, was recently approved for heavy menstrual bleeding associated with uterine fibroids (UF, Oriahnn) at a dose of 300 mg twice daily (BID) in combination with add-back therapy (oestradiol 1 mg/norethindrone acetate 0.5 mg [E2/NETA] once daily) for 24 months use. The limited duration of treatment is related to elagolix dose- and duration-dependent decrease in oestrogen that is mechanistically linked to changes in bone mineral density (BMD). The work herein supported the extended treatment duration of 24 months.

METHODS

An integrated exposure-response and epidemiological modelling framework of elagolix effects on femoral neck BMD (FN-BMD), informed by real-world data and phase 3 clinical trials data, was developed to predict the time course and magnitude of changes in BMD and its relation to risk of bone fracture in women with UF.

RESULTS

Model results indicated that women treated with elagolix 300 mg BID + E2/NETA in the long term (ie, >24 months) may experience less than 1% loss in FN-BMD per year, relative to placebo. The exposure-response model simulations and clinical risk factors were used to estimate 10-year risk of fractures using the clinically validated Fracture Risk Assessment Tool (FRAX). The impact of elagolix 300 mg BID + E2/NETA treatment on the 10-year risk of hip or major osteoporotic fractures estimated from the FRAX model was minimal compared to that of placebo.

CONCLUSION

The elagolix integrated exposure-BMD analysis and translation to fracture risk provided an interdisciplinary model-informed drug development framework for clinical benefit-risk evaluation and enabled approval of longer treatment duration to benefit the patient.

Computational Models for Diagnosing and Treating Endometriosis

Endometriosis is a common but poorly understood disease. Symptoms can begin early in adolescence, with menarche, and can be debilitating. Despite this, people often suffer several years before being correctly diagnosed and adequately treated. Endometriosis involves the inappropriate growth of endometrial-like tissue (including epithelial cells, stromal fibroblasts, vascular cells, and immune cells) outside of the uterus. Computational models can aid in understanding the mechanisms by which immune, hormone, and vascular disruptions manifest in endometriosis and complicate treatment. In this review, we illustrate how three computational modeling approaches (regression, pharmacokinetics/pharmacodynamics, and quantitative systems pharmacology) have been used to improve the diagnosis and treatment of endometriosis. As we explore these approaches and their differing detail of biological mechanisms, we consider how each approach can answer different questions about endometriosis. We summarize the mathematics involved, and we use published examples of each approach to compare how researchers: (1) shape the scope of each model, (2) incorporate experimental and clinical data, and (3) generate clinically useful predictions and insight. Lastly, we discuss the benefits and limitations of each modeling approach and how we can combine these approaches to further understand, diagnose, and treat endometriosis.

Endometriosis: Epidemiology, Classification, Pathogenesis, Treatment and Genetics (Review of Literature)

Endometriosis is a “mysterious” disease and its exact cause has not yet been established. Among the etiological factors, congenital, environmental, epigenetic, autoimmune and allergic factors are listed. It is believed that the primary mechanism of the formation of endometriosis foci is retrograde menstruation, i.e., the passage of menstrual blood through the fallopian tubes into the peritoneal cavity and implantation of exfoliated endometrial cells. However, since this mechanism is also observed in healthy women, other factors must also be involved in the formation of endometriosis foci. Endometriosis is in many women the cause of infertility, chronic pain and the deterioration of the quality of life. It also represents a significant financial burden on health systems. The article presents a review of the literature on endometriosis—a disease affecting women throughout the world.

HOX cluster and their cofactors showed an altered expression pattern in eutopic and ectopic endometriosis tissues

Endometriosis is major gynecological disease that affects over 10% of women worldwide and 30%-50% of these women have pelvic pain, abnormal uterine bleeding and infertility. The cause of endometriosis is unknown and there is no definite cure mainly because of our limited knowledge about its pathophysiology at the cellular and molecular levels. Therefore, demystifying the molecular mechanisms that underlie endometriosis is essential to develop advanced therapies for this disease. In this regard, HOX genes are remarkable because of their critical role in endometrial development and receptivity during implantation, which is attributed to their ability to mediate some of the sex steroid functions during the reproductive period. Access to the expression profiles of these genes would provide the necessary information to uncover new genes for endometriosis and assist with disease diagnosis and treatment. In this study we demonstrate an altered expression pattern for the HOX clusters (A-D) and their cofactors in both eutopic and ectopic conditions compared to control tissue biopsies. Remarkably, most of the intensive changes occurred in eutopic samples from endometriosis patients compared to control tissue biopsies. Pathway analysis revealed the involvement of differentially expressed genes in cancer that correlate with an association between endometriosis and cancer. Our results suggest critical roles for the HOX cluster and their cofactors in endometriosis pathophysiology.

Validation of a quantitative systems pharmacology model of calcium homeostasis using elagolix Phase 3 clinical trial data in women with endometriosis

Elagolix is a novel, oral gonadotropin‐releasing hormone receptor antagonist indicated for the management of moderate to severe pain associated with endometriosis and heavy menstrual bleeding associated with uterine fibroids. Consistent with its mechanism of action, elagolix exhibited dose‐dependent suppression of estradiol (E2) in clinical studies. A dose‐response model that describes the relationship between elagolix dosages and average E2 levels was combined with a previously published quantitative systems pharmacology (QSP) model of calcium homeostasis to predict bone mineral density (BMD) changes during and following elagolix treatment. In the QSP model, changes in E2 levels were linked to downstream changes in markers of bone resorption (carboxyterminal cross‐linked telopeptide of type 1 collagen [CTX]), formation (N‐terminal propeptide of type 1 procollagen [P1NP]) and BMD. The BMD, CTX, and P1NP predictions by the QSP model were validated against observed data from four phase III clinical trials of elagolix in premenopausal women with endometriosis. BMD, CTX, and P1NP were successfully described by the QSP model, without any model fitting, suggesting that the model was validated for further predictions of elagolix effects on BMD. Simulations using the validated QSP model demonstrated that elagolix 150 mg once daily dosing for 24 months is predicted to result in −0.91% change from baseline in lumbar spine BMD. The QSP model simulation results were part of the totality of evidence to support the approved duration of therapy for elagolix 150 mg once daily in patients with endometriosis.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

A Personalized Medicine Approach Using Clinical Utility Index and Exposure-Response Modeling Informed by Patient Preferences Data

Selection of a personalized dose for an individual patient can be informed by the patient's preferences, translated as weights on each of the clinically relevant safety and efficacy drug attributes, based on results from a brief patient preference elicitation questionnaire. In this analysis, the weighted attributes were simulated to represent various endometriosis patient profiles. Exposure-response simulations were performed for elagolix, a drug approved for management of moderate to severe pain associated with endometriosis, across a range of plasma exposures corresponding to a range of doses. The results were combined to calculate a personalized clinical utility index. An interactive user-friendly online application was developed and envisioned as a physician's desk tool to personalize the dose selection process based on individual patient preferences. This demonstration should serve as an example of how patient/physician conversation can be facilitated with quantitative tools for personalizing the dose.