Linzagolix therapy versus a placebo in patients with endometriosis-associated pain: a prospective, randomized, double-blind, Phase 3 study (EDELWEISS 3)

STUDY QUESTION

Does linzagolix administered orally once daily for up to 3 months at a dose of 75 mg alone or 200 mg in combination with add-back therapy (ABT) (1.0 mg estradiol; 0.5 mg norethindrone acetate, also known as norethisterone acetate [NETA]) demonstrate better efficacy than placebo in the management of endometriosis-related dysmenorrhea and non-menstrual pelvic pain?

SUMMARY ANSWER

Combining 200 mg linzagolix with ABT was found to significantly reduce dysmenorrhea and non-menstrual pelvic pain at 3 months of therapy, while a daily dose of 75 mg linzagolix yielded a significant decrease only in dysmenorrhea at 3 months.

WHAT IS KNOWN ALREADY?

A previously published Phase 2, dose-finding study reported that at a dose of 200 mg daily, linzagolix promotes full suppression of estradiol secretion to serum levels below 20 pg/ml and noted that the addition of ABT may be needed to manage hypoestrogenic side effects. At lower doses (75 mg and 100 mg/day), linzagolix maintains estradiol values within the target range of 20-60 pg/ml, which could be ideal to alleviate symptoms linked to endometriosis.

STUDY DESIGN, SIZE, DURATION

EDELWEISS 3 was a multicenter, prospective, randomized, placebo-controlled, double-blind, double-dummy Phase 3 study to evaluate the safety and efficacy of linzagolix for the treatment of moderate-to-severe endometriosis-associated pain. Treatment was administered orally once daily for up to 6 months.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In the EDELWEISS 3 trial, 486 subjects with moderate-to-severe endometriosis-associated pain were randomized at a 1:1:1 ratio to one of the three study groups: placebo, 75 mg linzagolix alone or 200 mg linzagolix in association with ABT. Pain was measured daily on a verbal rating scale and recorded in an electronic diary.

MAIN RESULTS AND THE ROLE OF CHANCE

At 3 months, the daily 200 mg linzagolix dose with ABT met the primary efficacy objective, showing clinically meaningful and statistically significant reductions in dysmenorrhea and non-menstrual pelvic pain, with stable or decreased use of analgesics. The proportion of responders for dysmenorrhea in the 200 mg linzagolix with ABT group was 72.9% compared with 23.5% in the placebo group (P < 0.001), while the rates of responders for non-menstrual pelvic pain were 47.3% and 30.9% (P = 0.007), respectively. The 75 mg linzagolix daily dose demonstrated a clinically meaningful and statistically significant reduction in dysmenorrhea versus placebo at 3 months. The proportion of responders for dysmenorrhea in the 75 mg linzagolix group was 44.0% compared with 23.5% in the placebo group (P < 0.001). Although the 75 mg dose showed a trend toward reduction in non-menstrual pelvic pain at 3 months relative to the placebo, it was not statistically significant (P = 0.279). Significant improvements in dyschezia and overall pelvic pain were observed in both linzagolix groups when compared to placebo. Small improvements in dyspareunia scores were observed in both linzagolix groups but they were not significant. In both groups, hypoestrogenic effects were mild, with low rates of hot flushes and bone density loss of <1%. A daily dose of 200 mg linzagolix with ABT or 75 mg linzagolix alone was found to significantly reduce dysmenorrhea and non-menstrual pelvic pain also at 6 months of therapy.

LIMITATIONS, REASONS FOR CAUTION

Efficacy was compared between linzagolix groups and placebo; however, it would be useful to have results from comparative studies with estro-progestogens or progestogens. It will be important to ascertain whether gonadotropin-releasing hormone antagonists have significant benefits over traditional first-line medications.

WIDER IMPLICATIONS OF THE FINDINGS

Linzagolix administered orally once daily at a dose of 200 mg in combination with add-back therapy (ABT) demonstrated better efficacy and safety than placebo in the management of moderate-to-severe endometriosis-associated pain. The quality of life was improved and the risks of bone loss and vasomotor symptoms were minimized due to the ABT. The 75 mg dose alone could be suitable for chronic treatment of endometriosis-associated pain without the need for concomitant hormonal ABT, but further research is needed to confirm this. If confirmed, it would offer a viable option for women who do not want to wish to have ABT or for whom it is contraindicated.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for the EDELWEISS 3 study was provided by ObsEva (Geneva, Switzerland). Analysis of data and manuscript writing were partially supported by ObsEva (Geneva, Switzerland), Theramex (London, UK) and Kissei (Japan) and grant 5/4/150/5 was awarded to M.-M.D. by FNRS. J.D. was a member of the scientific advisory board of ObsEva until August 2022, a member of the scientific advisory board of PregLem, and received personal fees from Gedeon Richter, ObsEva and Theramex. J.D. received consulting fees, speakers' fees, and travel support from Gedeon Richter, Obseva and Theramex, which was paid to their institution. C.B. has received fees from Theramex, Gedeon Richter, and Myovant, and travel support from Gedeon Richter-all funds went to the University of Oxford. He was a member of the data monitoring board supervising the current study, and served at an advisory board for endometriosis studies of Myovant. H.T. has received grants from Abbvie and was past president of ASRM. F.C.H. has received fees from Gedeon Richter and Theramex. O.D. received fees for lectures from Gedeon Richter and ObsEva and research grants for clinical studies from Preglem and ObsEva independent from the current study. A.H. has received grants from NIHR, UKRI, CSO, Wellbeing of Women, and Roche Diagnostics; he has received fees from Theramex. A.H.'s institution has received honoraria for consultancy from Roche Diagnostics, Gesynta, and Joii. M.P. has nothing to declare. F.P. has received fees from Theramex. S.P.R. has been a member of the scientific advisory board of Gedeon Richter and received fees from Gedeon Richter. A.P. and M.B. are employees of Theramex. E.B. was an employee of ObsEva, sponsor chair of the data monitoring board supervising the current study, and has been working as a consultant for Theramex since December 2022; she owns stock options in ObsEva. M.-M.D. has received fees and travel support from Gedeon Richter and Theramex.

TRIAL REGISTRATION NUMBER

NCT03992846.

TRIAL REGISTRATION DATE

20 June 2019.

DATE OF FIRST PATIENT’S ENROLLMENT

13 June 2019.

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.

Oral GnRH Antagonists in Combination with Estradiol and Norethindrone Acetate for Pain Relief Associated with Endometriosis: A Review of Evidence of a Novel Class of Hormonal Agents

Current medical treatment options for endometriosis associated pains are inadequate. Evidence on effects of nonsteroidal anti-inflammatory drugs is scarce. Around one third of patients are not responsive to oral contraceptives or progestins due to progesterone resistance. Gonadotropin-releasing hormone (GnRH) agonists can only be used for a short duration because of associated side effects. Oral GnRH antagonists, including elagolix, relugolix, and linzagolix allow oral administration, induce dose dependent reduction of estradiol levels, do not cause initial flare up of endometriosis symptoms, and allow the fast return of ovarian function and menstruation after discontinuation. Elagolix at a low dose of 150 mg once daily, or the higher dose of 200 mg twice daily, significantly increased the proportion of women achieving clinically meaningful decline of dysmenorrhea, noncyclic pelvic pain, and dyspareunia. Relugolix at an oral dose of 40 mg/day results in improvement in different forms of endometriosis related pelvic pain, with an efficacy and side effect profile similar to that of GnRH agonists. Adding 1 mg of estradiol and 0.5 mg of norethindrone to 40 mg of relugolix (relugolix combination therapy) allows extension of treatment to 24 weeks with maintained efficacy and an improved side effect profile. Linzagolix, in a dose of 75 mg/day, can be used alone to treat endometriosis associated pain. For severe pelvic pain and dyspareunia, linzagolix can be used in a high dose of 200 mg/day with hormonal add-back therapy to preserve bone health.

Considerations on implementation of the newest treatment for symptomatic uterine fibroids: Oral GnRH antagonists

Novel gonadotrophin releasing hormone (GnRH) antagonist treatments have recently been developed in combination with hormonal add-back therapy, as an oral treatment option for women suffering from uterine fibroids. Registration trials assessing the GnRH antagonist combination preparations with relugolix, elagolix and linzagolix have assessed treatment efficacy for fibroid-related heavy menstrual blood loss in comparison to placebo. Marketing authorization has been granted by several agencies including those in Europe, the United Kingdom and the United States. While the registration trials report a robust effect on the reduction of heavy menstrual blood loss and improvement in quality of life scores, reticence is advised before widespread prescription. In this review, we demonstrate limitations in the trial data, namely a lack of generalizability due to the restricted study population, the lack of transparency in the distribution of disease-level characteristics limiting the predictability of treatment success in the real-world diverse population, and the absence of any comparison to current alternative treatment methods. Importantly, no clinically meaningful volume reductions were found with GnRH antagonist combination preparations, and long-term safety data, particularly concerning modest but stable bone mineral density decline, need further addressing. Symptoms related to uterine fibroids adversely affect many women's quality of life and effective medical treatments are lacking. However, despite the urgent need for conservative treatments, it is vitally important that novel drugs, like combination oral GnRH antagonists, undergo sufficiently rigorous evaluation of safety, effectiveness and cost-effectiveness in a representative population and are compared with alternative treatment methods before introduction into mainstream clinical practice.

Suppression of hypothalamic-pituitary-gonadal function by linzagolix in benign prostatic hyperplasia and polycystic ovary syndrome animal models

The hypothalamic-pituitary-gonadal (HPG) axis is an important regulatory mechanism involved primarily in the development and regulation of the reproductive systems. The suppression of the HPG axis by gonadotropin-releasing hormone (GnRH) analogues is expected to be effective for the treatment of sex hormone-dependent diseases, such as endometriosis, uterine fibroid, prostate cancer, benign prostatic hyperplasia (BPH) and polycystic ovary syndrome (PCOS). Despite the established involvement of GnRH signalling in these disorders, the therapeutic efficacy of small molecular GnRH antagonists for BPH and PCOS has not been adequately evaluated in non-clinical studies. Therefore, the purpose of the present study was to evaluate the potential of linzagolix, a small molecular GnRH antagonist, as a potential new treatment option for BPH and PCOS. Dogs and rats exhibiting normal prostates and dogs diagnosed with prostatic hyperplasia were used to evaluate the effects of linzagolix in BPH. The effects of linzagolix were also examined in a rat model of PCOS induced by repeated administration of letrozole, an aromatase inhibitor. Linzagolix reduced serum luteinizing hormone and testosterone levels in male rats and normal or BPH model dogs and suppressed prostate weight without testosterone depletion, suggesting the existence of an optimal therapeutic testosterone level for BPH treatment. In a PCOS rat model, linzagolix improved both insulin resistance and ovarian dysfunction. Treatment with linzagolix decreased follicle-stimulating hormone levels, but did not alter serum luteinizing hormone and testosterone levels. These results indicate that linzagolix may provide a new treatment option for GnRH-related disorders, such as BPH and PCOS.

Suppressive effects of linzagolix, a novel non-peptide antagonist of gonadotropin-releasing hormone receptors, in experimental endometriosis model rats

Endometriosis is an oestrogen-dependent disease in which endometrial-like tissue grows outside the uterus in women of reproductive age. Accordingly, control of oestradiol (E2) levels is an effective treatment for endometriosis. Because gonadotropin-releasing hormone (GnRH) is the main controller of E2 secretion, control of GnRH signalling by GnRH antagonism is an effective strategy for the treatment of sex hormone-dependent diseases such as endometriosis. The purpose of the present study was to evaluate the effects of the potent, orally available and selective GnRH antagonist linzagolix on experimental endometriosis in rats and compare them with those of dienogest, which is used clinically to treat endometriosis. Experimental endometriosis was induced in female rats at the proestrus stage of the oestrous cycle via autotransplantation of endometrial tissue into the renal subcapsular space. Linzagolix significantly decreased cyst volumes compared with the control group at doses of 50 mg/kg or more. Indeed, a suppressive effect of dienogest on cyst volume was observed only at the highest dose evaluated (1 mg/kg). The effective concentration of linzagolix, calculated as the free form of the last-observed drug concentration, was ~1 μmol/L in endometriosis model rats. The present study also reveals that linzagolix exerts a sustained inhibitory effect on E2 secretion, indicating that the suppressive effect on endometriosis cyst volumes could be attributed to its pharmacological suppression of GnRH signalling and serum E2 concentrations. Altogether, our findings indicate that linzagolix may be a useful therapeutic intervention for hormone-dependent diseases including endometriosis.

Novel pharmacological therapies for the treatment of endometriosis

INTRODUCTION

Endometriosis is a chronic, estrogen-dependent, inflammatory disease associated with pelvic pain, infertility, impaired sexual function, and psychological suffering. Therefore, tailored patient management appears of primary importance to address specific issues and identify the appropriate treatment for each woman. Over the years, abundant research has been carried out with the objective to find new therapeutic approaches for this multifaceted disease.

AREAS COVERED

This narrative review aims to present the latest advances in the pharmacological management of endometriosis. In particular, the potential role of GnRH antagonists, selective progesterone receptor modulators (SPRMs), and selective estrogen receptors modulators (SERMs) will be discussed. We performed a literature search in PubMed and Embase, and selected the best quality evidence, giving preference to the most recent and definitive original articles and reviews.

EXPERT OPINION

Medical therapy represents the cornerstone of endometriosis management, although few advances have been made in the last decade. Most studies have focused on the evaluation of the efficacy and safety of GnRH antagonists (plus add-back therapy in cases of prolonged treatment), which should be used as second-line treatment options in selected cases (i.e. non-responders to first-line treatments). Further studies are needed to identify the ideal treatment for women with endometriosis.

Non-clinical studies indicating lack of interactions between iron/calcium ions and linzagolix, an orally available GnRH antagonist

Linzagolix is an orally available gonadotropin-releasing hormone antagonist used to treat sex-hormone-dependent diseases in women. This study aimed to investigate drug-drug interactions between linzagolix and iron/calcium ions in the intended clinical setting by conducting pharmacokinetic studies in vitro and in rats.Insoluble precipitate formation with metal ions was evaluated by measuring linzagolix concentrations in four types of bio-relevant dissolution media (fasted/fed state simulated gastric fluid and fasted/fed state simulated gastric fluid version 2), and chelate complex formation with metal ions was evaluated by release of linzagolix from a cellulose membrane sac. In these in vitro studies, linzagolix showed no potential for insoluble precipitate formation under fasted/fed conditions and no chelate complex formation in the presence of metal ions.In rats, the plasma concentration-time profiles of linzagolix and iron ion were similar regardless of whether they were administered with or without ferrous sulfate and linzagolix choline at clinically relevant doses. Thus, linzagolix and iron ion had no effect on each other's absorption in vivo.In conclusion, linzagolix is unlikely to cause clinically relevant drug-drug interactions by chelating metal ions according to the results of in vitro and in vivo studies.

Pharmacological characterization of linzagolix, a novel, orally active, non-peptide antagonist of gonadotropin-releasing hormone receptors

Control of gonadotropin-releasing hormone (GnRH) signaling is an effective strategy for the treatment of sex hormone-dependent diseases. GnRH analogs have been widely used for treating these diseases; however, initial stimulation or complete suppression of GnRH signaling by GnRH analogs results in the occurrence of several distinct adverse effects. Accordingly, we aimed to discover small molecule GnRH antagonists with superior pharmacokinetic (PK) and pharmacodynamic profiles. Linzagolix is a potent, orally available, and selective GnRH antagonist. Herein, we reported the pharmacological characterization of linzagolix in vitro and in vivo. Linzagolix selectively binds to the GnRH receptor and inhibits GnRH-stimulated signaling, in a manner comparable to cetrorelix, a peptide GnRH antagonist. Since the inhibitory effect of the gonad axis is useful for the treatment of gynecological conditions such as endometriosis and uterine fibroids, we investigated the effect of orally administered linzagolix on the gonadal axis in ovariectomized and intact cynomolgus monkeys. In ovariectomized monkeys, linzagolix immediately suppressed the serum luteinizing hormone concentration at doses over 1 mg/kg, indicating dose-dependent inhibition that correlated with serum linzagolix concentrations. In intact female monkeys, repeated linzagolix administration suppressed hormone surges and ceased or prolonged menstrual cycles. Furthermore, all animals presenting arrested menstrual cycles following linzagolix treatment showed recovery of hormone secretion and regular menstrual cycles after administration periods ended. Our results demonstrated that linzagolix has potential as a novel agent for reproductive-aged women suffering from sex hormone-dependent diseases. This article is protected by copyright. All rights reserved.

A model-based analysis to guide gonadotropin-releasing hormone receptor antagonist use for management of endometriosis

Aims

To identify linzagolix doses, an oral GnRH receptor antagonist, that effectively lower oestradiol (E2) to relieve endometriosis‐related pelvic pain without compromising bone health.

Methods

Integrated statistical, pharmacokinetic–pharmacodynamic and systems pharmacology models were developed from Phase 1 and 2 clinical trial data in healthy volunteers and patients, receiving linzagolix 25–200 mg daily or placebo, and analysed simultaneously. The main outcome measures were pelvic pain scores for dysmenorrhoea, nonmenstrual pelvic pain (NMPP), uterine bleeding and lumbar spine bone mineral density (BMD).

Results

Linzagolix pharmacokinetics were described by a 2‐compartment model with sequential zero/first‐order absorption process (CL/F: 0.422 L/h). E2 changes over time were well described as a function of linzagolix 24‐hour AUC (AUC₅₀: 1.68 × 10⁵ ng h/mL). For a Caucasian reference patient, a change in E2 from 50–20 pg/mL at 24 weeks increased the odds of relief of dysmenorrhoea 1.33‐fold and NMPP 1.07‐fold (95% CI: 1.22–1.47 and 1.02–1.12, respectively) and decreased bleeding days by 1.55 (95% CI: 1.39–1.72). A previously validated quantitative systems pharmacology BMD model was adjusted to the clinical data. The mean week 24 lumbar spine BMD change from baseline ranged from −0.092% in the 50 mg dose, −1.30% in the 100 mg dose group and −2.67% in the 200 mg dose group.

Discussion

The previously‐reported E2 target range (20–50 pg/mL) to balance efficacy and safety endpoints was confirmed. Linzagolix once daily doses between 75–125 mg daily were expected to meet endometriosis‐associated pain, efficacy, and BMD loss targets in Caucasian patients.

Uterine Adenomyosis Treated by Linzagolix, an Oral Gonadotropin-Releasing Hormone Receptor Antagonist: A Pilot Study with a New 'Hit Hard First and then Maintain' Regimen of Administration

(1) Background: The aim of the present pilot study was to study the effect of a new oral gonadotropin-releasing hormone antagonist on adenomyosis. (2) Methods: Eight premenopausal women, aged between 37 and 45 years, presenting with heavy menstrual bleeding, pelvic pain, and dysmenorrhea due to diffuse and disseminated uterine adenomyosis, confirmed by magnetic resonance imaging (MRI), received 200 mg linzagolix once daily for a period of 12 weeks, after which they were switched to 100 mg linzagolix once daily for another 12 weeks. The primary efficacy endpoint was the change in volume of the adenomyotic uterus from baseline to 24 weeks, evaluated by MRI. Secondary efficacy endpoints included the change in uterine volume from baseline to 12 and 36 weeks by MRI, and also weeks 12, 24, and 36 assessed by transvaginal ultrasound (TVUS). Other endpoints were overall pelvic pain, dysmenorrhea, non-menstrual pelvic pain, dyspareunia, amenorrhea, quality of life measures, bone mineral density (BMD), junctional zone thickness, and serum estradiol values. (3) Results: Median serum estradiol was suppressed below 20 pg/mL during the 12 weeks on linzagolix 200 mg, and maintained below 60 pg/mL during the second 12 weeks on linzagolix 100 mg. At baseline, the mean ± SD uterine volume was 333 ± 250 cm³. After 24 weeks of treatment, it was 204 ± 126 cm³, a reduction of 32% (p = 0.0057). After 12 weeks, the mean uterine volume was 159 ± 95 cm³, a reduction of 55% from baseline (p = 0.0001). A similar pattern was observed when uterine volume was assessed by TVUS. Improvements in overall pelvic pain, dysmenorrhea, non-menstrual pelvic pain, dyspareunia, and dyschezia, as well as quality of life measured using the EHP-30 were also observed. Mean percentage BMD loss at 24 weeks was, respectively, -2.4%, -1.3%, and -4.1% for the spine, femoral neck, and total hip. The most common adverse events were hot flushes, which occurred in 6/8 women during the first 12 weeks, and 1/8 women between 12 and 24 weeks. (4) Conclusions: Linzagolix at a dose of 200 mg/day reduced uterine volume, and improved clinically relevant symptoms. Treatment with 100 mg thereafter retains the therapeutic benefits of the starting dose while minimizing side effects. This 'hit hard first and then maintain' approach may be the optimal way to treat women with symptomatic adenomyosis.

GnRH Antagonists with or without Add-Back Therapy: A New Alternative in the Management of Endometriosis?

To evaluate the effectiveness of a new class of medical drugs, namely oral gonadotropin-releasing hormone (GnRH) antagonists, in the management of premenopausal women with endometriosis-associated pelvic pain. We reviewed the most relevant papers (n = 27) on the efficacy of new medical alternatives (oral GnRH antagonists) as therapy for endometriosis. We first briefly summarized the concept of progesterone resistance and established that oral contraceptives and progestogens work well in two-thirds of women suffering from endometriosis. Since clinical evidence shows that estrogens play a critical role in the pathogenesis of the disease, lowering their levels with oral GnRH antagonists may well prove effective, especially in women who fail to respond to progestogens. There is a need for reliable long-term oral treatment capable of managing endometriosis symptoms, taking into consideration both the main symptoms and phenotype of the disease. Published studies reviewed and discussed here confirm the efficacy of GnRH antagonists. There is a place for GnRH antagonists in the management of symptomatic endometriosis. Novel algorithms that take into account the different phenotypes are proposed.

Uterine Adenomyosis: From Disease Pathogenesis to a New Medical Approach Using GnRH Antagonists

Uterine adenomyosis is a common chronic disorder frequently encountered in reproductive-age women, causing heavy menstrual bleeding, intense pelvic pain, and infertility. Despite its high prevalence, its etiopathogenesis is not yet fully understood, so there are currently no specific drugs to treat the disease. A number of dysregulated mechanisms are believed to contribute to adenomyosis development and symptoms, including sex steroid signaling, endometrial proliferation and invasiveness, and aberrant immune response. Abnormal sex steroid signaling, particularly hyperestrogenism and subsequent progesterone resistance, are known to play a pivotal role in its pathogenesis, which is why various antiestrogenic agents have been used to manage adenomyosis-related symptoms. Among them, gonadotropin-releasing hormone (GnRH) antagonists are swiftly gaining ground, with recent studies reporting efficient lesion regression and symptom alleviation. The aim of the present review is to compile available information on the pathogenesis of adenomyosis, explore the etiology and mechanisms of hyperestrogenism, and discuss the potential of antiestrogenic therapies for treating the disease and improving patient quality of life.

Linzagolix: a new GnRH-antagonist under investigation for the treatment of endometriosis and uterine myomas

INTRODUCTION

Uterine myomas and endometriosis are benign hormone-dependent diseases affecting women of reproductive age. Substantial efforts have been made to develop innovative medical options for treating these gynecologic diseases. Elagolix and relugolix have been approved in some countries for treating endometriosis and myomas, respectively; however, linzagolix (OBE 2109, KLH 2109) is a new oral gonadotropin-releasing hormone (GnRH) antagonist in phase II-III trials. Treatment options for women with contraindications for hormonal therapies or who refuse particular options, are the driving force behind the development of new drugs in this area.

AREA COVERED

This drug evaluation highlights definitive and preliminary results from previous and ongoing studies of linzagolix for the treatment of endometriosis and myomas.

EXPERT OPINION

Linzagolix showed a dose-dependent and rapidly reversible action on the pituitary-gonadal axis. In a recent phase II trial (EDELWEISS), linzagolix significantly reduced pain related to endometriosis and improved quality of life at single daily doses of 75-200 mg. The preliminary results of international, double-blind phase III trials (PRIMROSE 1 and 2) reported its efficacy in treating heavy menstrual bleeding related to myomas with a good safety profile. Further studies will determine the necessity of add-back therapy during long-term use of linzagolix.

Treatment of endometriosis-associated pain with linzagolix, an oral gonadotropin-releasing hormone-antagonist: a randomized clinical trial

OBJECTIVE

To study the effect of a new investigational oral gonadotropin-releasing hormone antagonist, linzagolix, on endometriosis-associated pain (EAP).

DESIGN

A multinational, parallel group, randomized, placebo-controlled, double-blind, dose-ranging trial.

SETTING

Clinical centers.

PATIENT(S)

Women aged 18-45 years with surgically confirmed endometriosis and moderate-to-severe EAP.

INTERVENTION(S)

The interventions were 50, 75, 100, or 200 mg linzagolix (or matching placebo) administered once daily for 24 weeks.

MAIN OUTCOME MEASURE(S)

The primary endpoint was the number of responders (≥30% reduction in overall pelvic pain) after 12 weeks. Other endpoints included dysmenorrhea, non-menstrual pelvic pain, serum estradiol, amenorrhea, quality of life (QoL) measures, and bone mineral density (BMD).

RESULT(S)

Compared with placebo, doses ≥ 75 mg resulted in a significantly greater proportion of responders for overall pelvic pain at 12 weeks (34.5%, 61.5%, 56.4%, and 56.3% for placebo, 75, 100, and 200 mg, respectively). A similar pattern was seen for dysmenorrhea and non-menstrual pelvic pain. The effects were maintained or increased at 24 weeks. Serum estradiol was suppressed, QoL improved, and the rate of amenorrhea increased in a dose-dependent fashion. Mean BMD loss (spine) at 24 weeks was <1% at doses of 50 and 75 mg and increased in a dose-dependent fashion up to 2.6% for 200 mg. BMD of femoral neck and total hip showed a similar pattern.

CONCLUSION(S)

Linzagolix significantly reduced EAP and improved QoL at doses of 75-200 mg and decreased BMD dose-dependently.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02778399.

Gonadotropin-releasing hormone antagonist (linzagolix): a new therapy for uterine adenomyosis

OBJECTIVE

To compare the efficacy of a selective progesterone receptor modulator, ulipristal acetate, and a gonadotropin-releasing hormone antagonist, linzagolix, in a case of severe uterine adenomyosis.

DESIGN

Case report.

SETTING

Private clinic and infertility research unit.

PATIENT

One patient born in 1981 who presented because of heavy menstrual bleeding, pelvic pain, and dysmenorrhea due to diffuse and disseminated uterine adenomyosis confirmed by magnetic resonance imaging (MRI).

INTERVENTION

The patient received a first treatment of 5 mg UPA daily for one course of 3 months. This therapy was discontinued because MRI revealed a worsened aspect. One year later, a once-daily dose of 200 mg linzagolix administered orally was initiated for 3 months, followed by another 3-month course of 100 mg once daily.

MAIN OUTCOME MEASURES

Clinical symptoms and MRI aspect.

RESULTS

During treatment with UPA, the symptoms (pelvic pain, dysmenorrhea, bulk symptoms) worsened and MRI revealed aggravation of the adenomyotic lesions. During the 12-week course of once-daily 200 mg linzagolix, the patient remained in amenorrhea and noted a very significant improvement in symptoms. On MRI, the uterine volume had fallen from 875 cm³ to 290 cm³, and the adenomyotic lesions had significantly regressed. During the 100-mg linzagolix course (weeks 13-24), the patient reported continued alleviation of her symptoms.

CONCLUSION

To our knowledge, this is the first reported use of linzagolix, a new oral gonadotropin-releasing hormone antagonist that significantly reduced lesion size and improved quality of life in a patient with severe adenomyosis, who was previously nonresponsive to treatment with a selective progesterone receptor modulator, ulipristal acetate.