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.

Impact of neoadjuvant relugolix on patient-reported sexual function and bother

Introduction

Sexual function following local treatment for prostate cancer is an important quality of life concern. Relugolix is a novel oral GnRH receptor antagonist used in combination with radiation therapy in the treatment of unfavorable prostate cancer. It has been shown to achieve rapid and profound testosterone suppression. As a result, these very low testosterone levels may impact both sexual functioning and perceptions. This prospective study sought to assess neoadjuvant relugolix-induced sexual dysfunction prior to stereotactic body radiation therapy (SBRT).

Methods

Between March 2021 and September 2023, 87 patients with localized prostate cancer were treated with neoadjuvant relugolix followed by SBRT per an institutional protocol. Sexual function and bother were assessed via the sexual domain of the validated Expanded Prostate Index Composite (EPIC-26) survey. Responses were collected for each patient at pre-treatment baseline and after several months of relugolix. A Utilization of Sexual Medications/Devices questionnaire was administered at the same time points to assess erectile aid usage.

Results

The median age was 72 years and 43% of patients were non-white. The median baseline Sexual Health Inventory for Men (SHIM) score was 13 and 41.7% of patients utilized sexual aids prior to relugolix. Patients initiated relugolix at a median of 4.5 months (2-14 months) prior to SBRT. 95% and 87% of patients achieved effective castration (≤ 50 ng/dL) and profound castration (< 20 ng/dl) at SBRT initiation, respectively. Ability to have an erection, ability to reach orgasm, quality of erections, frequency of erections, and overall sexual function significantly declined following relugolix. There was a non- significant increase in sexual bother.

Discussion

In concordance with known side effects of androgen deprivation therapy (ADT), neoadjuvant relugolix was associated with a significant decline in self-reported sexual function. However, patients indicated only a minimal and non-significant increase in bother. Future investigations should compare outcomes while on relugolix directly to GnRH agonist-induced sexual dysfunction.

Evaluating relugolix for the treatment of prostate cancer in real-world settings of care: the OPTYX study protocol

OPTYX is a multi-center, prospective, observational study designed to further understand the actual experience of patients with advanced prostate cancer treated with relugolix (ORGOVYX®), an oral androgen deprivation therapy (ADT), by collecting clinical and patient-reported outcomes from routine care settings. The study aims to enroll 1000 consented patients with advanced prostate cancer from community, academic and government operated clinical practices across the USA. At planned timepoints, real-world data analysis on treatment patterns, adherence and safety as well as health outcomes and health-related quality-of-life (HRQOL) after treatment discontinuation will be published in scientific peer-reviewed journals and presented at relevant conferences. This study will provide real-world data for practitioners and researchers in their understanding of the safety and effectiveness of relugolix. Clinical Trial Registration: NCT05467176 (ClinicalTrials.gov).

Two-year efficacy and safety of relugolix combination therapy in women with endometriosis-associated pain: SPIRIT open-label extension study

STUDY QUESTION

What is the efficacy and safety of long-term treatment (up to 2 years) with relugolix combination therapy (CT) in women with moderate to severe endometriosis-associated pain?

SUMMARY ANSWER

For up to 2 years, treatment with relugolix CT improved menstrual and non-menstrual pain, dyspareunia, and function in women with endometriosis; after an initial decline of <1%, the mean bone mineral density (BMD) remained stable with continued treatment.

WHAT IS KNOWN ALREADY

Endometriosis is a chronic condition characterized by symptoms of dysmenorrhea, non-menstrual pelvic pain (NMPP), and dyspareunia, which have a substantial impact on the lives of affected women, their partners, and families. SPIRIT 1 and 2 were phase 3, randomized, double-blind, placebo-controlled studies of once-daily relugolix CT (relugolix 40 mg, oestradiol 1 mg, norethisterone acetate 0.5 mg) in premenopausal women (age 18-50 years) with endometriosis and moderate-to-severe dysmenorrhea and NMPP. These trials demonstrated a significant improvement of dysmenorrhea, NMPP, and dyspareunia in women treated with relugolix CT, with minimal decline (<1%) in BMD versus placebo at 24 weeks.

STUDY DESIGN, SIZE, DURATION

Patients participating in this open-label, single-arm, long-term extension (LTE) study of the 24-week SPIRIT pivotal studies (SPIRIT 1 and 2) received up to an additional 80 weeks of once-daily oral relugolix CT treatment between May 2018 and January 2023.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Premenopausal women with confirmed endometriosis and moderate to severe dysmenorrhea and NMPP who completed the 24-week pivotal studies (SPIRIT 1 and 2 trials; Giudice et al., 2022) and who met all entry criteria were eligible to enrol. Two-year results were analysed by treatment group based on original randomization in pivotal studies: relugolix CT, delayed relugolix CT (relugolix 40 mg monotherapy for 12 weeks, followed by relugolix CT), or placebo→relugolix CT (placebo for 24 weeks followed by relugolix CT). The primary endpoints of the LTE study were the proportion of dysmenorrhea and NMPP responders at Week 52 and Week 104/end-of-treatment (EOT). A responder was a participant who achieved a predefined, clinically meaningful reduction from baseline in Numerical Rating Scale (NRS) scores (0 = no pain, 10 = worst pain imaginable) for the specific pain type with no increase in analgesic use. The predefined clinically meaningful threshold for dysmenorrhea was 2.8 points and for NMPP was 2.1 points. Secondary efficacy endpoints included change from baseline in Endometriosis Health Profile-30 (EHP-30) pain domain scores, a measure of the effects of endometriosis-associated pain on daily activities (function), NRS scores for dysmenorrhea, NMPP, dyspareunia, and overall pelvic pain, and analgesic/opioid use. Safety endpoints included adverse events and changes in BMD.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 1261 randomized patients, 1044 completed the pivotal studies, 802 enrolled in the LTE, 681 completed 52 weeks of treatment, and 501 completed 104 weeks of treatment. Demographics and baseline characteristics of the extension population were consistent with those of the original randomized population. Among patients randomized to relugolix CT at pivotal study baseline who continued in the LTE (N = 277), sustained improvements in endometriosis-associated pain were demonstrated through 104 weeks. The proportion of responders at Week 104/EOT for dysmenorrhea and NMPP was 84.8% and 75.8%, respectively. Decreases in dyspareunia and improvement in function assessed by EHP-30 pain domain were also sustained over 2 years. At Week 104/EOT, 91% of patients were opioid-free and 75% of patients were analgesic-free. Relugolix CT over 104 weeks was well tolerated with a safety profile consistent with that observed over the first 24 weeks. After initial least squares mean BMD loss <1% at Week 24, BMD plateaued at Week 36 and was sustained for the duration of 104 weeks of treatment. Efficacy and safety results were generally consistent in women in the placebo→relugolix CT and delayed relugolix CT groups.

LIMITATIONS, REASONS FOR CAUTION

The study was conducted as an open-label study without a control group over the 80 weeks of the extension period. Of the 802 patients who were enrolled in this LTE study, 681 patients (84.9%) and 501 patients (62.5%) of patients completed 52 and 104 weeks of treatment, respectively. In addition, there currently are no comparative data to other hormonal medications. Finally, a third (37.4%) of the study population terminated participation early.

WIDER IMPLICATIONS OF THE FINDINGS

In conclusion, relugolix CT offers an additional option to help address an important unmet clinical need for effective, safe, and well-tolerated medical treatments for endometriosis that can be used longer-term, reducing the need for opioids and improving quality of life. The findings from this study may help support the care of women with endometriosis seeking longer-term effective medical management of their symptoms.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Myovant Sciences GmbH (now Sumitomo Pharma Switzerland GmbH). C.M.B. reports fees from Myovant, grants from Bayer Healthcare, fees from ObsEva, and Chair of ESHRE Endometriosis Guideline Group (all funds went to the University of Oxford); N.P.J. reports personal fees from Myovant Sciences, during the conduct of the study, personal fees from Guerbet, personal fees from Organon, personal fees from Roche Diagnostics; S.A.-S. reports personal fees from Myovant Sciences, personal fees from Bayer, personal fees from Abbvie, personal fees from UpToDate; J.S.P., and R.B.W. are employees and shareholders of Myovant Sciences; J.C.A.F. and S.J.I. are shareholders of Myovant Sciences (but at time of publicaion are no longer employess of Myovant Sciences); M.S.A. and K.W. have no conflicts to declare; V.M. is a consultant to Myovant; L.C.G. reports personal fees from Myovant Sciences, Inc and Bayer. The authors did not receive compensation for manuscript writing, review, and revision.

TRIAL REGISTRATION NUMBER

NCT03654274.

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.

Rheumatoid Arthritis-Like Symptoms After Taking Relugolix, With Primary Exacerbation After Discontinuation of the Drug

We report a case of a 43-year-old woman who developed rheumatoid arthritis-like symptoms after taking relugolix, presenting a diagnostic challenge in distinguishing between initial symptoms of rheumatoid arthritis and the side effects of the drug. The patient, scheduled for a total laparoscopic hysterectomy owing to uterine fibroids, started taking relugolix five and a half months prior to surgery. Three months later, she developed rheumatoid arthritis-like stiffness in both hands, especially in the mornings. Despite consultations with the rheumatology department and negative blood and imaging findings for rheumatoid arthritis, her joint symptoms worsened after surgery. Treatment for early-stage rheumatoid arthritis was initiated, and the symptoms peaked after six months. Similar to estrogen-lowering aromatase inhibitors that are known to cause joint symptoms, relugolix might also induce these effects.

Rapid reduction of adenomyosis coexisting with leiomyoma volume during treatment with Relugolix

OBJECTIVE

This study elucidated the efficacy of Relugolix (REL) on the reduction of uterine volume and clinical symptoms for the treatment of adenomyosis.

METHODS

We conducted a retrospective cohort study of patients who received REL (40 mg for about 20 weeks) and who underwent a hysterectomy for adenomyosis or fibroids. We divided patients into two groups: adenomyosis coexisting with fibroids (Group A) and fibroids only (Group B); the groups were determined by a postoperative pathological examination. The primary end points were the percent reduction in uterine volume, adenomyotic lesion, and the largest fibroid volume at week 16. The secondary end points were the rate of amenorrhea, pelvic pain, and anemia at week 12.

RESULTS

A total of 56 patients participated in the current study: 20 in Group A and 36 in Group B. Regarding the largest fibroid volume, there was no significant difference between the two groups. Uterine volume after REL treatment was significantly decreased in Group A (43%), as compared to Group B (27%) (p = .00972), In Group A, adenomyotic lesion was decreased by 61%. Irrespective of the group, adenomyosis showed a significant reduction compared to uterine fibroids (p < .001). There was no statistically significant difference in the mitigation of symptoms (amenorrhea, pelvic pain, and anemia) between the two groups.

CONCLUSIONS

REL is more effective in reducing adenomyotic lesion than uterine fibroids and in relieving symptoms (amenorrhea, pelvic pain, and anemia). It can be expected that REL will also be used as a preoperative treatment for adenomyosis.

LIBERTY randomized withdrawal study: relugolix combination therapy for heavy menstrual bleeding associated with uterine fibroids

BACKGROUND

In the pivotal LIBERTY 1 and 2 trials and long-term extension study, once-daily relugolix combination therapy (40 mg relugolix, 1 mg estradiol, 0.5 mg norethindrone acetate) reduced menstrual blood loss volume and pain among women with uterine fibroids. Relugolix combination therapy was well tolerated with preservation of bone mineral density through 52 weeks.

OBJECTIVE

This study aimed to report the 2-year relugolix combination therapy efficacy and safety results of the phase 3 LIBERTY randomized withdrawal study.

STUDY DESIGN

Women with uterine fibroid-associated heavy menstrual bleeding who completed the 24-week LIBERTY 1 or 2 trials, followed by the 28-week long-term extension study (up to 52 weeks total treatment), and who met the responder criteria (menstrual blood loss volume <80 mL and ≥50% reduction from pivotal study baseline at week 48 [week 24 of long-term extension]) were randomized in a 1:1 ratio to either blinded treatment with relugolix combination therapy or placebo for 52 weeks (total treatment period, 104 weeks). For women who had a relapse of heavy menstrual bleeding during the study (menstrual blood loss volume ≥80 mL), open-label relugolix combination therapy was offered. The primary endpoint was the proportion of women who maintained menstrual blood loss volume <80 mL through week 76 (week 24 of randomized withdrawal study). Secondary endpoints included time to menstrual blood loss volume ≥80 mL, proportion of women who maintained a menstrual blood loss volume of <80 mL through week 104 (over the 52-week randomized treatment period), the proportion of women who achieved or maintained amenorrhea at week 76 at the end of treatment, and the change in Uterine Fibroid Symptom-Quality of Life Bleeding and Pelvic Discomfort Scale and symptom severity scores. Analyses were performed for the modified intent-to-treat population, including all randomized women who received ≥1 dose of the study drug.

RESULTS

Of the 229 randomized women (relugolix combination therapy, n=115; placebo, n=114), 228 received the study drug and 175 (76.7%) completed the randomized withdrawal study. Through week 76, 78.4% of women on relugolix combination therapy maintained menstrual blood loss volume <80 mL vs 15.1% in the placebo group (difference, 63.4%; 95% confidence interval, 52.9%-73.9%; P<.0001). At week 104, 69.8% of women on relugolix combination therapy maintained menstrual blood loss volume <80 mL vs 11.8% in the placebo group (difference, 58.0%; 95% confidence interval, 47.0%-69.1%; P<.0001). Through week 104, 88.3% of women on placebo relapsed with heavy menstrual bleeding (median time to relapse, 5.9 weeks). Among the 89 women in the placebo group who relapsed and received open-label rescue treatment, 87 women responded to relugolix combination therapy with a menstrual blood loss volume <80 mL. The proportion of women who achieved or maintained amenorrhea were 57.4% vs 13.3% at week 76 (difference, 44.1%; 95% confidence interval, 33.10%-55.1%; P<.0001) and 58.3% vs 10.6% at week 104 (difference, 47.6%; 95% confidence interval, 37.0%-58.3%; nominal P<.0001) for relugolix combination therapy and the placebo group, respectively. Relugolix combination therapy was generally well tolerated; no new safety signals were identified, and the adverse event profile over the second year was consistent with that reported through the first year of treatment. Bone mineral density remained stable in women who received relugolix combination therapy from week 52 to week 104. In women continuously treated with relugolix combination therapy up to 2 years, bone mineral density was generally preserved.

CONCLUSION

After 2 years of treatment with relugolix combination therapy, there was evidence of durability of the effect in maintaining low menstrual blood loss volume in women with symptomatic uterine fibroids. Most women had return of heavy menstrual bleeding and associated symptoms after treatment cessation, which improved upon retreatment with relugolix combination therapy. Relugolix combination therapy was well tolerated, the adverse event profile remained consistent, and the mean bone mineral density was generally preserved through 2 years of treatment.

A Plain Language Summary to learn about relugolix combination therapy for the treatment of pain associated with endometriosis

WHAT IS THIS SUMMARY ABOUT?

This is a summary of research studies (known as clinical trials) called SPIRIT 1 and SPIRIT 2. The SPIRIT 1 and SPIRIT 2 studies compared how well a medicine called relugolix combination therapy worked in relieving pain in women with moderate to severe endometriosis compared to a placebo, a pill with no active medication. Endometriosis occurs when tissue similar to what normally lines the uterus grows in other places, such as the ovaries, fallopian tubes, and bowels.

WHAT WERE THE RESULTS?

Researchers looked at 1261 adult women with moderate to severe endometriosis. Randomly, 420 (33%) of these women were assigned to relugolix combination therapy, 420 (33%) were assigned to delayed relugolix combination therapy (relugolix alone first and then relugolix combination therapy for the remainder of the study), and 421 (33%) were assigned to placebo. The SPIRIT 1 and SPIRIT 2 studies showed that more women taking relugolix combination therapy (75% from SPIRIT 1 and 75% from SPIRIT 2) for 24 weeks had both less pelvic or groin pain during menstrual periods from endometriosis and no need for more pain medicines than women who took placebo (27% from SPIRIT 1 and 30% from SPIRIT 2). The SPIRIT 1 and SPIRIT 2 studies also showed that more women taking relugolix combination therapy (59% from SPIRIT 1 and 66% from SPIRIT 2) for 24 weeks had both less pelvic or groin pain between menstrual periods from endometriosis and no need for more pain medicines than women who took placebo (40% from SPIRIT 1 and 43% from SPIRIT 2). Women taking relugolix combination therapy had less pelvic or groin pain during and between menstrual periods within 4 weeks of starting the medicine. The most common side effects were headaches, the common cold, and hot flushes or feeling hot among women taking relugolix combination therapy, delayed relugolix combination therapy, and placebo. Relugolix combination therapy was considered safe for those with no major medical problems. Women taking relugolix combination therapy had little to no loss of bone mineral density (a way of knowing how strong bones are) after 24 weeks of treatment.

WHAT DO THE RESULTS OF THESE STUDIES TELL US?

Women with moderate to severe endometriosis taking relugolix combination therapy had much less pain from endometriosis than women taking placebo. Clinical Trial Registration: NCT03204318 (SPIRIT-1); NCT03204331 (SPIRIT-2) (ClinicalTrials.gov).

Adherence to Hormonal Therapies in Prostate Cancer

INTRODUCTION

Hormonal therapy is the standard of care in prostate cancer treatment. The approval of the first oral androgen deprivation therapy, relugolix, to treat prostate cancer patients provides an opportunity to review adherence to oral and injectable/implantable hormonal therapies to aid patients and physicians in making informed decisions.

METHODS

A PubMed search for available literature on adherence to hormonal therapy in prostate cancer was conducted, including published data on relugolix.

RESULTS

Adherence to oral antiandrogen therapy was above 90% by medication possession ratio in several studies worldwide and from 75% to 91% by proportion of days covered. For injectable/implantable androgen deprivation therapy, adherence to treatment ranged from 71% to 95%. In general, 60% and 29% of injections were reported to be delayed by more than 1 week and 2 weeks, respectively, with some patients experiencing testosterone increases (tests above 50 ng/dL). Although real-world data on adherence to relugolix are currently unavailable, pharmacokinetic/pharmacodynamics models demonstrated that, if necessary, treatment interruption up to 7 days would still maintain testosterone suppression levels.

CONCLUSIONS

In general, adherence to hormonal therapy is high in prostate cancer. Studies revealed that adherence to injectable androgen deprivation therapy dosing schedules is important to maintain castrate levels. Pharmacokinetic/pharmacodynamics models showed that relugolix treatment interruption up to 7 days had minimal impact on testosterone suppression levels.

Early biochemical outcomes following neoadjuvant/adjuvant relugolix with stereotactic body radiation therapy for intermediate to high risk prostate cancer

Introduction

Injectable GnRH receptor agonists have been shown to improve cancer control when combined with radiotherapy. Prostate SBRT offers an abbreviated treatment course with comparable efficacy to conventionally fractionated radiotherapy. Relugolix is a new oral GnRH receptor antagonist which achieves rapid, sustained testosterone suppression. This prospective study sought to evaluate early testosterone suppression and PSA response following relugolix and SBRT for intermediate to high prostate cancer.

Methods

Relugolix was initiated at least 2 months prior to SBRT. Interventions to improve adherence were not utilized. PSA and total testosterone levels were obtained prior to and 1-4 months post SBRT. Profound castration was defined as serum testosterone ≤ 20 ng/dL. Early PSA nadir was defined as the lowest PSA value within 4 months of completion of SBRT. Per prior trials, we examined the percentage of patients who achieved PSA level of ≤ 0.5 ng/mL and ≤ 0.2 ng/mL during the first 4 months post SBRT.

Results

Between July 2021 and January 2023, 52 men were treated at Georgetown with relugolix (4-6 months) and SBRT (36.25-40 Gy in 5 fractions) per an institutional protocol (IRB 12-1775). Median age was 71 years. 26.9% of patients were African American and 28.8% were obese (BMI ≥30 kg/m2). The median pretreatment PSA was 9.1 ng/ml. 67% of patients were ≥ Grade Group 3. 44 patients were intermediate- and 8 were high-risk. Patients initiated relugolix at a median of 3.6 months prior to SBRT with a median duration of 6.2 total months. 92.3% of patients achieved profound castration during relugolix treatment. Poor drug adherence was observed in 2 patients. A third patient chose to discontinue relugolix due to side effects. By post-SBRT month 4, 87.2% and 74.4% of patients achieved PSA levels ≤ 0.5 ng/ml and ≤ 0.2 ng/ml, respectively.

Discussion

Relugolix combined with SBRT allows for high rates of profound castration with low early PSA nadirs. We observed a 96% testosterone suppresion rate without the utilization of scheduled cues/reminders. This finding supports the notion that patients with localized prostate cancer can consistently and successfully follow an oral ADT protocol without daily reminders. Given relugolix's potential benefits over injectable GnRH receptor agonists, its usage may be preferred in specific patient populations (fear of needles, prior cardiovascular events). Future studies should focus on boundaries to adherence in specific underserved populations.

Leuprolide Effects on Castration Resistance-Free Survival from the Phase 3 HERO Study in Men with Advanced Prostate Cancer

Background: Relugolix is an oral GnRH receptor antagonist approved for men with advanced prostate cancer. Relugolix treatment has demonstrated an ability to lower testosterone to sustained castration levels in the phase 4 HERO study. Herein, we describe the results of a secondary endpoint of castration resistance-free survival (CRFS) during 48 weeks of treatment and profile patients with castration-resistant prostate cancer (CRPC). Methods: Subjects were 2:1 randomized to either relugolix 120 mg orally once daily (after a single 360 mg loading dose) or 3-monthly injections of leuprolide for 48 weeks. CRFS, defined as the time from the date of first dose to the date of confirmed prostate-specific antigen progression while castrated or death due to any reason was conducted in the metastatic disease population and the overall modified intention-to-treat (mITT) populations. Results: The CRFS analysis (mITT population) included 1074 men (relugolix: n = 717; leuprolide: n = 357) with advanced prostate cancer as well as 434 men (relugolix: n = 290; leuprolide: n = 144) with metastatic prostate cancer. In the metastatic disease populations, CRFS rates were 74.3% (95% CI: 68.6%, 79.2%) and 75.3% (95% CI: 66.7%, 81.9%) in the relugolix and leuprolide groups, respectively (hazard ratio: 1.03 [0.68, 1.57]; p = 0.84) at week 48. Results in the overall mITT population were similar to the metastatic population. No new safety findings were identified. Conclusions: In men with metastatic disease or in the overall population of the HERO study, CRFS assessed during the 48-week treatment with relugolix was not significantly different than standard-of-care leuprolide. Relugolix had similar efficacy for men with/without CRFS progression events.

Profile of Relugolix in the Management of Advanced Hormone-Sensitive Prostate Cancer: Design, Development, and Place in Therapy

Androgen deprivation therapy, primarily via a gonadotropin-releasing hormone receptor agonist or antagonist together with or without an androgen receptor antagonist, remains the mainstay of medical treatment for advanced prostate cancer. Meanwhile, relugolix has been developed as the first orally active, non-peptide, selective antagonist for the gonadotropin-releasing hormone receptor. Previous randomized studies involving patients with prostate cancer have demonstrated comparable efficacy in androgen suppression between relugolix vs other gonadotropin-releasing hormone antagonists or agonists. This review summarizes available data on the design and development of relugolix and its therapeutic application, and discusses if relugolix represents a promising oral alternative to injectable androgen deprivation therapy. Based on current published evidence, further investigation is likely required to determine the actual clinical benefits of relugolix therapy against prostate cancer.

A plain language summary of the long-term relugolix combination therapy study for uterine fibroids

What is this summary about? This is a summary of a research study (known as a clinical trial) called the LIBERTY extension study. The LIBERTY extension study is a long-term study looking at how well a medicine called relugolix combination therapy worked in reducing blood loss during menstrual periods in women with uterine fibroids with heavy menstrual periods. Women were included in the extension study if they finished the 24-week LIBERTY 1 or LIBERTY 2 studies. Heavy menstrual periods were considered to be menstrual blood loss of about one-third of a cup of blood (80 ml) per cycle for two cycles or about two-thirds of a cup of blood (160 ml) during one cycle. The LIBERTY extension study also looked at whether relugolix combination therapy was safe to take for up to 1 year. What were the results? Out of 770 total women with uterine fibroids with heavy menstrual bleeding who took part in the LIBERTY 1 and LIBERTY 2 studies, 476 took part in the LIBERTY extension study. From the start of the LIBERTY 1 and LIBERTY 2 studies through the end of the LIBERTY extension: 163 women took relugolix combination therapy for 52 weeks 149 women took relugolix alone for 12 weeks followed by relugolix combination therapy for 40 weeks 164 women took placebo for 24 weeks followed by relugolix combination therapy for 28 weeks The LIBERTY extension study showed that most women in all three treatment groups responded to relugolix combination therapy by having less bleeding during their menstrual periods, having improved anemia symptoms, and having stable bone mineral loss. Side effects were similar across treatment groups, and the most common side effects were headaches and hot flushes. What do the results mean? Women with uterine fibroids with heavy menstrual bleeding taking relugolix combination therapy may have fewer uterine fibroid bleeding symptoms for up to 1 year of treatment. Clinical Trial Registration: NCT03049735 (ClinicalTrials.gov) (LIBERTY 1) Clinical Trial Registration: NCT03103087 (ClinicalTrials.gov) (LIBERTY 2) Clinical Trial Registration: NCT03412890 (ClinicalTrials.gov) (LIBERTY extension study).

A plain language summary of the safety of relugolix combination therapy and improvement in symptoms in women with uterine fibroids from the LIBERTY 1 and LIBERTY 2 studies

WHAT IS THIS SUMMARY ABOUT?

This is a summary of research studies (known as clinical trials) called LIBERTY 1 and LIBERTY 2. The LIBERTY 1 and LIBERTY 2 studies looked at how well a medication called relugolix combination therapy worked to reduce heavy bleeding at the time of menstruation compared with placebo. The studies also looked at what side effects were reported in women with uterine fibroids and heavy menstrual bleeding.

WHAT WERE THE RESULTS?

Researchers looked at 388 adult women in the LIBERTY 1 study and 382 adult women in the LIBERTY 2 study. All women had heavy menstrual bleeding with uterine fibroids before the start of the LIBERTY 1 and LIBERTY 2 studies. The women were given one of three treatments during the studies: relugolix combination therapy or placebo for 24 weeks, or delayed relugolix combination therapy (relugolix alone for the first 12 weeks, then relugolix combination therapy for the last 12 weeks of the studies). More women taking relugolix combination therapy in the LIBERTY 1 study (73%) and LIBERTY 2 study (71%) had menstrual blood loss of less than one-third of a cup (80 mL) and had reduction of at least 50% less blood loss during their last menstrual period after 24 weeks of taking the medicine compared with placebo (LIBERTY 1: 19% and LIBERTY 2: 15%). The women taking relugolix combination therapy also had less pain than those taking placebo. Side effects were similar across treatment groups. Headaches and hot flushes were the most common side effects.

WHAT DO THE RESULTS MEAN?

More women with uterine fibroids taking relugolix combination therapy for 24 weeks were likely to have fewer uterine fibroid symptoms than women receiving placebo. Clinical Trial Registration: NCT03049735 (LIBERTY 1); NCT03103087 (LIBERTY 2).

Ultrasound-Guided Diagnosis of Multiple Uterine Fibroids in a Patient With Polycystic Ovaries and Treatment With Relugolix, Estradiol, and Norethisterone Acetate

Uterine fibroids and ovarian cysts are common gynecological conditions that, while benign, when present simultaneously with bacterial vaginosis, can present a more complicated course of management. Symptoms of uterine fibroids include menorrhagia and dysmenorrhea, while ovarian cysts may present with pelvic pain and an adnexal mass. Each condition is typically managed separately; however, they can coexist in some patients, leading to a more complex presentation. This case report presents a 35-year-old African American female patient with the simultaneous occurrence of uterine fibroids and ovarian cysts, complicated by recurrent vaginitis, along with the treatment approach. The treatment choice, relugolix, estradiol, and norethisterone (norethindrone) acetate, is the first once-daily U.S. Food and Drug Administration (FDA) combination hormonal medication approved for menorrhagia due to fibroids. This case is unique in that although the diagnoses are common, their coexistence makes for a more complex presentation, and the course of management presents a newly approved fixed-dose combination hormonal medication. This report discusses the incidence, pathophysiology, diagnosis, and management of uterine fibroids and ovarian cysts. Factors that may contribute to the concurrence of these conditions, such as genetic, hormonal, and environmental risks, are also explored. Diagnostic modalities and ultrasound techniques are reviewed, and treatment options, such as surgery and medical management, are discussed. The importance of a patient-centered approach in the treatment of multi-symptom gynecological disorders and the need to consider conservative management are emphasized.

A Practical Guide to Relugolix: Early Experience With Oral Androgen Deprivation Therapy

BACKGROUND

Relugolix is the newest form of androgen deprivation therapy (ADT) approved for prostate cancer. However, as an oral drug, several real-world concerns exist, particularly medication compliance, safety with other androgen receptor-targeted agents, and financial burden to patients.

METHODS

A single institution retrospective chart review was conducted evaluating all patients who were prescribed relugolix for any prostate cancer indication from January 1, 2021 to January 31, 2022. Demographic data, cardiac risk factors, concomitant therapy usage, and PSA/testosterone levels, were abstracted from the chart review. Adverse effects were obtained by examining progress notes. Compliance was assessed by clinic notes as well as prescription fills by specialty pharmacy records. The reasons patients did not fill or discontinued the medication were noted.

RESULTS

Hundred and one patients were prescribed relugolix, and 91 patients consented to research. Seventy-one (78%) patients filled the prescription to relugolix, with a median follow-up of 5 months. Prescription fill data were available for 45 (63%) patients, with 94% of days covered. The most commonly reported reason not to fill was cost at 50%. Sixty-six (93%) patients reported never missing a dose. PSA levels were available in 71 (100%) patients with 69 (97%) showing stable or improved PSA. Testosterone levels were available in 61 (86%) of patients, which showed 61 (100%) stable or successful castration. Twenty-four (34%) patients used relugolix in combination. No new major safety signals were seen in combination therapy. Nineteen (27%) patients had switched to another form of ADT. Fifteen of these (79%) felt similar or better on relugolix therapy.

CONCLUSIONS

Compliance with relugolix seemed acceptable. No major new safety signals were seen, even in combination. Among patients who switched therapy, most tolerated relugolix similarly or better than the previous form of ADT. The cost was a major reason for patients not initiating and for discontinuing therapy.

Oral Gonadotropin-Releasing Hormone Antagonist Relugolix Has the Same Effect as Gonadotropin-Releasing Hormone Agonist Injections in Terms of Preparation for Transcervical Resection Myomectomy

For preparing the optimal condition in transcervical resection (TCR) surgery, gonadotropin-releasing hormone (GnRH) agonist has been utilized. Recently, an oral GnRH antagonist (relugolix) is available and acts directly on GnRH receptor, avoiding flare up and reducing blood E2 levels rapidly. We retrospectively compared the oral GnRH antagonist (n = 14) effect to that of subcutaneous GnRH agonist (n = 19) for the pretreatment of endometrium in TCR myomectomy. Endometrial thickening was determined by intraoperative videos. The color tone of the endometrium in the normal part was assessed by digital image processing. The median duration of the first GnRH agonist injection and the surgery was 67 days (21-136 days), which is significantly longer than that of the oral GnRH antagonist group, 18.5 days (7-157 days P < 0.01). Both the GnRH agonist and antagonist groups did not exhibit prominence in the endometrium. The GnRH antagonist group showed the same degree of whiteness in the normal endometrium as the GnRH agonist group. The oral GnRH antagonist administration could rapidly atrophy the endometrium and create an optimal surgical field for TCR in a short period.

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.

Relugolix and elagolix directly inhibit leiomyoma extracellular matrix production in 2-dimesnional and 3-dimensional cell cultures

OBJECTIVE

To determine the effect relugolix and elagolix have on the production of extracellular matrix (ECM) proteins in human leiomyoma cells.

DESIGN

Laboratory study.

SETTING

University hospital.

PATIENT(S) OR ANIMALS

None. January 5, 2022 Cell culture, protein analysis, immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Production of GnRHR, COL1A1, FN1, VCAN, p-ERK, & ERK in treated/untreated leiomyoma cells.

RESULTS

100 nM relugolix resulted in decreased production of COL1A1 at 24 (1.78 0.06-fold; P < .05) and 48 hours (1.92 0.14-fold; P < .05). Elagolix treatment resulted in a decrease in COL1A1 production at 24 but not 48 hours. In 2D and 3D, 100 nM relugolix resulted in decreased production of FN1 at 24 (1.7 ± 0.07-fold; P < .05) and 48 hours (1.8 ± 0.07-fold; P < .05); 100 nM elagolix resulted in decreased production of FN1 at 24 (1.7 ± 0.14-fold; P < .05) and 48 hours (2.0 ± 0.09-fold; P < .05). For cells treated with relugolix 100 nM resulted in decreased VCAN production by 48 hours (0.66 ± 0.07-fold; P < .05). Contrary to our 3D data, 2D elagolix-treated cells demonstrated a decrease in VCAN production that was identified only at 24 hours. For GnRHR, no significant difference between the drugs was seen at 24 hours; at 48 hours production was only significantly decreased for relugolix (P < .05). Comparing both drugs, there was a significant difference in the concentration of p-ERK to ERK at 24 hours (P < .05); there was no difference by 48 hours.

CONCLUSIONS

Our findings demonstrated that treatment with either drug can 1) decrease ECM protein production and 2) inhibit the MAPK pathway.

Relugolix in the management of prostate cancer

INTRODUCTION

Relugolix is the first oral gonadotrophin-releasing hormone (GnRH) receptor antagonist. Based on the phase III HERO trial results, relugolix received Food and Drug Administration approval for adult patients with advanced prostate cancer (PCa).

AREAS COVERED

: We provide an overview of the preclinical and clinical development of relugolix and its role in the current treatment landscape of PCa.

EXPERT OPINION

Relugolix leads to rapid inhibition of testicular production of testosterone and its rapid recovery upon discontinuation. In the HERO trial, relugolix was associated with a superior cardiovascular safety profile compared to GnRH agonists. These attributes make relugolix a promising therapy for patients with pre-existing cardiovascular co-morbidities, those pursuing intermittent androgen deprivation therapy, and those who desire rapid testosterone recovery during "off-treatment" periods. In the HERO trial, very few patients received concomitant enzalutamide (n=17, 2.7%) or docetaxel (n<10, 1.3%). Safety of relugolix has not been established in combination with many androgen-receptor-axis targeted therapies (e.g. abiraterone, apalutamide), cabazitaxel, or lutetium Lu 177 vipivotide tetraxetan, which precludes its use in combination with these agents. In addition, being an oral drug, relugolix may also be associated with challenges of affordability, adherence, and compliance in this predominantly elderly population.

Plain language summary of the HERO study comparing relugolix with leuprolide for men with advanced prostate cancer

WHAT IS THIS SUMMARY ABOUT?

This is a summary of a research study (known as a clinical trial) called HERO. The HERO study compared how well relugolix and leuprolide worked in lowering blood testosterone to sustained castration levels in men with advanced prostate cancer. Sustained castration is a blood testosterone level below 50 ng/dl from Day 29 through 48 weeks of treatment.

WHAT WERE THE RESULTS?

Researchers looked at 930 adult men with advanced prostate cancer: 622 of these men took relugolix (by mouth once daily) and 308 received leuprolide (injected every 3 months). The HERO study showed that more men taking relugolix (97%) achieved sustained castration through 48 weeks than men receiving leuprolide (89%). This decrease in testosterone also happened more quickly in men taking relugolix. In 184 men who were followed up for 90 days after completing treatment, blood levels of testosterone returned to normal in more men who took relugolix than men who received leuprolide. Side effects were similar among men taking relugolix or receiving leuprolide, and most were identified as mild or moderate in terms of how bad they were.

WHAT DO THE RESULTS OF THE STUDY MEAN?

In men with advanced prostate cancer and compared with those receiving leuprolide, more men taking relugolix had lower levels of blood testosterone. ClinicalTrials.gov NCT number: NCT03085095.

Short-term administration of oral relugolix before single-port laparoscopic-assisted vaginal hysterectomy for symptomatic uterine myomas: A retrospective comparative study with leuprorelin injection

AIM

To investigate the efficacy of short-term administration of relugolix, a novel orally active gonadotropin-releasing hormone (GnRH) antagonist, before single-port laparoscopic-assisted vaginal hysterectomy (LAVH) for symptomatic uterine myomas, retrospectively compared with injection of leuprorelin, a GnRH agonist.

METHODS

A retrospective comparative study of each 35 women with symptomatic myomas in the relugolix and leuprorelin groups.

RESULTS

Before administration of relugolix and leuprorelin, the median uterine volume did not differ significantly between the two groups (p = 0.53). Median uterine volume change from baseline after short-term administration of relugolix and leuprorelin did not differ significantly (p = 0.17). Surgical duration (p = 0.84) and estimated blood loss (p = 0.48) were not different between the two groups. According to a patient questionnaire, the side effects of the drugs were not different between the two groups (p = 0.27). When patients were was asked if they wanted to have either of these drugs again, some relugolix users preferred leuprorelin due to concern about forgetting daily medication, while some leuprorelin users preferred relugolix to avoid pain at injection.

CONCLUSION

Oral relugolix medication or leuprorelin injection administered before single-port LAVH for uterine myomas yielded an equivalent reduction of uterine volume and perioperative outcomes with no significant adverse events. Patient preference for either oral daily relugolix or a monthly injection of leuprorelin could be considered when preoperative management is determined.

An evaluation of relugolix/estradiol/norethindrone acetate for the treatment of heavy menstrual bleeding associated with uterine fibroids in premenopausal women

INTRODUCTION

Uterine Fibroids (UFs) are the most predominant benign tumor in women who are coming of reproductive age, and causes intense economic load priced in billions of US dollars. Historically, surgery has been the main definitive treatment, albeit less attractive nowadays, especially for women with future fertility plans. Therefore, studies to explore the pharmacological treatment options are increasing especially as those that are currently available are limited for short-term use only.

AREAS COVERED

This drug evaluation features the clinical results from previous and ongoing studies of relugolix, in combination with the add back therapy of estradiol (E2) and norethindrone acetate (NETA), as a novel, orally administered, nonpeptide antagonist of gonadotropin-releasing hormone (GnRH) for the management of heavy menstrual bleeding (HMB) in premenopausal women with UFs.

EXPERT OPINION

The combination of relugolix/E2/NETA is an encouraging, well-tolerated and noninvasive pharmacological option for UFs patients. Relugolix induced a concentration-dependent decrease in HMB. However, it should be used with hormonal add-back therapy (E2+ NETA) to avoid induced hypoestrogenic side effects, importantly bone mineral density loss. Moreover, symptoms will likely resume shortly after the termination of the relugolix combination administration.

Advances with androgen deprivation therapy for prostate cancer

INTRODUCTION

Androgen deprivation therapy (ADT) has been a treatment of choice for prostate cancer in almost all phases, particularly in the locally advanced, metastatic setting in both hormone-sensitive and castration-resistant diseaseand in those who are unfit for any local therapy. Different ways of administering ADT comes in the form of surgical or chemical castration with the use of gonadotropin-releasing hormone (GnRH-agonists) being the foremost way of delivering ADT.

AREAS COVERED

This review encompasses ADT history, use of leuprolide, degarelix, and relugolix, with contextual use of ADT in combination with androgen-signaling inhibitors and potential mechanisms of resistance. Novel approaches with regard to hormone therapy are also discussed.

EXPERT OPINION

The use of GnRH-agonists and GnRH-antagonists yields efficacy that is likely equivalent in resulting in testosterone suppression. While the side-effect profile with ADT are generally equivalent, effects on cardiovascular morbidity may be improved with the use of oral relugolix though this is noted with caution since the cardiovascular side-effects were a result of secondary subgroup analyses. The choice of ADT hinges upon cost, availability, ease of administration, and preference amongst physicians and patients alike.

A novel orally active gonadotropin-releasing hormone antagonist, relugolix, is a potential substitute for injectable GnRH antagonists in controlled ovarian stimulation in assisted reproductive technology

Purpose

To evaluate the efficacy of an oral gonadotropin‐releasing hormone antagonist (GnRH Ant), relugolix (R), for assisted reproductive technology (ART).

Methods

We enrolled women undergoing ART using a GnRH Ant for controlled ovarian stimulation. We compared R; 20 mg/day with cetrorelix acetate (C); 0.125 mg. C was administered to 88 women in 2019, and R to 93 women in 2020. Clinical outcomes associated with ART were assessed in both groups.

Results

The luteinizing hormone levels on the day of human chorionic gonadotropin injection in the R group (1.26 ± 0.93 IU/L) were significantly lower than those in the C group (2.85 ± 3.02 IU/L). There were no cases in which egg retrieval was canceled in both groups. The total doses of gonadotropins administered were greater in the R group compared with the C group. The number of days of GnRH Ant administration in the R group (1.71 ± 0.57 days) was significantly longer compared with the C group (1.48 ± 0.58 days). The number of oocytes collected, fertilization rates, and pregnancy rates (R; 47.1% vs C; 45.8%) did not differ between the two groups.

Conclusion

An orally active GnRH Ant, relugolix, when used in controlled ovarian stimulation for ART, showed comparable clinical outcomes with cetrorelix.

Therapeutic effects of an oral gonadotropin-releasing hormone receptor antagonist, relugolix, on preventing premature ovulation in mild ovarian stimulation for IVF

Purpose

Can relugolix, a novel oral gonadotropin-releasing hormone receptor (GnRH) antagonist, function as an alternative ovulation inhibitor to GnRH antagonist injections?

Methods

This single-center, cross-sectional retrospective study compared premature ovulation rates and clinical outcomes in IVF treatment after mild ovarian stimulation with 40 mg of relugolix (relugolix group) or 0.25-mg injections of ganirelix acetate or cetrorelix acetate (injection group) between March 2019 and January 2020. Of 247 infertile women (256 IVF cycles) aged ≤42 years, 223 women (230 cycles) were evaluated. In the relugolix and injection groups, we compared 104 and 85 cycles after GnRH antagonist use before the LH surge (LH levels <10 mIU/ml) and 22 and 19 cycles during the LH surge (LH levels ≥10 mIU/ml), respectively.

Results

Before the LH surge, the ovulation rates in the two groups were very low (p = 0.838), however; during the LH surge, the cycles using relugolix had a high ovulation rate of 40.9% compared with no ovulation in the injection group (p = 0.002). There were no significant differences in embryo culture findings and pregnancy outcomes between the two groups.

Conclusions

Although relugolix had a high ovulation suppressive effect, when the LH surge occurred, its effect was insufficient.

Relugolix, an oral gonadotropin-releasing hormone receptor antagonist, reduces endometriosis-associated pain compared with leuprorelin in Japanese women: a phase 3, randomized, double-blind, noninferiority study

OBJECTIVE

To evaluate the efficacy and safety of 40-mg relugolix (REL) compared with those of leuprorelin (LEU) in women with endometriosis-associated pain.

DESIGN

Phase 3, multicenter, randomized, double-blind, double-dummy, active-controlled study in Japanese patients.

SETTING

Hospitals and clinics.

PATIENT(S)

Women aged ≥20 years with regular menstrual cycles (25-38 days) experiencing endometriosis or ovarian endometrioma and reporting pelvic pain.

INTERVENTION(S)

In the REL group, 40 mg of REL was orally administered once a day for 24 weeks. In the LEU group, 3.75 or 1.88 mg of LEU was subcutaneously injected every 4 weeks for 24 weeks.

MAIN OUTCOME MEASURE(S)

The primary endpoint was the change in the maximum visual analog scale score for pelvic pain from baseline until 28 days before the end of treatment.

RESULT(S)

Changes in the maximum visual analog scale score were -52.6 ± 1.3 for REL and -57.5 ± 1.4 for LEU. Ovarian endometrioma decreased by 12.26 ± 17.52 cm³ for REL and 14.10 ± 18.81 cm³ for LEU. Drug-related treatment emergent adverse events with an incidence of >10% for both groups were hot flush, metrorrhagia, headache, and genital hemorrhage. Discontinuations from treatment emergent adverse events were 2.9% for REL and 4.3% for LEU.

CONCLUSION(S)

Relugolix was noninferior to LEU for treating endometriosis-associated pelvic pain. Safety profiles of both medications were comparable, although menses returned earlier in patients taking REL, a huge benefit for women who plan to conceive after treatment.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT03931915.

Relugolix, an oral gonadotropin-releasing hormone antagonist for the treatment of prostate cancer

Androgen deprivation therapy using gonadotropin-releasing hormone (GnRH) analogues is standard treatment for intermediate and advanced prostate cancer. GnRH agonist therapy results in an initial testosterone flare, and increased metabolic and cardiovascular risks. The GnRH antagonist relugolix is able to reduce serum testosterone levels in men with prostate cancer without inducing testosterone flare. In the HERO Phase III trial, relugolix was superior to leuprolide acetate at rapidly reducing testosterone and continuously suppressing testosterone, with faster post-treatment recovery of testosterone levels. Relugolix was associated with a 54% lower incidence of major adverse cardiovascular events than leuprolide acetate. As the first oral GnRH antagonist approved for the treatment of advanced prostate cancer, relugolix offers a new treatment option.

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.

Current and emerging gonadotropin-releasing hormone (GnRH) antagonists for the treatment of prostate cancer

Introduction:Androgen deprivation therapy (ADT) is currently the backbone treatment of metastatic prostate cancer and is also used in combination with external beam radiotherapy (EBRT). Castration may be achieved either by bilateral orchiectomy or by administration of LHRH agonists or GnRH antagonists.Areas covered: In this article, the authors assess the current and emerging role of GnRH antagonists for the treatment of prostate cancer focusing on oncological results and safety (i.e. cardiovascular risk). In addition, updated data regarding the first orally administered GnRH antagonist, relugolix, is presented.Expert opinion: Studies demonstrate that GnRH antagonists are at least equal with LHRH agonists in terms of testosterone suppression and PSA progression free survival with a major advantage being rapid testosterone suppression. Thus, the optimal group of patients included symptomatic metastatic prostate cancer patients especially if cardiovascular comorbidities or LUTS are also present. Emerging data regarding benefit of the use of GnRH antagonists in patients with concomitant cardiovascular disease are of great interest. Relugolix has emerged as the first orally administered GnRH antagonist able to achieve and maintain testosterone castration levels and it is associated with a profound reduction of major cardiovascular events.

Recent Development and Future Prospects of Molecular Targeted Therapy in Prostate Cancer

Prostate cancer (PC) is a rapidly increasing ailment worldwide. The previous decade has observed a rapid advancement in PC therapies that was evident from the number of FDA approvals during this phase. Androgen deprivation therapies (ADT) have traditionally remained a mainstay for the management of PCs, but the past decade has experienced the emergence of newer classes of drugs that can be used with or without the administration of ADT. FDA approved poly (ADP-ribose) polymerase inhibitors (PARPi), such as olaparib and rucaparib, after successful clinical trials against gene-mutated metastatic castration-resistant prostate cancer. Furthermore, drugs like apalutamide, darolutamide, and enzalutamide with an androgen-targeted mechanism of action have manifested superior results in non-metastatic castration-resistant prostate cancer (nmCRPC), metastatic castration-sensitive prostate cancer (mCSPC), and metastatic castration-resistant prostate cancer (mCRPC), respectively, with or without previously administered docetaxel. Relugolix, an oral gonadotropin-releasing hormone antagonist, and a combination of abiraterone acetate plus prednisone were also approved by FDA after a successful trial in advanced PC and mCRPC, respectively. This review aims to analyze the FDA-approved agents in PC during the last decade and provide a summary of their clinical trials. It also presents an overview of the ongoing progress of prospective molecules still under trial.

Relugolix: a novel androgen deprivation therapy for management of patients with advanced prostate cancer

Androgen deprivation therapy (ADT) is the foundation of treatment for patients with locally advanced, recurrent and metastatic prostate cancer, most commonly using luteinizing releasing hormone (LHRH) agonists. More recently, a new approach to ADT has emerged with the development of gonadotropin-releasing hormone (GnRH) antagonists, which aim to overcome some of the potential adverse physiologic effects of LHRH agonists. This article focuses on the newest GnRH antagonist, relugolix - a once-daily treatment and the only oral GnRH antagonist that has now been approved for the treatment of advanced prostate cancer. In phase II and III studies, relugolix achieved rapid and sustained castration without the testosterone surge associated with LHRH agonists, thus avoiding the potential clinical consequences of tumor flare and the necessity for concomitant anti-androgen therapy. Relugolix also achieved rapid testosterone recovery, which may potentially reduce ADT-related adverse events and offer opportunities for combination and intermittent therapy strategies. Cardiovascular safety is a particular concern in men with prostate cancer and ADT further increases cardiovascular risk: indeed, LHRH agonists are required to have a drug label warning about an increased risk of cardiovascular disease. Data from the phase III HERO study demonstrate an improved cardiac safety profile for the GnRH antagonist relugolix compared with the LHRH agonist leuprolide, including a significantly reduced risk for a major adverse cardiovascular event. Taken together, the data indicate that relugolix may mitigate some of the cardiovascular concerns surrounding ADT and has the potential to become a new standard of care for men with prostate cancer. In summary, relugolix represents a novel and recently available prostate cancer management strategy, incorporating the mechanistic advantages of GnRH antagonists and the potential benefits of oral administration.

Progress in Clinical Research on Gonadotropin-Releasing Hormone Receptor Antagonists for the Treatment of Prostate Cancer

Gonadotropin-releasing hormone (GnRH) receptor agonists are still the most commonly used androgen deprivation treatment (ADT) drugs for prostate cancer in clinical practice. Currently, the GnRH receptor antagonists used for endocrine therapy for prostate cancer primarily include degarelix and relugolix (TAK-385). The former is administered by subcutaneous injection, while the latter is an oral drug. Compared to GnRH agonists, GnRH antagonists reduce serum testosterone levels more rapidly without an initial testosterone surge or subsequent microsurges. This review focuses on the mechanism of action of GnRH antagonists and agonists, the developmental history of GnRH antagonists, and emerging data from clinical studies of the two antagonists used as endocrine therapy for prostate cancer.

Relugolix, an oral gonadotropin-releasing hormone receptor antagonist, reduces endometriosis-associated pain in a dose-response manner: a randomized, double-blind, placebo-controlled study

OBJECTIVE

To evaluate the efficacy and safety of three dose levels of relugolix, a gonadotropin-releasing hormone receptor antagonist, compared with placebo and leuprorelin in women with endometriosis-associated pain.

DESIGN

Phase 2, multicenter, randomized, double-blind, placebo-controlled study.

SETTING

Hospitals and clinics.

PATIENT(S)

Adult premenopausal women with endometriosis who had dysmenorrhea and endometriosis-associated pelvic pain.

INTERVENTION(S)

During a 12-week treatment period, patients received relugolix 10 mg (n = 103), 20 mg (n = 100), or 40 mg (n = 103) as a daily oral dose; placebo (n = 97) as a daily oral dose; or leuprorelin 3.75 mg (n = 80) as a monthly subcutaneous injection.

MAIN OUTCOME MEASURE(S)

Primary endpoint was the change from baseline in mean visual analog scale score for pelvic pain during 28 days before the end of treatment.

RESULT(S)

The mean changes in mean visual analog scale score for pelvic pain were -3.8 mm in the placebo group; -6.2, -8.1, and -10.4 mm in the relugolix 10-mg, 20-mg, and 40-mg groups; respectively; and -10.6 mm in the leuprorelin group. The major adverse events with relugolix were hot flush, metrorrhagia, menorrhagia, and irregular menstruation, and bone mineral density decrease in a dose-response manner, which were also observed in the leuprorelin group with a frequency comparable with that in the relugolix 40-mg group.

CONCLUSION(S)

Oral administration of relugolix alleviated endometriosis-associated pain in a dose-response manner and was generally well tolerated. Relugolix 40 mg demonstrated efficacy and safety comparable with those of leuprorelin.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01458301.

Relugolix for the treatment of uterine fibroids

INTRODUCTION

Uterine fibroids (UF) are benign tumors common in premenopausal women, with strong impact on the health-care systems. For many years, surgery represented the only therapy for symptomatic fibroids. However, clinicians are observing a switch from surgery to noninvasive methods; in particular, medical treatment has been shown to be efficacious in obtaining a bleeding reduction and in ameliorating patient conditions.

AREAS COVERED

The authors review the current options available for the treatment of women with UF, with a special focus on the newest one, relugolix. It is an orally active non-peptide Gonadotropin-releasing hormone (GnRH)-receptor antagonist recently licensed for women with symptomatic fibroids. Relugolix is a well-tolerated safe drug; it is effective in inducing a dose-dependent decrease in menstrual blood loss, with faster reduction of heavy menstrual bleeding (HMB) and a greater shrinkage in fibroid volume compared to the current standard of GnRH agonist treatment.

EXPERT OPINION

Relugolix is a promising drug for the non-surgical treatment of women with UF. To date, the only published data come from a well-selected Japanese female population study while results from worldwide ongoing studies are ongoing in order to confirm the efficacy of this GnRH agonist receptor.

Relugolix, a novel oral gonadotropin-releasing hormone antagonist, in the treatment of pain symptoms associated with uterine fibroids: a randomized, placebo-controlled, phase 3 study in Japanese women

OBJECTIVE

To investigate the efficacy and safety of the oral gonadotropin-releasing hormone receptor antagonist, relugolix, in patients experiencing uterine fibroid-associated pain.

DESIGN

Phase 3, multicenter, randomized, double-blind, placebo-controlled study.

SETTING

Medical centers.

PATIENT(S)

Premenopausal Japanese women (N = 65) experiencing moderate-to-severe uterine fibroid-associated pain with a maximum Numerical Rating Scale (NRS) score of ≥4 were randomized and completed the study.

INTERVENTION(S)

Once-daily 40 mg relugolix (n = 33) or placebo (n = 32) for 12 weeks.

MAIN OUTCOME MEASURE(S)

Primary end point: proportion of patients with a maximum NRS score of ≤1 during the 28-day period before the final dose of study drug. Secondary end points: proportion of patients with no pain (NRS = 0) and percentage of days without pain during the 28-day period before the final dose of study drug; adverse events.

RESULT(S)

More patients receiving relugolix versus placebo achieved a maximum NRS score of ≤1 during the 28-day period before the final dose of study drug (57.6% vs. 3.1%). Similarly, more patients receiving relugolix versus placebo achieved a maximum NRS score of 0 (48.5% vs. 3.1%) and experienced more days without pain (96.4% vs. 71.4%). More patients receiving relugolix versus placebo experienced treatment-emergent adverse events (TEAEs; 87.9% vs. 56.3%); however, the rate of treatment discontinuation was low and not different between groups. Most TEAEs were mild to moderate in intensity. TEAEs (≥10%) included hot flush, metrorrhagia, hyperhidrosis, and menorrhagia, consistent with relugolix's mechanism of action, and viral upper respiratory tract infection.

CONCLUSION(S)

Relugolix improved uterine fibroid-associated pain and was well tolerated.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT02655224.

JAPIC CLINICAL TRIAL INFORMATION

JapicCTI-163127.