PI3K/mTOR inhibition induces tumour microenvironment remodelling and sensitises pS6high uterine leiomyosarcoma to PD-1 blockade.

BACKGROUND: Uterine leiomyosarcomas (uLMS) are aggressive tumours with poor prognosis and limited treatment options. Although immune checkpoint blockade (ICB) has proven effective in some 'challenging-to-treat' cancers, clinical trials showed that uLMS do not respond to ICB. Emerging evidence suggests that aberrant PI3K/mTOR signalling can drive resistance to ICB. We therefore explored the relevance of the PI3K/mTOR pathway for ICB treatment in uLMS and explored pharmacological inhibition of this pathway to sensitise these tumours to ICB. METHODS: We performed an integrated multiomics analysis based on TCGA data to explore the correlation between PI3K/mTOR dysregulation and immune infiltration in 101 LMS. We assessed response to PI3K/mTOR inhibitors in immunodeficient and humanized uLMS patient-derived xenografts (PDXs) by evaluating tumour microenvironment modulation using multiplex immunofluorescence. We explored response to single-agent and a combination of PI3K/mTOR inhibitors with PD-1 blockade in humanized uLMS PDXs. We mapped intratumoural dynamics using single-cell RNA/TCR sequencing of serially collected biopsies. RESULTS: PI3K/mTOR over-activation (pS6high) associated with lymphocyte depletion and wound healing immune landscapes in (u)LMS, suggesting it contributes to immune evasion. In contrast, PI3K/mTOR inhibition induced profound tumour microenvironment remodelling in an ICB-resistant humanized uLMS PDX model, fostering adaptive anti-tumour immune responses. Indeed, PI3K/mTOR inhibition induced macrophage repolarisation towards an anti-tumourigenic phenotype and increased antigen presentation on dendritic and tumour cells, but also promoted infiltration of PD-1+ T cells displaying an exhausted phenotype. When combined with anti-PD-1, PI3K/mTOR inhibition led to partial or complete tumour responses, whereas no response to single-agent anti-PD-1 was observed. Combination therapy reinvigorated exhausted T cells and induced clonal hyper-expansion of a cytotoxic CD8+ T-cell population supported by a CD4+ Th1 niche. CONCLUSIONS: Our findings indicate that aberrant PI3K/mTOR pathway activation contributes to immune escape in uLMS and provides a rationale for combining PI3K/mTOR inhibition with ICB for the treatment of this patient population.

Chemotherapy is not needed when complete evacuation of gestational choriocarcinoma leads to hCG normalization.

BACKGROUND: The standard treatment for gestational choriocarcinoma is chemotherapy. OBJECTIVE: To describe the risk of recurrence with expectant management of gestational choriocarcinoma that has reached a normal human chorionic gonadotropin level after tumor removal without adjuvant chemotherapy. METHODS: A retrospective multicenter international cohort study was conducted from 1981 to 2017 involving 11 gestational trophoblastic disease reference centers with patient's follow-up extended until 2023. Clinical and biological data of included patients were extracted from each center's database. The inclusion criteria were i) histological diagnosis of gestational choriocarcinoma in any kind of placental tissue retrieved, ii) spontaneous normalization of human chorionic gonadotropin level following choriocarcinoma retrieval, iii) patient did not receive any oncological treatment for the choriocarcinoma, iv) and at least 6 months of follow-up after the first human chorionic gonadotropin level normalization. RESULTS: Among 80 patients with retrieved gestational choriocarcinoma and whose human chorionic gonadotropin level normalized without any other oncological therapy, none had a recurrence of choriocarcinoma after a median follow-up of 50 months. The median interval between choriocarcinoma excision and human chorionic gonadotropin level normalization was 48 days. The International Federation of Gynecology and Obstetrics/World Health Organization risk score was ≤6 in 93.7% of the cases. CONCLUSIONS: This multicenter international study reports that selected patients with gestational choriocarcinoma managed in gestational trophoblastic disease reference centers did not experience any relapse when the initial tumor evacuation is followed by human chorionic gonadotropin level normalization without any additional treatment. Expectant management may be a safe approach for highly selected patients.

Progesterone signaling in uterine leiomyoma biology: Implications for potential targeted therapy.

Uterine leiomyomas (ULs) are the most common benign smooth muscle cell steroid-dependent tumors that occur in women of reproductive age. Progesterone (P4) is a major hormone that promotes the ULs development and growth. P4 action in ULs is mediated mainly by its nuclear progesterone receptors (PGRs), although rapid non-genomic responses have also been observed. Data on the membrane progesterone receptors (mPRs) regulated signaling pathways in ULs in the available literature is still very limited. One of the essential characteristics of ULs is the excessive production of extracellular matrix (ECM). P4 has been shown to stimulate ECM production and collagen synthesis in ULs. Recent research demonstrated that, despite their benign nature, ULs may present with abnormal vasculature. P4 has been shown to regulate angiogenesis in ULs through the upregulation of vascular endothelial growth factor (VEGF) and by controlling the secretion of permeability factors. This review summarizes the key findings regarding the role of PGRs and mPRs in ULs, especially highlighting the potential ECM and angiogenesis modulation by P4. An increased understanding of this mechanistic role of nuclear and specifically mPRs in the biology of P4-modulated ECM and angiogenesis in the growth of ULs could turn out to be fundamental for developing effective targeted therapies for ULs.

The clinical trial of alternative relugolix administration for uterine leiomyoma prior to surgically treatment: a study protocol for Non-Adverse Relugolix Administration (NARA) trial.

BACKGROUND: Uterine leiomyomas are common for reproductive-aged women and affect women's quality of life due to heavy menstrual bleeding or dysmenorrhea. Leiomyomas grow according to estradiol exposure and decrease after post-menopause. In case serious symptoms are caused by leiomyomas, pharmacotherapy or surgical treatment is proposed. Prior to surgical treatment, pharmacotherapies aimed at the reduction of leiomyoma and uterine volume or improvement of anemia are introduced to conduct minimum invasive surgery (i.e., to reduce blood loss or surgical duration). Recently, relugolix (40 mg orally once daily) as a gonadotropin-releasing hormone (GnRH) receptor antagonist has proved its sufficient efficacy in suppressing estradiol levels without the transient estradiol flare-up compared with GnRH agonist. However, long-term administration should not be permitted liable to for climacteric disorder or osteoporosis, and evidence is lacking on the actual efficacy and extent of adverse effects of the every-other-day dosing regimen. This trial aimed to prove non-inferiority in volume reduction effect on leiomyoma and safety (i.e., reduction of adverse effects) by every-other-day administration after 2 months of everyday administration compared to daily administration throughout the duration. METHODS: A minimization adaptive randomized control trial (RCT) will be conducted. Patients (over 20 years old) harboring leiomyoma who will be undergoing surgical treatment will be invited to participate. Patients who are enrolled in the intervention group will receive every-other-day administration for 16 weeks after 8 weeks of daily administration. Patients who are enrolled in the control group will receive daily throughout the 24 weeks. The primary outcome is the leiomyoma volume reduction, and the secondary endpoints are the reduction of uterine volume, the occurrence of the climacteric disorder, genital bleeding days, change rate of serum hormone or bone turnover markers, and bone mineral density after 24 weeks compared to before administration. DISCUSSION: This study aims to prove both the non-inferiority in leiomyoma volume reduction and superiority in adverse effects occurrence reduction, which will provide a novel method to escape adverse effects while maintaining the effect of leiomyoma reduction. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs051230078. Registered on 26 July 2023.

The impact of epigallocatechin gallate, vitamin D, and D-chiro-inositol on early surgical outcomes of laparoscopic myomectomy: a pilot study.

PURPOSE: A prospective investigation to assess the impact of 3 months of treatment with epigallocatechin gallate (EGCG), vitamin D and D-chiro-inositol (DCI) in the treatment of uterine fibroids (UF) with laparoscopic myomectomy as evidenced by surgical outcomes and effect on liver function. METHODS: Non-pregnant or lactating women aged between 30 and 40 years were scheduled for laparoscopic myomectomy to treat symptoms or looking to conceive. After enrollment, patients were assigned to either (1) intervention group, assuming a total of 300 mg EGCG, 50 µg vitamin D, and 50 mg DCI divided in 2 pills per day for 3 months, or (2) control group, including untreated women scheduled to undergo laparoscopic myomectomy after 3 months. RESULTS: 91 patients completed the study. The comparison of the surgical outcomes between the intervention (n = 44) and the control (n = 47) groups revealed that the treatment significantly reduces the duration of surgery (41.93 ± 7.56 min vs 56.32 ± 10.63 min, p < 0.001). Moreover, the treatment also reduced blood loss during surgery (149.09 ± 25.40 mL vs 168.41 ± 21.34 mL, p < 0.001), resulting in treated patients having higher Hb levels at discharge 11.27 ± 0.82 mL vs 10.56 ± 0.82 mL, p < 0.01). The surgery induced an increase in AST and in total bilirubin regardless of the assigned group, and the treatment induced no change in liver function. CONCLUSIONS: Our data suggest that EGCG plus vitamin D, and DCI could represent a safe option for women with UF scheduled for laparoscopic myomectomy, improving surgical outcomes without affecting liver functionality.

Chemotherapy regimen for recurrent uterine leiomyosarcoma.

INTRODUCTION: Uterine leiomyosarcoma is a rare gynecological malignancy, the limited literature indicated that doxorubicin alone or gemcitabine/docetaxel combination is the preferred chemotherapy regimen. Given the rarity of the disease and the lack of high-level clinical evidence, there is no consensus on the best treatment. CASE REPORT: We report a case of a patient with uterine leiomyosarcoma who recurred after adjustment treatment with doxorubicin, gemcitabine, docetaxel, and anlotinib; and required a new chemotherapy regimen. MANAGEMENT AND OUTCOMES: The follow-up chemotherapy regimen was doxorubicin-liposome 40 mg/m2 on one day in combination with dacarbazine 250 mg/m2 on one to five days of intravenous infusion every 21 days. We monitored adverse effects during chemotherapy and the process was smooth. DISCUSSION: It is important to comprehensively consider the patient's condition, and fully consider the efficacy, dosage, and adverse reactions of the chemotherapy regimen to determine the appropriate plan, in order to achieve the best therapeutic benefits for patients.

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.

Simvastatin induces degradation of the extracellular matrix in human leiomyomata: novel in vitro, in vivo, and patient level evidence of matrix metalloproteinase involvement.

OBJECTIVES: To assess the effect of simvastatin on uterine leiomyoma growth and extracellular matrix (ECM) deposition. DESIGN: Laboratory analysis of human leiomyoma cell culture, xenograft in a mouse model, and patient tissue from a clinical trial. SETTING: Academic research center. PATIENT(S): Tissue culture from human leiomyoma tissue and surgical leiomyoma tissue sections from a placebo-controlled randomized clinical trial. INTERVENTION(S): Simvastatin treatment. MAIN OUTCOME MEASURE(S): Serum concentrations, xenograft volumes, and protein expression. RESULTS: Mice xenografted with 3-dimensional human leiomyoma cultures were divided as follows: 7 untreated controls; 12 treated with activated simvastatin at 10 mg/kg body weight; and 15 at 20 mg/kg body weight. Simvastatin was detected in the serum of mice injected at the highest dose. Xenograft volumes were significantly smaller (mean 53% smaller at the highest concentration). There was dissolution of compact ECM, decreased ECM formation, and lower collagen protein expression in xenografts. Membrane type 1 matrix metalloproteinase was increased in vitro and in vivo. Matrix metalloproteinase 2 and low-density lipoprotein receptor-related protein 1 were increased in vitro. CONCLUSIONS: Simvastatin exhibited antitumoral activity with ECM degradation and decreased leiomyoma tumor volume in vivo. Activation of the matrix metalloproteinase 2, membrane type 1 matrix metalloproteinase, and low-density lipoprotein receptor-related protein 1 pathway may explain these findings.

Estrogen replacement therapy and non-hormonal medication use among patients with uterine cancer.

OBJECTIVE: As the prognosis for endometrial cancer is excellent, management of the effects of estrogen deprivation has an important influence on quality of life. We examined the trends in the use of estrogen replacement therapy (ERT) and non-hormonal medications among patients with uterine cancer following surgery. METHODS: The MarketScan Database was used to identify patients 18-49 years who underwent hysterectomy plus oophorectomy and those aged 50-75 years who underwent hysterectomy between 2008 and 2020. ERT and non-hormonal treatments of menopause were identified preoperatively and postoperatively. After propensity score balancing, difference-in-differences (DID) analyses were performed to compare the pre-and-postoperative changes in ERT and non-hormonal medication use between groups. The trends in postoperative use of ERT were assessed and tested using Cochran-Armitage trend tests. RESULTS: A total of 19,700 patients with uterine cancer and 185,150 controls were identified. Overall, postoperative ERT use decreased for both age groups and for patients with and without uterine cancer. The DID in ERT use between those with uterine cancer and those with benign pathology after hysterectomy was -37.1% (95% CI, -40.5 to -33.6%) for patients 18-49 years of age and - 10.4% (95% CI, -10.9 to -9.9%) for those 50-75 years. The DID for non-hormonal medication use between those with uterine cancer and those with benign pathology after hysterectomy was 11.2% (95% CI, 7.8 to 14.7%) for younger patients and 3.4% (95% CI, 2.9 to 4.0%) for those 50-75 years. The postoperative new ERT use has been declining over time in patients with uterine cancer in those 18-49 years of age (P = .02) and those 50-75 years of age (P < .001). CONCLUSIONS: The use of ERT is uncommon and has declined over time in patients with uterine cancer. Conversely, non-hormonal medications are more commonly used among patients with uterine cancer.

Hysteroscopic diode laser myolysis: from a case series to literature review of incisionless myolysis techniques for managing heavy menstrual bleeding in premenopausal women.

PURPOSE: This case series examined the safety and effectiveness of hysteroscopic myolysis using laser-induced interstitial thermo-therapy (LITT) for treating heavy menstrual bleeding (HMB) in premenopausal women with FIGO type 1 or 2 uterine fibroids, not planning for future fertility. Additionally, a comprehensive review of innovative, minimally invasive, incisionless myolysis techniques was conducted. METHODS: Women with HMB, sonographically diagnosed with a single FIGO type 1 or 2 fibroid, underwent hysteroscopic myolysis using the Leonardo® diode laser. Effectiveness was assessed via transvaginal ultrasound measurement of myoma size, volume and vascularization pre and post-procedure. Moreover, we also evaluated any improvements in symptoms using the Pictorial Blood Loss Assessment Chart (PBAC score) scores. RESULTS: The procedure resulted in significant HMB reductions and noticeable fibroid size, volume, and vascularization decrease in all three patients, with no reported complications. The literature review revealed both advantages and limitations of the minimally invasive, incisionless myolysis techniques. CONCLUSIONS: Hysteroscopic laser myolysis is a safe and effective therapeutic intervention for patients experiencing HMB, diagnosed with FIGO type 1 or 2 fibroids, and not planning for future fertility. The procedure resulted in significant reductions in menstrual blood loss and fibroid size. Despite the promising results, it is essential to note the limitations of this report, including its case series design, a small number of patients, and a short follow-up period. Further research is necessary to confirm these results.

Effect and Safety of Diluted Vasopressin Injection for Bleeding Control During Robot-assisted Laparoscopic Myomectomy in Reproductive Women With Uterine Fibroids: A Randomized Controlled Pilot Trial (VALENTINE Trial).

BACKGROUND/AIM: Vasopressin injected during myomectomy is known to effectively reduce bleeding but is sometimes associated with intraoperative vasoconstriction and hypertension due to systemic absorption. Although there is a growing preference for the use of diluted vasopressin, evidence of its effect and safety is still lacking. PATIENTS AND METHODS: We performed a randomized controlled pilot trial to evaluate the effect and safety of vasopressin diluted in a constant volume during robot-assisted laparoscopic myomectomy (RALM), where a total of 39 women with uterine fibroids were randomly assigned into the following three groups (group 1, 0.2 IU/ml; group 2, 0.1 IU/ml; group 3, 0.05 IU/ml with a total of 100 ml of normal saline). The primary endpoint was to compare estimated blood loss (EBL), and the secondary endpoints were to compare postoperative value and drop ratio of hemoglobin, operation time, transfusion, hospitalization, and complications among the three groups. RESULTS: There were no differences in the number and largest size of uterine fibroids, total weight of uterine fibroids, console time, and volumes of intravenous fluid administered during RALM among the three groups, whereas combined operation was performed more commonly in group 2 than in groups 1 and 3 (53.9% vs. 0 to 7.7%; p=0.01). The primary and secondary endpoints were also not different among the three groups. However, two patients in group 1 (15.4%) showed vasopressin-related hypertension. CONCLUSION: Vasopressin diluted in a volume of 100 ml showed an effective hemostatic effect and safety during RALM (Trial No. NCT04874246 in ClinicalTrial.gov).

Current and Emerging Treatment Options for Uterine Fibroids.

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

The combination of natural compounds Crila and epigallocatechin gallate showed enhanced antiproliferative effects on human uterine fibroid cells compared with single treatments.

OBJECTIVE: To investigate the combined effects of Crila and green tea extract, epigallocatechin gallate (EGCG), compared with single treatments, on human uterine fibroid cells. DESIGN: Human uterine leiomyoma (HuLM) cells were treated with different concentrations of Crila, alone or in combination with EGCG, and several experiments were employed. SETTING: A laboratory study. PATIENTSS: N/A. INTERVENTIONS: Crila, EGCG. MAIN OUTCOME MEASURES: Cell proliferation assay, drug synergy using combination index, protein and gene expression analysis of proliferation marker proliferating cell nuclear antigen, and apoptosis marker BAX using western blotting and quantitative polymerase chain reaction, respectively. RESULTS: Results showed that tested Crila concentrations, when combined with 25 and 50 µM EGCG, exerted synergistic growth inhibitory effects on HuLM viability. This inhibitory effect on HuLM cell viability was because of decreased cell proliferation, as shown by a decrease in the proliferation marker proliferating cell nuclear antigen at messenger RNA and protein levels, rather than inducing apoptosis. CONCLUSION: Our study concludes that the utility of natural compounds may provide a safe and cost-effective alternative to currently used short-term hormonal therapies against uterine fibroids.

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

OBJECTIVE: To evaluate the safety and efficacy of elagolix 150 mg once-daily monotherapy in patients with heavy menstrual bleeding associated with uterine leiomyomas. METHODS: A phase 4, randomized, double-blind, placebo-controlled, 6-month treatment study was conducted in premenopausal patients aged 18-51 years with heavy menstrual bleeding (defined as menstrual blood loss greater than 80 mL during one menstrual cycle) associated with uterine leiomyomas. Patients were randomized 2:1 to receive elagolix 150 mg once daily or placebo. The primary endpoint was reduction in menstrual blood loss volume to less than 80 mL at the final month and at least a 50% reduction in menstrual blood loss volume from baseline to the final month. RESULTS: Of 82 randomized patients, 54 received elagolix 150 mg and 28 received placebo. With elagolix, 49.4% (95% CI 35.1-63.8%) of patients met the primary endpoint, compared with 23.3% (95% CI 7.2-39.5%) of patients who received placebo ( P =.035). Statistically significant differences between elagolix and placebo in mean reduction of menstrual blood loss from baseline were seen as early as month 1 ( P <.05 for months 1-3 and 5). Significantly more patients receiving elagolix experienced suppression of bleeding compared with placebo ( P =.036). Greater improvements were observed in the elagolix group (vs placebo) in the proportion of patients with amenorrhea, in hemoglobin concentrations, and in health-related quality of life. No serious or severe adverse events were reported for elagolix, compared with 7.1% of participants in the placebo group having serious adverse events (coronavirus disease 2019 [COVID-19] n=1, enlarged uvula n=1). Three patients (5.6%) discontinued elagolix due to adverse events. CONCLUSION: Elagolix 150 mg once-daily monotherapy significantly improved heavy menstrual bleeding associated with uterine leiomyomas compared with placebo in premenopausal patients. Treatment with elagolix 150 mg once daily was generally well-tolerated in this study, with no new safety signals. FUNDING SOURCE: AbbVie Inc. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT03886220.

In Vivo and In Vitro Efficacy of Trastuzumab Deruxtecan in Uterine Serous Carcinoma.

Uterine serous carcinoma (USC) is a rare, biologically aggressive variant of endometrial cancer with a high recurrence rate and poor prognosis. HER2 overexpression (3+ positivity) by IHC and/or FISH ERBB2 gene amplification is detected in approximately one-third of patients with USC. Clinical trials incorporating trastuzumab with standard chemotherapy have recently demonstrated improved progression-free and overall survival in advanced-stage or recurrent USC that overexpresses HER2. However, a large number of patients with USC eventually developed resistance to trastuzumab. Trastuzumab deruxtecan (T-DXd) is a novel HER2-directed antibody-drug conjugate with a topoisomerase I inhibitor payload recently approved by the Food and Drug Administration (FDA) for multiple tumor indications. Here, we investigated the in vitro and in vivo efficacy of T-DXd in primary USC cell lines and xenografts with different HER2 expression. T-DXd-induced cell growth suppression in HER2-overexpressing cell lines in vitro, increased early and late apoptosis as assessed by annexin and propidium iodide staining, and, similarly to trastuzumab, T-DXd-induced significant antibody-dependent cellular cytotoxicity in the presence of peripheral blood lymphocytes. While negligible activity was detected against USC cell lines with low HER2 expression, T-DXd demonstrated significant bystander killing against USC tumors with low/negligible HER2 when such cells were admixed with HER2 3+ tumor cells in vitro. T-DXd showed tumor growth suppression in in vivo USC PDX models that overexpress HER2 at 3+ levels, prolonging survival when compared with controls, with minimal toxicity. Future clinical trials are warranted in patients with USC failing trastuzumab treatment.

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.