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.