BACKGROUND: Uterine fibroids are hormone-responsive neoplasms that are associated with heavy menstrual bleeding. Elagolix, an oral gonadotropin-releasing hormone antagonist resulting in rapid, reversible suppression of ovarian sex hormones, may reduce fibroid-associated bleeding.
METHODS: We conducted two identical, double-blind, randomized, placebo-controlled, 6-month phase 3 trials (Elaris Uterine Fibroids 1 and 2 [UF-1 and UF-2]) to evaluate the efficacy and safety of elagolix at a dose of 300 mg twice daily with hormonal "add-back" therapy (to replace reduced levels of endogenous hormones; in this case, estradiol, 1 mg, and norethindrone acetate, 0.5 mg, once daily) in women with fibroid-associated bleeding. An elagolix-alone group was included to assess the impact of add-back therapy on the hypoestrogenic effects of elagolix. The primary end point was menstrual blood loss of less than 80 ml during the final month of treatment and at least a 50% reduction in menstrual blood loss from baseline to the final month; missing data were imputed with the use of multiple imputation.
RESULTS: A total of 412 women in UF-1 and 378 women in UF-2 underwent randomization, received elagolix or placebo, and were included in the analyses. Criteria for the primary end point were met in 68.5% of 206 women in UF-1 and in 76.5% of 189 women in UF-2 who received elagolix plus add-back therapy, as compared with 8.7% of 102 women and 10% of 94 women, respectively, who received placebo (P
CONCLUSIONS: Elagolix with add-back therapy was effective in reducing heavy menstrual bleeding in women with uterine fibroids. (Funded by AbbVie; Elaris UF-1 and Elaris UF-2 ClinicalTrials.gov numbers, NCT02654054 and NCT02691494.).
Schlaff, William D.; Ackerman, Ronald T.; Al-Hendy, Ayman; Archer, David F.; Barnhart, Kurt T.; Bradley, Linda D.; Carr, Bruce R.; Feinberg, Eve C.; Hurtado, Sandra M.; Kim, JinHee; Liu, Ran; Mabey, R. Garn; Owens, Charlotte D.; Poindexter, Alfred; Puscheck, Elizabeth E.; Rodriguez-Ginorio, Henry; Simon, James A.; Soliman, Ahmed M.; Stewart, Elizabeth A.; Watts, Nelson B.; and Muneyyirci-Delale, Ozgul, "Elagolix for Heavy Menstrual Bleeding in Women with Uterine Fibroids." (2020). Department of Obstetrics and Gynecology Faculty Papers. Paper 59.