Phase 2 Study of Relugolix vs Placebo in Heavy Menstrual Bleeding Associated With Uterine Fibroids [17H

Abstract

INTRODUCTION: Relugolix is a potent nonpeptide gonadotropin-releasing hormone receptor antagonist. This dose-finding study explored the ability of relugolix to decrease the heavy menstrual bleeding (HMB) associated with uterine fibroids (UF). METHODS: This randomized, double-blind, placebo-controlled, phase 2 study was designed to evaluate relugolix 10 mg, 20 mg and 40 mg administered orally once daily for 12 weeks in Japanese women with UF and HMB defined as a Pictorial Blood Loss Assessment Chart (PBAC) score of at least 120. The primary endpoint was the proportion of women with a total PBAC score of less than 10 from Week 6 to 12. Secondary endpoints included the proportion of women with amenorrhea, and myoma and uterine volumes. RESULTS: Patients (N = 216) were randomized to placebo or one of three relugolix groups. The proportion of patients with PBAC score of less than 10 from Week 6 to 12 was 0% in placebo group, and 20.8%, 43.6% and 83.6% in relugolix 10 mg, 20 mg and 40 mg groups (P < 0.001 vs placebo).74% of patients in relugolix 40 mg group achieved amenorrhea, and a dose-dependent decrease in myoma and uterine volumes were observed. The incidence of headache, metrorrhagia, menorrhagia, and hot flush were more than 10% higher in relugolix 20 mg and 40 mg groups than in placebo group; these AEs were mild or moderate in severity. CONCLUSION: Treatment with relugolix showed significant dose-dependent decreases in menstrual blood loss compared with placebo and was generally well-tolerated with AEs consistent with the drug’s mechanism of action.