Efficacy and safety of fezolinetant for moderate to severe vasomotor symptoms associated with menopause among women in East Asia: a phase 3 randomized study (MOONLIGHT I).

OBJECTIVE: To evaluate the efficacy and safety of fezolinetant for moderate to severe vasomotor symptoms (VMS) associated with menopause in East Asian women. METHODS: In this phase 3, randomized, double-blind study, postmenopausal women with moderate to severe VMS (minimum average frequency in the 10 days before randomization, ≥7/day or 50/week) received fezolinetant 30 mg/day or placebo (weeks 1-12), followed by an open-label extension phase with fezolinetant 30 mg/day (weeks 13-24). The co-primary endpoints were the mean changes in the daily frequency and severity of VMS at weeks 4 and 12. RESULTS: Among 301 participants, the difference in the least squares mean change (95% confidence interval) from baseline in the daily frequency of moderate to severe VMS versus placebo was -0.65 (-1.41 to 0.12) at week 4 and -0.55 (-1.35 to 0.26) at week 12. The differences in the least squares mean change from baseline in the VMS severity score versus placebo were -0.06 (-0.14 to 0.03) and -0.13 (-0.27 to 0.01) at weeks 4 and 12, respectively. Serious adverse events occurred in 0.7% of participants receiving fezolinetant in weeks 1 to 12, compared with 1.3% of those receiving placebo. CONCLUSIONS: Fezolinetant was generally safe but did not reduce the frequency or severity of VMS versus placebo in postmenopausal women in this study. ClinicalTrials.Gov Identifier: NCT04234204.