Efficacy and Safety of Fezolinetant in Moderate to Severe Vasomotor Symptoms Associated With Menopause: A Phase 3 RCT

CONTEXT: Vasomotor symptoms (VMS) are common, bothersome, and can persist for years before and after menopause. OBJECTIVE: We aimed to assess efficacy/safety of fezolinetant for treatment of moderate to severe VMS associated with menopause. METHODS: In this double-blind, placebo-controlled, 12-week phase 3 trial with a 40-week active treatment extension (NCT04003142; SKYLIGHT 2), women aged 40 to 65 years with minimum average 7 moderate to severe VMS/day were randomized to 12 weeks of once-daily placebo, fezolinetant 30 mg, or fezolinetant 45 mg. Completers were rerandomized to fezolinetant 30/45 mg for 40 additional weeks. Coprimary efficacy endpoints were mean daily change from baseline to week 4 (W4) and W12 in VMS frequency and severity. Safety was also assessed. RESULTS: Both fezolinetant doses statistically significantly reduced VMS frequency/severity at W4 and W12 vs placebo. For VMS frequency, W4 least squares mean (SE) reduction vs placebo: fezolinetant 30 mg, -1.82 (0.46; P < .001); 45 mg, -2.55 (0.46; P < .001); W12: 30 mg, -1.86 (0.55; P < .001); 45 mg, -2.53 (0.55; P < .001). For VMS severity, W4: 30 mg, -0.15 (0.06; P < .05); 45 mg, -0.29 (0.06; P < .001); W12: 30 mg, -0.16 (0.08; P < .05); 45 mg, -0.29 (0.08; P < .001). Improvement in VMS frequency and severity was observed by W1 and maintained through W52. Serious treatment-emergent adverse events were infrequent, reported by 2%, 1%, and 0% of those receiving fezolinetant 30 mg, fezolinetant 45 mg, and placebo, respectively. CONCLUSION: Daily fezolinetant 30 and 45 mg were efficacious and well tolerated for treating moderate to severe VMS associated with menopause.