OR06-5 Fezolinetant for Treatment of Moderate-to-severe Vasomotor Symptoms Associated with Menopause: Results from a 52-week Study (Skylight 2)

BACKGROUND: SKYLIGHT 2 (NCT04003142) investigated safety and efficacy of fezolinetant (a neurokinin-3 receptor antagonist) on frequency and severity of moderate-to-severe vasomotor symptoms (VMS) and sleep disturbance. In this analysis, persistence of fezolinetant efficacy was investigated over 52 weeks. METHODS: This double-blind Phase 3 study randomized women aged ≥40–65 years with moderate-to-severe VMS associated with menopause (average of ≥7 hot flashes/day) to once-daily placebo or fezolinetant 30mg or 45mg for 12 weeks. Women completing 12 weeks entered an extension period, with those on placebo re-randomized to fezolinetant 30mg or 45mg (placebo/fezolinetant), and those originally on fezolinetant remaining on their dose for an additional 40-weeks. Fezolinetant efficacy was evaluated vs placebo for 12-weeks through change in VMS frequency, VMS severity, and Patient-reported Outcomes Measurement Information System Sleep Disturbance–Short Form 8b (PROMIS) Total Score. Persistence of efficacy for fezolinetant was evaluated descriptively (without statistical comparisons) over the extension period. RESULTS: The analysis comprised 484 women (fezolinetant 30mg n=166, fezolinetant 45mg n=167, placebo/fezolinetant 30mg n=76, placebo/fezolinetant 45mg n=75). Improvement in VMS frequency and severity observed through week 12 (statistically significant differences vs placebo) was maintained throughout the 52-week total study period for those receiving fezolinetant. Fezolinetant demonstrated further reductions in VMS frequency and severity from baseline to beyond week 12. For VMS frequency, there was a least squares (LS) mean (SE) baseline-to-week 12 reduction of –6.83 (0.39) VMS/day for fezolinetant 30mg and –7.50 (0.39) for 45mg, and a mean (SD) baseline-to-week 52 reduction of –8.03 (4.53) for fezolinetant 30mg and –8.48 (3.98) for 45mg. For VMS severity, LS mean (SE) baseline-to-week 12 reduction was –0.64 (0.06) for 30mg and –0.77 (0.06) for 45mg, and mean (SD) baseline-to-week 52 reduction was –0.83 (0.82) for fezolinetant 30mg, and –0.95 (0.78) for 45mg. Women re-randomized from placebo to fezolinetant experienced a reduction in frequency and severity of VMS consistent with that in women receiving fezolinetant throughout the study. Fezolinetant also reduced PROMIS-assessed sleep disturbance, with a LS mean (SE) baseline-to-week 12 reduction of –4.1 (0.5) for fezolinetant 30mg and –5.5 (0.5) for 45mg (statistically significant difference vs placebo for fezolinetant 45mg) and a mean (SD) baseline-to-week 52 reduction of – 6.3 (7.3) for fezolinetant 30mg and –5.7 (7.9) for 45mg. The safety profile observed for the 40-week extension period was consistent with that of the 12-week placebo-controlled period. CONCLUSION: Fezolinetant 30mg and 45mg once daily were efficacious for treatment of moderate-to-severe VMS associated with menopause. Efficacy was persistent and reductions in VMS frequency were maintained during the extension period, at levels consistent with weeks 1 through 12. Fezolinetant 45mg improved sleep at week 12 and improvement was maintained through the active treatment extension period. No safety signals of concern were apparent for either fezolinetant dose. Presentation: Saturday, June 11, 2022 12:30 p.m. - 12:45 p.m.