Astellas Pharma Inc. will present 12-week results from the pivotal Phase 3 SKYLIGHT 1™ clinical trial examining the efficacy and safety of fezolinetant, an investigational oral, nonhormonal compound being studied for the treatment of moderate to severe vasomotor symptoms associated with menopause (VMS), on Sunday, May 8, 2022 at the American College of Obstetricians and Gynecologists (ACOG) Annual Clinical and Scientific Meeting in San Diego. VMS, characterized by hot flashes (also called hot flushes) and/or night sweats, are common symptoms of menopause. Findings showed the SKYLIGHT 1 trial of fezolinetant 30 mg and 45 mg administered once daily met all four co-primary endpoints, demonstrating a statistically significant reduction from baseline in the frequency and severity of moderate to severe VMS at weeks 4 and 12 versus placebo.

The safety profile of fezolinetant in SKYLIGHT 1 is aligned with what was previously observed with fezolinetant. Fezolinetant is an investigational nonhormonal selective neurokinin 3 (NK3) receptor antagonist that blocks a specific receptor in the temperature control center of the brain (the hypothalamus) to reduce the frequency and severity of moderate to severe VMS associated with menopause. For the co-primary endpoint of reduction in daily (24 hours) mean frequency of moderate to severe VMS versus placebo, fezolinetant 30 mg demonstrated a -1.87 (p<0.001) and -2.39 (p<0.001) mean change at weeks 4 and 12, respectively.

At the 45 mg dose, fezolinetant showed a -2.07 (p<0.001) and -2.55 (p<0.001) mean change at weeks 4 and 12, respectively. Additionally, for the co-primary endpoint of reduction in daily (24 hours) mean severity of moderate to severe VMS versus placebo, fezolinetant 30 mg demonstrated a -0.15 (p=0.012) and -0.24 (p=0.002) mean change at weeks 4 and 12, respectively. The 45 mg dose of fezolinetant showed a -0.19 (p=0.002) and -0.20 (p=0.007) mean change versus placebo at weeks 4 and 12, respectively.

Treatment emergent adverse events (TEAEs) were reported by 37.4%, 43.4% and 44.6% of individuals in the SKYLIGHT 1 trial in the 30 mg, 45 mg and placebo groups, respectively. Headache was the most common TEAE in the fezolinetant groups and was reported by 5.2%, 6.4% and 7.4% in the 30 mg, 45 mg and placebo groups, respectively. Serious TEAEs occurred in less than 2% of patients in the fezolinetant groups.

The safety and efficacy of fezolinetant are under investigation and have not been established. If approved by regulatory authorities, fezolinetant would be a first-in-class, nonhormonal treatment option to reduce the frequency and severity of moderate to severe VMS associated with menopause.