Sage Therapeutics, Inc. and Biogen Inc. announced that the Phase 3 SKYLARK Study of zuranolone, an investigational oral drug being evaluated in women with postpartum depression (PPD), met its primary and all key secondary endpoints. Women treated with zuranolone 50 mg (n=98) demonstrated a statistically significant and clinically meaningful improvement in depressive symptoms at Day 15, the primary endpoint, compared to placebo (n=97) as measured by a change from baseline (CFB) in the 17-item Hamilton Rating Scale for Depression (HAMD-17) total score. The least-squares (LS) mean (SE) CFB in HAMD-17 total score at Day 15 for women who received zuranolone 50 mg was -15.6 (0.82) compared with -11.6 (0.82) for women who received placebo (LS mean difference -4.0 points; p=0.0007).

The study met all key secondary endpoints with rapid and statistically significant improvement in depressive symptoms as early as Day 3 for participants treated with zuranolone 50 mg compared to placebo, which was sustained at all measured timepoints through Day 45 as measured by CFB in HAMD-17 total score. In addition, the study demonstrated statistically significant improvement in the key secondary endpoint of change from baseline in the Clinical Global Impression Severity (CGI-S) scale at Day 15 for participants treated with zuranolone 50 mg as compared to placebo (zuranolone -2.2 vs. placebo -1.6, p= 0.0052).

The CGI-S is a clinician-administered 7-point scale that rates the severity of a person's disease at the time of assessment. Zuranolone is an investigational two-week, once-daily oral drug being developed for major depressive disorder (MDD) and PPD. The SKYLARK Study in PPD was a randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of zuranolone 50 mg dosed once daily for 14 days compared to placebo.

Women enrolled in the study (n=200) had a total score of equal to or greater than 26 at baseline in the HAMD-17 and were followed for up to 45 days. The study population included approximately 22% Black or African American women and 38% Hispanic or Latina women. Zuranolone 50 mg was generally well-tolerated and demonstrated a safety profile consistent with that observed in the clinical development program to date.

In women in both treatment groups who experienced treatment emergent adverse events (TEAEs), the majority were mild to moderate in severity. The most common TEAEs (>5% in the zuranolone 50 mg arm) were somnolence, dizziness, sedation, headache, diarrhea, nausea, urinary tract infection and COVID-19. No evidence of withdrawal symptoms or increased suicidal ideation or behavior were identified as assessed by the 20 item Physician Withdrawal Checklist and the Columbia Suicide Severity Rating Scale, respectively.

PPD is one of the most common medical complications during and after pregnancy and is estimated to affect approximately one in eight women who have given birth in the U.S. or approximately 500,000women annually. Symptoms of PPD can include depressed mood, loss of interest in activities, changes in sleep patterns and appetite, decreased energy, feelings of guilt or worthlessness, trouble concentrating and in some cases thoughts of suicide. While recognized by the U.S. Department of Health and Human Services as a high-priority public health issue, screening rates vary and nearly 70% of women with PPD may go undiagnosed.

The NEST clinical development program for zuranolone in PPD includes the SKYLARK and ROBIN Studies. The first study in the NEST program, the Phase 3 ROBIN Study, also met its primary endpoint. The ROBIN Study was a multicenter, randomized, double-blind, placebo-controlled study evaluating the efficacy, safety, and pharmacokinetics of zuranolone 30 mg in the treatment of PPD.

The LANDSCAPE and NEST development program for zuranolone includes 7 clinical studies evaluating the safety and efficacy of zuranolone in MDD and PPD. Sage Therapeutics and Biogen have initiated a rolling submission of a New Drug Application (NDA) to the U.S. Food and Drug Administration for zuranolone in the treatment of MDD and plan to complete the MDD NDA filing in the second half of 2022. An associated NDA filing for PPD is anticipated in early 2023.