Zuranolone is an investigational positive allosteric modulator of synaptic and extrasynaptic GABAA receptors and a neuroactive steroid in clinical development as a once-daily, oral, 14-day treatment course for adults with major depressive disorder or postpartum depression (PPD). The randomized, double-blind, placebo-controlled SKYLARK Study (NCT04442503) demonstrated that zuranolone 50 mg significantly improved depressive symptoms (as assessed by 17-item Hamilton Rating Scale for Depression total score) at Day 15 (primary endpoint; p<0.001) and was generally well tolerated in adults with PPD.

In the SKYLARK Study, patients were randomized 1:1 to receive zuranolone 50 mg or placebo for 14 days. Safety and tolerability were assessed by the incidence and severity of treatment-emergent adverse events (TEAEs), rates of dose reduction and treatment discontinuation, as well as weight gain and sexual dysfunction.

The SKYLARK Study assessed safety data from 98 patients treated with zuranolone 50 mg and 98 patients treated with placebo. TEAEs were reported in 66.3% of zuranolone-treated patients and 53.1% of placebo-treated patients. In patients that experienced TEAEs, most reported mild (zuranolone, 50.8%; placebo, 75%) or moderate (zuranolone, 44.6%; placebo, 23.1%) events. The most common (≥5%) TEAEs were somnolence (26.5%), dizziness (13.3%), sedation (11.2%), headache (9.2%), diarrhea (6.1%), nausea (5.1%), urinary tract infection (5.1%), and COVID-19 (5.1%) with zuranolone, and headache (13.3%), dizziness (10.2%), nausea (6.1%), and somnolence (5.1%) with placebo. Dose reduction due to TEAEs was 16.3% in patients receiving zuranolone vs 1.0% in patients receiving placebo; the most common TEAEs (>1 patient) leading to zuranolone dose reduction were somnolence (7.1%), dizziness (6.1%), and sedation (3.1%). Treatment discontinuation due to TEAEs was 4.1% in patients receiving zuranolone vs 2.0% in patients receiving placebo; TEAEs leading to zuranolone discontinuation in >1 patient included somnolence (2.0%). Serious TEAEs were reported in 2.0% of zuranolone-treated and 0% of placebo-treated patients; these included upper abdominal pain (1.0%, [1/98]), peripheral edema (1.0%, [1/98]), perinatal depression (1.0%, [1/98]), and hypertension (1.0%, [1/98]). Per investigators, serious TEAEs were not related to zuranolone. No signals for weight gain or sexual dysfunction were identified.

In adults with PPD, zuranolone 50 mg was generally well tolerated. Most TEAEs were mild or moderate in severity. Dose reduction due to TEAEs mainly resulted from somnolence, dizziness, and sedation, while treatment discontinuation due to TEAEs was low. No signals for weight gain or sexual dysfunction were identified.

Sage Therapeutics, Inc., and Biogen Inc.