A Study of Esketamine Nasal Spray in Korean Participants With Treatment-resistant Depression

This single-group, open-label Phase IV study will administer intranasal esketamine (56 mg or 84 mg) twice weekly for 4 weeks to adults with treatment-resistant major depressive disorder to assess symptom change.

Primary outcome is change from baseline in the 17-item Hamilton Depression Rating Scale (HAM-D) total score from Day 1 to Day 28; safety and tolerability will be monitored throughout the treatment and follow-up periods.