In a long-term extension study (SUSTAIN-3) involving 1,148 adults with treatment-resistant depression, esketamine nasal spray combined with an oral antidepressant was evaluated for safety and efficacy over up to 79 months (median 45.8 months). Common adverse events included headache (36.9%), dizziness (33.9%), and nausea (33.6%). Nine participants died, with causes including COVID-19 and suicide. Depressive symptoms, measured by the MADRS, improved during the initial induction phase (average reduction of 12.8 points) and this improvement was maintained during the optimization/maintenance phase. At the end of maintenance, 49.6% of participants were in remission. No new safety concerns emerged, and depression improvement generally persisted for those continuing treatment.
In a phase 2b trial, adolescents aged 12 to 17 with major depressive disorder at imminent risk for suicide received either esketamine nasal spray (28, 56, or 84 mg) or a psychoactive placebo (oral midazolam) twice weekly for four weeks, alongside standard care including hospitalization, an antidepressant, and psychotherapy. Pooled esketamine doses (56 and 84 mg) reduced depressive symptoms more than midazolam at 24 hours after the first dose, though individual doses did not reach statistical significance. Suicidality severity improved across all groups. Common side effects included dizziness, nausea, and dissociation.