Background: Elderly patients with major depression have a poorer prognosis, are less responsive to treatment, and show greater functional decline compared with younger patients, highlighting the need for effective treatment.
Methods: This phase 3 double-blind study randomized patients with treatment-resistant depression (TRD) ≥65 years (1:1) to flexibly dosed esketamine nasal spray and new oral antidepressant (esketamine/antidepressant) or new oral antidepressant and placebo nasal spray (antidepressant/placebo). The primary endpoint was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to day 28. Analyses included a preplanned analysis by age (65-74 versus ≥75 years) and post-hoc analyses including age at depression onset.
Results: For the primary endpoint, the median-unbiased estimate of the treatment difference (95% CI) was -3.6 (-7.20, 0.07); weighted combination test using MMRM analyses z = 1.89, two-sided p = 0.059. Adjusted mean (95% CI) difference for change in MADRS score between treatment groups was -4.9 (-8.96, -0.89; t = -2.4, df = 127; two-sided nominal p = 0.017) for patients 65 to 74 years versus -0.4 (-10.38, 9.50; t = -0.09, two-sided nominal p = 0.930) for those ≥75 years, and -6.1 (-10.33, -1.81; t = -2.8, df = 127; two-sided nominal p = 0.006) for patients with depression onset <55 years and 3.1 (-4.51, 10.80; t = 0.8, two-sided nominal p = 0.407) for those ≥55 years. Patients who rolled over into the long-term open-label study showed continued improvement with esketamine following 4 additional treatment weeks.
Conclusions: Esketamine/antidepressant did not achieve statistical significance for the primary endpoint. Greater differences between treatment arms were seen for younger patients (65-74 years) and patients with earlier onset of depression (<55 years).
Keywords: Ketamine; elderly; esketamine; major depressive disorder; treatment-resistant depression.
Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.