A randomized, double-blind, placebo-controlled study of the efficacy and safety of vortioxetine 10 mg and 20 mg in adults with major depressive disorder

Context: Vortioxetine (Lu AA21004) is an antidepressant with a mechanism of action thought to be related to a combination of 2 pharmacologic actions: direct modulation of several receptors and inhibition of the serotonin transporter. Objective: To evaluate the efficacy of vortioxetine 10 and 20 mg once daily in outpatients with major depressive disorder. Design, Setting, and Participants: This 8-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group study was conducted from July 2010 to January 2012 among adults with a primary diagnosis of recurrent major depressive disorder (DSM-IV-TR). Intervention: Eligible subjects were randomized in 1:1:1 ratio to 1 of 3 treatment arms: vortioxetine 10 mg, vortioxetine 20 mg, or placebo once daily for 8 weeks. Subjects who completed the 8-week trial entered a 2-week blinded discontinuation period to assess potential discontinuation symptoms. Main Outcome Measure: The primary endpoint was the least squares mean change in Montgomery-Asberg Depression Rating Scale (MADRS) total score from baseline. Key secondary outcomes were analyzed in the following prespecified sequential order: MADRS response (≥ 50% decrease from baseline in total score), Clinical Global Impressions-Improvement score, change from baseline in MADRS total score in subjects with baseline Hamilton Anxiety Rating Scale score ≥ 20, MADRS remission (total score ≤ 10), and change from baseline in Sheehan Disability Scale total score (all at week 8). Results: A total of 462 subjects were randomized to placebo (n = 157), vortioxetine 10 mg (n = 155), and vortioxetine 20 mg (n = 150). Mean (SE) reductions from baseline in MADRS total score (week 8) were -10.77 (± 0.807), -12.96 (± 0.832), and -14.41 (± 0.845) for the placebo, vortioxetine 10 mg (P = .058 vs placebo), and vortioxetine 20 mg (P = .002 vs placebo) groups. MADRS response/remission was achieved in 28.4%/14.2%, 33.8%/21.4%, and 39.2%/22.3% of subjects, respectively, in the 3 groups. Only MADRS response for vortioxetine 20 mg significantly separated from placebo (P = .044). Treatment was well tolerated, with the most frequently reported adverse events consisting of nausea, headache, diarrhea, and dizziness. Conclusions: Vortioxetine 20 mg significantly reduced MADRS total score at 8 weeks in this study population. Overall, vortioxetine was well tolerated in this study.