Randomized, double-blind, placebo-controlled 8-week trial of the efficacy, safety, and tolerability of 5, 10, and 20 mg/day vortioxetine in adults with major depressive disorder.

Aim: This study assessed the efficacy and safety of vortioxetine in adults with major depressive disorder.

Methods: In this double-blind, placebo-controlled study, 600 patients with major depressive disorder were randomly assigned (1:1:1:1) to receive vortioxetine 5, 10, or 20 mg, or placebo once daily for 8 weeks. The primary end-point was change from baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) total score at week 8, evaluated by the last-observation-carried-forward method. Secondary end-points included response (≥ 50% decrease in the MADRS total score from baseline) and remission (MADRS total score ≤ 10), Clinical Global Impression Scale-Improvement, and change from baseline in Sheehan Disability Scale. Adverse events were summarized.

Results: Vortioxetine failed to show significant differences from placebo in the primary end-point. Nominally significant improvements over placebo were observed for vortioxetine doses of 10 and 20 mg when the primary end-point was evaluated using the mixed model for repeated measures as the secondary analysis, and 10 mg in secondary measures of response and patient functioning. Vortioxetine was well tolerated. Nausea, constipation, dry mouth, dizziness, and insomnia each occurred at a >twofold higher rate than placebo. Discontinuation symptom scores were comparable between all groups after 1 and 2 weeks following withdrawal of the study drug.

Conclusion: While vortioxetine failed to meet significance versus placebo in the primary efficacy analysis, there was evidence of efficacy for the 10- and 20-mg doses in secondary analyses. Vortioxetine was safe and well tolerated. Additional studies appear warranted.