A randomized, double-blind, placebo-controlled study of the efficacy and safety of 2 doses of vortioxetine in adults with major depressive disorder.

BACKGROUND: This 8-week, randomized, double-blind, placebo-controlled study, conducted August 2010-May 2012 in the United States, evaluated the safety and efficacy of vortioxetine 10 mg and 15 mg in patients with major depressive disorder (MDD). The mechanism of action of vortioxetine is thought to be related to direct modulation of serotonin (5-HT) receptor activity and inhibition of the serotonin transporter.

METHOD: Adults aged 18-75 years with MDD (DSM-IV-TR) and Montgomery-Asberg Depression Rating Scale (MADRS) total score ≥ 26 were randomized (1:1:1) to receive vortioxetine 10 mg or 15 mg or placebo once daily, with the primary efficacy end point being change from baseline at week 8 in MADRS analyzed by mixed model for repeated measures. Adverse events were recorded during the study, suicidal ideation and behavior were assessed using the Columbia-Suicide Severity Rating Scale (C-SSRS), and sexual dysfunction was assessed using the Arizona Sexual Experience (ASEX) scale.

RESULTS: Of the 1,111 subjects screened, 469 subjects were randomized: 160 to placebo, 157 to vortioxetine 10 mg, and 152 to vortioxetine 15 mg. Differences from placebo in the primary efficacy end point were not statistically significant for vortioxetine 10 mg or vortioxetine 15 mg. Nausea, headache, dry mouth, constipation, diarrhea, vomiting, dizziness, and flatulence were reported in ≥ 5% of subjects receiving vortioxetine. Discontinuation due to adverse events occurred in 7 subjects (4.4%) in the placebo group, 8 (5.2%) in the vortioxetine 10 mg group, and 12 (7.9%) in the vortioxetine 15 mg group. ASEX total scores were similar across groups. There were no clinically significant trends within or between treatment groups on the C-SSRS, laboratory values, electrocardiogram, or vital sign parameters.

CONCLUSIONS: In this study, vortioxetine did not differ significantly from placebo on MADRS total score after 8 weeks of treatment in MDD subjects.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01179516.