Vortioxetine (Lu AA21004) 5 mg in generalized anxiety disorder: results of an 8-week randomized, double-blind, placebo-controlled clinical trial in the United States

The goal of the current clinical study, conducted in the United States (US), was to evaluate the efficacy and tolerability of vortioxetine 5mg vs placebo in adults with a primary diagnosis of generalized anxiety disorder (GAD; HAM-A total score ≥20 and MADRS score ≤16). Subjects were randomized (1:1) to receive vortioxetine 5mg (n=152) or placebo (n=152) for 8 weeks. Efficacy was assessed using change from baseline in HAM-A total scores after 8 weeks of treatment compared with placebo, using mixed-model repeated measures (MMRM) analyses. Adverse events (AEs) were assessed throughout the study. A total of 304 subjects were randomized (mean age, 41.2 years). After 8 weeks of treatment, there was no statistically significant difference in the reduction in HAM-A total score from baseline between the Vortioxetine (n=145) and placebo (n=145) groups. There were no statistically significant differences in any key secondary efficacy outcome between vortioxetine and placebo. Factors potentially contributing to the differences between the results of this study and those of one of identical design conducted outside the US are discussed. The most common treatment-emergent AEs were nausea, headache, dizziness, and dry mouth. Nausea was more frequently reported in the vortioxetine group (25% vs 4.6% for the placebo group). Most AEs were mild to moderate in severity. In conclusion, in this trial, vortioxetine did not improve symptoms of GAD (compared with placebo) over 8 weeks of treatment. Vortioxetine was well tolerated in this study.