A randomized, double-blind, fixed-dose study comparing the efficacy and tolerability of vortioxetine 2.5 and 10 mg in acute treatment of adults with generalized anxiety disorder.

Background: Vortioxetine is a recently approved multimodal antidepressant with anxiolytic properties in preclinical studies.

Objective: This double-blind, placebo-controlled study assessed the efficacy and tolerability of vortioxetine in subjects with a primary diagnosis of generalized anxiety disorder.

Methods: Subjects (n = 457) were randomized 1:1:1 to treatment with placebo or vortioxetine 2.5 or 10 mg once daily. The primary efficacy endpoint was reduction in Hamilton Anxiety Scale (HAM-A) total scores from baseline after 8 weeks of treatment. Key secondary outcomes were changes from baseline in HAM-A total scores for the 2.5 and 10 mg dose, Hospital Anxiety and Depression anxiety subscore, 36-Item Short-Form Health Survey, Sheehan Disability Scale, and Clinical Global Impression-Improvement Scale score, as well as HAM-A response rate at week 8.

Results: Neither vortioxetine dose achieved a statistically significant improvement over placebo on the primary endpoint (least-squares mean difference ± standard error from placebo: -0.87 ± 0.803 [p = 0.279] for 2.5 mg and -0.81 ± 0.791 [p = 0.306] for 10 mg vortioxetine) or on any secondary efficacy endpoints. Common adverse events (≥5% in either vortioxetine group) were nausea, dry mouth, headache, diarrhea, constipation, and vomiting.

Conclusions: Vortioxetine 2.5 and 10 mg treatment did not significantly improve generalized anxiety disorder symptoms versus placebo. Vortioxetine was safe and well tolerated in this patient population.