Randomized, 8-week, double-blind, placebo-controlled trial of vortioxetine in Japanese adults with major depressive disorder, followed by a 52-week open-label extension trial

Aim: Safety and efficacy of vortioxetine (5-20mg/day) in Japanese patients with major depressive disorder were evaluated in two phase 3 studies consisting of a short-term, 8-week, placebo-controlled, double-blind study followed by a long-term, 52-week, open-label extension study. Methods: The primary end-point of the short-term study was change from baseline in Montgomery-angstrom sberg Depression Rating Scale (MADRS) total score at week 8. The primary objective of the extension study was vortioxetine's long-term safety; efficacy end-points included change in MADRS total score, Clinical Global Impression Scale (CGI)-Severity (S) score from the long-term study baseline, and CGI-Improvement (CGI-I) score over 52weeks. Results: Of the 366 randomized patients, 338 completed the short-term study, and 119 patients continued into the extension study. Primary (analysis of covariance) and secondary (mixed model for repeated measurements) analyses in the short-term study showed numerically greater, but not statistically significant, decreases in change in MADRS total score from baseline between the vortioxetine and placebo groups at week 8. In the long-term study, 86.6% of patients reported at least one treatment-emergent adverse event, with the most common being nasopharyngitis (40.3%) and nausea (21%). MADRS total score and CGI-I and CGI-S scores improved with continued vortioxetine treatment from baseline of the open-label study to week 52. Conclusion: Vortioxetine failed to meet significance versus placebo in the primary efficacy analysis at week 8 in the short-term study. The extension trial indicated continued improvement of depressive symptoms from baseline of this study throughout the 52-week treatment period. Vortioxetine treatment was safe and well tolerated in both studies.