Evidence for Efficacy and Tolerability of Vilazodone in the Treatment of Major Depressive Disorder

Abstract

The efficacy and tolerability of vilazodone, a combined selective serotonin reuptake inhibitor and partial 5-hydroxytryptamine-1A (5-HT(1A)) receptor agonist, were evaluated in adult patients with major depressive disorder (MDD). This was a randomized, double-blind, placebo-controlled trial conducted from February 2006 to May 2007. Patients aged 18 through 65 years with MDD (DSM-IV criteria) and a baseline 17-item Hamilton Rating Scale for Depression (HAM-D-17) score of >or= 22 were randomly assigned to vilazodone or placebo for 8 weeks. Vilazodone was titrated from 10 mg to 40 mg once a day over 2 weeks. Efficacy was assessed by mean change from baseline to week 8 on the Montgomery-Asberg Depression Rating Scale (MADRS), HAM-D-17, and Hamilton Rating Scale for Anxiety. Response rates were determined at week 8 for the MADRS, HAM-D-17, and Clinical Global Impressions-Severity of Illness (CGI-S) and -Improvement (CGI-I) scales. Data were analyzed using a modified last-observation-carried-forward method in the intention-to-treat (ITT) sample. The Arizona Sexual Experience Scale (ASEX) was also measured at baseline and week 8. Of 410 randomly assigned patients, 198 receiving vilazodone and 199 receiving placebo were included in the ITT population. The mean changes in MADRS and HAM-D-17 total scores from baseline to week 8 were significantly (p = .001 and p = .022, respectively) greater with vilazodone than with placebo. Significant (p < .05) improvements in MADRS and HAM-D-17 scores were noted at week 1, the earliest time point measured. Response rates were significantly higher with vilazodone than with placebo on the MADRS (p = .007), HAM-D-17 (p = .011), and CGI-I (p = .001). Treatment-emergent adverse events with vilazodone included diarrhea, nausea, and somnolence; most adverse events were of mild or moderate intensity. There were no clinically significant differences for either gender in ASEX scores at end of treatment. Vilazodone is effective for the treatment of MDD in adults, with symptom relief starting at 1 week, and is well tolerated at a dose of 40 mg/day. clinicaltrials.gov Identifier: NCT00285376.