A Phase 3, Double-Blind, Randomized, Placebo-Controlled Study of Vilazodone in Adolescents with Major Depressive Disorder

Background: Major depressive disorder (MDD) is a serious illness in children and adolescents. Vilazodone is a selective serotonin reuptake inhibitor approved for MDD in adults. This study evaluated the efficacy, safety, and tolerability of vilazodone in adolescent patients, ages 12–17 years, with MDD (NCT01878292). Methods: This double-blind, randomized, placebo-controlled, parallel-group, fixed-dose study was conducted at 56 study centers in the United States and was 10 weeks in duration (a 1-week screening period, an 8-week double-blind treatment period, and a 1-week double-blind down-taper period). Outpatients with an MDD diagnosis based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria were included in the study. Clinical inclusion criteria required a Children’s Depression Rating Scale–Revised (CDRS-R) total score of ≥ 40 and Clinical Global Impressions–Severity (CGI-S) score of ≥ 4. Patients were randomized 1:1:1 to 8 weeks of double-blind treatment with placebo (n = 174), vilazodone 15 mg/day (n = 175), or vilazodone 30 mg/day (n = 180). The primary and secondary efficacy parameters were change from baseline to week 8 in CDRS-R total score and CGI-S score, respectively. Safety parameters included adverse events (AEs); clinical laboratory, vital sign, and electrocardiogram parameters; and the Columbia-Suicide Severity Rating Scale. Results: Approximately 86% of patients completed double-blind treatment. There was no statistically significant difference between vilazodone 15 mg/day or 30 mg/day and placebo in change from baseline in CDRS-R score. Change in CGI-S score was not significant after adjustment for multiple comparisons. The most common treatment-emergent AEs were nausea, upper abdominal pain, vomiting, diarrhea, nasopharyngitis, headache, and dizziness. Reports of suicidal ideation (placebo, 33.3%; vilazodone 15 mg/day, 36.0%; vilazodone 30 mg/day, 31.1%) and suicidal behavior (placebo, 1.8%; vilazodone 15 mg/day, 1.1%; vilazodone 30 mg/day, 1.1%) were similar between treatment groups. There were no deaths in the study. Conclusions: The efficacy of vilazodone for the treatment of MDD in adolescent patients could not be confirmed in this study. Vilazodone was generally safe and well tolerated, with treatment-emergent AEs similar to those in adult patients. Clinical Trial Registration: NCT01878292.