A randomized, double-blind, placebo-controlled trial of desvenlafaxine succinate in adult outpatients with major depressive disorder

Objective: This study evaluated the efficacy and tolerability of desvenlafaxine succinate (desvenlafaxine) in the treatment of major depressive disorder (MDD). Method: In this 8-week, multicenter, randomized, double-blind, placebo-controlled trial, adult outpatients (aged 18-75 years) with a primary diagnosis of MDD (DSM-IV criteria) were randomly assigned to treatment with desvenlafaxine (100-200 mg/day) or placebo. The primary outcome measure was the 17-item Hamilton Rating Scale for Depression (HAM-D,7) score at final on-therapy evaluation. The Clinical Global Impressions-Improvement scale (CGI-I) was the key secondary measure. Other secondary measures included the Montgomery-Asberg Depression Rating Scale (MADRS), Clinical Global Impress ions-Severity of Illness scale, Visual Analog Scale-Pain Intensity (VAS-PI) overall and subcomponent scores, and HAM-D,, response and remission rates. The study was conducted from June 2003 to May 2004. Results: Of the 247 patients randomly assigned to treatment, 234 comprised the intent-to-treat population. Following titration, mean daily desvenlafaxine doses ranged from 179 to 195 mg/day. At endpoint, there were no significant differences in scores between the desvenlafaxine (N = 120) and placebo (N = 1 14) groups on the HAM-D,, or CGI-I. However, the desvenlafaxine group had significantly greater improvement in MADRS scores (p = .047) and in VAS-PI overall pain (p = .008), back pain (p = .006), and arm, leg, or joint pain (p < .001) scores than the placebo group. The most common treatmentemergent adverse events (at least 10% and twice the rate of placebo) were nausea, dry mouth, constipation, anorexia, somnolence, and nervousness. Conclusion: Desvenlafaxine was generally safe and well tolerated. In this study, it did not show significantly greater efficacy than placebo on the primary or key secondary efficacy endpoints, but it did demonstrate efficacy on an alternate depression scale and pain measure associated with MDD.