Desvenlafaxine for the Prevention of Relapse in Major Depressive Disorder Results of a Randomized Trial

Objectives: To compare the efficacy and safety of desvenlafaxine (administered as desvenlafaxine succinate) with placebo in reducing relapse rate in patients with major depressive disorder (MDD). Methods: This phase 3, multicenter, randomized trial included a 12-week, open-label (OL) treatment phase (intent-to-treat population, n = 575) followed by a 6-month, double-blind (1313) relapse prevention phase. Patients who responded to the OL treatment (17-item Hamilton Rating Scale for Depression total score <= 11) with desvenlafaxine (200-400 mg/d) were eligible to enter the DB phase. The primary efficacy end point was time until relapse (17-item Hamilton Rating Scale for Depression total score >= 16 at any visit, Clinical Global Impression-Improvement score >= 6 at any visit, or discontinuation due to unsatisfactory response). Results: Patients receiving desvenlafaxine (n = 189) experienced significantly longer times to relapse of MDD versus patients receiving placebo (n = 185) during the DB period (log-rank test, P < 0.0001). The percentages of patients relapsing were 42% (78/185) and 24% (45/189) for placebo and desvenlafaxine, respectively (P < 0.001). The most common primary reason cited for discontinuation in the OL period was adverse events (19%), which consisted of nausea, dizziness, and insomnia. A total of 159 patients (42%) discontinued treatment during the DB period, including 101 placebo- (55%) and 58 desvenlafaxine-treated patients (31%). The most frequent adverse event reported as reason for treatment discontinuation in the DB period was depression, reported by 14 placebo- (8%) and 7 desvenlafaxine-treated patients (4%). Conclusions: Desvenlafaxine effectively prevented relapse of MDD during 6 months of DB treatment in patients who had responded to 12 weeks of OL desvenlafaxine therapy