Objective: To examine long-term (11-month) antidepressant efficacy of desvenlafaxine 50 mg/d across a broad range of clinical and functional outcomes in patients with major depressive disorder.
Method: Adult outpatients (≥ 18 years) with major depressive disorder (DSM-IV criteria) and a 17-item Hamilton Depression Rating Scale (HDRS-17) total score ≥ 20 at screening and baseline who responded to 8 weeks of open-label desvenlafaxine 50 mg/d and had a continuing stable response through week 20 were randomly assigned to receive placebo or desvenlafaxine 50 mg/d in a 6-month, double-blind, randomized withdrawal period. Depressive symptoms were evaluated using the HDRS-17, 6-item HDRS, and Clinical Global Impressions-Severity of Ilness and -Improvement (CGI-S, CGI-I). Health outcomes included the Work Productivity and Activity Impairment (WPAI) questionnaire and the World Health Organization 5-Item Well-Being Index (WHO-5). The trial was conducted from June 2009 to March 2011 at 87 study sites in 14 countries worldwide.
Results: Of 874 patients enrolled in open-label treatment, 548 patients were randomly assigned to receive double-blind placebo (n = 276) or desvenlafaxine 50 mg/d (n = 272). At the end of the 6-month double-blind treatment, improvements in depressive symptoms were better maintained among the desvenlafaxine- than placebo-treated patients on all efficacy endpoints (all P ≤ .001); in the desvenlafaxine group, 21.8% (vs 42.9% in the placebo group) had CGI-I ratings of 5, 6, and 7 (minimally worse/much worse/very much worse), and 74.4% met criteria for remission (placebo: 54.2%). WPAI and WHO-5 scores indicated significantly better productivity and well-being with continued desvenlafaxine (vs placebo, P ≤ .001).
Conclusions: Long-term treatment with desvenlafaxine 50 mg/d maintained improvements in major depressive disorder among adult outpatients who exhibited a stable therapeutic response.
Trial registration: ClinicalTrials.gov identifier: NCT00887224.