Efficacy and Safety of Desvenlafaxine 50 mg/d for Prevention of Relapse in Major Depressive Disorder

To evaluate the long-term (11-month) efficacy and safety of desvenlafaxine (administered as desvenlafaxine succinate) at the recommended 50-mg/d dose in preventing relapse in patients with major depressive disorder (MDD).Adult outpatients (age ≥ 18 years) with MDD (DSM-IV criteria) and a 17-item Hamilton Depression Rating Scale (HDRS17) total score ≥ 20 at screening and baseline were enrolled in a multicenter, double-blind, placebo-controlled, randomized withdrawal trial conducted between June 2009 and March 2011. Patients who responded to 8-week open-label treatment with desvenlafaxine 50 mg/d with 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. The primary efficacy endpoint was time to relapse following randomization to double-blind treatment, which was compared between groups using the log-rank test. Relapse was defined as HDRS17 total score ≥ 16, discontinuation for unsatisfactory response, hospitalization for depression, suicide attempt, or suicide. Safety and tolerability data were collected throughout the trial.A total of 874 patients were enrolled; 548 patients were randomly assigned to receive placebo (n = 276) or desvenlafaxine 50 mg/d (n = 272) in the double-blind withdrawal period. Time to relapse was significantly shorter for placebo versus desvenlafaxine (P < .001). At the end of the 6-month double-blind treatment, the estimated probability of relapse was 30.2% for placebo versus 14.3% for desvenlafaxine 50 mg/d. Safety and tolerability results were generally consistent with those in short-term studies of desvenlafaxine 50 mg/d.Desvenlafaxine at the recommended dose of 50 mg/d was effective in relapse prevention of depression during a 6-month period in patients who demonstrated stable response after 20 weeks of open-label desvenlafaxine treatment.ClinicalTrials.gov identifier: NCT00887224.