title: An Analysis of Relapse Rates and Predictors of Relapse in 2 Randomized, Placebo-Controlled Trials of Desvenlafaxine for Major Depressive Disorder.
abstract: OBJECTIVE
  To evaluate relapse rates and predictors of relapse in 2 randomized, placebo-controlled trials of desvenlafaxine for major depressive disorder (MDD).
  
  
  METHODS
  Study 1: week 8 responders to open-label desvenlafaxine 50 mg/d entered a 12-week open-label stability phase. Patients with a continuing, stable response at week 20 were randomly assigned to 6-month, double-blind treatment (desvenlafaxine 50 mg/d or placebo). Study 1 was conducted between June 2009 and March 2011 at 87 sites worldwide. Study 2: week 12 responders to open-label desvenlafaxine 200 or 400 mg/d were randomly assigned to 6-month, double-blind treatment (desvenlafaxine 200 mg/d, 400 mg/d, or placebo). Study 2 was conducted between June 2003 and August 2005 at 49 sites in Europe, the United States, and Taiwan. Relapse was assessed separately by study with log-rank test using protocol definitions of relapse and with 17-item Hamilton Depression Rating Scale (HDRS-17) score ≥ 16 at any time during the double-blind phase. Kaplan-Meier estimates evaluated time to relapse, censoring data at months 1, 2, and 3 and overall; treatments were compared using hazard ratios. Cox proportional hazards models assessed relapse predictors.
  
  
  RESULTS
  Overall relapse rates for all definitions were significantly lower for desvenlafaxine versus placebo for both studies (all P ≤ .002). In study 1, rates were significantly lower for desvenlafaxine versus placebo at month 2 (P = .016) and month 3 (P = .007) using the protocol definition. In study 2, relapse rates were significantly lower for desvenlafaxine versus placebo at months 1, 2, and 3 for both definitions (P < .0001-.002). Hazard ratios were similar at months 1, 2, and 3 and overall for both studies (0.382-0.639).
  
  
  CONCLUSIONS
  Desvenlafaxine 50 to 400 mg/d effectively prevented relapse at 6 months. Desvenlafaxine significantly prevented relapse early (month 1) versus placebo only in study 2.
  
  
  BACKGROUND
  ClinicalTrials.gov identifiers:NCT00887224 and NCT00075257.
authors.affiliation: Department of Psychiatry and Pharmacology, University of Toronto, Toronto, Ontario, Canada (Dr McIntyre); Pfizer Inc, New York, New York (Dr Fayyad); CGP Strategic Solutions LLC Lansdale, Pennsylvania (Dr Guico-Pabia); and Pfizer Canada, Inc, Kirkland, Quebec, Canada (Dr Boucher).
authors.forename: Roger S
authors.initials: RS
authors.lastname: McIntyre
authors.affiliation: Department of Psychiatry and Pharmacology, University of Toronto, Toronto, Ontario, Canada (Dr McIntyre); Pfizer Inc, New York, New York (Dr Fayyad); CGP Strategic Solutions LLC Lansdale, Pennsylvania (Dr Guico-Pabia); and Pfizer Canada, Inc, Kirkland, Quebec, Canada (Dr Boucher).
authors.forename: Rana S
authors.initials: RS
authors.lastname: Fayyad
authors.affiliation: Department of Psychiatry and Pharmacology, University of Toronto, Toronto, Ontario, Canada (Dr McIntyre); Pfizer Inc, New York, New York (Dr Fayyad); CGP Strategic Solutions LLC Lansdale, Pennsylvania (Dr Guico-Pabia); and Pfizer Canada, Inc, Kirkland, Quebec, Canada (Dr Boucher).
authors.forename: Christine J
authors.initials: CJ
authors.lastname: Guico-Pabia
authors.affiliation: Department of Psychiatry and Pharmacology, University of Toronto, Toronto, Ontario, Canada (Dr McIntyre); Pfizer Inc, New York, New York (Dr Fayyad); CGP Strategic Solutions LLC Lansdale, Pennsylvania (Dr Guico-Pabia); and Pfizer Canada, Inc, Kirkland, Quebec, Canada (Dr Boucher).
authors.forename: Matthieu
authors.initials: M
authors.lastname: Boucher