Objective: The purpose of this study was to assess the 1-year maintenance of the efficacy of desvenlafaxine 100 mg/day (administered as desvenlafaxine succinate) established on week 12 in a 1-year, double-blind, randomized, placebo-controlled trial in postmenopausal women seeking treatment of bothersome vasomotor symptoms.
Methods: Primary efficacy endpoints were changes in hot flush (HF) frequency and severity on weeks 12, 26, and 52 in an efficacy substudy population (≥50 moderate and severe HFs per week at baseline). Secondary endpoints were Greene climacteric scale, patient global impression symptom rating, and patient global impression of change scores (weeks 12, 26, and 52) for the main study efficacy population. Safety was assessed throughout the trial.
Results: The mean baseline HF frequency (efficacy substudy population, n = 365) was 12 moderate and severe HFs per day; the mean baseline severity score was 2.4. At 1 year, women treated with desvenlafaxine maintained the efficacy established on week 12. Desvenlafaxine reduced HF frequency by 7.47 moderate and severe HFs per day on week 12 (adjusted mean difference from placebo, -2.48; 95% CI, -3.47 to -1.50; P < 0.001) and by 7.70 moderate and severe HFs per day on month 12 (adjusted mean difference from placebo, -2.86; 95% CI, -4.14 to -1.57; P < 0.001). Desvenlafaxine reduced the mean severity score by 0.63 on week 12 (placebo, -0.30; P < 0.001) and by 0.75 on month 12 (placebo, -0.44; P = 0.003). Reductions in Greene Climacteric Scale total score (main study efficacy population, n = 1,950) were significantly greater for desvenlafaxine than for placebo on months 3, 6, and 12 (all P < 0.001). Treatment-emergent adverse event rates were 84% for desvenlafaxine and 79% for placebo (P = 0.006). Full safety results are reported separately.
Conclusions: The treatment efficacy of desvenlafaxine 100 mg/day achieved on week 12 in postmenopausal women with vasomotor symptoms is maintained for 1 year.
Trial registration: ClinicalTrials.gov NCT00683800.