Clinical Profile of Suvorexant for the Treatment of Insomnia over 3 Months in Women and Men: Subgroup Analysis of Pooled Phase-3 Data
Herring WJ, Connor KM, Snyder E, Snavely DB, Zhang Y, Hutzelmann J, Matzura-Wolfe D, Benca RM, Krystal AD, Walsh JK, Lines C, Roth T, and Michelson D. Clinical profile of suvorexant for the treatment of insomnia over 3 months in women and men: subgroup analysis of pooled phase-3 data. Psychopharmacology 2017; 234(11):1703-1711.
Rationale: Sex-related differences in the clinical profiles of some insomnia medications have been previously reported. Objective: To evaluate the clinical profile of suvorexant, a novel orexin receptor antagonist approved for treating insomnia at doses up to 20 mg, by sex subgroups. Methods: Efficacy analyses by sex were based on pooled data from two similar phase 3, randomized, double-blind, placebo-controlled, 3-month trials in elderly (≥65 years) and non-elderly (18–64 years) insomnia patients. Two age-adjusted (non-elderly/elderly) dose regimes of 40/30 and 20/15 mg were evaluated, with fewer patients assigned to 20/15 mg. Efficacy was assessed by patient-reported outcomes (N = 1264 women, 707 men) and by polysomnography endpoints in ~75% of patients. Safety analyses by sex (N = 1744 women, 1065 men) included pooled data from the two 3-month trials plus 3-month data from a safety trial of 40/30 mg. Results: The sex subgroup efficacy analyses mirrored the improvements seen for suvorexant 40/30 and 20/15 mg over placebo on patient-reported outcomes and polysomnography sleep maintenance and onset endpoints in the primary analyses; 95% CIs excluded zero in favor of suvorexant for most endpoints in both sexes, and similar efficacy was observed between sexes (95% CIs overlapped). Suvorexant was well-tolerated in women and men, although women in all treatment groups (including placebo) reported more adverse events than men. The most frequent adverse event was somnolence (women: 11.1% for 40/30 mg, 8.5% for 20/15 mg, 2.3% for placebo; men: 10.1% for 40/30 mg, 3.4% for 20/15 mg, 4.2% for placebo). Conclusion: Suvorexant was generally effective and well-tolerated in both women and men with insomnia. ClinicalTrials.gov trial registration numbers: NCT01097616, NCT01097629, NCT01021813.