VANCOUVER, BC—Suvorexant (20mg/15mg and 40mg/30mg) improves sleep for patients with insomnia and reduces the impact of insomnia on patients’ daytime functioning, as assessed using the Insomnia Severity Index questionnaire [ISI], reported authors of a Merck & Co., Inc. study at the 68th AAN Annual Meeting.
“Improvement in sleep onset/maintenance as well as a reduction of the impact of sleep problems on daytime function contribute to the overall improvement observed in ISI total score,” reported William J. Herring, MD, and coauthors, of Merck, in Kenilworth, NJ. “Given that the maximum approved dose is 20mg, the 20mg/15mg data are the most clinically relevant.”
Suvorexant (Belsomra) is an orexin-receptor antagonist that was approved by the Food and Drug Administration (FDA) in 2014 for insomnia treatment. It has been shown to improve sleep onset and maintenance.
The authors sought to evaluate its effects using the ISI, a 7-item questionnaire used in the assessment of sleep disorders and patients’ daytime function, they reported in a poster presentation.
The analysis included pooled-data from 2 similar randomized, double-blind, placebo-controlled, parallel-group, 3-month trials in elderly (≥65 years) and non-elderly (18–64 years) insomnia patients. “Age-adjusted (non-elderly/elderly) dose regimes of 40mg/30mg and 20mg/15mg were evaluated,” they explained. “The elderly dose adjustment was made to match non-elderly exposures.”
Study participants were administered the ISI at Months 1 and 3. Data for 1,824 patients were included in the coauthors’ analysis.
Compared to placebo, suvorexant improved change from baseline in total score at both time points (Month 3: -6.2 for 20mg/15mg, -6.7 for 40mg/30mg, -4.9 for placebo; P-values <0.001) and the percentage of responders (≥6-point improvement from baseline) at both time points (Month 3: 55.5% for 20mg/15mg, 54.9% for 40mg/30mg, 42.2% for placebo; P-values <0.001). Overall, a greater percentage of patients treated with suvorexant had “no insomnia” vs. the placebo group. The percentage of patients with “severe” and “moderate” insomnia was also lower after treatment with suvorexant.
Scores for individual items of the ISI “showed numerical improvement for both suvorexant dose regimes versus placebo at both time points,” they wrote. “The ‘impact of insomnia’ component (last 3 items) which assesses the impact of insomnia on daytime function/quality of life was also improved by both dose regimes.”
The study was conducted by Merck & Co. Inc., Kenilworth, NJ, USA.