Results from a study evaluating the safety and efficacy of suvorexant (Merck) for the treatment of insomnia in patients with mild to moderate Alzheimer disease dementia were presented at the 2019 American Academy of Neurology Annual Meeting.

The phase 3 placebo-controlled trial included 277 patients who were randomized to receive either suvorexant 10mg (which could be increased to 20mg based on clinical response) or matching placebo. The primary efficacy endpoint was change from baseline in polysomnography-measured mean total sleep time (TST) in minutes (higher score indicating improved sleep) at Week 4.

Findings from the study showed that treatment with suvorexant was associated with an increase in TST compared with placebo (model-based least squares mean change from baseline: suvorexant 73.4 minutes, placebo 45.2 minutes; treatment difference: 28.2 minutes [95% CI: 11.1, 45.2; P <.005]) at Week 4.

In addition, an improvement in wake after persistent sleep onset (WASO; secondary endpoint), defined as the total wake time over the polysomnography recording period after the first period of continuous sleep lasting ≥10 minutes, was observed in the suvorexant arm compared with placebo (model-based least squares mean change from baseline: suvorexant -41.8 minutes, placebo -32.5 minutes; treatment difference: 15.7 minutes [95% CI: -28.1,-3.3; P =.01]).

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With regard to safety, adverse events were reported in 22.5% of patients receiving suvorexant compared with 16.1% of those receiving placebo. Somnolence of mild to moderate severity was reported as the most common adverse event (4.2% of suvorexant-treated patients vs 1.4% of placebo patients).

“We are encouraged by the efficacy and safety results of Belsomra in those living with Alzheimer disease dementia,” said Dr W. Joseph Herring, associate vice president, Global Clinical Research, Neuroscience, Merck Research Laboratories. “Merck plans to file these data with the US Food and Drug Administration for potential inclusion into the Belsomra prescribing information.”

Belsomra, an orexin receptor antagonist, is currently approved for the treatment of insomnia characterized by difficulties with sleep onset and/or sleep maintenance.

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