Eisai and Purdue Pharma announced new topline data for lemborexant, a drug candidate being studied for the treatment of multiple sleep disorders.
Lemborexant, a dual orexin receptor antagonist, inhibits orexin neurotransmission by binding competitively to the 2 subtypes of orexin receptors. It is thought to regulate sleep and wake by dampening wakefulness without hindering the ability to awaken to external stimuli.
In the Phase 3 SUNRISE 1 study, lemborexant achieved its primary and key secondary objectives vs. placebo and vs. zolpidem tartrate extended-release (active comparator) in patients aged ≥55 years with difficulty staying asleep through the night. The change from baseline in both sleep onset and sleep maintenance variables were measured, including the time spent awake in the second half of the night. Objective polysomnography data was used to determine if lemborexant 5mg and 10mg were superior to zolpidem ER 6.25mg and to placebo. Treatment with lemborexant showed similar rates of discontinuation due to adverse events with placebo; headache and somnolence were the most commonly reported adverse events.
Study 108, a Phase 1 safety study, evaluated the ability to maintain postural stability, awaken to an auditory stimulus, and perform on test of memory and attention in the middle of the night. In addition, the study assessed how fast the patients could return to sleep after being awakened. The data showed treatment with zolpidem ER 6.25mg led to clinically meaningfully worse postural stability vs. lemborexant 5mg and 10mg in patients aged ≥55 years. Headache was the only adverse event seen in ≥2 patients.
Another Phase 1 study (Study 106), evaluated residual next morning effects via an on-road driving test, in which lemborexant also met its primary objective. The study compared lemborexant vs. placebo with zopiclone as a positive control. The most common adverse events reported among lemborexant-treated patients were somnolence and headache.
Full findings from these studies will be presented at upcoming medical meetings.