Eisai Co., Ltd. announced it will present clinical data on its investigational selective orexin 2 receptor agonist E2086 and established orexin receptor antagonist lemborexant at the World Sleep Congress 2025 in Singapore from September 5-10, delivering a total of 11 presentations focused on sleep disorder therapeutics.
Phase Ib Results for Novel Narcolepsy Treatment
The company will present results from a Phase Ib clinical study exploring the efficacy and proof of mechanism of E2086 in patients diagnosed with narcolepsy type 1 (NT1). E2086 represents Eisai's in-house discovered novel selective orexin 2 receptor agonist designed to address the underlying orexin deficiency characteristic of narcolepsy.
Nonclinical studies have demonstrated that E2086 produces statistically significant increases in time spent awake and significant reductions in rates of cataplexy. The compound targets the fundamental pathophysiology of narcolepsy type 1, where patients demonstrate a loss of orexinergic neurons and low cerebrospinal fluid orexin levels.
Lemborexant Data in Comorbid Conditions
Eisai will also present findings from the Phase IV SELENADE Study investigating lemborexant's effects in patients whose insomnia was comorbid with depressive episodes of major depressive disorder and bipolar disorder. This data will be presented as Poster 3-133, expanding the evidence base for lemborexant's utility in complex patient populations.
Lemborexant, marketed as DAYVIGO, is an orexin receptor antagonist that inhibits orexin neurotransmission by binding competitively to both orexin receptor subtypes. The compound's fast on/off receptor kinetics may contribute to its potential for facilitating improvements in sleep onset and maintenance with minimal morning residual effects.
Therapeutic Focus on Sleep Disorders
The presentations underscore Eisai's strategic focus on neurology, including sleep disorders such as insomnia and narcolepsy, as a key therapeutic area. The company positions these conditions as areas with high unmet medical needs, particularly given the disease burden associated with narcolepsy, which includes problems with fatigue, cognition, and persistence of residual symptoms despite treatment.
Narcolepsy is classified into two subtypes: type 1 (narcolepsy with cataplexy) and type 2 (narcolepsy without cataplexy), both characterized by excessive daytime sleepiness. E2086 has the potential to improve patients' symptoms by enhancing orexin receptor activity, addressing the underlying orexin deficiency that drives the condition.
Global Market Presence
Lemborexant has received approval for insomnia treatment in more than 25 countries including Japan, the United States, China, Canada, Australia, and countries across Asia and the Middle East. The company will host a symposium titled "RISE – Regional Insights in Sleep Excellence" on September 8, introducing the latest evidence on lemborexant in Asia.
The World Sleep 2025 presentations represent Eisai's continued commitment to advancing therapeutic options for neurological diseases, with both compounds targeting different aspects of orexin pathway dysfunction in sleep disorders.
