E2086, a selective orexin 2 receptor agonist, aims to address the pathophysiology of narcolepsy by activating orexinergic neurons.
Key takeaways:
- The Ministry of Health, Labour and Welfare in Japan granted orphan drug designation to E2086 for narcolepsy.
- E2086 is a novel selective orexin 2 receptor agonist discovered and developed by Eisai.
- Clinical data from a Phase 1b study suggests the agent may improve excessive daytime sleepiness in patients with narcolepsy type 1.
- The mechanism of action differs from Eisai’s insomnia treatment DAYVIGO, which inhibits orexin activity.
The Ministry of Health, Labour and Welfare in Japan has granted orphan drug designation to Eisai Co Ltd’s investigational compound E2086 for the prospective indication of narcolepsy.
E2086 is a novel selective orexin 2 receptor agonist discovered and developed in-house by Eisai. Orexin is a neurotransmitter central to regulating sleep and wakefulness. While inhibiting orexinergic neurons promotes the transition to sleep—the mechanism behind Eisai’s insomnia treatment DAYVIGO (lemborexant)—activating these neurons helps maintain stable wakefulness.
E2086 is designed to improve symptoms by enhancing orexin receptor activity, directly acting on the pathophysiology of narcolepsy.
According to the company, nonclinical studies have demonstrated statistically significant increases in time spent awake and significant reductions in rates of cataplexy.
Eisai presented data from a Phase 1b clinical study involving patients with narcolepsy type 1 at the World Sleep 2025 congress. The data suggested that E2086 demonstrated a statistically significant reduction in excessive daytime sleepiness compared to placebo or the existing drug modafinil.
Eisai considers neurology, including sleep-wake disorders such as insomnia and narcolepsy, a therapeutic area of focus. The company states it is leveraging the orexin platform established through the development of DAYVIGO to create products for areas with high unmet medical needs.
