Eisai launches in-house developed anti-insomnia drug Dayvigo (lemborexant) in China

Eisai Co., Ltd. announced that the in-house discovered and developed orexin receptor antagonist Dayvigo (brand name in China: “达卫可®“ generic name: lemborexant) has launched in China for the treatment of adults with insomnia, characterized by difficulties with sleep onset and/or sleep maintenance. Eisai received approval for Dayvigo in China on 27 May 2025. This marks the first orexin receptor antagonist to be launched in China.

Dayvigo is a dual orexin receptor antagonist that inhibits orexin neurotransmission regulating sleep-wake rhythm by binding competitively to the two subtypes of orexin receptors (OX1R and OX2R). Unlike conventional treatments such as benzodiazepines that act directly on sleepiness, Dayvigo acts on the orexin neurotransmitter system, which regulates wakefulness. Dayvigo is believed to facilitate sleep onset and sleep maintenance, and wake by regulating sleep-wake rhythm by suppressing hyperactive wakefulness. Dayvigo binds to orexin receptors OX1R and OX2R and acts as a competitive antagonist with stronger inhibition effect on OX2R, which suppresses both REM and non-REM sleep drive, such that Dayvigo may provide faster sleep onset and better sleep maintenance to patients.
Insomnia is characterized by difficulty falling asleep, staying asleep, or both despite an adequate opportunity to sleep, that has occured at least three times a week for at least one month, and which can lead to fatigue, difficulty concentrating and irritability. The prevalence of insomnia among adults in China is reported to be 15.0%3, with approximately 172.5 million people thought to suffer from insomnia. Currently, the mainstream prescription drugs for insomnia in China are treatments that act directly on sleepiness, and there is increasing demand for new treatment options.
Eisai will deliver novel action mechanism, Dayvigo, as a new treatment option to Chinese insomnia patients with the hope of contributing to restoration of daytime function and recovery for patients with insomnia by potentially delivering an active daytime life through fast sleep onset and good quality sleep.