Eisai Co., Ltd. announced that its Hong Kong subsidiary Eisai (Hong Kong) Co., Ltd. has obtained approval for the in-house-discovered and developed orexin receptor antagonist DAYVIGO (generic name: lemborexant) for the treatment of adults with insomnia, characterized by difficulties with sleep onset and/or sleep maintenance. This approval is the first approval for DAYVIGO in Asia outside of Japan.

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). DAYVIGO acts on the orexin neurotransmitter system and is believed to facilitate sleep onset, sleep maintenance, and wake by regulating sleep-wake rhythm. 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.

In June 2020, DAYVIGO was launched in the U.S. for the treatment of adult patients with insomnia, characterized by difficulties with sleep onset and/or sleep maintenance; and in July 2020, DAYVIGO was launched in Japan for the treatment of insomnia. In addition, DAYVIGO has been approved in Canada, and an application for approval has been submitted in Australia. In Asia, Eisai has currently submitted applications to the respective regulatory authorities in India, Indonesia, Malaysia, the Philippines, Singapore, Taiwan and Thailand, and plans to further expand submissions of applications for approval in other countries.