Eisai's Dayvigo gets approval in Hong Kong

Japanese drug major Eisai (TYO: 4523) says that its Hong Kong subsidiary Eisai (Hong Kong) Co has obtained approval for the in-house-discovered and developed orexin receptor antagonist Dayvigo (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. The drug was approved by the Food and Drug Administration in 2019, and was launched onto the American market in June 2020, when it became first new insom.nia prescription drug to be launched in the USA for five years. It is also approved in Canada.

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 the drug may provide faster sleep onset and better sleep maintenance to patients.

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.