Eisai’s anti-insomnia drug Dayvigo approved in China

Japanese drugmaker Eisai (TYO: 4523) today announced that the in-house-discovered and developed orexin receptor antagonist Dayvigo (lemborexant) has been approved in China for the treatment of adults with insomnia, characterized by difficulties with sleep onset and/or sleep maintenance. Eisai plans to launch this medicine in China in the second quarter of fiscal year 2025.

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. 53.8

The drug, which reported sales of 53.8 billion yen ($374.3 million) in the last fiscal year, was approved in Japan and by the US Food and Drug Administration in 2019, and was launched onto the American market in June 2020, when it became first new insomnia prescription drug to be launched in the USA for five years. It is also approved in Canada.