Eisai Inc. and Purdue Pharma L.P. have entered into a worldwide collaboration agreement for the development and commercialization of Eisai’s clinical candidate lemborexant (E2006), a dual orexin receptor antagonist entering Phase III clinical development for the treatment of insomnia.

Eisai and Purdue Pharma will share the costs of lemborexant global clinical studies. While the potential indication for the product candidate is for the treatment of insomnia, the companies may also seek to develop other indications in the future. In addition, the two companies will form a joint steering committee to manage development and pursue marketing authorizations for lemborexant worldwide. Once approved, Eisai and Purdue Pharma will co-promote the product and share co-promotion costs and profits in the United States and other territories, which may include the European Union, China, Japan and Canada.

Discovered by Eisai, lemborexant is a dual orexin receptor antagonist, which competitively binds to the two subtypes of orexin receptors. It is believed that the orexin system promotes wakefulness, and therefore, orexin receptor antagonists such as lemborexant have the potential to promote sleep.

With the signing of this agreement, the Phase III clinical development program will commence immediately. The global trial program is designed to evaluate the efficacy of lemborexant on both objective and subjective measures of sleep. In addition, the development program will evaluate the impact of treatment of insomnia on daytime function. Safety and tolerability will also be evaluated during the clinical program.