Sepracor and Eisai partner to develop and commercialise Lunesta in Japan

US-based Sepracor has signed an agreement with Japanese pharmaceutical firm Eisai for the development and commercialisation of Sepracor's sleep aid treatment Lunesta (eszopiclone) in Japan.

Per the agreement, Eisai will be responsible for completing the remaining clinical trials necessary for attaining marketing approval from the Japanese regulatory authorities, and contingent on regulatory approval, commercialisation of the product in Japan. Sepracor has said that the Japanese marketing application will be submitted in 2010/2011.

Sepracor will receive an initial milestone payment and subsequent payments upon accomplishment of various development, regulatory and pricing milestones, as well as royalties on product sales and compensation for providing the product's active ingredient.

Lunesta has been commercially available in the US since 2005 for the treatment of insomnia and posted sales of USD 566.8m in FY06. The sedative hypnotic market in Japan was valued at around USD 500m in 2006.