Eisai's insomnia drug Lunesta is now available in Japan and will be well received on account of its efficacy in terms of both sleep onset and sleep maintenance. An identical pricing strategy to the current market leader, Sanofi's and Astellas's Myslee, suggests that Eisai has ambitious plans for Lunesta and has already identified its major competitor.
Having launched in Japan on April 18, Lunesta (eszopiclone; Eisai) represents the first non-benzodiazepine type GABAA agonist to be launched in the country in 12 years. It is typically devoid of issues such as dependency and long-term tolerance that afflict benzodiazepine sleep aides.
Lunesta has been available in the US since April 2005, where it was developed by Sunovion, now a wholly owned subsidiary of Dainippon Sumitomo Pharma. Eisai obtained the Japanese rights to Lunesta in July 2007 and has since rapidly concluded its clinical development.
The Ministry of Health, Labour and Welfare (MHLW) approval of Lunesta in January 2012 was supported by a pivotal Japanese Phase II/III trial (Study 126) that demonstrated a statistically significantly improvement in sleep latency and reduction in latency to persistent sleep. Furthermore, a long-term safety trial (Study 150) revealed a favorable safety profile in adult and elderly Japanese insomnia patients.
Following its launch in Japan, Lunesta will be competing with the well-established market leader Myslee/Ambien (zolpidem; Sanofi/Astellas) and Rozerem (ramelteon; Takeda), a melatonin agonist that has been available since July 2010. Its pricing on the Japanese National Health Insurance list reflects this; the typical 2mg Lunesta dose will cost JPY78.70, equivalent to Myslee 10mg and a slight discount on Rozerem 8mg.
Datamonitor believes that Japan represents a particularly receptive market in which to launch Lunesta, on account of the drug's efficacy in treating both sleep onset and sleep maintenance difficulties and the country's growing elderly population, who are prone to sleep maintenance problems. Indeed, Datamonitor estimates there to be over eight million prevalent cases of insomnia in those aged over 18 years in Japan in 2012.
At present, no drug is available in Japan that addresses both sleep onset and maintenance difficulties and Lunesta is set to benefit from the absence of Ambien CR (zolpidem extended release; Sanofi) in this market. Uptake of Lunesta in Japan will be further aided by Eisai's in-depth understanding of its domestic market, in which it already has an extensive neurology portfolio including Aricept (donepezil) for Alzheimer's disease and Zonegran (zonisamide) for epilepsy.