GlaxoSmithKline and Sepracor have linked up for an alliance which will see the UK drugs giant sell the latter’s insomnia drug Lunesta on international markets, under the brand name Lunivia.

GSK says it will market Lunivia (eszopiclone) worldwide, excluding the USA, Canada, Mexico and Japan, and under the terms of the agreement, Sepracor will receive an initial payment of $20 million and milestones which could take that figure up to $155 million. In addition, the US firm will get compensation for the supply of the drug, as well as double-digit royalties on product sales.

Lunesta has been available in the USA and it is a big earner for Sepracor, contributing $143 million to total revenues in the second quarter, a rise of 2.7% which the firm said was an impressive performance given that the hypnotic area saw the introduction in the USA of generic versions of Sanofi-Aventis’ blockbuster and market leader Stilnox/Ambien (zolpidem) during the quarter. Sepracor signed up Eisai as its Japanese partner for Lunesta in July and a marketing application there is expected to be submitted in 2010-11.

As for Europe, the drug was filed, also in July, with the European Medicines Agency and its Marketing Authorisation Application contained results from 122 preclinical and 35 clinical studies of eszopiclone involving more than 5,500 subjects. In addition, two six-month, placebo-controlled studies in primary insomnia as well as two driving studies showing no effect on next-day driving were included as part of this submission.

Adrian Adams, Sepracor’s chief executive, said that GSK’s “knowledge, experience and success in the central nervous system area, together with its broad commercialisation infrastructure, provide an optimal launch platform from which to expand our Lunivia franchise”, while Andrew Witty, president of Pharmaceuticals Europe at GSK, claimed that upon approval, the drug will be an additional option for people suffering from insomnia - it has a proven benefit in chronic insomnia in helping sufferers get to sleep and stay asleep”.

Analysts say that Lunivia may have a tough time differentiating itself from generic hypnotics but GSK clearly sees an opportunity. The firm noted that in 2006, the sedative hypnotic market in Europe was worth $500 million and in the continent’s five largest markets, some 45 million people suffer from insomnia. However, “the current prescription treatment rate is only approximately 24% of this population,” GSK concluded.