Lundbeck is confident that the launch of its big-selling antidepressant escitalopram in Japan in the near future will make a major contribution to its coffers.

The Danish firm has announced that partner Mochida Pharmaceutical Co has filed a new drug application for escitalopram for the treatment of depression with the Japanese Ministry of Health, Labour and Welfare. The blockbuster pill is sold by Lundbeck as Cipralex and marketed in the USA by licensee Forest Laboratories as Lexapro.

In Japan, Mochida started the development of escitalopram in 2002, having signed a pact with Lundbeck in May of that year. Financial details of the alliance have not been disclosed but the Valby-headquartered group is to receive regulatory milestone payments and royalties.

If approved, Lundbeck claims the commercialisation of escitalopram will be supported "by two highly CNS-experienced Japanese companies", ie Mochida and Mitsubishi Tanabe. Those two will have more than 1,500 sales reps on the case, "which is fully competitive in the Japanese market".

Lundbeck chief executive Ulf Wiinberg noted that the filing was earlier than expected. He added that "the Japanese antidepressant market represents a substantial commercial opportunity" and should "contribute meaningfully to Lundbeck's financial performance already in the period 2012-2014".

IMS values the Japanese antidepressant market at around $1.1 billion and it has been experiencing double-digit growth rates in the past few years. The number of patients with depression in Japan is currently estimated at over one million.

Escitalopram will go up against some well-established competition. The three best-selling antidepressants in Japan at the end of 2009 were GlaxoSmithKline's Paxil (paroxetine) which had a market share of 42%, Pfizer's Zoloft (sertraline; 20%) and Luvox (fluvoxamine; 16%), marketed by Astellas.