Lundbeck has submitted its antidepressant drug candidate vortioxetine in Europe, raising hopes that it could become the first novel drug treatment for depression to reach the market since 2007.

Vortioxetine (formerly Lu AA21004) is described as a multimodal antidepressant, working as a serotonin 5-HT3 and 5-HT7 receptor antagonist, and 5-HT1b receptor partial agonist, and 5-HT1a receptor agonist and an inhibitor of the serotonin transporter SERT.

The drug is a critical pipeline product for Lundbeck as it tries to find replacements for big-selling antidepressant Lexapro/Cipralex (escitalopram) as well as other products that stand to lose patent protection over the next few years, putting around $1.6bn in revenues at risk of generic competition.

The marketing authorisation application (MAA) contains 10 placebo-controlled studies in more than 5,000 patents with major depression, with "statistically significant results were established in major depression on all doses from 5 to 20mg", according to the company.

Lundbeck said it has also carried out studies indicating that the drug is effective in preventing relapse and in elderly patients, while safety data from the trials programme indicate it is well-tolerated with the most common side effect being nausea.

"The multimodal activity profile of vortioxetine may translate into therapeutic benefits in depression that current therapies do not sufficiently address," said Lundbeck in a statement, adding that it intends to seek approval for the drug in the US and Canada later this year and in Japan in 2013.

In the US, Lundbeck has a co-marketing partnership for vortioxetine with Takeda and the latter will also sell the drug in Japan on a royalty-bearing license.

Vortioxetine could achieve peak sales of $1.3bn at peak, according to analysts at Jefferies, which would go a long way towards plugging the gap left by Cipralex and Lundbeck's Alzheimer's disease product Ebixa (memantine), which started to lose patent protection earlier this year.

Lundbeck is considered to have one of the highest patent cliffs in the pharma sector, with two-thirds of its current revenues at risk of competition.