By Ben Hirschler
LONDON (Reuters) - Denmark's Lundbeck got a fresh boost for its experimental antidepressant Brintellix on Monday when a clinical trial showed benefits over another medicine called agomelatine that some doctors use when cheap generic pills fail.
Lundbeck and its Japanese partner Takeda submitted Brintellix, also known as vortioxetine, for regulatory approval in the United States and Europe at the end of last year.
Industry analysts at Deutsche Bank see the new drug having sales potential in excess of $1.5 billion and possibly up to $3 billion a year, although consensus forecasts for 2016 are a more modest $500 million, according to Thomson Reuters Pharma.
In the latest study, Lundbeck said that after four weeks of treatment Brintellix proved significantly more effective than agomelatine, which is sold as Valdoxan by private French drugmaker Servier.
Current antidepressants are mainly selective serotonin reuptake inhibitors, or SSRIs, and many are widely available as cheap generics, including Prozac.
A large number of patients, however, do not respond adequately to SSRIs or another class of antidepressants known as serotonin and noradrenaline reuptake inhibitors (SNRIs), prompting doctors to seek alternatives.
It is this market in "second-line" treatments that Lundbeck aims to tap into with Brintellix.
"This latest study clearly demonstrates that patients who have not had an adequate response on SSRIs or SNRIs can be switched to Brintellix and get a treatment effect - which is the relevant question for physicians," Lundbeck R&D head Anders Gersel Pedersen said in an interview.
Agomelatine was approved in Europe in 2009, making it the most recent new antidepressant to reach the market, although it is not sold in the United States.
Lundbeck hopes the new antidepressant will provide a new source of revenue as its existing antidepressant, Cipralex, sold as Lexapro in the United States and Japan, comes off patent protection.
Lundbeck also reported more positive clinical trial results for Selincro, its alcohol dependence drug. Selincro was recently approved in Europe, but is seen by analysts as a relatively modest seller.
Shares in the Danish group were 1.3 percent higher by 4:00 a.m. EST.
(Reporting by Ben Hirschler; Editing by Tom Pfeiffer)