* Forest gets exclusive rights to smoker's lung drug in U.S.
* Forest to pay $100 million upfront, up to $500 million more later
* Daxas would be first pill to treat COPD
* Nycomed expects U.S., European Daxas registration next yr
(Adds CEO comment on IPO, pantoprazole, no comment on Solvay)
By Quentin Webb
LONDON, Aug 10 (Reuters) - Forest Laboratories Inc, the U.S. specialty drugmaker whose biggest drug Lexapro is soon to lose patent protection, paid $100 million upfront for U.S. rights to Nycomed's promising "smoker's lung" drug Daxas.
Nycomed will also receive up to $500 million in further payments based on regulatory approvals and commercialisation milestones, Chief Executive Hakan Bjorklund told Reuters in a telephone interview on Monday.
The privately owned Swiss drug company, which is working towards a multi-billion dollar flotation, also stands to receive royalties that will be "standard" for a product of this size and development stage, he added. Forest will have exclusive rights to develop, make and commercialise Daxas in the United States, utilising its 2,700-strong sales force.
Forest is expected to lose patent protection on Lexapro, the blockbuster antidepressant that is its top-selling drug, in early 2012. It sells Lexapro in conjunction with Danish drugmaker Lundbeck.
Nycomed has recently submitted Daxas to European and U.S. regulators for approval, and Bjorklund said it hopes for registration in both jurisdictions next year.
Daxas is the first tablet-based treatment for chronic obstructive pulmonary disease (COPD) -- the world's fifth-biggest cause of death in 2002, according to the World Health Organisation (WHO).
BLOCKBUSTER POTENTIAL
The drug could compete with GlaxoSmithKline's Advair and Spiriva, marketed by Pfizer and Boehringer Ingelheim, in the multibillion-dollar worldwide COPD market.
Bjorklund said Daxas had "blockbuster potential" -- meaning it could ultimately top $1 billion in annual sales.
He said Nycomed picked Forest from a handful of partnership candidates, based partly on its big sales force and its track record of partnering to develop drugs.
Nycomed, whose biggest owners are private equity firms Nordic Capital and Credit Suisse's DLJ unit, aims to use junk bonds and fresh equity from its owners to fund a planned buyout of Solvay's drugs unit, people familiar with the matter told Reuters recently.
Bjorklund declined to comment on Solvay. He said the Daxas agreement did not immediately affect Nycomed's plans for an initial public offering (IPO).
"I don't think it has any immediate bearing on when and how we would do a public listing," he said. "But of course it's a step in the right direction, it strengthens the company, and it's proof that not only we but other people see a lot of value in Daxas."
He added that sales of pantoprazole, the heartburn treatment that is Nycomed's best-selling drug, were holding up "somewhat better" than expected, months after it lost patent protection in Europe. (Editing by Ben Hirschler and Gilbert Kreijger)