Aliso Viejo-based Valeant Pharmaceuticals International said Thursday that it signed a deal with GlaxoSmithKline PLC that gives the British drug maker worldwide rights to retigabine, an epilepsy drug.
The deal could be worth up to $820 million. Valeant said it would get an upfront payment of $125 million for granting Glaxo the development and commercialization rights to retigabine.
Glaxo will also pay the drug maker up to $545 million based on achieving certain regulatory, development and commercialization milestone and additional indications for retigabine.
Shares of Valeant originally rose to $21 in morning New York Stock Exchange trading their highest value in almost three years. Later, however, shares were down about 6% at close of trading with a market value of about $1.7 billion.
Retigabine has already completed its third-phase clinical trials in patients whose epilepsy is difficult to treat. Valeant and Glaxo said they would submit retigabine for regulatory approval in the United States and Europe by early 2009.
Besides epilepsy, retigabine is also being studied for post-herpetic neuralgia, a common complication of shingles.
