By Bill Berkrot
NEW YORK (Reuters) - U.S. health regulators on Friday approved Biogen Idec Inc's Plegridy, a long-acting multiple sclerosis drug that the company expects will eventually replace its older big-selling Avonex treatment.
The company received European approval on July 23 for the drug that is intended to reduce relapses of the debilitating disease and slow its progression.
Plegridy, like Avonex, is a type of interferon. It is designed to be injected every two weeks compared with weekly injections for Avonex. It is also injected subcutaneously rather than intramuscularly, meaning it requires a smaller needle.
Some other MS treatments from the interferon class of medicines, such as Pfizer Inc's Rebif, are dosed more frequently than Avonex.
Biogen said it will continue to support Avonex, which has compiled global sales of more than $1.5 billion in the first half of this year, for patients who are comfortable with the treatment and not looking to switch. Avonex has U.S. patent protection until 2026, Biogen said.
The company expects Plegridy to diminish Avonex sales and take market share from other rivals even as overall sales from the class decline with the increasing popularity of oral treatments, such as Biogen's Tecfidera, which was approved in 2013.
"We believe Plegridy has the potential to be the leading interferon on the market," Tony Kingsley, Biogen's head of global commercial operations, said in a telephone interview.
"As the class shrinks, we will be in a position gain share within that class," Kingsley said. "The most convenient product wins over time."
The company will be ready to launch the new drug quickly, Kingsley said, as it already had the MS sales force in place, given its existing portfolio of three other medicines, including Tysabri.
The FDA nod marks the fourth U.S. approval for Biogen in the last 16 months along with Tecfidera and two recently approved long-acting hemophilia drugs, Alprolix and Eloctate, that put the MS focused company into a new therapeutic category.
(Reporting by Bill Berkrot; Editing by David Gregorio)