Biogen Idec's multiple sclerosis drug Avonex can cause severe liver damage, US regulatory officials and the company warned yesterday, the latest in a series of blows to MS patients.
"In some cases, these events have occurred in the presence of other drugs that have been associated with hepatic injury," the Food and Drug Administration and Biogen said in a statement posted to the agency's website.
Biogen shares suffered their second recent blow on the news, which came about two weeks after the company halted sales of its other MS drug, Tysabri, which it was developing with Elan, when a patient died from an infection.
Company shares were down $1.49 (€1.11), or 3.91 per cent, to $36.58 in late afternoon trade on the Nasdaq. The shares earlier fell nearly 9 per cent.
At least one analyst downplayed the Avonex warning.
"Avonex has been safely used for almost a decade," said Max Jacobs, a biotech analyst for Mehta Partners.
He called the selloff in Biogen shares "an overreaction".
"This basically just says don't mix Avonex with alcohol," Mr Jacobs said.
Last month, the company said two cases of a rare but often fatal infection of the central nervous system occurred in patients taking Tysabri in combination with Avonex, an older drug, for more than two years.
Earlier yesterday, GlaxoSmithKline Plc said the FDA halted clinical trials on drugs similar to Tysabri, including its experimental product known as SB 683699. - (Reuters)
