European drug regulators have approved a label change on multiple sclerosis drug Tysabri to tell doctors and patients that signs of a virus are a risk factor for developing a serious brain illness.
The blockbuster drug is produced by Irish biotech group Elan and its US partner Biogen Idec.
The summary of product characteristics will state that patients who have antibodies against the JC virus have a higher risk of developing a serious brain infection known as progressive multifocal leukoencephalopathy, or PML, compared with patients who don't have the antibodies, the companies said today in a statement.
Tysabri increases the risk of PML, which usually leads to death or disability, the drugmakers said.
"This label change can help give confidence to physicians and patients by providing additional guidance on stratifying the potential risk for developing PML in Tysabri-treated patients," Tomas Olsson, professor of neurology in the Department of Clinical Neurosciences at the Karolinska Institute in Stockholm, said in the statement.
With the new label in place, sales of Tysabri are expected to reach $2.7 billion by 2016, with $1.7 billion for Elan that year, Olav Zilian, a Geneva-based analyst with Helvea, said in a note to clients today.
The European Commission, the executive arm of the European Union, also renewed five-year marketing authorization for Tysabri, the companies said.
Elan fell nine cent, or 1.2 per cent, to €7.26 in Dublin trading.
Bloomberg
