Elan has confirmed another case of progressive multifocal leukoencephalopathy (PML) in a multiple sclerosis patient being treated with its Tysabri drug. The case occurred in the European Union, the company added.
The patient had been treated with the drug for the past 26 months or so.
Elan and Biogen Idec, which is involved in the manufacture of the drug with the Athlone-based firm, withdrew Tysabri from the market in February 2005 after three patients, two of whom died, contracted PML.
The drug returned to the market in 2006 with warnings after the US Food and Drug Administration decided MS patients willing to accept the risks should be able to have access to the drug's potential benefits. The drug is given by injection once a month.
Elan said another patient had contracted PML in October, while another two were diagnosed in July.
At the end of September, about 35,500 patients were using Tysabri worldwide.
Elan shares closed four cent higher at €5.10 in Dublin this evening despite the news.
