LONDON (SHARECAST) - Irish drug giant Elan said the risk of a fatal brain disease in patients treated with its multiple sclerosis drug Tysabri “cannot be precisely estimated.”
The group made the comments as it saw losses narrow for the half year on strong sales of the MS drug.
Shares in Elan more than halved last month after it confirmed two more cases of progressive multifocal leukoencephalopathy (PML) in patients treated with its multiple sclerosis drug Tysabri.
“Patients and their physicians have chosen Tysabri because of its efficacy while being informed of the risk of PML,” it added.
Tysabri, which Elan developed in collaboration with US partner Biogen, recorded in-market sales in the first half of $359.7m, an increase of almost 200% over the $120.5m recorded in the same period of 2007.
At the end of June 2008, approximately 31,800 patients were on therapy worldwide, an increase of 127%.