Pharmaceutical company Biogen, with which Elan sells the multiple sclerosis drug Tysabri, has reported a fall in profits in the first three months of this year.
Biogen's net profits fell 11% from a year earlier to $217m. Though sales of Tysabri rose 28% to $292m, this was a smaller rise than analysts had expected. Total revenue rose 7% to $1.1 billion.
Tysabri was temporarily withdrawn from the market in 2005 after it was associated with a potentially deadly brain infection known as progressive multifocal leukoencephalopathy, or PML. It was brought back in 2006 with stricter safety warnings, but safety concerns have continued to dampen sales.
Biogen executives told investors Tysabri sales growth nay have been hurt by a recent update to the drug's label to reflect an increased risk of PML with longer-term use.
As of April 6, 46 cases of PML had been diagnosed in patients taking the drug, with 11 deaths. By the end of March, about 50,300 patients were on commercial and clinical Tysabri therapy worldwide. That compares with a figure of 48,800 patients at the end of 2009.
