Tysabri

Multiple sclerosis drug increases risk of deadly brain virus

Multiple sclerosis patients treated with Tysabri (natalizumab) have a 10 times greater risk of developing a deadly brain virus, according to new findings. The virus – John Cunningham virus (JCV) – is a pathogen that causes a rare and deadly condition known as progressive multifocal leukoencephalopathy (PML). The link between Tysabri and PML is not new. ...click here to read more