Risk of PML with TYSABRI Incorrectly Reported
- By BSTQ Staff
In the article titled “Research Development for Multiple Sclerosis,” published in the January 2013 issue of BioSupply Trends Quarterly, we incorrectly reported on the risk of progressive multifocal leukoencephalopathy with the immunomodulatory drug TYSABRI. Following is the corrected information:
The anti-JCV antibody test for those taking the immunomodulatory TYSABRI (natalizumab) indicates whether there is a risk of progressive multifocal leukoencephalopathy (PML), a rare brain infection caused by the JC virus, which can be fatal or cause severe disability, and is characterized by progressive damage or inflammation of the white matter of the brain. Those testing positive for anti-JCV antibodies and taking TYSABRI less than 25 months have either a less-than-one-in-1,000- chance of developing PML if there was no prior immunosuppressant use, or a two-in-1,000-chance if there was prior immunosuppressant use. For those testing positive and taking TYSABRI between 25 months and 48 months, the risk of developing PML is either five-in- 1,000 if there was no prior immunosuppressant use, or 11-in-1,000 if there was prior immunosuppressant use. Those who test negative are at significantly lower risk for developing PML, as presence of the JC virus is necessary for the development of PML.
