“The downside of washing-out natalizumab is that it also allows MS to reactivate, so called rebound, and hence something needs to be done about this. DMTs that suppress the immune system are a no-no as the immune system is required to fight the PML, hence the only drugs possible in this situation are immunomodulators; IFNbeta, GA and possibly DMF. I say possibly DMF as it is probably not an immunosuppressive drug, unless it causes a very low lymphocyte count, which happens rarely. The important thing about natalizumab and PML is that it does not have to occur. Those at high-risk should really come of the drug, or at least go onto regular 3-monthly MRI monitoring so that PML can be detected early, in the asymptomatic phase, and treated early. The outcome of PML when it is detected early, before it causes symptoms, is so much better (see slide 35 & 36 in the deck below.”
“I still have sleepless nights over natalizumab and PML. Despite advising all our high-risk patients to come off the drug a few patients want to stay on the drug. These are typically patients who have had very bad MS and are now doing very well on natalizumab. I keep telling the MS Team that it is simply a numbers game and it is only a matter of time before we have our first case of PML at the Royal London Hospital. I fear that day!”
Epub: Vennegoor et al. Application of serum natalizumab levels during plasma exchange in MS patients with progressive multifocal leukoencephalopathy. Mult Scler. 2014 Jul 30.
Background: Progressive multifocal leukoencephalopathy (PML) is a severe complication of natalizumab treatment. Restoring immune function by plasmapheresis/immunoadsorption (PLEX/IA) is important for the outcome of PML.