Guidelines on PML risk stratification and diagnosis in patients with MS treated with natalizumab: so far so good?

Natalizumab is the cutting-edge drug for relapsing multiple sclerosis (MS) and the first registered monoclonal antibody in the field. The convincing efficacy on clinical and MRI outcome measures created new expectations, such as ‘freedom of disease activity’. Nonetheless, the beneficial effects are contrasted with the risk of developing potentially highly disabling or even fatal JC virus (JCV)-associated progressive multifocal leukoencephalopathy (PML) during therapy. As such, the benefits need to be weighed with the risks.

Expert opinion can aid clinicians and patients in such situations. In their JNNP paper, an expert panel led by McGuigan et al1 present the UK and Ireland guidelines for stratification and monitoring the risk of natalizumab-associated PML. The article provides suggestions, regarding regular monitoring using MRI, on frequency and interpretation …