Three cases of non-carryover fingolimod-PML

Abstract

The risk of PML under fingolimod is low, but there are no reliable predictors. Despite a mild IRIS phase, it causes profound disability. Patients older than 45 years, especially with known comorbid immunodeficiencies or manifestation of other opportunistic infections, should be monitored more closely. Increased surveillance and identification of further risk factors are urgently needed in Japan.