Two cases of relapses in primary progressive multiple sclerosis after fingolimod withdrawal.

We report two cases of primary progressive multiple sclerosis (PPMS) included in the INFORMS cohort, experiencing a relapse related to a single MRI gadolinium-enhancing lesion 3 months after fingolimod withdrawal. These two patients share similarities with relapsing-remitting multiple sclerosis cases described in the same situation, suggesting that the initiating process of the active demyelinating plaques is also present in PPMS, even without relapses, but may be triggered as fingolimod is withdrawn. Although the results of the INFORMS study suggest that fingolimod may not slow down the progression, some PPMS patients might still benefit from a disease-modifying treatment.