Purpose: Interruption of natalizumab (NTM) treatment in multiple sclerosis (MS) patients may be followed by disease reactivation. On the other hand, patients with positive John Cunningham virus (JCV) antibodies treated with NTM over 24 months demonstrate a higher risk for developing progressive multifocal encephalopathy (PML). No established therapeutic approach is available for treating these patients to prevent disease reactivation.
Materials and methods: Of the MS patients treated with NTM at the authors' institution, 30 were found positive for JCV abs. NTM was interrupted followed by a washout period of 6 months. During this period, 20/30 patients received monthly intravenous (i.v.) methylprednisolone (MPD) 1000 mg infusion and regular clinical assessment. On months 3 and 6, brain MRI was performed and 1000 mg MPD was administered for 5 days.
Results: All patients were clinically and radiologically stable at the time of NTM break. No clinical relapse was observed during the six-month washout period for the MS patients under monthly MPD treatment, while one patient had a relapse and active lesions in the MRI on month 6. Of the other patients not receiving i.v. MPD regularly after NTM withdrawal, one showed several active lesions in brain MRI and the other had a severe relapse.
Conclusions: Despite the limited size of this patients' cohort, the results of this study support that monthly MPD treatment for 6 months may result in a clinically stable disease status, thus ensuring safe transition to another second-line therapy such as fingolimod, following NTM withdrawal.
Keywords: fingolimod; multiple sclerosis; natalizumab; pulsed corticosteroid treatment.