Observational Study of Switching from Natalizumab to Immunomodulatory Drugs

Objective: To determine the effect of disease -modifying drugs (DMDs) on disease activity rebound in patients discontinuing natalizumab (NTZ). Methods: Twenty-one patients with relapsing -remitting multiple sclerosis (RRMS) treated with NTZ for >= 1 year and who switched to DMDs (glatiramer acetate [GA] or interferon) were followed up for 12 months in clinical practice. Clinical outcomes after NTZ cessation were assessed every 3 months for 1 year and MRI was performed at 12 months. Results: Twelve months after switching from NTZ to DMDs, there were no significant differences in the annualized relapse rate (ARR) compared to the days that NTZ was used (0.3 vs. 0.1; p = 0.083); and the ARR never reached similar values to those prior to NTZ use (1.61; p < 0.001). The percentage of relapse -free patients after switching from NTZ was 71.4%. These patients did not have lower disease activity before NTZ compared with those with clinical relapses (1.3 vs. 1.7; p = 0.302), but they had lower Expanded Disability Status Scale scores (3.4 vs. 5.7;p = 0.001). DMDs had beneficial effects on MRI parameters, as 10 of 16 patients (62.5%) presented no evidence of radiological activity 12 months after NTZ discontinuation. Conclusions: Patients with RRMS and moderate disability who discontinued NTZ for safety reasons may benefit from the DMDs GA and interferon with no known risk for progressive multifocal leukoencephalopathy. (C 2017 S. Karger AG, Basel