Dimethyl fumarate: a possible exit strategy from natalizumab treatment in patients with multiple sclerosis at risk for severe adverse events.

DMF appeared generally safe and no carryover PML among investigated cases was observed. Although DMF did not eliminate the possibility of disease reactivation, it seems anyway a promising drug for those patients who shall discontinue NTZ. The clinical and radiological activity preceding the DMF treatment might be used as a prognostic marker of therapy response.