Disease reactivation after switching from natalizumab to daclizumab.

Discontinuation of natalizumab can lead to severe rebound of disease activity in patients with relapsing-remitting multiple sclerosis (RRMS); nevertheless, the treatment regimen in this clinical situation remains controversial. We report the case of a 25-year-old male patient with RRMS who was clinically stable under 3 years of natalizumab before treatment was stopped due to progressive multifocal leucencephalopathy (PML) safety concerns. After initiation of daclizumab, the patient suffered from disease reactivation, which was ultimately controlled by intravenous methylprednisolone and alemtuzumab treatment. Therefore, in some patients, daclizumab might not be sufficient to control disease activity after discontinuing natalizumab treatment.