Treatment of natalizumab-associated PML with filgrastim.

Objective: There is no consensus on the treatment of progressive multifocal leukoencephalopathy (PML) occurring in multiple sclerosis (MS) patients treated with natalizumab (Nz). We report novel immune activating treatment with filgrastim of Nz-associated PML in MS patients treated at Rush University Medical Center.

Methods: We retrospectively analyzed 17 Nz-PML patients treated at this single tertiary referral center between 2010 and 2017.