Maraviroc as possible treatment for PML-IRIS in natalizumab-treated patients with MS.

Progressive multifocal leukoencephalopathy (PML) is a serious complication of natalizumab treatment in patients with relapsing-remitting MS (RRMS)1 with 638 confirmed cases as of March 2016. Therapeutic re-establishment of cerebral immune surveillance in PML management is complicated by immune reconstitution inflammatory syndrome (IRIS), an exuberant inflammatory response that aggravates damage caused by John Cunningham virus (JCV) infection and ultimately leads to a combined PML/IRIS syndrome.2 Currently, plasma exchange (PLEX) for the elimination of natalizumab and reconstitution of immune surveillance is used as standard of care, although this might lead to rebound MS activity or enhanced IRIS. Here, we report 2 cases of patients with PML/IRIS who did not receive PLEX, but were instead treated with the CCR5 antagonist maraviroc that has been associated with an amelioration of IRIS.3