(1) Background: Complement system activation has been proposed as one of the different factors that contribute to Multiple Sclerosis (MS) pathogenesis. In this study, we aimed to describe the potential effects of eculizumab, an anticomplement therapy, on MS disease activity in a cohort of relapsing-remitting (RR) MS patients who discontinued IFN-β therapy due to IFN-β-related thrombotic microangiopathy (TMA) onset. (2) Methods: In this retrospective observational multicentric study, we searched for all patients with MS treated by eculizumab with a survey of several nephrological and neurological centers (over 45 centers). (3) Results: Nine patients were included. The mean follow-up time under eculizumab was 3.72 ± 2.58 years. There were no significant differences in disease activity (EDSS, relapses, new T2, and/or Gd-enhancing lesions at MRI) considering the two years before and after eculizumab therapy. No adverse events potentially related to eculizumab therapy were reported during follow-up. (4) Conclusions: In this preliminary study, we described a good safety profile for eculizumab therapy in MS. However, the available data are not sufficient to make firm conclusions about the possible efficacy of eculizumab as a disease-modifying therapy for MS patients.
Keywords: adverse event; anticomplement therapy; complement; disease-modifying therapy; eculizumab; interferon beta; multiple sclerosis.