Are natalizumab and fingolimod analogous second-line options for the treatment of relapsing-remitting multiple sclerosis? A clinical practice observational study.

Background: It is unclear whether natalizumab and fingolimod have analogous efficacy for relapsing-remitting multiple sclerosis (RRMS). Objective: To compare the outcome of RRMS patients treated with either therapy. Methods: RRMS patients treated with natalizumab or fingolimod at Verona Hospital, Italy, were included. The study design was retrospective, based on prospectively collected clinical and MRI data. As efficacy outcomes, time to relapse, relapse rate, expanded disability status scale (EDSS) score change, and new T2/gadolinium-enhancing lesions on brain MRI were compared over treatment period between the two groups. Multivariate Cox and logistic regression models were used to control for potential confounders. Results: Fifty-seven subjects receiving natalizumab and 30 receiving fingolimod for a median duration of 23 (1-63) and 22 (2-35) months, respectively (p = 0.22) were included. Patients treated with natalizumab had a more active pre-treatment disease course compared to those treated with fingolimod. In multivariate analysis, the relapse risk was reduced in patients on natalizumab (Hazard Ratio = 0.33; 95% CI = 0.11-1.03; p = 0.056) compared to those on fingolimod. There was no significant difference in EDSS and MRI outcomes. No relevant unexpected adverse events occurred. One patient discontinued natalizumab for progressive multifocal leukoencephalopathy. Conclusions: RRMS patients receiving natalizumab had higher baseline disease activity and lower relapse risk over 20 months of treatment compared to those receiving fingolimod. Head-to-head randomized clinical trials are needed.