Fingolimod reduces the clinical expression of active demyelinating lesions in MS

Background: Fingolimod is a modulator of Central and peripheral sphingosine pathways, which is currently approved for treatment of Multiple Sclerosis (MS). In animal models it reduces inflammation, but it is also able to potentiate glutamatergic transmission and synaptic plasticity. We aimed to explore whether Fingolimod is able to modify the clinical expression of new demyelinating lesions with respect to IFNβ−1a in relapsing remitting MS (RRMS) patients suboptimal responders to IFNβ−1a. Methods: 103 patients with RRMS switching for inefficacy from IFNβ−1a to Fingolimod and treated for at least 12 months were included. Annualised Relapse Rate (ARR), EDSS and the number of new brain and spinal gadolinium enhancing (Gd +) and T2 lesions were retrospectively assessed in the whole group during each treatment period. The likelihood of co-occurrence of new Gd + lesions and clinical relapses during IFNβ−1a and Fingolimod treatment was analysed. Results: The mean duration of treatment with IFNβ−1a and Fingolimod was 3.14 (SD 1.6) and 3.22 years (SD 1.1) respectively. Significant reduction of ARR (p <.001), total number of Gd + and T2 lesions (p <.001) was found switching from IFNβ−1a to Fingolimod. Gd + lesions occurring during treatment with Fingolimod were more likely to be asymptomatic compared with IFNβ−1a (88% vs 30.9%, p = <.025). Conclusion: Fingolimod reduces clinical and radiological inflammation in MS. Additionally, it limits the clinical expression of new Gd + lesions, possibly reducing local inflammatory processes and improving brain network plasticity in patients with suboptimal response to IFNβ−1a.