Comparative effectiveness of natalizumab and fingolimod treatment on cognitive functions in relapsing multiple sclerosis. ECTRIMS 2016 - Poster Session 2

Background: Natalizumab (NTZ) exerts a positive impact on cognitive functions in Relapsing Multiple Sclerosis (RRMS). Little is known about the effect of Fingolimod (FIN) on these functions. Objectives: to compare the effect on cognitive functions of 1-year treatment with FIN or NTZ. Methods: All consecutive RRMS scheduled for treatment with NTZ or FIN underwent neuropsychological evaluations using the Brief Repeatable Battery, Stroop Test, Fatigue Severity Scale (FSS) and Beck Depression Inventory (BDI) at baseline and every 12 months. A test was considered failed if the corresponding z-score was 2 standard deviation (SD) below the mean Italian normative values. The Cognitive Impairment Index (CII) as a measure of global cognitive function was calculated for each patient. Patients were propensity score (PS)-matched on a 1-to-1 basis at the time of treatment start using the following covariates: sex, age, prior treatment exposure, relapses prior the treatment, school education, and BDI score. The relapse risk during the treatment was estimated through a Poisson regression model. A generalized linear mixed model for repeated measures with an autoregressive variance-covariance structure was applied to evaluate changes in CII, the mean number of cognitive tests failed and FSS score at 1 year of treatment. Results: the effect of treatment on cognitive functions was evaluated in 62 matched RRMS patients receiving NTZ(n=31) or FIN(n=31). The relapse incidence was not significant different between the treatments (FIN vs NTZ: Incidence rate ratio=0.71, p=0.6). The mean±SD number of cognitive tests failed was significantly reduced only in FIN treated patients (2.8±2.2 vs 1.7±1.8, p=0.0014). The CII significantly improved in both groups (NAT 18.5±6.1 vs 14.5±6.1, p=0.0075; FIN 14.0±7.3 vs 11.5±7.5, p< 0.0001), but there was not a significant interaction between group X time. The FSS was unchanged in both groups. Conclusions: Our results indicates, for the first time, that both NAT and FIN treatments significantly ameliorate cognitive functions in RRMS. Moreover, the effect on the number of tests failed suggest that FIN could have a greater impact on cognition than NTZ. The effect on cognition of these two drugs goes in parallel with the reduction of the relapse rate. This latter finding support the hypothesis that in the short-term, NTZ and FIN, exert a positive impact on cognition likely by means of their anti-inflammatory properties