“…In the present study, we observed that treatment with natalizumab significantly reduced the number of relapses at one and two years (93.9 and 92.9%, respectively). This was comparable with the 90.7% reduction in ARR achieved in TOP 32 and 83.2% in a recently published study in the US 6 , as well as in other observational studies 14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31 . In addition, the TOP study reported that PwRMS treated with natalizumab presented associations with reductions in relapse-related hospitalizations and steroid treatment, despite longer follow-up in the on-natalizumab period than in the pre-natalizumab period 33 .…”