Therapeutic options are growing for active RRMS patients, but few prospective studies are available to compare their efficacy. Best Escalation Strategy in MS (BEST MS) started in France in 2013 when NTZ and FTY were the two most employed therapies in active RRMS.

BEST-MS is a French prospective multicentric study. Patients with active RRMS (defined as at least 1 relapse in the last 12 months on a well-conducted 1^st line therapy with at least 9 T2 hyperintensities on MRI, OR at least 2 relapses in the last 12 months with evidence of active disease on MRI for naïve patients) were enrolled to be treated either with NTZ or FTY. Treatment choice was at the discretion of the physician. Relapses, EDSS and brain MRI were collected at baseline and at 12 months.

230 patients were included (mean age: 38.2 yrs, F/M: 3.1, FTY: 117, NTZ: 113). There was no statistical difference between groups regarding baseline clinical and radiological characteristics.

At M12, NTZ indicated a better efficacy regarding new T2 lesions (0.7 vs 1.4, p=0.01) and gadolinium enhancing lesions (0.03 vs 0.5, p<0.0001). Relapse rate (ARR) was lower in NTZ group (0.20 vs 0.27, p = 0.04), even if most relapses occurred during the first 4 months of treatment in both groups. 50% of NTZ patients were free of disease activity compared to 25% in the FTY group (p=0.05). Drop out rate was higher in FTY group (22% vs 12%, p<0.0001).

NTZ demonstrates higher efficacy than FTY on MRI in active RRMS patients. ARR is lower in favor of NTZ, and most relapses occurred early. Drop out is higher on FTY mostly due to adverse events.