IFNA1 and myeloid sarcoma: In previously treated RR-MS patients (CARE-MS II trial), the proportion of cases with CDW at year 2 was 12.7% (95% CI 9.9 – 16.3) in the alemtuzumab group, with a significant risk reduction of 42% compared with IFN (proportion with CDW: 21.1%, 95% CI 15.9 - 27.7, p=0.0084) (95 EDSS change from baseline was different between the two groups and EDSS score improved of mean -0.17 points in the alemtuzumab arm, whereas it worsened of mean 0.24 points in the IFN arm (p<0.0001).