Proportion of alemtuzumab-treated patients converting from relapsing-remitting multiple sclerosis to secondary progressive multiple sclerosis over 6 years.

Background: Few data exist concerning conversion to secondary progressive MS in patients treated with disease-modifying therapies.

Objective: Determine the proportion of alemtuzumab-treated patients converting from relapsing-remitting to secondary progressive MS during the CARE-MS core and extension studies.

Methods: Patients ( = 811) were analyzed post hoc for secondary progressive MS conversion.