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

• Published in: Multiple sclerosis journal - experimental, translational and clinical translational and clinical, 2020-10, Vol.6 (4), p.2055217320972137-2055217320972137
• Main Authors: Horáková, Dana, Boster, Aaron, Bertolotto, Antonio, Freedman, Mark S, Firmino, Isabel, Cavalier, Steven J, Jacobs, Alan K, Thangavelu, Karthinathan, Daizadeh, Nadia, Poole, Elizabeth M, Baker, Darren P, Margolin, David H, Ziemssen, Tjalf
• Format: Article
• Language: English
• Subjects: Immunotherapy; Monoclonal antibodies; Multiple sclerosis; Original Research Paper
• ISSN: 2055-2173; 2055-2173
• DOI: 10.1177/2055217320972137

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 (N = 811) were analyzed post hoc for secondary progressive MS conversion. Optimal conversion definition: Expanded Disability Status Scale (EDSS) score ≥4, pyramidal functional system score ≥2, and confirmed progression over ≥3 months including confirmation within the functional system leading to progression, independent of relapse. Results Over 6.2 years median follow-up, 20 alemtuzumab-treated patients converted (Kaplan-Meier estimate, 2.7%; 95% confidence interval, 1.8%–4.2%). Sensitivity analysis accounting for dropouts showed similar results (3%), as did analyses using alternative definitions with different EDSS thresholds and/or confirmation periods, and analysis of core study subcutaneous interferon beta-1a-treated patients who received alemtuzumab in the extension. Patients converting to secondary progressive MS were older, and had higher EDSS scores and greater brain lesion volumes at baseline, but did not need additional alemtuzumab or other therapies. Conclusions The 6-year conversion rate to secondary progressive MS was low for alemtuzumab-treated patients, supporting further study of the role alemtuzumab may play in reducing risk of secondary progression. ClinicalTrials.gov identifiers: NCT00530348, NCT00548405, NCT00930553.