Effect of Disease-Modifying Therapy on Disability in Relapsing-Remitting Multiple Sclerosis Over 15 Years

Tomas Kalincik, Ibrahima Diouf, Sifat Sharmin, Charles Malpas, Tim Spelman, Dana Horakova, Eva Kubala Havrdova, Maria Trojano, Guillermo Izquierdo, Alessandra Lugaresi, Alexandre Prat, Marc Girard, Pierre Duquette, Pierre Grammond, Vilija Jokubaitis, Anneke van der Walt, Francois Grand'Maison, Patrizia Sola, Diana Ferraro, Vahid ShaygannejadRaed Alroughani, Raymond Hupperts, Murat Terzi, Cavit Boz, Jeannette Lechner-Scott, Eugenio Pucci, Vincent Van Pesch, Franco Granella, Roberto Bergamaschi, Daniele Spitaleri, Mark Slee, Steve Vucic, Radek Ampapa, Pamela McCombe, Cristina Ramo-Tello, Julie Prevost, Javier Olascoaga, Edgardo Cristiano, Michael Barnett, Maria Laura Saladino, Jose Luis Sanchez-Menoyo, Suzanne Hodgkinson, Csilla Rozsa, Stella Hughes, Fraser Moore, Cameron Shaw, Ernest Butler, Olga Skibina, Orla Gray, Allan Kermode, Tunde Csepany, Bhim Singhal, Neil Shuey, Imre Piroska, Bruce Taylor, Magdolna Simo, Carmen Adella Sirbu, Attila Sas, Helmut Butzkueven, on behalf of the MSBase Study Group

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52 Citations (Scopus)


OBJECTIVE: To test the hypothesis that immunotherapy prevents long-term disability in relapsing-remitting multiple sclerosis (MS), we modeled disability outcomes in 14,717 patients. METHODS: We studied patients from MSBase followed for ≥1 year, with ≥3 visits, ≥1 visit per year, and exposed to MS therapy, and a subset of patients with ≥15-year follow-up. Marginal structural models were used to compare the cumulative hazards of 12-month confirmed increase and decrease in disability, Expanded Disability Status Scale (EDSS) step 6, and the incidence of relapses between treated and untreated periods. Marginal structural models were continuously readjusted for patient age, sex, pregnancy, date, disease course, time from first symptom, prior relapse history, disability, and MRI activity. RESULTS: A total of 14,717 patients were studied. During the treated periods, patients were less likely to experience relapses (hazard ratio 0.60, 95% confidence interval [CI] 0.43-0.82, p = 0.0016), worsening of disability (0.56, 0.38-0.82, p = 0.0026), and progress to EDSS step 6 (0.33, 0.19-0.59, p = 0.00019). Among 1,085 patients with ≥15-year follow-up, the treated patients were less likely to experience relapses (0.59, 0.50-0.70, p = 10-9) and worsening of disability (0.81, 0.67-0.99, p = 0.043). CONCLUSION: Continued treatment with MS immunotherapies reduces disability accrual by 19%-44% (95% CI 1%-62%), the risk of need of a walking aid by 67% (95% CI 41%-81%), and the frequency of relapses by 40-41% (95% CI 18%-57%) over 15 years. This study provides evidence that disease-modifying therapies are effective in improving disability outcomes in relapsing-remitting MS over the long term. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that, for patients with relapsing-remitting MS, long-term exposure to immunotherapy prevents neurologic disability.

Original languageEnglish
Pages (from-to)e783-e797
Number of pages15
Issue number5
Publication statusPublished - 2 Feb 2021

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