Switching to second-line therapies in interferon-beta-treated relapsing-remitting multiple sclerosis patients.
BACKGROUND
Interferon-beta (IFNB) therapies are the most widely used as first-line intervention in the treatment of relapsing-remitting (RR) multiple sclerosis (MS). Despite long-term experience, however, the definition and prediction of response remain controversial.


OBJECTIVE
The objective of this study was to assess the long-term validity of the main clinical definitions of response applied after 1 and 2 years of IFNB therapy in a cohort of RRMS patients followed up for at least 5 years.


METHODS
We tested these different definitions against a 'hard' parameter of treatment failure, represented by the need to suspend IFNB and switch to an intravenous immunosuppressive (IVIS) treatment, using Kaplan-Meier and Cox survival analyses.


RESULTS
Out of 147 RRMS patients treated with IFNB therapy and followed up for 7.8 +/- 2.1 years, 26 (18%) were switched to an IVIS therapy. On the whole, disability progression as indicated using the Expanded Disability Status Scale (EDSS) and a higher number of relapses in the first 2 years of therapy were related to long-term treatment failure.


CONCLUSIONS
Our study highlights the role of disability and high relapse rate in the first 2 years of treatment in predicting long-term response and the switching to second-line therapies.
Portaccio
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Department of Neurology, University of Florence, Viale G. Morgagni 5, Florence, Italy. portilio@tin.it
Zipoli
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Siracusa
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Sorbi
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Amato
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MP
D000328:Adult; D015331:Cohort Studies; D005260:Female; D005544:Forecasting; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D016899:Interferon-beta / Q000627:therapeutic use*; D053208:Kaplan-Meier Estimate; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy*; D015999:Multivariate Analysis; D012008:Recurrence; D012044:Regression Analysis; D017211:Treatment Failure
D007166:Immunosuppressive Agents; D016899:Interferon-beta