Switching to second-line therapies in interferon-beta-treated relapsing-remitting multiple sclerosis patients

Abstract

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.

Aim: 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.

Conclusion: 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.