[Glatiramer acetate in interferon beta non respondent relapsing-remitting multiple sclerosis]

There are 4 immunomodulator treatments approved as first line therapy for patients with re-lapsing-remitting multiple sclerosis (RRMS). The objective of this study is to assess if glatiramer acetate (GA) is useful or not in patients who have discontinued interferon beta due to a suboptimal response or adverse events.

This is an observational and retrospective study in RRMS patients who discontinued IFN-beta therapy (2.9+/-2.4 years of treatment) and switched to GA (1.9+/-1.4 years). They were classified in 2 groups depending on the reason for discontinuation: suboptimal response or side effects. In both treatments we analysed number of relapses, treatment duration and causes of discontinuation.

We included 58 patients of which 20 discontinued IFN-beta for lack of effectiveness whereas 38 were due to adverse events. Patients who discontinued for suboptimal response changed from 1.38 +/- 0.95 relapses per year with IFN-beta to 0.52+/-0.86 with GA. Patients who discontinued for adverse events changed from 0.33 +/- 0.64 relapses per year with IFN-beta to 0.37+/-0.79 with GA.

GA can be considered a good alternative treatment for MS patients with a suboptimal response or adverse events with IFN-beta which confirms the existence of different mechanisms of action in both drugs.