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

Introduction and objective. There are 4 immunomodulator treatments approved as First line therapy for patients with relapsing-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 (IFN beta) due to a suboptimal response or adverse events. Methods. 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. Results. 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. Conclusions. 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.