Stopping beta-interferon therapy in multiple sclerosis: an analysis of stopping patterns

Abstract

Estimates of the beta-interferon (IFNB) stopping rate in relapsing-remitting multiple sclerosis (RRMS) and secondary progressive MS (SPMS) vary and have been mainly derived from multicentre studies. This is a retrospective, hospital chart-based study of 394 patients treated by a single neurologist for up to eight years. The aims of the study were to ascertain the frequency and timing of IFNβ discontinuation in a well supported cohort, and to investigate whether the clinical disease type at the initiation of IFNβ or the reason for discontinuation influenced stopping rates. The median follow-up was 49 months. The overall IFNβ stopping rate was 28% over five years; there was a significant difference between the IFNβ stopping rates for RRMS (14%) and SPMS (23%) after three years of follow-up (P=0.0003). Patients stopped IFNβ due to side effects after a median of 13 months, and due to failure of therapy after a median of 35 months (P=0.0004). Significantly more patients with SPMS than with RRMS stopped IFNβ due to treatment failure (P=0.037). Conclusion: IFNβ discontinuation occurred earlier in the treatment course when due to side effects. Stopping IFNβ therapy was more common in SPMS and was more often due to treatment failure than side effects.