Introduction. Prompt successful control of disease activity in multiple sclerosis (MS) patients improves outcomes. Therefore, tools to aid drug selection and detect non-responders are urgently needed. Although several biochemical markers for predicting response to treatment have been proposed, clinical markers involving relapses, imaging activity and disability progression in the initial years of therapy remain competitive and appear cost-effective in a real-life setting. The aim of this study was to evaluate the prognostic value of select clinical scores in interferon beta-1b (IFNβ-1b) treated MS patients.

Materials and methods. Eighty-eight relapsing-remitting MS (RRMS) patients initiating treatment with IFNβ-1b in a Polish outpatient clinic were followed for a median of 5.5 years. Rio, modified Rio and BREMSO scores, as well as two-year no evidence of disease activity (NEDA), were assessed as predictors of disease activity during the observation.

Results. A Rio score of 1 had a Positive Predictive Value (PPV) of 83.3% and a Negative Predictive Value (NPV) of 71.4% for the occurrence of relapses in the first five years. A Rio and modified Rio score of 1 was associated with MRI activity after year 3. A loss of NEDA within the first two years was associated with a failure to maintain NEDA in the next three years. The BREMSO score was higher in patients with early relapse activity. Only baseline EDSS and total number of pre-treatment relapses were significantly associated with disability progression.

Conclusions. Rio, modified Rio, early NEDA on treatment and BREMSO score are relatively specific, but insensitive, predictors of relapse activity in the first years of IFNβ-1b treatment. Higher pre-treatment EDSS and relapse activity is associated with disability progression, but not overall NEDA, in subsequent observation. While none of the markers is sufficiently sensitive or specific to make a certain prognosis, they may aid treatment decisions in patients with continued early disease activity.