Clinical and MRI predictors of response to interferon-beta and glatiramer acetate in relapsing-remitting multiple sclerosis patients.

BACKGROUND AND PURPOSE: It is still unclear which patients benefit more from available disease-modifying treatments (DMTs) in multiple sclerosis (MS). Our objective is to identify the baseline clinical and magnetic resonance imaging (MRI) predictors of response to first-line DMTs in a cohort of relapsing-remitting (RR) MS patients in a real-world clinical setting.

METHODS: Consecutive naïve RRMS patients treated with interferon-beta or glatiramer acetate have been included and followed for 2 years. Patients were grouped into responders (R) in case of absence of clinical and MRI activity, and non-responders (NR) if the on-treatment annualized relapse rate (ARR) reduction was < 50% of the ARR in the 2 years before treatment or in the presence of MRI activity (≥ 2 active lesions at 1-year MRI or ≥ 4 active lesions at 1 + 2-year MRI).

RESULTS: At 2-year follow-up, 272 patients were R (34.6%) and 322 NR (40.9%), and multivariate analysis revealed that a later age at onset of the disease (P < 0.0001), a lower disability (P < 0.0001) and a lower number of gadolinium-enhancing lesions at baseline MRI (P = 0.002) were predictors of efficacy of DMTs. Moreover, the first year response had a good predictive power on the second year, as 73.7% of 1-year R had no evidence of clinical and MRI activity within the ensuing year.

CONCLUSION: A lower baseline MRI and clinical activity have been identified as predictors of DMT efficacy in patients with RRMS in routine clinical practice. Evaluation of clinical and MRI activity at 1 year is recommended to monitor patients over time.