"Effectiveness and associated factors of response to Fampridine in multiple sclerosis: A prospective observational study from an expert center"

Abstract

Objective: To evaluate the effectiveness of fampridine on gait performance in patients with multiple sclerosis (MS) and to identify clinical predictors of therapeutic response.

Methods: Prospective observational study of 197 MS consecutive patients with walking impairment (EDSS 4.0-7.00) treated with fampridine between 2018 and 2024. Gait was assessed using the Timed 25-Foot Walk (T25FW), 2-Minute Walk Test (2MWT), and the 12-item Multiple Sclerosis Walking Scale (MSWS-12) at five timepoints over a 12-month follow-up. Responders were defined as those with ≥20 % improvement in T25FW or ≥6-point reduction in MSWS-12. A multivariable logistic regression was performed to identify independent predictors of response.

Results: Significant improvements were observed across all gait measures (p < 0.001) in the follow-up visits. Male sex (OR=2.375; p = 0.018) and higher baseline MSWS-12 scores (OR=1.141; p = 0.001) were associated with increased likelihood of response. Older age (OR=0.962; p = 0.028) and higher baseline EDSS (OR=0.356; p < 0.001) were associated with reduced probability of response. Fampridine was well tolerated, with a 33 % discontinuation rate at the end of follow-up, mainly due to perceived lack of benefit.

Conclusion: Fampridine significantly improves gait performance in MS patients in real-world settings. Simple clinical variables such as age, sex, EDSS, and subjective walking impairment (MSWS-12) may help identify individuals most likely to benefit from treatment.

Keywords: Fampridine; Gait impairment; MSWS-12; Multiple sclerosis; Predictors of response; Real-world evidence; T25FW.