Experience with fampridine in clinical practice: analysis of a possible marker of clinical response

Purpose of the study: Approximately 85% of patients with multiple sclerosis experience reduced mobility, which negatively affects quality of life. Fampridine is the first symptomatic treatment aimed at improving gait. We analyzed effectiveness and tolerance in clinical practice. We also sought a prevalent gait pattern in responders as a potential clinical response marker. Material and methods: Six-month prospective study of fampridine in patients with multiple sclerosis. Response was evaluated using the Timed 25-Foot Walk Test (T25FW) and the 12-Item Multiple Sclerosis Walking Scale (MSWS-12). Response was defined as increased gait speed (≥20%) and decreased MSWS-12 score (≥4 points). Results: Fifty-five patients (67.3% women; mean age, 51.7 [11.1] years) with a baseline Expanded Disability Status Scale (EDSS) score of 5.8. Gait pattern was paraparetic (40%), hemiparetic (21.8%) and ataxic (38.2%). Of all patients, 70.9% demonstrated clinical benefit based on response criteria established, at the 14-d follow-up, 61.8% at 3 months and 45.5% at 6 months. A similar response pattern was observed in the MSWS-12. A significant decrease in the mean (SD) EDSS score was observed in responders at 6 months (6.1 [0.9] vs. 5.64 [0.1], p < 0.05). Adverse effects were recorded in 50.9%, although most were mild-moderate and resolved completely. We did not identify a prevalent gait pattern among responders. After a washout period, some patients received fampridine a second time obtaining response recovery. Conclusions: In our patients’ cohort, fampridine proved clinical benefit, being safe and well tolerated in most cases. We did not identify a gait pattern that was predictive of clinical response.