We retrospectively analysed data from 44 patients using different generic (n=25) or original (n=19) fingolimod products between March 2011 and April 2019 at an MS clinic of Buenos Aires, Argentina. For efficacy, we evaluated annualized relapse rate, change in EDSS, and proportion of radiological activity-free patients at last follow-up. Rates of no evidence of disease activity (NEDA) were also evaluated at year 1, year 2 and last follow-up. For safety outcomes, rates of adverse events, serious adverse events and treatment discontinuation were evaluated.

At treatment initiation, patients on generic fingolimod products were significantly older (40.2 vs 33.8 years; p=0.02). They also had shorter treatment duration (3 vs 4 years), lower mean baseline EDSS scores (2.6 vs 3.1) and were more frequently treatment-naive (44% vs 26%) These differences were not significant. Regarding efficacy, results at last follow-up showed (generics versus original): annualized relapse rate: 0.01 vs 0.09, change in EDSS score: -0.1 vs +0.5, proportion of radiological activity-free patients: 81% both groups. NEDA rates at year 1: 76% vs 70%, at year 2: 82% vs 64%, at last follow-up: 61% vs 38%. Results regarding safety: any adverse events: 64% vs 47%, serious adverse events: 8% vs 10%, treatment discontinuation: 16% vs 31%. No difference was statistically significant.       

In this observational study, no significant difference was observed regarding efficacy and safety outcomes between generic versus original fingolimod products. Due to study design and small sample size, results demand caution. Larger studies are eagerly needed.