Clinical effectiveness of dimethyl fumarate in multiple sclerosis patients from Argentina.

Background: We assessed the effectiveness, safety and patient-reported outcomes (PROs) of dimethyl fumarate (DMF) in real-world clinical practice in patients with multiple sclerosis (PwMS) from Argentina.

Methods: We conducted a multicenter ambispective cohort study in Argentina between September 2020 and March 2023. Changes in annualized relapse rate (ARR), Expanded Disability Status Scale (EDSS) score, magnetic resonance imaging (MRI), no evidence of disease activity (NEDA), PROs (depression, anxiety, fatigue, burden of treatment and quality of life), and safety data were collected at clinical visits performed every 6 months for at least 24 months.

Results: We included 161 PwMS (64% female). DMF treatment was associated with a significant reduction in ARR from baseline after 24 months of treatment (from 0.87 to 0.23, p < 0.001). Disability progression was observed in 27.9% vs. 9.3% pre- and post-DMF, and disability improvement was found in 13% of patients from baseline to month 24. MRI activity was significantly reduced compared with baseline. Fatigue, depression, and quality of life scores were significantly improved from baseline to 24 months. Flushing was the most frequent adverse event reported in 19.2%. No significant reduction was observed in the hospitalization rate pre- and post-DMF (19.8% vs. 5.6%, p = 0.32). During follow-up, 135 (83%) patients were relapse-free, 110 (68.3%) were MRI free activity (Gad + lesion) and 108 (67%) reached NEDA.

Conclusions: DMF significantly reduced disease activity in PwMS from Argentina with a good safety profile in real-world settings. A significant impact on the quality of life during follow-up was found.