Safety of disease-modifying therapies in multiple sclerosis: real-world data from the Austrian MS Treatment Registry...

In the therapeutic landscape of multiple sclerosis (MS), more than a dozen disease-modifying therapies (DMT) are currently available. In Austria, only certified MS centers are authorized to prescribe DMT and are obliged to enter patient data into the Austrian MS Therapy Registry (AMSTR). Here, we report the safety profiles of different DMT documented in this registry.

Adverse events (AE) data from the AMSTR, collected at least biannually from August 2006 to July 2025, were extracted. AE were classified by system organ classes according to the Medical Dictionary for Regulatory Activities.

This analysis included 7913 patients (67.7% female, median age 37 years [IQ 29-45]), with the majority receiving dimethyl fumarate (2572/7913, 32.5%), followed by fingolimod (2129/7913, 26.9%) and natalizumab (2021/7913, 25.5%). For alemtuzumab, the most frequent AE were immune-related (41/90, 45.5%) including thyroid disorders (24/90, 26.7%). For cladribine, natalizumab, ocrelizumab and ofatumumab, infections constituted the most common AE (21/458, 4.6%; 123/2021, 6.1%; 27/698, 3.9%; 16/792, 2%). Gastrointestinal AE were most frequently observed with dimethyl fumarate and teriflunomide (364/2572, 14.2%, and 78/781, 10%, respectively), whereas AE related to the blood system were most common with sphingosine-1 phosphate receptor modulators (S1P-modulators; fingolimod: 245/2129, 11.5%). Regarding neoplasms, all DMT showed low rates, though S1P-modulators had the highest (fingolimod 31/2129, 1.4%-13/31 [42%] basal cell carcinomas).

The safety data from the AMSTR do not reveal any new safety issues, particularly regarding neoplasms and infections. Hence, people with MS as well as their treating neurologists are reassured to continue treatment with DMT, as the benefit-risk profile of DMT could be reaffirmed.