An update on the evaluation of treatment switching criteria in multiple sclerosis.
Multiple sclerosis (MS) is a complex disorder driven by both inflammatory and neurodegenerative processes. While disease-modifying therapies (DMTs) have significantly improved prognosis, robust treatment switching criteria remain essential to balance efficacy and safety over the disease course. This review examines historical and current criteria for escalating DMTs from moderate- to high-efficacy therapies (HET). The authors summarize emerging clinical, imaging, and biological markers that inform decision-making and explore strategies for de-escalation, including DMT discontinuation and innovative approaches such as exit and bridge therapies. Recent advances in MS management emphasize earlier initiation of HET and more stringent switching criteria. Although innovative monitoring tools - including clinical evaluations, imaging, biological markers, and patient-reported outcomes (PROs) - enhance disease assessment, they require further validation, standardization, and broader accessibility. Similarly, de-escalation criteria need additional research to optimize patient selection.