The therapeutic approach in multiple sclerosis (MS) requires a personalized medicine frame beyond the precision medicine concept, which is not currently implementable due to the lack of robust biomarkers and detailed understanding of MS pathogenesis. Personalized medicine demands a patient-focused approach, with disease taxonomy informed by characterization of pathophysiological processes. Important questions concerning MS taxonomy are: when does MS begin? When does the progressive phase begin? Is MS really two or three diseases? Does a therapeutic window truly exist? Newer evidence points to a disease spectrum and a therapeutic lag of several years for benefits to be observed from disease-modifying therapy. For personalized treatment, it is important to ascertain disease stage and any worsening of focal inflammatory lesions over time.
Keywords: disease definition; multiple sclerosis; personalized medicine; taxonomy.