Disease-modifying drugs for multiple sclerosis must be globally available according to therapeutic guidelines suitable to different regions of the world

Abstract

EDITORIAL Disease-modifying drugs for multiple sclerosis must be globally available according to therapeutic guidelines suitable to different regions of the worldOs medicamentos que modificam a história natural da esclerose múltipla devem ser disponibilizados a todos os doentes segundo normas terapêuticas adequadas às diferentes regiões do globo Maria José Sá S ince the early nineties of the XX century, multiple sclerosis (MS) moved drastically from a scarcely treated disease to a neurological chronic condition which is targeted by an increasing number of drugs that can significantly modify its natural evolution. These disease-modifying drugs (DMD) were specifically designed to intervene in the various inflammatory and immunological steps which underpin the MS pathogenesis, so their main indication is the relapsing-remitting (RR) form, and more recently, the clinically isolated syndromes (CIS). The first licensed drug was interferon beta 1-b, then formulations of interferon beta 1-a, glatiramer acetate, and, for aggressive forms, mitoxantrone. More recently natalizumab was introduced, and approximately one and a half year ago fingolimod was approved. Interferon beta and glatiramer acetate constitute the first-line group of DMD, being worldwide known due to the expected efficacy in clinical (≈30% reduction in the annualized relapse rate) imaging (reduction in T2 lesion burden and in gadolinium-enhancing lesions) parameters, as well as in many other aspects: side effects; production of neutralizing antibodies to interferon, thus compromising its efficacy; need of adherence evaluation since these are self-injectable drugs which may lead to needle tiredness and perception of lower than expected efficacy after long-term therapy. Second-line DMD are significantly more efficient and its therapeutic administration regimens is easier, yet, its safety profile is worse, thus imposing strict vigilance programs: mitoxantrone is cardiotoxic and increases the risk of blood malignancies; natalizumab generates risk of progressive multifocal leukoencephalopathy, especially in patients previously submitted to immunosupressants with positive blood serology and after two-years of exposure; fingolimod, the first oral DMD approved for MS, needs strict cardiac monitoring and ophthalmologic assessment to exclude macular edema.All DMD are expensive, representing a major cost to MS clinics and hospitals in countries in which the health system entirely reimburses them, the insurance companies and even the patients treated in private units in countries with strict health systems. The need for a health team specialized in MS, which would be able to provide frequent assistance, including patient and caregiver education, is determinant for a successful management, but it also would increase the economic burden of MS.Before DMD, MS patients were treated with immunosupressants such as cyclophosphamide, azathioprine, methotrexate, and also with plasma exchange and human immunoglobulins, which non-specifically alter the immunological process, bein...