A COMPARATIVE ANALYSIS OF EFFICACY OF INTERFERON BETA 1-B AND NATALIZUMAB TREATMENT IN PATIENTS WITH RELAPSING-REMITTING MULTIPLE SCLEROSIS

Background: Disease modifying drugs for multiple sclerosis have similar indications for use and at the same time, their specifics of the effect on the pathophysiological process. This complicates the choice of an optimal therapy for a  given patient. Aim: To assess efficacy of treatment for multiple sclerosis with interferon beta-1b (IFN-β-1b) and natalizumab. Materials and methods: We performed an open label prospective study in 110  patients with multiple sclerosis who were followed up in the Moscow Regional Center of multiple sclerosis from 2012 to 2015. From those, 99  patients with relapsing-remitting multiple sclerosis (disease modifying drugs naïve) were treated with IFN-β-1b, 11 were non-responders to interferon (1 and more attacks for the previous year of therapy with IFN-β-1b) or had progressive course of multiple sclerosis (more than 2  attacks and an increase in the Expanded Disability Status Scale (EDSS) score by 1 and more within 1 year) and were treated with natalizumab. Analysis of treatment efficacy was performed with consideration of their past history, results of a  3-year neuromonitoring with Kurtzke EDSS and Functional System Scale, neuroophthalmologic testing with Farnsworth dichotomous test, and changes in optical coherent tomography parameters. Results: During 3  years of treatment with IFN-β-1b, the mean number of attacks decreased by over 70% (from 1.28±0.7 in the year before treatment to 0.35±0.09 in the 3rd year of treatment; p<0.05), whereas the degree of disability assessed by EDSS increased nonsignificantly by 0.44 (p>0.05). During the follow-up in the natalizumab group, the number of attacks decreased from 2.3±0.04 to 0.13±0.01 (p<0.05), and the degree of disability by EDSS decreased by 0.8 (p>0.05). There was a significant difference between changes in the thickness of peripapillar nervous fibers during 2  years of the follow up, this parameter decreasing by 2.5 mcm in patients treated with IFN-β-1b and by 0.1  mcm in those treated with natalizumab (p<0.01). Conclusion: Although the patients from natalizumab group had initial more severe course of multiple sclerosis, both agents were highly effective, with the most prominent clinical effect observed for natalizumab. The results obtained may serve as a  basis for recommendation of the 2nd line disease modifying drugs for patients with aggressive course of the multiple sclerosis and failure of the 1st line disease modifying drugs. Also, we were able to demonstrate the efficacy of neuroophthalmological monitoring in the assessment of disease modifying drugs efficacy. The strict safety policy is essential while using natalizumab.