RESUMO
OBJECTIVE: To assess the efficacy and safety of sampeginterferon-ß1a (samPEG-IFN-ß1a) 180 µg and 240 µg administered once every 2 weeks compared to placebo and low dose interferon beta-1a (LIB) 30 µg administered once weekly. MATERIAL AND METHODS: Patients with relapsing-remitting multiple sclerosis aged 18-60 years, with Expanded Disability Status Scale score ≤5.5 were randomized at a ratio of 2:2:2:1 to the following groups: samPEG-IFN-ß1a 180 µg, samPEG-IFN-ß1a 240 µg, LIB, placebo. After 20 weeks, the placebo group completed the study. After week 52, the final analysis was performed, which included the primary endpoint analysis, the LIB group patients completed their participation in the study. The patients in samPEG-IFN-ß1a groups continued to receive therapy with samPEG-IFN-ß1a 240 µg until week 100 inclusive. The results of the final analysis after 52 weeks have been previously published. The current article presents a long-term efficacy and safety of samPEG-IFN-ß1a after 104 weeks of the trial. RESULTS: The annualized relapse rate over the second year was 0.16 in the samPEG-IFN-ß1a 180 µg group and 0.09 in the samPEG-IFN-ß1a 240 µg group. By week 104, the proportion of relapse-free patients was 77.0% (87/113) and 83.3% (95/114) in the samPEG-IFN-ß1a 180 µg and 240 µg groups, respectively. There were no negative dynamics of MRI markers, neurological deficit parameters and cognitive functions by scales and tests. The safety profile of samPEG-IFN-ß1a was consistent with the known safety profile of IFN-ß therapy. CONCLUSION: Treatment with samPEG-IFN-ß1a is an effective and safe first-line therapy for relapsing-remitting multiple sclerosis patients.