RESUMEN
OBJECTIVE: To evaluate the efficacy and safety of samPEG-IFN-ß1a 180 µg and 240 µg administered once every 2 weeks for the treatment of relapsing remitting multiple sclerosis (RRMS) compared to placebo and low dose interferon beta-1a (LIB) 30 µg administered once weekly. The primary endpoint after 52 weeks of therapy was the time to first relapse, the hypotheses of non-inferiority and superiority to LIB were tested. MATERIAL AND METHODS: This international, multicenter, double blind, comparative, placebo-controlled clinical study enrolled 399 patients with the diagnosis of RRMS, randomized in 4 groups: samPEG-IFN-ß1a180 µg (n=114), samPEG-IFN-ß1a 240 µg (n=114), LIB (n=114) and placebo (n=57). Placebo group patients participated in the study for 20 weeks. After 52 weeks of therapy and 4 weeks of follow-up, LIB group patients completed their participation in the study, patients from PEG-IFN-ß1a groups continued to receive therapy until week 100 inclusive. The article presents the results of an analysis conducted after the end of 52 weeks of a double-blind, comparative, randomized, placebo-controlled clinical trial. RESULTS: Final analysis of the efficacy and safety was performed after 52 weeks of study. Main statistical hypothesis testing proved that both doses of samPEG-IFN-ß1a were equally effective when compared to LIB by the primary endpoint - «Time to first relapse¼. Due to detection of statistically significant differences in the primary endpoint between the study drug and the reference drug, indicating a greater efficacy of the study drug, an additional testing was carried out and the hypothesis of superiority of samPEG-IFN-ß1a at a dose of 240 µg over the reference LIB was proved. Evaluation of the dynamics of certain key parameters of magnetic resonance imaging (MRI) of the brain and clinical outcomes demonstrated a positive effect of samPEG-IFN-ß1a therapy in the form of decreased activity of the demyelinating process in the brain and reduce the number of relapses. The proportion of patients without new T2 lesions after 52 weeks was 87.6% and 90.4% in 180 µg and 240 µg samPEG-IFN-ß1a groups, versus 72.6% in the LIB group (p=0.0199 and p=0.0033). No progression of multiple sclerosis was shown based on EDSS scale evaluation. During the study, the most common adverse reactions were flu-like symptoms and injection site reactions. CONCLUSION: The new drug samPEG-IFN-ß1a is an effective and safe agent for relapsing remitting multiple sclerosis treatment, while having an advantage over other low-dose interferons in the form of reduced frequency of intramuscular injections.