To evaluate the efficacy and safety of the anti-CD20 monoclonal antibody divozilimab (DIV) used as an intravenous infusion at a dose of 500 mg every 24 weeks during 100 weeks for the treatment of patients with multiple sclerosis (MS), including relapsing-remitting multiple sclerosis (RRMS) and secondary progressive MS (SPMS) with relapses. The multicenter, randomized, double-blind and double-masked phase III clinical trial (CT) BCD-132-4/MIRANTIBUS (NCT05385744) included 338 adult patients with MS distributed in a 1:1 ratio into two groups: DIV 500 mg and teriflunomide (TRF) 14 mg. After screening, subjects were included in the main CT period, which consisted of two cycles of therapy over 48 weeks, then entered an additional period from weeks 49 to 100, which included three cycles of therapy. The efficacy was assessed based on the results of brain MRI and registration of data on relapses. 308 subjects completed 5 therapy cycles according to the study protocol. An analysis of the effectiveness of DIV therapy over 2 years showed a persistent suppression of MRI and clinical activity of the disease in comparison with TRF, which was confirmed by all the studied MRI indicators (including CUA; total number of gadolinium-enhancing (GdE) lesions on T1-weighted scans ; number of new or enlarged lesions on T2-weighted scans; lesions volume change on T2-weighted scans; change in the volume of hypointense lesions on T1-weighted scans). The use of DIV was associated with a statistically significant decrease in ARR compared to TRF (p=0.0001). The ARR in the DIV group was 0.057, in the TRF group - 0.164 with 95% confidential interval for the frequency ratio [0.202; 0.593]. The incidence of GdE lesions on T1-weighted scans in the DIV group was significantly lower than in the TRF group. The average number of such lesions was 0.0±0.08 and 1.0±4.46 in the DIV and TRF groups, respectively (p<0.0001). Progression of EDSS was detected in 18 (10.7%) and 36 (21.3%) patients in the DIV and TRF groups, respectively (p=0.0075). The proportion of patients with relapses was 11.2% (n=19) in the DIV group and 23.1% (n=39) in the TRF group (p=0.0039). In the subpopulation of patients with SPMS, no cases of increase in EDSS were detected, and not a single case of exacerbation was recorded over 2 years of using DIV. Also, DIV has shown a favorable safety profile. Among the adverse reactions (AR), infusion reactions and laboratory abnormalities, such as a decrease in the number of leukocytes, neutrophils, and lymphocytes, were most often recorded. Identified AR were expected, had mild to moderate severity, and resolved without any negative consequences. The results of the BCD-132-4/MIRANTIBUS CT indicate a high sustained efficacy and safety of long-term use of DIV in comparison with TRF during 2 years of therapy.