BCD-055 is a biosimilar of innovator infliximab (IFX). Here we present the 54-week results from phase 3 clinical study in patients with rheumatoid arthritis (RA). The aim of this study was to demonstrate the equivalent efficacy and safety of BCD-055 and IFX in patients with active rheumatoid arthritis. 426 adults with active RA were enrolled. Patients were randomized into 2 study arms in 2:1 ratio to receive BCD-055 or IFX innovator in dose of 3 mg/kg at week 0, 2, 6 and then every 8 weeks up to week 54. Primary efficacy endpoint was the rate of American College of Rheumatology (ACR) 20 response at week 14. The equivalence margin was set as 15%. Immunogenicity and safety were also assessed. Rate of ACR20 at week 14 in PP (Per-Protocol) population was 71.2% in BCD-055 group and 67.9% in IFX group. Difference in ACR20 rates between groups was 3.2% with 95% CI [- 7.0%; 13.5%] (р = 0.587). Throughout 54-week study period, both groups were characterized by similar rates of ACR20/50/70 response at all timepoints without significant differences (p > 0.05). The rates of adverse events (AE) were similar in groups (74.64% in BCD-055 arm vs 66.67% in IFX arm, p = 0.111). Antibodies to infliximab were detected in 28.46% patients for BCD-055 arm and 26.56% for IFX arm (p = 0.786). BCD-055 and IFX were comparable in efficacy (including radiographic progression), safety and immunogenicity throughout the 54-week study.Trial registration ClinicalTrials.gov ID, number NCT02762838.