Subjects meeting the eligibility criteria will be randomized in 3 groups to receive one of two studied doses of BCD-180 or placebo.~After the primary endpoint assessment subjects in placebo group will be switched to BCD-180 in minimal studied dose. After the completion of the main period of the study in each of the BCD-180 groups subjects who meet the criterion of non-active radiographic axSpA (ASDAS-CRP <1.3 at two subsequent visits) will be subjected to repeated randomization in two groups for the use of two different dosing regimens. Subjects of the Placebo group will continue to receive BCD-180 infusions.
The aim of the study is to evaluate the efficacy, safety, immunogenicity, pharmacokinetics and pharmacodynamics of two doses of study drug (BCD-180) in comparison with placebo in patients with active radiographic axial spondyloarthritis (axSpA). The study will include HLA-B27+ patients with radiographic axSpA who had no response to prior therapy with Non-steroidal anti-inflammatory drugs (NSAIDs), have not received biologic therapy or targeted Disease-modifying antirheumatic drugs (DMARDs).