Background:Therapy with interleukin 17 (iIL17) inhibitors in Russia is indicated for patients with ankylosing spondylitis (AS) or psoriatic arthritis (PSA). If standard therapy is ineffective in these diseases, both tumor necrosis factor inhibitors (iTNF) and iIL17 can be prescribed as the first biologics.Objectives:To study the clinical features of patients with spondyloarthritis (SPA) who were first prescribed iIL17 in a rheumatology center for 12 months.Methods:During the period from January to December 2019, iIL17 was initiated to 43 SPA patients. To compare the clinical picture, the study additionally included 40 SPA patients who were prescribed iTNF during the same period. The diagnosis of AS was based on the mNY criteria, and psoriatic arthritis was based on the CASPAR criteria. In the combined group of 83 patients, AS was in 52 (62.7%), and PSA – in 31; the age of patients was 39.3±10.8 years, and the duration of the disease was 15.1±8.2 years; men were 47 (56.6%).Results:In the iIL17 group, AS had 23 (53.5%) patients, and PSA – 20 (46.5%), while in the iTNF group, respectively, 29 (72.5%) and 11 (27.5%; χ2=3.2, p=0.76). Among the patients who were prescribed iIL17, men were 29 (67%), and in the iTNF group – 18 (45%; χ2=4.2, p=0.04). In terms of activity indicators (ESR, CRP, BASDAI ASDAS-CRP), patients who were prescribed iIL17 or iTNF did not differ significantly from each other. Peripheral arthritis, dactylitis, and entesitis were observed with almost the same frequency in both groups. In the iIL17 group, there were almost 2 times more patients with psoriasis (53.5% and 25.0%; p<0.05) than in group iTNF and among them, significantly more frequent the patients had previous experience of iTNF treatment (41,9% and 17.5%; p<0.05). Disease-modifying antirheumatic drugs often received patients in iTNF group (80.0% and 48.8%; p<0.05).Conclusion:Thus, in clinical practice iIL17 often prescribed for SPA male patients with psoriasis and previous treatment experience by iTNF. The activity of the disease and the presence of non-axial manifestations practically do not affect the choice of biological therapy.Disclosure of Interests:None declared.