Aim. To enhance the efficiency of treatment in patients with secondary osteoarthritis (ОА) in the presence of comorbid condition, by using an interleukin-1 inhibitor (IL-1i) and laser therapy (LT). Subjects and methods. A total of 248 patients aged 38 to 65 years with RA and secondary OA who had predominantly Stage II in accordance with the Disease Activity Score 28 (DAS28) were examined. According to the received therapy, the patients were divided into 4 groups: 1) IL-1i + LT + mrthotrexate (MT); 2) IL-1i + MT; 3) LT + MT; 4) MT. The efficiency of treatment was evaluated from changes in the KOOS (Knee injury and Osteoarthritis Outcome Score), DAS 28, IL-1, and cartilage oligomeric matrix protein (COMP) 6 months later. Results. There were statistically significant functional improvements in KOOS and DAS28 in Groups 1 and 2 patients with secondary OA in RA. Clinical efficacy was confirmed by positive changes in serum IL-1 and COMP levels. Conclusion. Incorporation of an IL-1i into a therapy regimen for secondary OA in RA patients during basic therapy could not only improve the functional status of patients, but also decrease activity of the underlying disease according to the DAS 28.