Rheumatoid arthritis (RA) is a severe, autoimmune disorder characterized by relatively high prevalence among working-age adult population, significant quality of life and work performance impact, as well as high risk of complete disability in case of inadequate or ineffective treatment. The creation of Biologic Disease-modifying anti-rheumatic drugs (bDMARDs) has allowed to significantly improving prognosis for many RA patients, however, the issue of choosing therapy for patients with RA, especially in case of resistance to methotrexate treatment remains problematic, especially in terms of pharmacoeconomic justification of bDMARD choice. Ongoing improvement of clinical understanding of bDMARDs also ensures the significance of further investigating the pharmacoeconomic qualities of these drugs. Aim. To perform the pharmacoeconomic analysis (PHe) of therapy using tocilizumab, adalimumab, as first-line bDMARD therapy in patients with RA receiving standard combination therapy with methotrexate, as well as in patients who require bDMARD monotherapy due to methotrexate resistance, methotrexate nonresponse, or other issues within context of Russian healthcare Methodology. This PHe is conducted from societal perspective which includes interests of Russian healthcare system within context of Obligatory Medical Insurance system and interests of Russian economic system as a whole, including impact on. The time horizon for this research was 2 years. Randomized controlled clinical trials investigating safety and efficacy of these drugs when used in combination with methotrexate and as monotherapy were used as data source on safety and efficacy. A complex PHe model consisting of a «decision tree» (used to form simulated cohorts of patients for each investigated drug, 1 000 simulated patients per cohort) and a Markov model for evaluating treatment outcomes was constructed. Cycle length for the Markov component of the model was 1 week. Clinical improvement of ACR70 was chosen as efficacy end-point because of its high clinical and social relevance. Patients achieving ACR70 can return to workforce. The results of this modelling were used to perform cost-effectiveness analysis (CEA) and budget impact analysis (BIA). Result stability was confirmed by performing sensitivity analyses (SA). Result. During CEA, tocilizumab dominated in terms of cost-effectiveness ratio (CER). CER was 28 525 007 rub. for tocilizumab, 30 898 104 rub. for adalimumab per 1 000 simulated per year in patients receiving standard combination therapy and 21 564 612 rub. for tocilizumab, 30 970 348 rub. for adalimumab per 1 000 simulated per year in patients receiving monotherapy), as well as in terms of clinical effectiveness (as expressed with number of patients achieving ACR70) and with highest healthcare resource utilization effectiveness. BIA indicates that tocilizumab is associated with 4,8% reduction in budget burden compared to adalimumab (estimated per 100 000 per 2 years of Russian population (246 patients), accounted for RA prevalence) in case of standard combination therapy and a 3,98% reduction of budget burden in patients receiving monotherapy. That amounts to 35 575 400 rub. and 28 835 840 rub. respectively (taking into consideration 3,5% discounting factor). SA confirms result robustness to price fluctuations up to 20%.for patients receiving combination therapy and more than 25% for patients receiving monotherapy. Additional sensitivity analysis investigating possible effects of assuming strict safety and efficacy equivalence between the investigated drugs confirms tocilizumab advantage even under such assumption. Conclusion. Modelling results indicate that tocilizumab is pharmacoeconomically rational which is associated with higher effectiveness of healthcare resource utilization. Tocilizumab treatment is also attractive in terms of budget impact as it is associated with up to 4,8% budget burden reduction within scope of 2 years, which is a significant result in context of treating an expensive, potentially debilitating pathology such as RA. Aforementioned results demonstrate that tocilizumab is attractive, pharmacoeconomically effective option for treating patients with in the RF. Prioritization of tocilizumab within context of relevant purchasing channels is thus highly recommended.