Objective:This study was designed to evaluate the cost utility of tocilizumab in rheumatoid arthritis (RA) patients, with inadequate responses to traditional disease-modifying anti-rheumatic drugs (tDMARDs) from a payer’s perspective in Italy.Methods:An individual patient simulation model was used to project lifetime medical costs (payer’s perspective) and quality-adjusted life-years (QALYs). Treatment sequences starting with tocilizumab or the most commonly prescribed biologics (etanercept, adalimumab, or infliximab) were compared. The addition of tocilizumab to standard of care, without the replacement of anti-tumor necrosis factor (TNF)-α treatments, was also evaluated. Patient characteristics, treatment efficacy, and quality-of-life data were based on three phase 3 tocilizumab clinical trials (TOcilizumab Pivotal Trial in Methotrexate Inadequate respONders [OPTION], Tocilizumab in cOmbination With traditional DMARD therapy [TOWARD], and TociLIzumab Safety and THE Prevention of Structural Joint Damage [LITHE]). Mixed-treatment comparison was used to estimate response probabilities. Resource utilization, treatment acquisition, administration, and monitoring costs were estimated using Italian secondary sources. Uncertainty in model parameters was evaluated by probabilistic sensitivity analysis.Results:Replacement of anti-TNF-α treatments with tocilizumab reduced total costs over a patient’s lifetime (base-case analysis: tocilizumab sequence, €141,100 vs standard of care sequence, €143,500). Patients receiving tocilizumab realized more QALYs than patients receiving standard of care (9.8881 vs 9.3502 QALYs). Therefore, according to the base-case analysis, the tocilizumab sequence dominated the standard of care. In a sensitivity analysis, the model base-case result was robust to input changes. When tocilizumab was added to standard of care, without replacing anti-TNF-α treatments, the incremental cost-effectiveness ratio was €17,100 per QALY.Conclusion:The analysis demonstrates that, in Italy, replacing another biologic DMARD with tocilizumab or adding tocilizumab to the current standard of care is a cost-effective strategy in the treatment of RA patients with inadequate responses to tDMARDs.