Cost-effectiveness analysis of subcutaneous biosimilar tocilizumab in patients with rheumatoid arthritis in Spain

Rheumatoid arthritis (RA) is the most common chronic inflammatory rheumatic disease, its management and morbidity impose a great burden to healthcare systems. Development and rollout of biological disease modifying anti-rheumatic drugs has contributed to improvements for patients, however, high costs have prevented them to be widely used. This is being addressed with biosimilars, with equal benefit-risk profile and reduced costs. The objective is to analyze the cost-effectiveness of subcutaneous biosimilar tocilizumab (bsTCZ) for patients with moderate-severe RA in Spain from a healthcare system perspective. A Markov model was developed with a lifetime horizon including 5 health states: remission of the disease; low, moderate, or high activity; and death. A PICO-S-T search retrieved efficacy of treatments in meta-analysis and network meta-analysis, and was further complemented with published clinical trials. Pharmacological costs were obtained from the BotPlus database, and medical resources costs from regional tariffs. Deterministic and probabilistic sensitivity analysis were performed to validate the robustness of results. Incremental cost-effectiveness ratio (ICER) for cost/percentage of remission and cost/quality-adjusted life year (QALY) gain were calculated. Lifetime cost of bsTCZ was 183 741€ (lowest) versus comparative costs ranging from 184 317€ for infliximab to 201 972€ (highest) for certolizumab. QALYs were 13.74 for upadacitinib and 13.73 for sarilumab and tocilizumab with values between 13.53 and 13.72 for the comparators. ICERs as €/remission and €/QALY showed that bsTCZ was either dominant in most of the comparisons or the most cost-effective alternative. The sensitivity analysis showed that bsTCZ long term cost, and transition from low to moderate disease activity health status were the most influential factors. Moreover, bsTCZ was either dominant or cost-effective in all the comparisons. bsTCZ demonstrated to be a cost-effective and cost-saving alternative for the treatment of patients with RA in Spain when compared to all the available therapeutic alternatives.