RESUMO
OBJECTIVES: This study aimed to evaluate the cost-effectiveness of anti-epidermal growth factor receptor (cetuximab and panitumumab) or anti-vascular endothelial growth factor (bevacizumab) monoclonal antibodies associated with conventional chemotherapy (CT) (fluorouracil and leucovorin with irinotecan) as a first-line treatment for unresectable metastatic colorectal cancer. METHODS: A partitioned survival analysis model was adopted to simulate direct health costs and benefits comparing therapeutic options in a 10 years' time horizon. Model data were extracted from the literature and costs were obtained from Brazilian official government databases. The analysis considered the perspective of the Brazilian Public Health System; costs were measured in local currency (BRL) and benefits in quality-adjusted life-years (QALY). A 5% discount rate was applied to costs and benefits. Alternative willingness-to-pay scenarios, varying from 3 to 5 times the cost-effectiveness threshold established in Brazil, were estimated. The results were presented incremental cost-effectiveness ratio (ICER), and both deterministic and probabilistic sensitivity analyses were performed. RESULTS: The most cost-effective choice would be the association of CT with panitumumab, with an ICER of $58 330.15/QALY compared with isolated CT. The second-best option was CT with bevacizumab and panitumumab, with an ICER of $71 195.40/QALY compared with panitumumab alone. Although having higher costs, the second-best option was the most effective. Both strategies were cost-effective in part of the Monte Carlo iterations, considering the 3× threshold. CONCLUSIONS: The therapeutic option CT + panitumumab + bevacizumab represents the most significant effectiveness gain in our study. It is the second-lowest cost-effectiveness, and this option includes monoclonal antibodies association for patients with and without KRAS mutation.