Avaliação econômica dos anticorpos monoclonais no tratamento do câncer colorretal metastático.

Abstract

Background: The last decade was marked by the widespread use of molecular biological agents in the treatment of metastatic colorectal cancer (mCRC). Such drugs have dramatically increased the costs of oncological treatments for pharmaceutical care, leading to concerns about the future sustainability of the drug policy and universal access health systems. In Brazil, the three monoclonal antibodies - MABs (bevacizumab, cetuximab and panitumumabe) compared in this study can only be used when there are a litigation against the State, since they are not incorporated into the SUS. Objective: To perform an economic analysis of monoclonal antibodies in the treatment of metastatic colorectal cancer from the SUS perspective. Methods: Two studies were carried out to achieve the objective of this investigation. a Systematic Review with meta-analyzes of observational studies published until November 2017. The outcomes analyzed were overall survival, progression-free survival, post-progression survival, response rate, metastasectomy, and safety. The second was an analysis of budgetary impact that evaluated the scenarios of incorporation of the three monoclonal antibodies most sued by court for treatment of the CRCm in Minas Gerais. Results: In the systematic review, 21 studies were included. The results showed an advantage in favor of bevacizumab with statistically significant and clinically relevant benefits, as opposed to patients who were treated in non-bevacizumab regimens. Differentials were found in overall survival, progression-free survival, post-progression survival and metastasectomy outcomes. Increases in treatment-related toxicities have been observed, especially severe hypertension and gastrointestinal perforation. The budget impact study allowed to identify that 351 lawsuits involving the three MABs had their applications granted for the treatment of the mCRC in the first line, in actions against the state of MG. In three alternative scenarios analyzed there was an increase in costs, ranging from 331 to 364% in relation to the reference scenario, which is composed of chemotherapy (QT) based fluoropyrimidine associated with irinotecan and or oxaliplatin regimens. The results were favorable to panitumumab, costing R $ 7,042,977.00, to prevent 83 events (death) per 1000 patients treated per year. Second, bevacizumab could prevent 106 deaths a year at a cost of $ 11,599,699. The total cost to the health system with new drugs for metastatic CRC may increase by about R$ 400 million in five years. Conclusion: The results obtained reinforce the need to incorporate the judicialized biological drugs in cancer care to improve the access to treatment of metastatic colorectal cancer in an equitable manner in every state of Minas Gerais. However, it is necessary to clarify the influence of the heterogeneity of the treatments from the survival studies, the prevalence of the genetic mutations dependent on the mechanisms of action related to the drugs, as well as to carry out comparative cost effectiveness studies of the treatments. Attention is drawn to the fact that such monoclonal antibodies are not used in substitution for the reference treatment with QT, currently incorporated in SUS, but in association with the already available regimen. Taking into account the results of both studies, both in effectiveness and safety as well as in economic impact, the evidences hitherto studied show advantages for the use of bevacizumab. However, it is necessary to deepen the debate in the genomic perspective to better assist the decision making process and choice regarding the incorporation of these biological drugs into cancer care.