Cost-effectiveness of Cetuximab as a treatment strategy for metastatic colon cancer in Peru: chemotherapy/Cetuximab versus chemotherapy alone

© 2018 Royal Pharmaceutical Society Objective: To evaluate cost-effectiveness – from a local perspective – of cetuximab when it is added to conventional chemotherapy for the treatment of metastatic colon cancer. Methods: A Markov model was structured based on the systematic review of the evidence and the opinion of local experts. The economic model consists of three health states: (a) progression free survival (PFS), (b) progressive disease (PD) and (c) death. The basic measure to determine the effectiveness of the intervention was the Quality Adjusted Life Year (QALY); however, other intermediate outcomes of impact on survival were considered, such as ‘R0 metastases resections’ and ‘early tumour shrinkage’ (ETS). Quarterly cycles were considered with a time horizon of 19 quarters (approximately 5 years). The analysis perspective was based on the Ministry of Health (MoH). Key findings: The cost per quality adjusted life year (cost/QALY) for chemotherapy + cetuximab treatment (CT/Cet) with respect to the baseline strategy approaches S/. 20 078 (equivalent to 1 Gross Domestic Product per capita [GDP-pc]). The probabilistic analysis of the ICER (Incremental Cost-Effectiveness Ratio) shows that, in all the cases, the CT/Cet strategy becomes more cost-effective with a payment threshold of S/. 30 000 (1.5 GDP-pc). Likewise, the acceptability curves showed that, from a threshold of S/. 20 000, the intervention with cetuximab becomes more cost-effective than chemotherapy alone (CT). Conclusions: The cost/QALY was S/. 20 078 (1 local GDP-pc) for the intervention with CT plus cetuximab. Other results of clinical relevance, such as ‘additional R0-resections’, ‘additional ETS cases’, ‘disease progressions avoided’ and ‘deaths avoided’ also favour the combination treatment.