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

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.