Valutazione economica e analisi di budget impact di S-1 (tegafur/gimeracil/oteracil) in pazienti con carcinoma gastrico avanzato

Abstract

Objective

The aim of this study was to assess whether S-1 might represent a valuable therapeutic option for patients with advanced gastric cancer in comparison to other available therapies (5-FU, capecitabine), considering both costs and outcomes associated with the different therapeutic strategies. The perspective of the analysis was that of the Italian National Health Service (NHS).

Design

The economic analysis was carried out using different approaches, taking into account the available clinical evidence. A cost-minimization analysis was based on the non-inferiority hypothesis of S-1 and capecitabine versus 5-FU (in terms of overall survival) observed in the FLAGS study (2010) and in Kang et al. (2010). Moreover, a Markov model was developed to evaluate costs of S-1 versus 5-FU per treatment failure avoided. The model was based on three health states (advanced gastric cancer, progression after treatment failure, death) and combined efficacy data from a published clinical trial (FLAGS) with costs of therapies and other direct costs. Costs and effects were both discounted at 3.5%. Deterministic and probabilistic sensitivity analyses were carried out to test the robustness of the results. A further analysis was conducted in order to assess the potential budget impact of S-1 on the Italian NHS.

Results

Cost-minimization analysis showed the possibility for the NHS to obtain greater cost-savings by treating patients with S-1 rather than with capecitabine. The average total cost per patient amounted to €6,689 for S-1, €7,464 for capecitabine and €18,207 for 5-FU. The cost-effectiveness analysis revealed that S-1 is dominant, if compared to 5-FU, because of cost-savings of about €6,243 for approximately 0.11 cases of treatment failure avoided over a lifetime horizon. These savings were mainly due to the different administration setting (S-1 oral therapy, 5-FU infusion), and to the better safety profile of S-1 compared to 5-FU.

Conclusions

The introduction of S-1 in the treatment of advanced gastric cancer would result in savings for the Italian NHS, mainly due to the reduction of adverse events and hospitalizations. Further studies are warranted in order to carry out a direct comparison with capecitabine, which represents the most appropriate comparator for the cost-effectiveness analysis.