707P - A cost-effectiveness analysis of three years of adjuvant imatinib in KIT+ gastrointestinal stromal tumors (GIST) in Greece

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Bioethics, Legal, and Economic Issues
GIST
Presenter Maria Raikou
Authors M. Raikou1, I. Boukovinas2, M. Geitona3
  • 1Social Sciences, London School of Economics & Political Sciences, London/UK
  • 2Oncology Unit, London School of Economics & Political Sciences, London/UK
  • 3Social Policy, University of Peloponnese, Athens/GR

Abstract

Background and objective

Clinical studies have demonstrated the clinical benefit of adjuvant imatinib for patients who undergo complete gross resection for KIT+ GIST both in terms of overall and recurrence-free survival. The aim of this study is to assess the cost-effectiveness of the following treatment options a) 3 yr adjuvant imatinib (IM) vs 1yr IM, b) 3yr IM vs. surgical resection only c) lifetime IM vs. 1 yr IM as adjuvant therapy in patients with KIT GIST, from the perspective of the Greek National Health Service (NHS).

Methods

A Markov transition state model was developed and populated with data from published literature and expert opinion. All patients enter the model free of recurrence and over subsequent cycles, a patient may remain free of GIST, may enter a state of recurrent GIST or may die of GIST or other causes. The mean starting patient age was 58 years old and the discount rate 3% per year. Resource utilization reflects Greek disease management. Pharmaceutical and adverse events cost was based on 2012 prices. Extensive sensitivity analysis was also undertaken.

Results

Mean total cost per patient was estimated at €72,899 for 1 yr of adjuvant IM versus €112,910 for 3yr IM. Effectiveness was estimated to be 10.80 and 12.76 life-years and 7.63 and 9.19 QALYs respectively for 1yr vs. 3yr. The incremental cost-effectiveness was thus €20,387 per life-year gained and €25,700 per QALY gained over a patient's lifetime. These results were most sensitive to the rate of GIST recurrence beyond 5 years. The incremental cost of 3 years of IM versus surgical resection alone was €14,649 per life-year gained and €18,448 per QALY gained and €65,943 per life-year gained and €82,851 per QALY gained over a patient's lifetime for lifetime IM treatment versus 1 year of imatinib. These results were most sensitive to the monthly cost of IM.

Conclusions

This analysis has shown that 3yr adjuvant IM therapy is considered highly cost-effective for the Greek NHS when compared to either 1yr adjuvant IM or surgical resection alone. Lifetime vs. 1y adjuvant IM is associated with a moderate incremental cost-effectiveness ratio that is far below the acceptable threshold of €100.000 for life-threatening diseases.

Disclosure

M. Raikou: This study was sponsored by Novartis Hellas S.A.

All other authors have declared no conflicts of interest.