A pharmaco-economic evaluation of deferasirox for treating patients with iron overload caused by transfusion-dependent thalassemia in Taiwan

Abstract

The newly available iron chelator deferasirox (Exjade, Novartis) is expected to provide better long-term clinical outcomes and improved quality of life for patients with thalassemia than its predecessor, deferoxamine (Desferal, Novartis), because of its oral tablet form. Methods: We used the Markov model to estimate total additional lifetime costs and quality-adjusted life years (QALYs) gained with deferasirox versus deferoxamine in patients with transfusion-dependent thalassemia. Patients were assumed to be 2 years of age at initiation of chelation therapy. Clinical outcomes in terms of morbidity and mortality from associated complications and life expectancy for the study population were estimated using the databases of the Bureau of National Health Insurance and the Health and Vital Statistics of Taiwan. Treatment costs were based on analyses of health insurance claims for patients with transfusion-dependent thalassemia. Utilities in terms of quality of life were also included in the model. The incremental cost–utility ratio of deferasirox versus deferoxamine was defined by the ratio of the difference in expected lifetime costs to the difference in QALYs. One-way sensitivity analyses were performed to examine the robustness of the results to key assumptions. Results: Patients treated with deferasirox are expected to experience a lower incidence of associated complications and obtain 2.3 QALYs (discounted) at an additional lifetime cost of US$36,291 per patient (US$15,596 per QALY). Sensitivity analyses showed that the unit drug cost of deferasirox had the greatest impact on the incremental cost–utility ratio. In addition, the incremental cost–utility ratio will increase by delaying the starting age (2 years of age in our study) of chelation therapy. Conclusion: Compared with infusional deferoxamine, oral deferasirox improved clinical outcomes and quality of life in terms of iron chelation in transfusion-dependent patients with thalassemia at a reasonable cost from a healthcare perspective.

Keywords

• cost–utility
• deferasirox
• quality-adjusted life year
• thalassemia
• transfusion-dependent