Abstract
Background. Patients with symptomatic myelodysplastic syndrome (MDS) frequently receive chronic transfusions, along with chelation therapy to prevent complications of iron overload. Deferoxamine (DFO) is an effective iron chelator, but must be administered as an 8–12 hour infusion 5–7 times per week, leading to poor compliance and/or reduced quality of life. Deferasirox (DSX) is an investigational once-daily oral iron chelator that has been shown to produce reductions in liver iron concentrations and serum ferritin similar to those obtained with DFO. The objective of this analysis was to evaluate from a US perspective the cost-effectiveness (CE) of DSX vs DFO in patients with transfusion-dependent MDS.
Methods. Data from a variety of published and unpublished sources were used to estimate the CE of chelation therapy with DSX vs DFO in MDS patients receiving frequent transfusions (≥8 per year). As there are no long-term studies describing the complications of iron overload in MDS, we focused on the short-term (i.e., one year) cost and quality-of-life effects of chelation therapy. As comparative data for DSX vs DFO in MDS are unavailable, we estimated the average dose (mg/kg/d) of DSX based on results for MDS patients in a non-comparative Phase II study. The relative dose of DFO that would result in similar efficacy was based on data from comparative studies in other transfusion-dependent anemias. To be conservative, we assumed that all patients would be fully compliant with chelation therapy. CE was measured in terms of the ratio of the difference (DSX vs DFO) in costs of chelation therapy to the difference in quality adjusted life years (QALYs) over one year of treatment. Analyses were based on the wholesale acquisition cost of generic DFO and the anticipated cost of DSX in the US. Mean weight was estimated to be 70 kg, based on data for MDS patients in DSX clinical studies. The cost of DFO administration was based on analyses of health insurance claims data for patients with transfusion-dependent anemias. Utilities (weights representing patient quality of life) for MDS patients receiving transfusions were based on published data for patients with anemia from metastatic cancer. The difference in quality of life for DSX vs DFO was based on results of a study that used time-trade-off methods to estimate community-based preferences for oral vs infusional iron chelation therapy.
Results. Total annual costs are estimated to be $7,679 greater with DSX ($35,672 vs $27,993 with DFO). Annual costs of DFO included $20,185 for drug acquisition and $7,808 for drug administration. One year of treatment with DSX is estimated to result in a gain of 0.23 QALYs (0.78 vs 0.55 with DFO). The CE of DSX vs DFO is therefore estimated to be $33,387 per QALY gained. CE of DSX vs DFO was sensitive to the assumed dosages of DSX and DFO, the cost of infusional therapy, and the decrement in quality of life associated with infusional therapy.
Conclusion: The CE of DSX versus DFO in patient with transfusion-dependent MDS is favorable compared with that of other generally-accepted treatments for patients with hematologic/oncologic disorders. These results may be conservative, as they did not consider the potential benefits of improved compliance with DSX or side effects of infusion therapy.
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