Once-Daily Oral Deferasirox (Exjade®, ICL670) Versus Infusional Deferoxamine as Iron Chelation Therapy in Patients with Sickle-Cell Disease Receiving Frequent Transfusions: A Cost-Effectiveness Analysis.

Background. Patients with sickle-cell disease (SCD) receiving chronic transfusions require chelation therapy to prevent complications from iron overload. Although deferoxamine (DFO) is an effective iron chelator, it 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 in magnitude to those obtained with DFO. Cost-effectiveness (CE) analysis is a technique used to determine whether the benefits of new therapies are worth their additional costs. The objective of this analysis was to evaluate from a US perspective the CE of DSX versus DFO in SCD patients receiving frequent transfusions.

Methods. Data from a variety of published and unpublished sources were used to estimate the CE of chelation therapy with DSX versus DFO in SCD patients receiving frequent transfusions (≥8 per year). As there are no long-term studies describing the complications of iron overload in patients with SCD, we focused on the short term (i.e., one year) costs and quality-of-life effects of chelation therapy. We assumed that patients would receive dosages (mg/kg/d) of DSX and DFO that have been found to be similarly effective in patients with SCD. 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 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 52 kg, based on data from deferasirox 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) were based on results of a study that used time-trade-off methods to estimate community-based preferences for oral versus infusional iron chelation therapy.

Results. Total annual costs were estimated to be $1,486 greater with DSX ($22,922 vs $21,436 with DFO). Annual costs of DFO included $13,628 for drug acquisition and $7,808 for drug administration. One year of treatment with DSX is estimated to result in a gain of 0.25 QALYs (0.82 vs 0.57 with DFO). The CE of DSX versus DFO is therefore estimated to be $5,944 per QALY gained. CE of DSX versus DFO was sensitive to the assumed dosages of DSX and DFO and the cost of infusional therapy.

Conclusion. In patients with SCD receiving frequent transfusions, DSX versus DFO is highly cost-effective compared with other generally-accepted treatments for patients with hematologic and oncologic disorders. These results may understate the CE of DSX, as they did not consider the potential benefits of improved compliance or side effects of infusion therapy. Further research is needed to assess the potential implication of DSX on the risk-benefit profile of transfusion therapy in patients with SCD.