Cost-Effectiveness of Once-Daily Oral Chelation Therapy with Deferasirox (Exjade®, ICL670) Versus Infusional Deferoxamine in Transfusion-Dependent Thalassemic Patients.

Background. Transfusion-dependent thalassemic patients require chelation therapy to treat iron overload and prevent its complications. 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 chelator that has been shown to produce reductions in liver iron concentrations and serum ferritin similar to those obtained with DFO. Cost-effectiveness 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 cost-effectiveness (CE) of DSX vs DFO in patients with transfusion-dependent thalassemia.

Methods. A decision-analysis model was used to estimate the total additional lifetime costs and quality-adjusted life year (QALY) gained with DSX versus DFO in patients with transfusion-dependent thalassemia (≥8 transfusions per year). Compliant patients were assumed to receive dosages of DSX and DFO that have been shown to be similarly effective in such patients. Probabilities of complications of iron overload and death by average compliance with chelation were estimated using data from published studies. Compliance with DFO and costs of complications of iron overload and DFO administration were based on analyses of health insurance claims data of transfusion-dependent thalassemic patients. Because data on compliance with DSX in typical clinical practice are unavailable, to be conservative, we used published data on compliance with the three-times-daily oral chelator deferiprone vs DFO. Utilities (weights representing patient quality of life) were obtained from a study that used time-trade-off techniques to measure patient preferences for oral vs infusional chelation therapy, as well as published literature and assumption. Analyses were based on the wholesale acquisition cost of generic DFO and the anticipated cost of DSX in the US. Results were generated alternatively for DFO-naïve patients (age 5 years, no prior DFO therapy) and DFO-experienced patients (age 17 years [mean of thalassemia patients in DSX trials] and 12 years of prior DFO therapy). Costs and QALYs were discounted at 3% annually.

Results. In DFO-naïve patients, DSX results in a gain of 4.4 QALYs per patient. These benefits are obtained at an additional expected lifetime cost of $165,207 per patient. CE is $37,516 per QALY gained. In DFO-experienced patients, the benefits of DSX are attenuated by prior inadequate chelation with DFO, with DSX resulting in a gain of 2.7 QALYs per patient at an additional expected lifetime cost of $143,832 per patient. CE in DFO-experienced patients is $53,239 per QALY.

Conclusion: The CE of DSX vs DFO in patients with transfusion-dependent thalassemia is favorable compared with other generally-accepted treatments for patients with hematologic/oncologic disorders (e.g., rHuEPO for chemotherapy-induced anemia). Results were most favorable for DSX in DFO-naïve patients, suggesting that earlier initiation of DSX may be more cost-effective.