Cost of Current Iron Chelation Infusion Therapy and Cost-Effectiveness of Once-Daily Oral Deferasirox in Transfusion-Dependent Thalassemia Patients in Canada.

Background: Deferasirox (Exjade^®) is a recently approved once-daily oral chelator that has been shown to produce reductions in liver iron concentrations and serum ferritin similar to those with infusional deferoxamine (Desferal^®), in patients with β-thalassemia major or sickle cell disease (SCD) and chronic iron overload from blood transfusions. The objective of this study was to estimate the cost of deferoxamine administration in Canada and evaluate the cost-effectiveness of deferasirox versus deferoxamine for chronic iron overload from blood transfusions from the Ontario provincial healthcare system.

Methods: Cost of chelation therapy with deferoxamine was estimated from five major treatment centers in Canada. Costs comprised the material used and the time spent by hospital pharmacists in preparing deferoxamine infusions. Cost-effectiveness of the new oral iron chelator, deferasirox, which could replace deferoxamine, was estimated using a Markov model. The model estimates and compares the total lifetime costs and quality-adjusted life years (QALYs) related to the use of deferasirox or deferoxamine in patients with β-thalassemia major at risk of chronic iron overload from blood transfusions. Dosages of deferasirox and deferoxamine used in the model were those that have been shown to be similarly effective in such patients. Compliance with deferoxamine was based on analyses of health-insurance claims data from transfusion-dependent thalassemia patients. Probabilities of complications of iron overload and death by compliance with chelation were estimated from published studies. Because data on compliance with deferasirox in typical clinical practice are unavailable, we used published data on compliance with the oral chelator deferiprone versus deferoxamine. Costs of deferasirox, deferoxamine, and drugs used in the treatment of complications of iron overload were based on publicly available data sources. Utilities were based on a study of patient preferences for oral versus infusional chelation therapy, as well as published literature and assumption. Future costs and QALYs were discounted at 5% annually. Costs were adjusted to 2004 Canadian dollars.

Results: Cost of yearly infusion therapy in Canada was estimated at $6,000 per patient, excluding deferoxamine drug cost. Cost-effectiveness of deferasirox compared to deferoxamine was estimated at $45,054 per QALY gained resulting mainly from a gain in 2.9 QALYs obtained at an expected lifetime cost of $130,058 per patient. Cost-effectiveness is sensitive to the estimated costs of deferoxamine and infusional therapy, as well as the quality of life benefit associated with oral versus infusional therapy, and is more favorable in younger patients.

Conclusion: In patients with transfusion-dependent β-thalassemia, the cost-effectiveness of deferasirox versus deferoxamine is within the range generally considered acceptable in Canada.