Erythropoiesis-stimulating agents (ESAs) are genetically engineered forms of erythropoietin that are used in the treatment of anaemia. Their successful use in the treatment of anaemia associated with renal disease, cancer and other diseases, as well as the development of multiple agents, has increased the visibility of these agents in the clinical and health economics literature. The circumstances under which the use of ESAs is cost effective, or indeed, whether it is cost effective, is of central concern for clinicians and payers who must make informed decisions regarding the management of these costly resources. Much of the recent literature on ESAs in the treatment of anaemia associated with chronic kidney disease and cancer, the two major therapeutic areas for ESA treatment, has focused on comparisons between individual ESAs, particularly epoetin alfa and darbepoetin alfa. While there have been some studies of cost effectiveness, many studies in these treatment areas have employed a cost-minimization approach and have relied on published prices rather than actual market prices. In general, this review of the literature suggests a cost advantage for epoetin alfa relative to darbepoetin alfa in the treatment of anaemia in renal and oncology indications. For other indications in which the literature is less developed, such as anaemia induced by antiviral therapy and blood management in surgery, small prospective studies or decision-analytic models comparing ESA therapy and standard care have been most common. Few conclusions can be drawn about the overall and relative costs or cost effectiveness of ESAs in these treatment areas. With the recent concerns about the safety of ESAs, especially when used outside the approved product labelling, future evaluations of epoetin alfa and darbepoetin alfa should factor their safety profiles into estimates of cost effectiveness. Moreover, additional studies are needed to evaluate whether the treatment of anaemia with ESAs is cost effective compared with no treatment or minimal blood transfusions, and whether the cost effectiveness of ESAs would be improved if ESA doses and durations were reduced. With the introduction of new longer-acting ESAs, such as the continuous erythropoietin receptor activator, the relative cost effectiveness among the different ESAs will continue to be an important question for public and private payers, policy makers and clinicians who must consider the emergence of new data and changing dosing patterns when making decisions about the use of these important but costly agents.
