Clinical and economic comparison of epoetin alfa and darbepoetin alfa

The pharmacoeconomics of erythropoietic therapy for the treatment of anemia is receiving renewed attention due to the current availability of two agents. Epoetin alfa has been the standard of therapy for patients with renal disease and cancer-related anemia for more than a decade. Darbepoetin alfa, an alternative agent, is now approved for anemia resulting from renal disease and cancer chemotherapy.

Although direct comparative trials have not been performed with these agents, information published in the last several years regarding their clinical efficacy, safety, and dosing is sufficient, in most cases, to compare costs. With the disclaimer that any efficacy comparison of competing products using published reports has certain limitations, a cost-minimization approach from a provider's perspective was conducted.

To provide background for the economic evaluation, pharmacokinetic and pharmacodynamic data for these two agents are discussed. Recent clinical trials in the nephrology and oncology therapeutic areas are summarized, highlighting study designs, dosing regimens, patient entry criteria, study endpoints, and published results. Cost data, based on average wholesale prices (AWP) in 2003, are compared and calculated from available clinical data with an emphasis on efficacy.

These evaluations largely conclude that epoetin alfa is the better pharmacoeconomic value of the two currently available erythropoietic agents.