Costs Associated With Intravenous Darbepoetin Versus Epoetin Therapy in Hemodialysis Patients: A Randomized Controlled Trial

BACKGROUND: Anemia of chronic kidney disease is associated with adverse outcomes and a reduced quality of life. Erythropoiesis-stimulating agents (ESAs) have improved anemia management, and 2 agents are available in Canada, epoetin alfa (EPO) and darbepoetin alfa (DA). EPO and DA are considered equally effective in achieving target hemoglobin (Hb), but it is not clear whether there is a cost difference. There have been few head-to-head comparisons; most published studies are observational switch studies. OBJECTIVE: To compare the cost of DA and EPO and to determine the dose conversion ratio over a 12-month period. DESIGN: Randomized controlled trial. SETTING: Canadian outpatient hemodialysis center. PATIENTS: Eligible patients were adult hemodialysis patients requiring ESA therapy. MEASUREMENTS: The primary outcome was ESA cost (Can$) per patient over 12 months. Secondary outcomes included the dose conversion ratio, deviation from target ranges in anemia indices, iron dose and cost, and time and number of dose changes. METHODS: An open-label randomized controlled trial of intravenous (IV) DA versus EPO was conducted in 50 hemodialysis patients. Participants underwent a minimum 6-week run-in phase followed by a 12-month active study phase. ESA and iron were dosed using a study algorithm. RESULTS: The median cost was $4179 (interquartile range [IQR]: $2416-$5955) for EPO and $2303 (IQR: $1178-$4219) for DA with a difference of $1876 (P = .02). The dose conversion ratio was 280:1 (95% confidence interval [CI]: 197-362:1) at the end of the run-in phase, 360:1 (95% CI: 262-457:1) at the 3-month point of the active phase, and 382:1 (95% CI: 235-529:1) at the 6-month point of the active phase. There were no significant differences between the 2 groups in weekly iron dose, Hb, serum ferritin, or transferrin saturation. The number of dose changes and the time to Hb stability were similar. LIMITATIONS: Results may not be generalizable to hemodialysis units without algorithm-based anemia management, with subcutaneous ESA administration, or to the nondialysis chronic kidney disease population. The effective conversion ratio between EPO and DA is known to increase at higher doses; the Hb targets used in the study were slightly higher than those recommended today so it is possible that the doses used were also higher. Because of this, the cost savings estimated for DA could differ somewhat from the savings realizable in current practice. CONCLUSIONS: In this study of hemodialysis patients with comparable anemia management, IV DA cost $1876 less per year per patient than IV EPO. The dose conversion ratio was greater than 350:1 by the 3-month point. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02817555).