RESUMO
BACKGROUND: Although an erythropoiesis-stimulating agent (ESA) is most frequently administered intravenously for treatment of anemia in patients with chronic kidney disease who are on dialysis, few studies have compared the efficacy of different intravenous (i.v.) dosing schedules. METHODS: This multicenter, phase IIIb, open-label, controlled study randomized 289 stable hemodialysis patients to continue with conventional dosing of i.v. epoetin alfa or darbepoetin, or to switch to once-weekly i.v. epoetin alfa at the same cumulative weekly starting dose, to maintain hemoglobin levels at 11.0-13.0 g/dL, and within 1.0 g/dL of the baseline value. Hemoglobin levels and ESA doses were recorded every 4 weeks for 28 weeks. RESULTS: Hemoglobin levels fell significantly and ESA doses increased significantly between baseline and week 28 (mean of week 16-28 values) in the once-weekly epoetin alfa group, compared with the conventional treatment group (p< 0.001). The adjusted difference in mean hemoglobin levels between the groups was 0.73 g/dL (greater than the threshold for therapeutic equivalence of 0.5 g/dL). The changes between groups from baseline was significant at all time points for hemoglobin levels (0.36, 0.46, 0.81, 0.87, 0.78, 0.62 and 0.49 g/dL) and from week 12 for ESA dose (718.5, 1,326.5, 1,732.0, 1,839.7 and 1,959.1 IU/week; p=0.005). Hemoglobin was maintained at the target level in 78% and 84% of patients on conventional dosing, and 67% and 64% of those on once-weekly epoetin alfa in the intention-to-treat (p=0.1) and per protocol (p=0.016) populations, respectively. CONCLUSIONS: This study did not show therapeutic equivalence of once-weekly i.v. epoetin alfa with conventional dosing regimens.