Darbepoetin alfa effectively maintains haemoglobin concentrations at extended dose intervals relative to intravenous or subcutaneous recombinant human erythropoietin in dialysis patients

Background. Darbepoetin alfa is a unique molecule that stimulates erythropoiesis by the same mechanism as endogenous erythropoietin. Due to its � 3-fold longer half-life and greater biological activity than recombinant human erythropoietin (rHuEpo), darbepoetin alfa maintains effective haemoglobin control at extended dose intervals compared with rHuEpo. This study assessed the efficacy and safety of unit doses of darbepoetin alfa for the treatment of renal anaemia. Methods. In this multicentre, prospective, open-label study, 1502 dialysis subjects maintained on stable rHuEpo treatment were switched to darbepoetin alfa at extended dose intervals by the same route of administration as previous rHuEpo therapy [intravenous (i.v.), n ¼ 900 or subcutaneous (s.c.), n ¼ 602]. Subjects receiving rHuEpo two (n ¼ 408, 27%) or three times (n ¼ 884, 59%) a week were switched to darbepoetin alfa once a week, and those receiving rHuEpo once a week (n ¼ 210, 14%) were switched to darbepoetin alfa once every 2 weeks. The unit doses of darbepoetin alfa (10–150mg) were titrated to maintain haemoglobin concentrations of 10–13 g/dl for 24 weeks. Results. Haemoglobin concentrations were maintained effectively in subjects regardless of whether they received darbepoetin alfa once a week or once every 2 weeks. The overall mean change in haemoglobin from baseline to the evaluation period (weeks 21–24) was þ0.10 g/dl [95% confidence interval (CI) 0.04± 0.17]. The mean haemoglobin concentration increased by 0.19 g/dl (95% CI 0.11±0.27) in subjects receiving i.v. darbepoetin alfa, and was unchanged (� 0.02 g/dl; 95% CI � 0.12 to 0.07) in patients treated with s.c. darbepoetin alfa. Subjects with baseline haemoglobin