Conversion from Recombinant Human Erythropoietin to Once Every 4 Weeks Darbepoetin Alfa for Treatment of Renal Anemia in CAPD Patients

BackgroundDarbepoetin alfa is a new erythropoietic protein with a three-fold longer half-life than recombinant human erythropoietin (rHuEPO), allowing for an extended dosing interval of once every 2 weeks in patients with chronic renal failure. The objective of this study was to investigate the possibility of further extending the dose interval of this erythropoietic agent to once every 4 weeks in the treatment of renal anemia in dialysis patients.MethodsA prospective study was carried out in 14 continuous ambulatory peritoneal dialysis (CAPD) patients stably maintained on subcutaneous rHuEPO with hemoglobin level of 10–13 g/dL. They were switched to subcutaneous darbepoetin alfa administered once every 4 weeks for a period of 24 weeks. The starting dose was 40 [.proportional]g. The dose of darbepoetin alfa was then adjusted to maintain a target hemoglobin level between 10 and 13 g/dL. When darbepoetin alfa was increased by 100%, the dosing interval was shortened to maintain the target hemoglobin. Evaluation was done during the last 4 weeks.ResultsOf the 14 patients recruited, 11 patients completed the study. Of these 11 patients, 9 (82%) successfully maintained the target hemoglobin with once every 4 weeks darbepoetin alfa. For those successful patients, the mean hemoglobin level during the evaluation period was 11.13 ± 2.04 g/dL (mean ± standard deviation), and the mean change in hemoglobin level from baseline was −1.03 g/dL (95% CI: −2.34, 0.27). The mean weekly darbepoetin alfa dose requirement during the evaluation period was 12.33 ± 4.80 [.proportional]g/week, and the mean change in weekly dose from baseline was +2.33 [.proportional]g/week (95% CI: −1.35, 6.02). No serious adverse event related to darbepoetin alfa occurred during the study.ConclusionDarbepoetin alfa administered once every 4 weeks effectively maintained hemoglobin level in most CAPD patients after conversion from previously stabilized rHuEPO treatment. Darbepoetin alfa is safe and well tolerated, allowing for less frequent dosing. [Hong Kong J Nephrol 2007;9(2):77–81]