Darbepoetin alfa administered once monthly maintains haemoglobin levels in stable dialysis patients

Background. Darbepoetin alfa, a glycoprotein that stimulates erythropoiesis by the same mechanism as endogenous erythropoietin, has a 3-fold longer terminal half-life than recombinant human erythropoietin, allowing for an extended dosing interval. Darbepoetin alfa is currently recommended for once-weekly and once every 2 weeks administration in patients with chronic renal failure (CRF). The objective of this study was to explore once-monthly administration in this patient population. Methods. Clinically stable dialysis patients (mean haemoglobin concentration, 10.0–13.0 g/dl) receiving stable darbepoetin alfa therapy administered once every 2 weeks in a long-term treatment study were converted to darbepoetin alfa once every 3 weeks for 20 weeks and then, if haemoglobin concentrations were successfully maintained between 10.0 and 13.0 g/dl, were converted to darbepoetin alfa once every 4 weeks for 20 weeks. The darbepoetin alfa dose was titrated to maintain haemoglobin within a target range (−1.0 to +1.5 g/dl of baseline haemoglobin, and between 10.0 and 13.0 g/dl). Success with the extended dosing interval was defined as maintenance of mean haemoglobin ≥10.0 g/dl during a 4-week evaluation at the end of the dosing period. Results. Of the 54 patients who entered the study, 38 patients were converted to darbepoetin alfa administered once every 4 weeks. Of these, 36 patients were considered evaluable and 30 (83%) of those evaluable patients successfully maintained the target haemoglobin. For successful patients the mean (SD) haemoglobin during evaluation was 11.16 (0.60) g/dl, and the mean change in haemoglobin from baseline to evaluation was −0.26 g/dl (95% CI: −0.51, −0.01). The median change from baseline in average weekly darbepoetin alfa dose was 1.61 μg (95% CI: 0.00, 4.75). Adverse events were consistent with those expected for this patient population. Conclusions. Darbepoetin alfa, administered once monthly, maintained haemoglobin effectively and safely in most dialysis patients stabilized previously on once every 2 weeks dosing. Once-monthly dosing may optimize anaemia management for patients with CRF and for health care providers.