[Multicenter study of darbepoetin alfa in the treatment of anemia secondary to chronic renal insufficiency on dialysis]

Abstract

This Spanish single-arm, multicenter, prospective clinical trial assessed the maintenance of hemoglobin concentrations (Hb) between 10-13 g/dL with unit doses of darbepoetin alfa and the safety of the treatment in dialysis patients. Eight-hundred twenty-six patients with chronic renal failure (CRF) (94% receiving haemodialysis and 6% receiving peritoneal dialysis) previously maintained on stable recombinant human erythropoietin (r-HuEPO) therapy with stable hemoglobin (Hb) concentrations (mean Hb concentration = 11.7 g/dL) were switched to darbepoetin alfa at a reduced dosing frequency for 24 weeks (a 20-week titration phase plus a 4-week treatment evaluation phase). Subjects receiving r-HuEPO two or three times weekly were switched to darbepoetin alfa once weekly, and those. who were receiving r-HuEPO once weekly were switched to darbepoetin alfa once every two weeks. The initial dose of darbepoetin alfa was determined from the r-HuEPO dose at inclusion into the study using a formula equating the peptide mass of the two molecules and rounding to the nearest available prefilled syringe dose. Overall, 86.8% of patients completed the 24-weeks of study. Changing the treatment from r-HuEPO to darbepoetin alfa and increasing the dose interval did not result in any clinically significant change in the Hb concentration. From base-line to the evaluation phase, the mean Hb fell 0.09 (95% CI, -0.2; -0.0) g/dl, with an increase of 0.19 (95% CI, 0.0;0.3) g/dL i.v. and a decrease of 0.22 (95% CI, -0.3; -0.1) g/dL s.c.). This maintenance of the mean Hb concentration was accompanied by a mean 9.8% reduction of the darbepoetin alfa dose (19.7% (95% CI, -24.9; -14.2) i.v. and 4.7% (95% CI, -8.5; -0.7) s.c. Treatment with darbepoetin alfa was well tolerated and no unexpected adverse events were reported. In conclusion, the replacement of previous r-HuEPO treatment by darbepoetin alfa in the therapy of anemia secondary to chronic renal failure in diaiyzed patients was effective, well tolerated, and decreased the frequency of dose administration compared with the previous r-HuEPO treatment. Darbepoetin alfa administered once weekly or once every two weeks maintained the baseline Hb levels whilst allowing dose reduction, which was higher in patients receiving i.v. darbepoetin alfa.