Efficacy, tolerability and safety of darbepoetin alfa injection for the treatment of anemia associated with chronic kidney disease (CKD) undergoing dialysis: a randomized, phase-III trial

BACKGROUND

Darbepoetin alfa (DA-α) is a long-acting erythropoiesis-stimulating glycoprotein which has half-life three-fold longer than that of Erythropoietin alfa (EPO). The objective of this study was to compare the efficacy and safety of DA-α injection versus EPO for treating renal anemia amongst Indian patients with end-stage renal disease (ESRD) undergoing dialysis.

METHODS

Patients of either gender (aged 18-65 years) with ESRD undergoing dialysis who had hemoglobin (Hb) levels < 10 g/dL after receiving EPO were switched to DA-α (0.45 μg/kg) once weekly subcutaneously or EPO 50 IU/kg thrice weekly subcutaneously (centrally randomized 1:1) for 12-24 weeks (correction phase) followed by 12 weeks maintenance phase (for Hb levels ≥10 g/dL). The primary efficacy endpoint was mean change in Hb level from baseline to end of correction phase.

RESULTS

In the intention-to-treat population (n = 126), the between group difference in mean Hb change was - 0.01 g/dL (95% CI - 0.68 to - 0.66, p = 0.97). After adjusting for covariates, the difference was - 0.2878 g/dL (95% CI -0.936 to0.360). The lower limit of the two-sided 95% CI of primary endpoint was above the pre-specified non-inferiority margin of - 1.0 g/dL. Similar trend of non-inferiority was observed for per-protocol population. Safety profile of DA-α and EPO were observed to be similar.

CONCLUSION

Our study results demonstrated that for patients with ESRD undergoing dialysis, administering DA-α at lower dose frequency, is equally effective and well tolerated as EPO for treating renal anemia.

TRIAL REGISTRATION

CTRI/2012/07/002835 [Registered on: 27/07/2012]; Trial Registered Prospectively.

Randomized cross-over comparison of intravenous and subcutaneous darbepoetin dosing efficiency in haemodialysis patients

BACKGROUND

Studies have consistently shown the superior dosing efficiency of subcutaneous (s.c.) compared to intravenous (i.v.) erythropoietin (r-HuEPO). Unlike r-HuEPO, data from pivotal darbepoetin trials support s.c. and i.v. dosing equivalence, however, no blinded cross-over randomized studies of s.c. and i.v. dose efficiency or intra-patient variability in response have been published.

METHODS

During this 12-month study, 53 haemodialysis patients were randomized to s.c. or i.v. darbepoetin for a 6-month period and then switched to the alternative route for a second 6-month period. Darbepoetin dose was titrated during the first 4-months of each period to achieve a stable haemoglobin during the final 2-month observation period of each arm.

RESULTS

Twenty-four patients were included in analysis. No significant difference between s.c. and i.v. administration was observed for any measured parameter. Patients achieved a non-significantly higher haemoglobin (123.6 +/- 3.76 vs 120.9 +/- 4.42 g/L, P = 0.11) from a non-significantly lower darbepoetin dose (40.8 +/- 10.7 vs 42.5 +/- 11.0 mcg/week, P = 0.23) with i.v. administration. The population-based weight normalized s.c./i.v. dose ratio was 1.04 (0.97-1.11). Despite no significant overall difference, some patients experienced changes in individual dose efficiency response. Three of 24 patients recorded a greater than 30% change, four of 24 recorded between a 20 and 30% change, and five of 24 patients recorded between a 10 and 20% change relative to i.v. dose efficiency.

CONCLUSIONS

This study further supports s.c. and i.v. dosing equality and that overall the more convenient i.v. route can be used with equal dosing efficiency. However, patients switching routes of administration should be monitored due to the wide range in individual response.