Every-other-week darbepoetin alfa in the correction and maintenance of haemoglobin levels in elderly patients with chronic kidney disease: post hoc subanalysis of data from two clinical trials.

Background: Anaemia is a common complication of chronic kidney disease (CKD) and is associated with increased rates of mortality and diminished quality of life in patients with CKD. Although extended dosing with darbepoetin alfa, an erythropoiesis-stimulating agent (ESA), has been shown to be effective in maintaining haemoglobin (Hb) levels in CKD patients, little information is published on the use of darbepoetin alfa in the correction and maintenance of Hb levels in elderly CKD patients naive to ESA therapy.

Objective: This post hoc subanalysis of data from two clinical trials was conducted to investigate the efficacy and safety profile of de novo every-other-week (q2w) darbepoetin alfa in elderly patients with CKD-associated anaemia (not on dialysis), as compared with that of a younger (aged <65 years) patient cohort.

Methods: This analysis was based on data obtained from two open-label, single-arm, multicentre studies of similar design. Patients were aged >or=18 years and naive to previous ESA therapy. Darbepoetin alfa administration was initiated at 0.75 microg/kg and titrated according to individual patient requirements to achieve and maintain Hb levels between 11.0 and 13.0 g/dL. The proportion of patients who achieved the primary endpoint, Hb >or=11.0 g/dL (study 1), and an Hb level between 11.0 and 13.0 g/dL (study 2) at weeks 4, 8 and 12 weeks and at the end of the study were determined. The results of this subanalysis were stratified by age (<65, 65-74 and >or=75 years).

Results: A total of 203 patients were enrolled in the two studies; 60% were female, 84 (41%) were aged <65 years, 57 (28%) were aged 65-74 years and 62 (31%) were aged >or=75 years. The proportion of patients who achieved Hb levels of >or=11.0 g/dL in study 1 and 11.0-13.0 g/dL in study 2 at week 20 were 93%, 96% and 92%, respectively, for the three age groups. Weight-adjusted q2w darbepoetin alfa doses were similar between the age groups and stable throughout the study period. The mean (standard deviation) Hb levels at week 21 were 12.0 (1.2), 12.7 (1.1) and 12.6 (1.0) g/dL in subjects aged <65, 65-74 and >or=75 years, respectively. The median (standard error) time to reach the primary endpoint was 5.0 (4.7), 5.0 (5.7) and 5.0 (5.7) weeks for subjects aged <65 years, 65-74 years and >or=75 years, respectively. The safety profiles of q2w darbepoetin alfa in both the older and younger age-groups were consistent with those expected for patients with CKD not receiving dialysis.

Conclusions: The results of this study suggest that ESA-naive subjects aged <65, 65-74 and >or=75 years of age with CKD (not receiving dialysis) who received q2w darbepoetin alfa were able to achieve and maintain Hb levels at 11.0-13.0 g/dL. The de novo q2w treatment regimen with darbepoetin alfa described in the present report may help optimize anaemia management in CKD-associated anaemia patients, including those in the older adult population.