Early response to erythropoiesis-stimulating agents in non-dialysis chronic kidney disease patients

Factors affecting the doses of roxadustat vs darbepoetin alfa for anemia treatment in hemodialysis patients

Roxadustat is an oral hypoxia‐inducible factor prolyl hydroxylase inhibitor for the treatment of anemia in chronic kidney disease (CKD). Emerging evidence suggests that roxadustat may be beneficial for patients who inadequately respond to erythropoiesis‐stimulating agents (ESAs). This post‐hoc analysis of a Japanese, double‐blind, randomized, phase 3 study in hemodialysis‐dependent CKD patients treated with traditional ESAs assessed the impact of factors associated with ESA hyporesponsiveness on roxadustat and darbepoetin alfa (DA) doses required to maintain target hemoglobin. Endpoints included mean of average doses of roxadustat and DA per administration in the last 6 weeks (AAD/6W) by prior ESA‐resistance index (ERI), iron repletion (transferrin saturation; ferritin), and high‐sensitivity C‐reactive protein (hs‐CRP). Of 415 enrolled patients, 303 were randomized (roxadustat, n = 151; DA, n = 152). Weight‐adjusted AAD/6W increased with increasing ERI for roxadustat (ERI <3.3, 0.89 mg/kg; ERI ≥8.4, 1.51 mg/kg) and DA (ERI <3.3, 0.26 μg/kg; ERI ≥8.4, 0.91 μg/kg); the weight‐adjusted AAD/6W relative to within‐arm mean AAD/6W showed a trend toward increased DA doses for the ERI ≥8.4 category (P = .089). AAD/6W remained stable for roxadustat but increased for DA with decreasing baseline iron repletion markers. The relationship between roxadustat doses and end of treatment (EoT) hs‐CRP was not significant (estimated slope, −0.494; P = .814); a trend toward increased DA doses was observed with increasing EoT hs‐CRP (estimated slope, 2.973; P = .075). Roxadustat doses required to maintain target hemoglobin appear to be less affected by factors that underlie ESA hyporesponsiveness, relative to DA; roxadustat may be beneficial for patients hyporesponsive to ESAs.

Low white blood cell count is independently associated with chronic kidney disease progression in the elderly: the CKD-ROUTE study

BACKGROUND

Elevated white blood cell (WBC) count is a well-known predictor of chronic kidney disease (CKD) progression. However, elderly patients commonly fail to develop a high WBC count in response to several diseased states and may instead present a low WBC count. Therefore, we hypothesized that low WBC count, in addition to high WBC count, is associated with CKD progression in the elderly.

METHODS

We conducted a prospective cohort study using 3-year follow-up data from the CKD Research of Outcomes in Treatment and Epidemiology study. In the present study, participants aged over 60 years with pre-dialysis CKD stages G2-G5 were eligible. Patients were stratified into three groups according to WBC count using tertiles (T). The primary outcome was a composite of end-stage renal disease and a 50% reduction in estimated glomerular filtration rate. Data were analyzed using Cox proportional hazard models with adjustments for covariates.

RESULTS

We enrolled 697 patients (males, 69%). The median WBC count was 6100 cells/µl (T1, <5400, n =  222; T2, 5400-6900, n =  235; T3, ≥6900, n = 240). During a median follow-up of 868 days, the primary outcome was observed in 170 patients, whereas 54 patients died. T1 and T3 had significantly higher hazard ratios (HR) than T2 (T1, HR 1.69, 95% confidence interval 1.14-2.51; T3, HR 1.63, 95% confidence interval 1.10-2.41). Moreover, T1 had a significantly higher adjusted HR (1.54, 95% confidence interval 1.00-2.37).

CONCLUSION

Low WBC count is independently associated with CKD progression in the elderly.