A Study to Investigate the Effect of Roxadustat Versus Recombinant Human Erythropoietin (rHuEPO) on Oral Iron Absorption in Chinese Patients With Anemia of Chronic Kidney Disease (CKD)

Inclusion Criteria: Informed consent • Provision of signed and dated, written informed consent form (ICF) prior to any mandatory study specific procedures, sampling, and analyses. Type of patient and disease characteristics At Visit 1 prior to screening Dialysis patients: * Patients receiving hemodialysis (HD) or peritoneal dialysis (PD) for treatment of end-stage renal disease (ESRD) for at least 12 weeks. Patients treated with HD must have access consisting of an arteriovenous (AV) fistula, AV graft, or tunneled (permanent) catheter. Patients on PD must have a functioning PD catheter in place. * Hemodialysis patients should be on 3x/week dialysis with evidence of achievement of adequate dialysis as defined by standardized Kt/V ≥2.1 in HD, and total (renal + PD) weekly Kt/V ≥1.7 in PD documented twice during the 16 weeks preceding screening for the study. * Patients should be on a stable rHuEPO dose as defined by change in rHuEPO dose, not exceeding 20% within 4 weeks prior to screening. Non-dialysis patients: * Patients with estimated glomerular filtration rate (eGFR) \<30 mL/minute/1.73 m\^2, corresponding to Stage 4 or Stage 5 CKD according to the Kidney Disease Outcomes Quality Initiative (KDOQI), and not receiving dialysis. * Patients should either be on a stable dose of rHuEPO for 4 weeks before screening or be rHuEPO-naïve. Dialysis and non-dialysis patients: • Patients agree not to take any new traditional Chinese medicine (TCM) and not to change, dose, sche…