Safety and Efficacy Study of Roxadustat to Treat Anemia in Patients With Chronic Kidney Disease, on Dialysis.

Inclusion criteria:

1. Provision of Informed Consent prior to any study specific procedures

2. Age ≥18 years at screening visit 1

3. Previous versions of the protocol prior to US amendment ver 6.0 and outside of USamendment ver 7.0: Receiving or initiating hemodialysis or peritoneal dialysis for treatment of nativekidney end-stage renal disease (ESRD) at least 30 days prior to visit 1. Patientstreated with hemodialysis must have access consisting of an arteriovenous fistula, AVgraft, or tunneled (permanent) catheter. Patients on peritoneal dialysis must have afunctioning peritoneal dialysis catheter in place. Starting with US amendment ver. 6.0 and outside of US amendment ver 7.0 (changed torecruit incident dialysis patients only): Receiving or initiating hemodialysis or peritoneal dialysis for treatment of nativekidney end-stage renal disease (ESRD) for a minimum of 2 weeks and a maximum of 4months prior to randomization. Patients treated with hemodialysis must have accessconsisting of an arteriovenous fistula, AV graft, or tunneled (permanent) catheter.Patients on peritoneal dialysis must have a functioning peritoneal dialysis catheterin place.

4. Two central laboratory Hb values during the screening period, obtained at least 7 daysapart, must be <12 g/dL in patients currently treated with an erythropoietin analogueor <10 g/dL in patients not currently treated with an erythropoietin analogue.Patients are considered not currently treated if they have not received eitherMircera® for at least 8 weeks or any other erythropoietin analogue for at least 4weeks prior to visit 1.

5. Ferritin ≥100 ng/mL at randomization (obtained from screening visit)

6. TSAT ≥20% at randomization (obtained from screening visit)

7. Serum folate level ≥ lower limit of normal (LLN) at randomization (obtained fromscreening visit)

8. Serum vitamin B12 level ≥ LLN at randomization (obtained from screening visit)

9. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤3x upper limit ofnormal (ULN), and total bilirubin (Tbili) ≤1.5 x ULN at randomization (obtained fromscreening visit)

10. Body weight 45 to 160 kg (prescribed dry weight)

Exclusion criteria:

1. Involvement in the planning and/or conduct of the study (applies to both AstraZenecastaff and/or staff at the study site)

2. Previous randomisation in the present study

3. New York Heart Association Class III or IV congestive heart failure at enrolment

4. Myocardial infarction, acute coronary syndrome, stroke, seizure or athrombotic/thromboembolic event (e.g., deep vein thrombosis or pulmonary embolism)within 12 weeks prior to randomization

5. History of chronic liver disease (e.g., chronic infectious hepatitis, chronicauto-immune liver disease, cirrhosis or fibrosis of the liver)

6. Known hereditary hematologic disease such as thalassemia, sickle cell anemia, ahistory of pure red cell aplasia or other known causes for anemia other than CKD

7. Known and untreated retinal vein occlusion or known and untreated proliferativediabetic retinopathy (risk for retinal vein thrombosis)

8. Diagnosis or suspicion (e.g. complex kidney cyst of Bosniak Category IIF, III or IV)of renal cell carcinoma on renal ultrasound (or other imaging procedure e.g. CT scanor MRI) conducted at screening or within 12 weeks prior to randomization.

9. Uncontrolled hypertension at the time of randomization (defined as systolic BP ≥180mmHg or diastolic BP ≥100 mmHg on repeated measurement post-dialysis in hemodialysispatients or at any time in peritoneal dialysis patients), contraindication to epoetinalfa treatment (e.g., pure red cell aplasia, hypersensitivity or know inability totolerate epoetin alfa)

10. History of prostate cancer, breast cancer or any other malignancy, except thefollowing: cancers determined to be cured or in remission for ≥5 years, curativelyresected basal cell or squamous cell skin cancers, cervical cancer in situ or resectedcolonic polyps.

11. Positive for any of the following: human immunodeficiency virus (HIV), hepatitis Bsurface antigen (HBsAg) or anti-hepatitis C virus antibody (anti-HCV Ab)

12. Chronic inflammatory diseases such as rheumatoid arthritis, SLE, ankylosingspondylitis, psoriatic arthritis or inflammatory bowel disease that is determined tobe the principal cause of anemia

13. Known hemosiderosis, hemochromatosis or hypercoagulable condition

14. Any prior organ transplant with the exception of an autologous renal transplant or arenal transplant that was subsequently removed ("explanted") or scheduled organtransplantation date

15. Any red blood cell (RBC) transfusion during the screening period

16. Any current condition leading to active significant blood loss

17. Any prior treatment with roxadustat or a hypoxia-inducible factor prolyl hydroxylaseinhibitor (HIF-PHI)

18. Has received another new chemical entity (defined as a compound which has not beenapproved for marketing) or has participated in any other clinical study that includeddrug treatment within the month preceding the first administration of IP in thisstudy. (Note: patients consented and screened, but not randomized in this study or aprevious study are not excluded)

19. History of alcohol or drug abuse within 2 years prior to randomization

20. Females of childbearing potential, unless using contraception as detailed in theprotocol or sexual abstinence (see Section 3.8)

21. Pregnant or breastfeeding females

22. Known allergy to the investigational product or any of its ingredients

23. Any medical condition, including active, clinically significant infection, that in theopinion of the investigator or Sponsor may pose a safety risk to a patient in thisstudy, which may confound efficacy or safety assessment, or may interfere with studyparticipation