Study of Roxadustat's Effect on Anemia in Patients With Diabetic Kidney Disease

Inclusion Criteria: 1. Ages 18 to 60 years 2. Subject has voluntarily signed and dated an informed consent form (ICF), approved by an EC, after the nature of the study has been explained and the subject has had the opportunity to ask questions. 3. Diagnosed as Type 2 diabetic kidney disease (usually a clinical diagnosis made based on the presence of albuminuria and/or reduced eGFR in the absence of signs or symptoms of other primary causes of kidney damage), with KDOQI Stage 3 or 4 (an eGFR≧15 ml/min/1.73 m2 and \<60 ml/min/1.73 m2 estimated using the CKD-EPI equation). 4. The recent Hb value during the Screening Period, must be ≥7.0 g/dL and \<10 g/dL. 5. Either transferrin saturation (TSAT) ≥5% or serum ferritin ≥30 ng/mL during the screening period. 6. No use of an erythropoiesis stimulating agent for 1 week before enrolment. 7. ALT and AST ≤1.5 x ULN, and normal total bilirubin at screening visits. 8. Body weight: 40 to 100 kg inclusive. Exclusion Criteria: * Subjects should not enter the study if any of the following exclusion criteria are fulfilled: 1. Chronic kidney disease attribute to cause(s) other than diabetic kidney disease. 2. eGFR\<15ml ml/min/1.73 m2 or receiving dialysis or renal transplantation. 3. Uncontrolled severe hypertension (SBP≧180mmHg, DBP≧100mmHg). 4. Any clinically significant infection or evidence of an active underlying infection. 5. New York Heart Association Class III or IV congestive heart failure. 6. Myocardial infarction, acute coronary syndrome, stroke, seizure, or a thromboembolic event (e.g., deep venous thrombosis or pulmonary embolism) within 24 weeks prior to Day 1. 7. Diagnosis or suspicion (e.g., complex kidney cyst of Bosniak Category IIF or higher) of renal cell carcinoma on screening renal ultrasound. 8. History of malignancy, except the following: cancers determined to be cured or in remission for ≥5 years, curatively resected basal cell or squamous cell skin cancers, or in situ cancer at any site. 9. Chronic inflammatory disease that could impact erythropoiesis (e.g., SLE, rheumatoid arthritis, celiac disease). 10. Clinically significant gastrointestinal bleeding. 11. Known history of myelodysplastic syndrome, multiple myeloma, hereditary hematologic disease such as thalassemia, sickle cell anemia, pure red cell aplasia, or other known causes for anemia other than CKD, hemosiderosis, hemochromatosis, known coagulation disorder, or hypercoagulable condition. 12. Any prior functioning organ transplant or a scheduled organ transplantation. 13. Anticipated elective surgery that could lead to significant blood loss during the study period. 14. Anticipated use of dapsone or acetaminophen (paracetamol) \>2.0 g/day, or \>500 mg per dose repeated every 6 hours for more than 3 days. 15. Serum albumin \<2.5 g/dL. 16. Androgen, deferoxamine, deferiprone, or deferasirox therapy within 12 weeks prior to Day 1. 17. Life expectancy of \<6 months. 18. Blood transfusion within 12 weeks prior to Day 1 or anticipated need for transfusion. 19. IV iron supplement during the Screening Period and /or unwilling to withhold IV iron. 20. Immune suppressive or systemic steroid treatment within 12 weeks prior to Day 1. 21. History of alcohol or drug abuse within the past 2 years and inability to avoid consumption of more than \>3 alcoholic beverages per day. 22. Prior treatment with any HIF-PH inhibitor (HIF-PHI). 23. Use of an investigational medication or treatment, participation in an interventional study. 24. Women who are pregnant or breastfeeding. 25. Women of childbearing potential and men with sexual partners of childbearing potential who are not using adequate contraception. 26. Any medical condition that, in the opinion of the Investigator, may pose a safety risk to a subject in this study, may confound efficacy or safety assessment, or may interfere with study participation.