Efficacy and Safety Study to Evaluate Vadadustat for the Maintenance Treatment of Anemia in Participants With Non-dialysis-dependent Chronic Kidney Disease (NDD-CKD)

Inclusion Criteria: * ≥18 years of age * Diagnosis of chronic kidney disease (CKD) with an estimated glomerular filtration rate ≤60 milliliters per minute per 1.73 square meter (mL/min/1.73 m\^2) at Screening and not expected to start dialysis within 6 months of Screening * Currently maintained on erythropoiesis-stimulating agents therapy, with a dose received within 6 weeks prior to or during Screening * Mean Screening hemoglobin between 8.0 and 11.0 grams per deciliter (g/dL) (inclusive) in the United States (US) and between 9.0 and 12.0 g/dL (inclusive) outside of the US * Serum ferritin ≥100 nanograms per milliliter (ng/mL) and transferrin saturation (TSAT) ≥20% during Screening Exclusion Criteria: * Anemia due to a cause other than CKD or participant with active bleeding or recent blood loss * Red blood cell transfusion within 8 weeks prior to randomization * Uncontrolled hypertension * Severe heart failure at Screening (New York Heart Association Class IV) * Acute coronary syndrome (hospitalization for unstable angina or myocardial infarction), surgical or percutaneous intervention for coronary, cerebrovascular, or peripheral artery disease (aortic or lower extremity), surgical or percutaneous valvular replacement or repair, sustained ventricular tachycardia, hospitalization for heart failure, or stroke within 12 weeks prior to or during Screening * Hypersensitivity to Darbepoetin or Vadadustat or to any of their excipients