Clinical Trials

Inclusion Criteria:

• Age: 18 to 99 years of age (inclusive).
• CKD stage: Kidney Disease Outcomes Quality Initiative (KDOQI) CKD stages 3, 4, or 5 defined by electronic estimated glomerular filtration rate (eGFR) using the CKD Epidemiology Collaboration (CKD-EPI) formula.
• Erythropoietin-stimulating agents (ESAs)/Hgb: Group 1 (not using ESAs): No ESA use within the 6 weeks prior to screening and no ESA use between screening and randomization (Day 1). Hgb concentration: On randomization (Day 1): Hgb 8 to 10 grams (g)/deciliter (dL). Group 2 (ESA users): Use of any approved ESA for the 6 weeks prior to screening and continuing between screening and randomization. Hgb concentration: On randomization (Day 1): Hgb 8 to 11 g/dL and receiving at least the minimum ESA dose.
• Compliance with placebo [randomization (Day 1) only]: >=80% and <=120% compliance with placebo during run-in period.
• Informed consent: capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the consent form and in this protocol.

Exclusion Criteria:

• Dialysis: On dialysis or clinical evidence of impending need to initiate dialysis within 90 days after study start (Day 1).
• Ferritin: <=100 nanograms (ng)/milliliter (mL) (<=100 micrograms/liter [L]) at screening.
• Transferrin saturation (TSAT) (screening only): <=20%.
• Aplasias: History of bone marrow aplasia or pure red cell aplasia.
• Other causes of anemia: Pernicious anemia, thalassemia major, sickle cell disease or myelodysplastic syndrome.
• Gastrointestinal (GI) bleeding: Evidence of actively bleeding gastric, duodenal, or esophageal ulcer disease or clinically significant GI bleeding <=4 weeks prior to screening through to randomization (Day 1).
• MI or acute coronary syndrome: <=4 weeks prior to screening through to randomization (Day 1).
• Stroke or transient ischemic attack: <=4 weeks prior to screening through to randomization (Day 1).
• Heart failure (HF): Chronic Class IV HF, as defined by the New York Heart Association (NYHA) functional classification system.
• Current uncontrolled hypertension: Current uncontrolled hypertension as determined by the investigator that would contraindicate the use of recombinant human erythropoietin (rhEPO).
• Bazett's corrected QT interval (QTcB) (Day 1): QTcB >500 millisecond (msec), or QTcB >530 msec in subjects with bundle branch block. There is no Q-T Interval Corrected for Heart Rate (QTc) exclusion for subjects with a predominantly paced rhythm.
• Alanine transaminase (ALT): >2x upper limit of normal (ULN) at screening.
• Bilirubin: >1.5xULN at screening.
• Current unstable liver or biliary disease per investigator assessment, generally defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminaemia, esophageal or gastric varices, persistent jaundice, or cirrhosis.
• Malignancy: History of malignancy within the 2 years prior to screening through to randomization (Day 1) or currently receiving treatment for cancer, or complex kidney cyst (example [e.g.] Bosniak Category II F, III or IV) > 3 centimeter (cm); with the exception of localized squamous cell or basal cell carcinoma of the skin that has been definitively treated >=4 weeks prior to screening.
• Severe allergic reactions: History of severe allergic or anaphylactic reactions or hypersensitivity to excipients in the investigational product, or darbepoetin alfa.
• Drugs and supplements: Use of strong inhibitors of Cytochrome P4502C8 (CYP2C8) (e.g., gemfibrozil) or strong inducers of CYP2C8 (e.g., rifampin/rifampicin).
• Prior investigational product exposure: Use of an investigational agent <=30 days or within five half lives of the investigational agent (whichever is longer) prior to screening.
• Prior treatment with daprodustat: Any prior treatment with daprodustat for treatment duration of >30 days.
• Females only: Subject is pregnant [as confirmed by a positive urine human chorionic gonadotrophin (hCG) test for females of reproductive potential (FRP) only], subject is breastfeeding, or subject is of reproductive potential and does not agree to follow one of the contraceptive options listed in the List of Highly Effective Methods for Avoiding Pregnancy.
• Other Conditions: Any other condition, clinical or laboratory abnormality, or examination finding that the investigator considers would put the subject at unacceptable risk, which may affect study compliance (e.g., intolerance to darbepoetin alfa) or prevent understanding of the aims or investigational procedures or possible consequences of the study.