This study is being conducted to demonstrate the effect of Auryxia, when used as the primary phosphate lowering therapy, on the overall cumulative use of erythropoiesis-stimulating agent and intravenous iron as well as on the laboratory parameters indicative of phosphate and anemia management.

Approximately 200 participants will be randomized 1:1 (stratified by modality and hemoglobin level) to receive either Auryxia or standard of care phosphate lowering therapy to determine the impact of Auryxia when used as the primary phosphate lowering therapy as compared to standard of care on the utilization of erythropoiesis-stimulating agent and intravenous iron in both in-center and home dialysis populations. This study will also seek to determine the impact of Auryxia, when used as the primary phosphate lowering therapy versus standard of care, on the biochemical assessments of serum phosphate and hemoglobin in both in-center and home dialysis populations.

Inclusion Criteria:

1. Adult participants greater or equal to 18 years old.
2. Diagnosis of end-stage kidney disease and receiving maintenance dialysis (in-center, home hemodialysis or peritoneal dialysis) for greater or equal to 12 weeks prior to randomization.
3. Most recent transferrin saturation less than or equal to 50 percent
4. Most recent serum phosphate is greater or equal to 3.0 milligrams per deciliter
5. Receiving treatment for greater or equal to 8 weeks prior to screening with non-Auryxia phosphate lowering therapy. No requirement for stable dosing within this time frame.
6. Receiving treatment for greater or equal to 8 weeks prior to screening with erythropoiesis-stimulating agent (any dose, any type). No requirement for stable dosing within this time frame.
7. Understands the procedures and requirements of the study and provides written informed consent and authorization for protected health information disclosure.

Exclusion Criteria:

1. A known allergy or intolerance to Auryxia or any of its constituents.
2. Hypersensitivity reaction to previous oral iron therapy.
3. History of hemochromatosis or other iron overload syndrome.
4. Active malignancy requiring current treatment except for non-melanoma skin cancer regardless of treatment.
5. Active drug or alcohol dependence or abuse (excluding tobacco use or medicinal or recreational marijuana) within the 12 months prior to Screening or evidence of such abuse (in the opinion of the Investigator).
6. Limited life expectancy (less than 6 months), (in the opinion of the Investigator).
7. Scheduled organ transplant and participants on the kidney transplant wait-list who are expected to receive a transplant within 6 months of screening. Being active on transplant list is not an exclusion. Previous kidney transplant is not an exclusion.
8. Unable to comply with study requirements or in the opinion of the Investigator not clinically stable to participate in the study.
9. Females who are known to be pregnant or are breast-feeding during Screening or are planning to become pregnant and breastfeeding during the study period.
10. Evidence of clinically active infection at the time of Screening.
11. Use of an investigational medication or participation in an investigational study within 30 days prior to Screening.