A Pilot Study of KRX-0502 (Ferric Citrate, Administered Without Food, in Treating Iron-deficiency Anemia

Inclusion Criteria: * Males and non-lactating females with negative serum pregnancy test (for females of child-bearing potential) at Screening * Age ≥ 18 years * Serum ferritin ≤ 300 ng/mL and TSAT ≤ 25% at Screening * Hemoglobin ≥9.0 g/dL and ≤11.5 g/dL at Screening * eGFR \<60 mL/min at Screening using the 4-variable Modification of Diet in Renal Disease (MDRD) equation Exclusion Criteria: * Subjects receiving phosphate binder medication(s) at, or within 4 weeks prior to, screening * Symptomatic gastrointestinal bleeding, inflammatory bowel disease, inflammatory bowel syndrome and/or Crohn's Disease within 24 weeks prior to \\ Screening * Evidence of acute kidney injury or requirement for dialysis within 8 weeks prior to Screening * Kidney transplant anticipated or start of dialysis expected within 16 weeks of Screening * History of hemochromatosis * IV iron administered within 4 weeks prior to Screening * Erythropoiesis-Stimulating Agent (ESA) administered within 4 weeks prior to Screening * Blood transfusion within 4 weeks prior to Screening * Receipt of any investigational drug within 4 weeks prior to Screening * Cause of anemia other than iron deficiency or chronic kidney disease * History of malignancy in the last five years * Active drug or alcohol dependence or abuse (excluding tobacco use) within the 12 months prior to Screening * Any known allergies to iron products * Previous intolerance to oral ferric citrate * Psychiatric disorder that interferes with the subject's ability to comply with the study protocol * Planned surgery or hospitalization during the trial * Any other medical condition that, in the opinion of the PI, renders the subject unable to or unlikely to complete the trial or that would interfere with optimal participation in the trial or produce significant risk to the subject