Supplementary Material for: Ferric Citrate Dosing in Iron Deficiency Anemia in Nondialysis-Dependent Chronic Kidney Disease

Introduction: Ferric citrate (FC) is indicated as an oral iron replacement for iron deficiency anemia in adult patients with chronic kidney disease (CKD) not on dialysis. The recommended starting dose is one 1-g tablet three times daily (TID). This study investigated long-term efficacy and safety of different FC dosing regimens for treating anemia in nondialysis-dependent CKD (NDD-CKD). Methods: In this phase 4, randomized, open-label, multicenter study, patients with anemia with NDD-CKD (estimated glomerular filtration rate, ≥20 mL/min and <60 mL/min) were randomized 1:1 to one FC tablet (1-g equivalent to 210 mg ferric iron) TID (3 g/day) or 2 tablets twice daily (BID; 4 g/day). At week 12, dosage was increased to 2 tablets TID (6 g/day) or 3 tablets BID (6 g/day) in patients whose hemoglobin (Hb) levels increased <0.5 g/dL or were <10 g/dL. Primary endpoint was mean change in Hb from baseline to week 24. Results: Of 484 patients screened, 206 were randomized and 205 received FC. Mean (standard deviation) changes from baseline in Hb at week 24 were 0.77 (0.84) g/dL with FC TID 3 g/day and 0.70 (0.98) g/dL with FC BID 4 g/day. Discussion/Conclusions: FC administered BID and TID for 48 weeks was safe and effective for treating anemia in this population, supporting potentially increased dosing flexibility.