Table 3.

Ferric Citrate and Chronic Kidney Disease in Children (FIT4KiD) study hypotheses. FC, ferric citrate; FGF23, fibroblast growth factor 23

Primary endpoint

Compared to placebo, from baseline, active treatment with FC will lower serum intact FGF23 concentrations

Safety and tolerability endpoint

Compared to placebo, active treatment with FC will be safe and tolerable

Secondary endpoints

Compared to placebo, from baseline, active therapy with FC will be associated with: -Increased hemoglobin -Increased serum transferrin saturation -Increased serum ferritin -Increased serum 1,25-dihydroxyvitamin D -Decreased serum parathyroid hormone

Exploratory endpoints

Compared to placebo, from baseline, active therapy with FC will be associated with: -Smaller decrease in estimated glomerular filtration rate -Decreased bone FGF23 -Increased osteoid thickness -Decreased biomarkers of bone turnover -Decreased phosphaturia -Increased serum calcium -Increased serum klotho -Decreased serum C-terminal (total) FGF23