We will conduct a double-blind, randomized, placebo-controlled trial to assess the effects of therapy with ferric citrate (FC) on changes in intact FGF23 levels (iFGF23, primary endpoint) aged 6-17 years of either sex with chronic kidney disease (CKD) stages 3-4 and age-appropriate normal serum phosphate levels. Participants will be randomized to one of the two groups: 1) FC or 2) FC placebo. Participants will be recruited from 12 core clinical sites.~Schedule of Intervention: During the 12-month trial, participants will be given a daily fixed weight-based dose of FC.~Schedule for data collection/analyses to be performed:~Blood for primary outcome assessments will be collected at screening, baseline and at months 1, 2, 3, 6, 9, 12. Blood for safety assessments will be collected at the same intervals.~The primary analyses for this 2-arm trial will evaluate changes from baseline in iFGF23 levels over 12 months between the treatment and the placebo arms. The analysis will use a linear mixed-effects model, with random participant effects accounting for repeated measurements, random site effects accounting for clustering of participants into study sites, and a fixed treatment effect, which interacts with a time indicator (Months 3-12 vs. Months 1-3).~Primary objectives:~To assess the effects of therapy with FC on changes in iFGF23 levels~To determine safety and tolerability of FC.~Secondary objectives:~• To assess the effects of FC on anemia and indices of mineral and bone metabolism.~Primary Endpoint:~• Change in iFGF23 level~Safety and Tolerability Endpoints:~• Ability to safely tolerate FC~Secondary Endpoints:~Change in anemia~Change in the indices of mineral and bone metabolism~This is a Phase 2 study with participation from 12 sites that will take 36 months to complete enrollment and a total of 48 months to complete data collection with each participant being part of the study for 12 months.
We will conduct a 12-month, double-blind, randomized, placebo-controlled trial to assess the effects of therapy with ferric citrate (FC) on changes in intact FGF23 levels (iFGF23, primary endpoint) in 160 pediatric patients (80 in each of the two arms) aged 6-17 years of either sex with chronic kidney disease (CKD) stages 3-4 and age-appropriate normal serum phosphate levels. Participants will be randomized to one of the two groups: 1) FC or 2) FC placebo. Participants will be recruited from 12 core clinical sites.