Ferric Citrate and Chronic Kidney Disease in Children

Recruitment Status
RECRUITING
(See Contacts and Locations)Verified March 2026 by University of California, Los Angeles
Sponsor
University of California, Los Angeles
Information Provided by (Responsible Party)
Isidro Salusky, MD
Clinicaltrials.gov Identifier
NCT04741646
Other Study ID Numbers:
U01DK122013
First Submitted
February 1, 2021
First Posted
February 4, 2021
Last Update Posted
April 16, 2026
Last Verified
March 2026

ClinicalTrials.gov processed this data on April 2026. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

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 6-18 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 20 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 3, 6, 9, 12. Blood for safety assessments will be collected at the the months 1, 2, 3, 6, 9, 12.

The primary analyses for this 2-arm trial will compare log-transformed iFGF23 values over 12 months between the treatment and the placebo arms. The analysis will use a linear mixed-effects model, including stratification factors CKD stage and urine protein to creatinine ratio, with random participant effects accounting for repeated measurements, and a fixed treatment effect, which interacts with a time indicator (Months 3-12 vs. Baseline/Screening).

Primary objectives:

* To assess the effects of therapy with FC on 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:

• iFGF23 level

Safety and Tolerability Endpoints:

• Ability to safely tolerate FC

Secondary Endpoints:

* Anemia

* Indices of mineral and bone metabolism

This is a Phase 2 study with participation from 20 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.

Study website: fit4kid.dgsom.ucla.edu

Condition or DiseaseIntervention/Treatment
Chronic Kidney Diseases
Drug: Ferric CitrateDrug: Placebo

Study Design

Study TypeInterventional
Actual Enrollment160 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingQuadruple
Primary PurposeTreatment
Official TitlePhosphate Binder Therapy and Chronic Kidney Disease in Children
Study Start DateJune 16, 2022
Actual Primary Completion Date1yr 5mos from now
Actual Study Completion Date2yrs 7mos from now

Groups and Cohorts

Group/CohortIntervention/Treatment
Treatment Arm
During the 12-month trial, participants will be given a fixed weight-based dose of Ferric Citrate (FC). The full medication dose will be 3g/day for participants weighing \<31 kg, 5g/day for those weighing \>31 - \<51 kg, and 6g/day for participants \>51 kg. These doses will be divided into three doses to be taken with meals.
Drug: Ferric Citrate
Auryxia&reg; 210 mg ferric iron tablets equivalent to 1 g of FC will be supplied as 200 tablets in 400cc high-density polyethylene bottles.
Control Arm
During the 12-month trial, participants will be given a fixed weight-based dose of Placebo. The full medication dose will be 3g/day for participants weighing \<31 kg, 5g/day for those weighing \>31 - \<51 kg, and 6g/day for participants \>51 kg. These doses will be divided into three doses to be taken with meals.
Drug: Placebo
Placebo to match Ferric Citrate tablets

Outcome Measures

Primary Outcome Measures
  1. iFGF23 levels
    Compared to placebo, active treatment with FC will lower iFGF23 levels
  2. Safety of Ferric Citrate
    Comparing proportion of subjects with AE and SAE between arms
  3. Tolerability of Ferric Citrate
    Compared with placebo, active treatment will be tolerable
Secondary Outcome Measures
  1. Effects on Transferrin Saturation (TSAT)
    Compared with placebo, active treatment with FC will be associated with larger increase in hemoglobin, higher TSAT and higher Ferritin from baseline
  2. Effects on PTH and 1,25 D
    Compared to placebo, active treatment with FC will be associated with a larger decrease in PTH and larger increase in 1,25 D from baseline

Eligibility Criteria

Ages Eligible for Study(Child, Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
1. Ages 6 to 18 years (inclusive); 2. Estimated Glomerular Filtration Rate (GFR) of 15-59 ml/min per 1.73 m2 by modified Chronic Kidney disease in Children (CKiD) under 25 (U25) formula;56 3. Serum phosphate \<=5.9 mg/dl; 4. Serum ferritin \<500 ng/ml and TSAT \<50%; 5. For those patients treated with growth hormone, calcitriol, nutritional vitamin D, iron, and/or erythropoiesis-stimulating agents (ESAs) such treatments must have stable dosing for at least 2 weeks prior to screening; 6. Able to swallow tablets; 7. Able to eat at least two meals a day; 8. In the opinion of the investigator, willing and able to follow the study treatment regimen and comply with the site investigator's recommendations.
Exclusion Criteria
1. Patients currently treated with phosphate binders. 2. History of allergy to all ingredients (including non-medical ingredients) in both products (i.e. investigational product and placebo) 3. Current intestinal malabsorption, documented in the medical record; disease, inflammatory bowel syndrome, and/or Crohn's Disease. 4. Anticipated initiation of dialysis or kidney transplantation within 6 months 5. Current or planned future systemic immunosuppressive therapy 6. Prior solid organ transplantation 7. Receipt of bone marrow transplant within two years of screening 8. Current pregnancy, lactation or female subjects who have reached menarche, unless using highly-effective contraception as outlined in section 7.1.1 of Protocol 9. Patients participating in other interventional study (observational study participation permitted) 10. Poor adherence to medical treatments in the opinion of the investigator 11. Cystinosis 12. Fanconi syndrome 13. Hemochromatosis or laboratory tests indicating possible hemochromatosis or other iron overload (primary or secondary) syndrome

Contacts and Locations

Sponsors and CollaboratorsUniversity of California, Los Angeles
Locations
University of California, Los Angeles | Los Angeles California, United States, 90095Children's Hospital of Orange County | Orange California, United States, 92868University of California, San Francisco | San Francisco California, United States, 94143Arnold Palmer Hospital for Children | Orlando Florida, United States, 32806Emory University | Atlanta Georgia, United States, 30322Indiana U | Indianapolis Indiana, United States, 46202Children's Mercy Hospital, Kansas City | Kansas City Missouri, United States, 64110Washington U | St Louis Missouri, United States, 63130Cohen's Childrens | New York New York, United States, 11040Children's Hospital at Montefiore | The Bronx New York, United States, 10467Duke | Durham North Carolina, United States, 27708Cincinnati Children's Hospital Medical Center | Cincinnati Ohio, United States, 45229Nationwide Children's | Columbus Ohio, United States, 43205OHSU | Portland Oregon, United States, 97239Children's Hospital of Philadelphia | Philadelphia Pennsylvania, United States, 19104Children's Medical Center, Dallas | Dallas Texas, United States, 75235Baylor College of Medicine | Houston Texas, United States, 77030UTH | Houston Texas, United States, 77030BC Children's Hospital Research Institute | Vancouver British Columbia, Canada, V5Z 4H4SickKids | Toronto Ontario, Canada, M5G 1E8
Investigators
Principal Investigator: Isidro B Salusky, MD, University of California, Los Angeles