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Chronic Kidney DiseasesPhase 2FIT4KIDNCT04741646

Ferric Citrate and Chronic Kidney Disease in Children

A Phase 2 study testing Ferric Citrate in people with Chronic Kidney Diseases, run by University of California, Los Angeles at 20 sites in 2 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

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 6-18 years of either sex with chronic kidney disease (CKD)… Read more about this study

Who is it for?
Ages 6 to 18 years
Conditions the study is for
Chronic Kidney Diseases
What is being tested?
Ferric Citrate
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
160 participants
Where
20 sitesin 2 countries
Study dates
17 Jun 2022to 30 Nov 2028
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 6 to 18 years
  • All sexes
  • No healthy volunteers
  • Child, Adult

Who may be able to join

  • Ages 6 to 18 years (inclusive);
  • 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
  • Serum phosphate <=5.9 mg/dl;
  • Serum ferritin <500 ng/ml and TSAT <50%;
  • 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;
  • Able to swallow tablets;
  • Able to eat at least two meals a day;
  • In the opinion of the investigator, willing and able to follow the study treatment regimen and comply with the site investigator's recommendations.

Who cannot join

  • Patients currently treated with phosphate binders.
  • History of allergy to all ingredients (including non-medical ingredients) in both products (i.e. investigational product and placebo)
  • Current intestinal malabsorption, documented in the medical record; disease, inflammatory bowel syndrome, and/or Crohn's Disease.
  • Anticipated initiation of dialysis or kidney transplantation within 6 months
  • Current or planned future systemic immunosuppressive therapy
  • Prior solid organ transplantation
Show all 13Show fewer
  • Receipt of bone marrow transplant within two years of screening
  • Current pregnancy, lactation or female subjects who have reached menarche, unless using highly-effective contraception as outlined in section 7.1.1 of Protocol
  • Patients participating in other interventional study (observational study participation permitted)
  • Poor adherence to medical treatments in the opinion of the investigator
  • Cystinosis
  • Fanconi syndrome
  • Hemochromatosis or laboratory tests indicating possible hemochromatosis or other iron overload (primary or secondary) syndrome

Trial locations and contacts

20 sites in 2 countries. Contact the study team or a site near you to ask about taking part.

JENNY BROOK, MS contact

310-7943144

jbrook@mednet.ucla.edu

Barbara Gales, RN contact

310-206-0799

bgales@mednet.ucla.edu

20 sites in 2 countries

United States18 sites, 18 recruiting

  • Emory University

    Atlanta, Georgia, 30322

    Alexandria Wilkerson, BS, 4047270851, Awilke3@emory.edu

    Sabina Kennedy, MD

    Recruiting

  • Cincinnati Children's Hospital Medical Center

    Cincinnati, Ohio, 45229

    Elizabeth Siry, 513-636-7832, Elizabeth.Siry@cchmc.org

    Mark Mitsnefes, MD

    Recruiting

  • Nationwide Children's

    Columbus, Ohio, 43205

    Cindy Dong, cindy.dong@nationwidechildrens.org

    John Mahan, MD

    Recruiting

  • Children's Medical Center, Dallas

    Dallas, Texas, 75235

    Melaku Lemma, 214-456-8577, melaku.lemma@childrens.com

    Raymond Quigley, MD

    Recruiting

  • Duke

    Durham, North Carolina, 27708

    Salma Sarah, 919-681-1321, salma.sarah@duke.edu

    Not yet recruiting

  • Baylor College of Medicine

    Houston, Texas, 77030

    Franca Ofudu, 832-824-7391, franca.ofudu@bcm.edu

    Poyyapakkam R Srivanthos, MD

    Recruiting

  • UTH

    Houston, Texas, 77030

    Ruby Cerda, Ruby.D.Cerda@uth.tmc.edu

    Joyce Samuel, MD

    Recruiting

  • Indiana U

    Indianapolis, Indiana, 46202

    Sherry Wilson, slw2@iu.edu

    khalid Myda, MD

    Recruiting

  • Children's Mercy Hospital, Kansas City

    Kansas City, Missouri, 64110

    Stephen Morrison, 816-302-3573, ssmorrison@cmh.edu

    Bradley Warady, MD

    Recruiting

  • University of California, Los Angeles

    Los Angeles, California, 90095

    Barbara Gales, RN, 310-206-0799, bgales@mednet.ucla.edu

    Isidro Salusky, MD

    Recruiting

  • Cohen's Childrens

    New York, New York, 11040

    Suzanne Vento, svento@northwell.edu

    Christina Sethna, MD

    Recruiting

  • Children's Hospital of Orange County

    Orange, California, 92868

    Mai Ngo, pngo@choc.org

    Shoba Nayran, MD

    Recruiting

  • Arnold Palmer Hospital for Children

    Orlando, Florida, 32806

    Estefania Bobe Cortes, 3218424773, Estefania.BobeCortes@orlandohealth.com

    Jorge Ramirez, MD

    Recruiting

  • Children's Hospital of Philadelphia

    Philadelphia, Pennsylvania, 19104

    Hannah Derwick, DERWICKH@chop.edu

    Michelle Denburg, MD

    Recruiting

  • OHSU

    Portland, Oregon, 97239

    Jessica Stockton, stocktje@ohsu.edu

    Amira Al-Uzri, MD

    Not yet recruiting

  • University of California, San Francisco

    San Francisco, California, 94143

    Daniel Schrader, 415-476-9657, daniel.schrader@ucsf.edu

    Farzana Perwad, MD

    Recruiting

  • Washington U

    St Louis, Missouri, 63130

    Joel Brune, jbrune@wustl.edu

    Keith Hruska, MD

    Recruiting

  • Children's Hospital at Montefiore

    The Bronx, New York, 10467

    Patricia Flynn, 718-655-1120, pflynn@montefiore.org

    Frederick Kaskel, MD

    Recruiting

Other trials in United States

Canada2 sites, 2 recruiting

  • SickKids

    Toronto, Ontario, M5G 1E8

    Yasmine Hejri-Rad, 416-813-7910 ext. 309031

    Michael Zappitelli, MD

    Recruiting

  • BC Children's Hospital Research Institute

    Vancouver, British Columbia, V5Z 4H4

    Phillip Ly, 604-875-2000 ext. 7558, phillip.ly@bcchr.ca

    Tom Blydt-Hansen, MD

    Recruiting

Other trials in Canada

About this study

Official title: Phosphate Binder Therapy and Chronic Kidney Disease in Children

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 6-18 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.

Read the detailed 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

Being tested
Ferric Citrate, Placebo
Keywords
Pediatric, CKD, Phosphate Binder
Medical subject headings
Renal Insufficiency, Chronic

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Ferric CitrateDrug

    Also called Auryxia

    Auryxia® 210 mg ferric iron tablets equivalent to 1 g of FC will be supplied as 200 tablets in 400cc high-density polyethylene bottles.

  • PlaceboDrug

    Placebo to match Ferric Citrate tablets

Study groups in NCT04741646
Study groupRoleWhat they receive
Treatment ArmExperimentalDuring 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.
Receives: Drug: Ferric Citrate
Control ArmPlacebo comparatorDuring 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.
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. iFGF23 levels

    Compared to placebo, active treatment with FC will lower iFGF23 levels

    Measured: 12 months

  2. Safety of Ferric Citrate

    Comparing proportion of subjects with AE and SAE between arms

    Measured: 12 months

  3. Tolerability of Ferric Citrate

    Compared with placebo, active treatment will be tolerable

    Measured: 12 months

Secondary outcomes (2)

  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

    Measured: 12 months

  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

    Measured: 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Feb 2021
  2. Study start17 Jun 2022
  3. Primary completionOct 2027 (estimated)
  4. Study completion30 Nov 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
160 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04741646
Sponsor's protocol ID
U01DK122013
Other IDs
1U01DK122013, 22-001133
Acronym
FIT4KID
Status last verified
Apr 2026
First submitted
2 Feb 2021
Last updated
17 Apr 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: All de-identified clinical data, including study outcomes and participant characteristics will be submitted to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repository at the completion of the study. De-identified research samples blood and urine will also be provided to the NIDDK central reporsitory

Publications

  • Hanudel MR, Laster ML, Portale AA, Dokras A, Quigley RP, Guzman GAL, Zaritsky JJ, Hayde NA, Kaskel FJ, Mitsnefes MM, Ramirez JA, Imani PD, Srivaths PR, Kogon AJ, Denburg MR, Blydt-Hansen TD, Reyes LZ, Greenbaum LA, Weidemann DK, Warady BA, Elashoff DA, Mendley SR, Isakova T, Salusky IB. A review of ferric citrate clinical studies, and the rationale and design of the Ferric Citrate and Chronic Kidney Disease in Children (FIT4KiD) trial. Pediatr Nephrol. 2022 Nov;37(11):2547-2557. doi: 10.1007/s00467-022-05492-7. Epub 2022 Mar 2.

    PubMed 35237863

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Ferric Citrate in people with Chronic Kidney Diseases, run by University of California, Los Angeles at 20 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 17 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 20 sites in United States, Canada. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact JENNY BROOK, MS (310-7943144, jbrook@mednet.ucla.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

iFGF23 levels (time frame: 12 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04741646, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Apr 2026.

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