Study to Evaluate the Safety and Tolerability of KRX-0502 (Ferric Citrate) in Children With Iron Deficiency Anemia Associated With Non-Dialysis Dependent Chronic Kidney Disease

November 17, 2025 updated by: Keryx Biopharmaceuticals

A 24-Week, Open-Label, Randomized, 2-Arm Study to Evaluate the Safety and Tolerability of KRX-0502 (Ferric Citrate) in Children With Iron Deficiency Anemia Associated With Non-Dialysis Dependent Chronic Kidney Disease

This study will be conducted to evaluate the safety and tolerability of ferric citrate in pediatric participants with iron deficiency anemia (IDA) associated with non-dialysis dependent chronic kidney disease (NDD-CKD).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Withdrawn

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

6 years to 18 years (Child, Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 6 years to <18 years at Screening
  • Body Weight ≥12 kilograms (kg) at Screening
  • Chronic kidney disease (CKD) stage 3 to 5, not on dialysis, with estimated glomerular filtration rate (eGFR) <60 milliliters per minute (mL/min)/1.73 meters squared (m^2) utilizing the "Bedside Schwartz" equation
  • Hemoglobin (Hgb) ≥8.5 and ≤11.5 grams per deciliter (g/dL) at Screening
  • Transferrin saturation (TSAT) ≤25% at Screening
  • Ferritin ≤200 nanograms per milliliter (ng/mL) at Screening

Exclusion Criteria:

  • Serum phosphorus level at Screening:

    • 6 to <13 years: ≤4.0 milligrams per deciliter (mg/dL);
    • 13 to <18 years: ≤2.7 mg/dL
  • Liver transaminases (aspartate aminotransferase [AST] and/or alanine aminotransferase [ALT]) ˃3× the upper limit of normal at Screening
  • Active significant gastrointestinal (GI) disorder, including overt gastrointestinal (GI) bleeding or active inflammatory bowel disease
  • Unable to swallow pills
  • Anemia due to causes other than iron deficiency anemia (IDA) of CKD
  • Intravenous iron therapy or blood transfusion within 4 weeks before the Screening visit
  • Participants with a functioning organ transplant
  • Receipt of any investigational drug within 4 weeks before Screening
  • Phosphate binder use during the Screening period

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Ferric citrate
Participants aged 12 to <18 years and 6 to <12 years will receive ferric citrate for 24 weeks at a starting dose based on body weight categories.
Drug: ferric citrate
oral tablets
Other Names:
  • KRX-0502
Active Comparator: Standard of care
Participants aged 12 to <18 years and 6 to <12 years will receive standard of care treatment for 24 weeks.
Drug: standard of care
administered per the approved label and at the Investigator's discretion

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Number of Participants with Serious and Non-serious Treatment-emergent Adverse Events
Time Frame: up to Week 28
up to Week 28
Number of Participants with Clinically Significant Laboratory Abnormalities or Changes in Laboratory Results
Time Frame: up to Week 24
up to Week 24
Number of Participants with Treatment-emergent Adverse Events Leading to the Discontinuation of Ferric Citrate
Time Frame: up to Week 28
up to Week 28

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Change from Baseline in Hemoglobin to Week 24/Early Termination Visit
Time Frame: Baseline; Week 24
Baseline; Week 24
Change from Baseline in Transferrin Saturation (TSAT) to Week 24/Early Termination Visit
Time Frame: Baseline; Week 24
Baseline; Week 24
Change from Baseline in Ferritin to Week 24/Early Termination Visit
Time Frame: Baseline; Week 24
Baseline; Week 24
Change from Baseline in Serum Phosphorus to Week 24/Early Termination Visit
Time Frame: Baseline; Week 24
Baseline; Week 24
Change from Baseline in Calcium to Week 24/Early Termination Visit
Time Frame: Baseline; Week 24
Baseline; Week 24
Change from Baseline in Bicarbonate to Week 24/Early Termination Visit
Time Frame: Baseline; Week 24
Baseline; Week 24

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Keryx Biopharmaceuticals

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Chief Medical Officer, Akebia Therapeutics Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 24, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 24, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 2, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 20, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 17, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • KRX-0502-309

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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