Study to Evaluate the Safety and Tolerability of Ferric Citrate in Children With Hyperphosphatemia Related to Chronic Kidney Disease

NCT ID: NCT04523727

Last Updated: 2025-10-14

Basic Information

• Recruitment Status: SUSPENDED
• Clinical Phase: PHASE3
• Total Enrollment: 45 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-06-16
• Study Completion Date: 2026-10-31

Brief Summary

This study will be conducted to assess the safety and tolerability of ferric citrate in pediatric participants with hyperphosphatemia related to chronic kidney disease (CKD).

Conditions

Hyperphosphatemia Related to Chronic Kidney Disease

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Ferric citrate

Participants aged 6 to \< 17 years will receive ferric citrate for 36 weeks at a starting dose based on body weight categories.

Group Type: EXPERIMENTAL

ferric citrate

Intervention Type: DRUG

oral tablets

Interventions

ferric citrate

oral tablets

Intervention Type: DRUG

Other Intervention Names

KRX-0502

Eligibility Criteria

Inclusion Criteria

• Age 6 years to <17 years at Screening.
• Weight ≥ 20 kilograms (kg) (dry weight for dialysis participants) at Screening.
• Chronic kidney disease (CKD) requiring chronic dialysis (i.e., hemodialysis or peritoneal dialysis), or CKD not on dialysis with an estimated glomerular filtration rate (eGFR) <30 milliliters per minute (mL/min)/1.73 meters squared (m^2) at Screening.
• Documented history of CKD-related hyperphosphatemia for at least 3 months prior to the screening visit.
• If participant is or is not on phosphate binder(s) at Visit 1, serum phosphorus must be:

• 6 to <13 years: >5.8 milligrams per deciliter (mg/dL).
• 13 to <17 years: >4.5 mg/dL.
• If participant is on phosphate binder(s) at Visit 1, and serum phosphorus is not greater than the above stated age-limit criteria, approximately 1 to 4-weeks of washout period is required and at Visit 1a or Visit 1b, serum phosphorus must be greater than the age above stated age-limit criteria.
• Transferrin saturation (TSAT) <50%.
• Serum ferritin of <650 nanograms per milliliter (ng/mL).
• Parent/legal guardian must be willing and able to give written informed consent, and child (participant) willing and able to give age-appropriate assent according to local regulatory requirements.
• Female participants of childbearing potential, defined as post menarche and not surgically sterile, must have a negative serum pregnancy test.
• Dialysis adequacy stable on current mode of dialysis prior to screening and agree to maintain dialysis prescription for the duration of the pharmacodynamic assessment period unless changes are needed for safety. A minimum dialysis adequacy (dialysis clearance of urea-dialysis time/volume of distribution of urea [Kt/V]), defined by the following:

1. Hemodialysis adequacy: single-pool Kt/V ≥1.2 for at least 1 hemodialysis session within 2 months.

2. Peritoneal dialysis: At least 1Kt/V reading ≥1.8 within 4 months.

Exclusion Criteria

• Active significant GI disorder, including overt GI bleeding or active inflammatory bowel disease.
• Liver transaminases (aspartate aminotransferase [AST] or alanine aminotransferase [ALT]) >3× the upper limit of normal at Screening.
• Unable to swallow pills, if participant requires tube feeding, ferric citrate must be taken orally and not administered via feeding tube.
• Non-renal cause of hyperphosphatemia.
• Active drug or alcohol dependence or abuse (excluding tobacco use or medicinal marijuana) within the 12 months prior to Screening or evidence of such abuse (in the opinion of the Investigator).
• Malignancy, except for participants who have been disease-free for at least 2 years after curative therapy.
• Participants with a functioning organ transplant.
• A known allergy or intolerance to ferric citrate or any of its constituents.
• Female participants who do not agree to remain abstinent or assent to use a combination of 2 of the following highly effective birth control methods for at least 28 days before the first dose, during the study (including during dose interruptions), and for at least 30 days after the last dose:

• Barrier method of contraception: condoms (female or male) with or without a spermicidal agent, diaphragm, or cervical cap with spermicide.
• Intrauterine device (IUD).
• Hormone-based contraceptives which are associated with inhibition of ovulation.
• Females who are pregnant or breast-feeding other children. Participants who are being breastfed are eligible to participate in this study.
• Any other medical condition that, in the opinion of the Investigator, renders the participant unable to or unlikely to complete the trial or that would interfere with optimal participation in the trial or produce significant risk to the participant.
• The participant, in the opinion of the Investigator, is unable to adhere to the requirements of the study.
• Receipt of any investigational drug within 4 weeks before Screening.
• History of hemochromatosis or iron overload syndrome (e.g, hereditary sideroblastic anemia, thalassemia).

• Minimum Eligible Age: 6 Years
• Maximum Eligible Age: 16 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Keryx Biopharmaceuticals

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Chief Medical Officer

Role: STUDY_DIRECTOR

Akebia Therapeutics Inc.

Locations

University of Alabama at Birmingham (UAB) - Children's of Alabama

Birmingham, Alabama, United States

Phoenix Childrens Hospital

Phoenix, Arizona, United States

University of California, San Francisco (UCSF) - Department of Nephrology

San Francisco, California, United States

Stanford University Medical Center

Stanford, California, United States

Children's Hospital Colorado

Aurora, Colorado, United States

University of South Florida

Tampa, Florida, United States

Johns Hopkins Hospital

Baltimore, Maryland, United States

Helen DeVos Children's Hospital at Spectrum Health

Grand Rapids, Michigan, United States

University of Minnesota

Minneapolis, Minnesota, United States

Children's Mercy Hospital - Kansas City

Kansas City, Missouri, United States

University of New Mexico

Albuquerque, New Mexico, United States

Cincinnati Children's Hospital Medical Center

Cincinnati, Ohio, United States

University of Utah

Salt Lake City, Utah, United States

Seattle Children's Hospital

Seattle, Washington, United States

Countries

United States

Other Identifiers

KRX-0502-308

Identifier Type: -

Identifier Source: org_study_id