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A Long-Term Safety Extension Trial of Ferric Citrate in Patients With End-Stage Renal Disease (ESRD) on Dialysis

This study has been completed.
Information provided by (Responsible Party):
Keryx Biopharmaceuticals Identifier:
First received: March 12, 2012
Last updated: June 2, 2016
Last verified: June 2016
A long-term safety study of ferric citrate (KRX-0502) in renal failure patients who have completed study KRX-0502-304. Only patients who participated in the KRX-0502-304 trial may participate in this trial.

Condition Intervention Phase
End Stage Renal Disease
Kidney Failure
Renal Failure
Drug: ferric citrate
Phase 3

Study Type: Interventional
Study Design: Endpoint Classification: Safety Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A Long-Term Safety Extension Trial of KRX-0502 (Ferric Citrate) in Patients With End-Stage Renal Disease (ESRD) on Dialysis

Resource links provided by NLM:

Further study details as provided by Keryx Biopharmaceuticals:

Primary Outcome Measures:
  • Safety Parameters [ Time Frame: 48 Weeks ] [ Designated as safety issue: Yes ]
    Safety was assessed by recording and monitoring adverse events (AEs), serious adverse events (SAEs), and sequential laboratory data. Rates of AEs were summarized by system organ class, preferred term, severity, and suspected relationship to KRX-0502 (ferric citrate).

Other Outcome Measures:
  • Serum Phosphorus- Baseline [ Time Frame: Baseline ] [ Designated as safety issue: Yes ]
  • Serum Phosphorus- Week 48 [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
  • Ferritin- Baseline [ Time Frame: Baseline ] [ Designated as safety issue: Yes ]
  • Ferritin- Week 48 [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
  • Transferrin Saturation (TSAT) - Baseline [ Time Frame: Baseline ] [ Designated as safety issue: Yes ]
  • TSAT- Week 48 [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
  • Hemoglobin- Baseline [ Time Frame: Baseline ] [ Designated as safety issue: Yes ]
  • Hemoglobin- Week 48 [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
  • IV Iron Use [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
    Percent of subjects with No IV iron intake from first dose of study drug to Week 48

Enrollment: 168
Study Start Date: August 2012
Study Completion Date: August 2014
Primary Completion Date: June 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Ferric Citrate
Open label extension of those completing study KRX-0304
Drug: ferric citrate
Dose based on monthly serum phosphorus levels with goal of 3.5-5.5 mg/dL for all patients.
Other Names:
  • Auryxia
  • KRX-0502

Detailed Description:
This study was an open-label, 48-week safety extension of Study KRX-0502-304 (Study 304), to evaluate the safety of long-term use of KRX-0502 in subjects with ESRD for up to 2 years of cumulative exposure. Subjects who completed the Safety Assessment Period (SAP) and, if eligible, the Efficacy Assessment Period (EAP) of Study 304, independent of their assigned treatment arm in the SAP or EAP of Study 304, were eligible for participation in this long-term safety extension study. No new subjects were permitted to enter this study.

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Males or non-pregnant, non-breast-feeding females who participated in the Safety Assessment Period (SAP), and if eligible, the Efficacy Assessment Period (EAP) of Study KRX-0502-304
  2. Willing and able to give informed consent

Exclusion Criteria:

  1. Subjects on KRX-0502 (ferric citrate) in KRX-0502-304 who were treatment failures in first period
  2. Any subject in Study KRX-0502-304 SAP who early terminated from the trial
  3. Any subject who participated in Study KRX-0502-304 but declined EAP
  4. Actively symptomatic gastrointestinal bleeding or inflammatory bowel disease
  5. History of malignancy in the last five years
  6. Previous intolerance to KRX-0502 (ferric citrate)
  7. Intolerance to oral iron-containing products
  8. Absolute requirement for oral iron therapy
  9. Absolute requirement for Vitamin C (multivitamins [Nephrocaps, Renaphro, etc.] allowed)
  10. Absolute requirement for calcium-, magnesium-, or aluminum-containing drugs with meals
  11. Inability to tolerate oral drug intake
  12. Any other medical condition that rendered the subject unable to or unlikely to complete the trial or that would interfere with optimal participation in the trial or produce significant risk to the subject
  13. Inability to cooperate with study personnel or history of noncompliance
  14. Unsuitable for this trial per Principal Investigator's (PI) clinical judgment.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01554982

  Show 34 Study Locations
Sponsors and Collaborators
Keryx Biopharmaceuticals
Study Chair: Julia B Lewis, MD Collaborative Study Group
  More Information

Responsible Party: Keryx Biopharmaceuticals Identifier: NCT01554982     History of Changes
Other Study ID Numbers: KRX-0502-307 
Study First Received: March 12, 2012
Results First Received: September 24, 2015
Last Updated: June 2, 2016
Health Authority: United States: Food and Drug Administration

Keywords provided by Keryx Biopharmaceuticals:
Participation Limited
Long Term
Safety Extension

Additional relevant MeSH terms:
Renal Insufficiency
Kidney Diseases
Kidney Failure, Chronic
Renal Insufficiency, Chronic
Urologic Diseases
Phosphorus Metabolism Disorders
Metabolic Diseases
Citric Acid
Ferric Compounds
Calcium Chelating Agents
Chelating Agents
Sequestering Agents
Molecular Mechanisms of Pharmacological Action
Hematinics processed this record on October 21, 2016