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A Safety and Tolerability Study of Zerenex (Ferric Citrate) in Patients With End-Stage Renal Disease (ESRD)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00648167
Recruitment Status : Completed
First Posted : April 1, 2008
Results First Posted : October 9, 2014
Last Update Posted : April 4, 2017
Collaborative Study Group (CSG)
Information provided by (Responsible Party):
Keryx Biopharmaceuticals

Brief Summary:
This study is to evaluates the safety and tolerability of Zerenex™ (ferric citrate) as a treatment for hyperphosphatemia in patients with End-Stage Renal Disease.

Condition or disease Intervention/treatment Phase
Hyperphosphatemia End-stage Renal Disease Drug: ferric citrate Phase 2

Detailed Description:
The purpose of this study is to evaluate the safety and tolerability of Zerenex™ (ferric citrate) as a treatment for hyperphosphatemia in patients with End-Stage Renal Disease. These patients will be switched to Zerenex™ from their current high dose of phosphate binder and, based on their serum phosphorus levels, will be titrated up from 3.4g/day of Zerenex™ to maximum tolerated and safe doses of Zerenex™. Doses will be adjusted weekly, based on serum phosphorus levels, with the maximum dose administered being approximately 12g/day.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 55 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Safety and Tolerability Study of Zerenex (Ferric Citrate) in Patients With End-Stage Renal Disease (ESRD)
Study Start Date : March 2008
Actual Primary Completion Date : January 2009
Actual Study Completion Date : January 2009

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: KRX-0502 (ferric citrate)
All patients will be switched from their current phosphate binder to Zerenex, and titrated to the maximum tolerated dose (up to about 12g/day) based on their serum phosphorus levels.
Drug: ferric citrate
ferric citrate will be provided as a 375mg capsule. Dosing and frequency are dependent on patient's serum phosphorus levels. Dosing will occur over the 28-day study.
Other Name: KRX-0502

Primary Outcome Measures :
  1. The Difference in Serum Phosphorus Between Baseline (Day 0) and End of Treatment (Day 28) [ Time Frame: 28 days ]

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Males and non-pregnant, nonlactating females
  • Age > 18 years
  • On thrice weekly hemodialysis for at least the previous 3 months prior to randomization
  • Phosphorous levels ≥3.5mg/dL at Screening Visit
  • On at least 12 tablets/capsules/day of calcium acetate (667mg), calcium carbonate (500mg), lanthanum carbonate (500mg), sevelamer hydrochloride (800mg or two 400mg tablets), or any combination of these agents
  • Serum ferritin <1000micrograms/L and Transferrin Saturation (TSAT) <50%
  • Willing to be discontinued from current phosphate binder(s) and initiated on Zerenex
  • Willing and able to give informed consent

Exclusion Criteria:

  • Parathyroidectomy within 6 months prior to Screening
  • Actively symptomatic GI disease such as peptic ulcer disease, gastro esophageal reflux, diverticulosis, irritable bowel syndrome (treated asymptomatic is permitted)
  • History of documented inflammatory bowel disease or erosive esophagitis
  • Serum Phosphorus levels >10.0 mg/dL documented in the 3 monthly laboratories (done routinely in the dialysis unit) in the 3 months prior to the Screening Visit
  • History of multiple drug allergies
  • History of malignancy in the last 5 years (treated cervical or skin cancer may be permitted if approved by CCC)
  • Previous intolerance to oral ferric citrate
  • Absolute requirement for oral iron therapy
  • Absolute requirement for Vitamin C (multivitamins [Neprocaps, Renaphro, etc.] allowed)
  • Absolute requirement for calcium, magnesium, or aluminum containing drugs with meals
  • Psychiatric disorder that interferes with the patient's ability to comply with the study protocol
  • Inability to tolerate oral drug intake
  • Planned surgery or hospitalization during the study (scheduled outpatient access surgery allowed)
  • Any other medical condition that renders the patient unable to or unlikely to complete the study or that would interfere with optimal participation in the study or produce significant risk to the patient
  • Receipt of any investigational drug within 30 days of randomization
  • Inability to cooperate with study personnel or history of noncompliance

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00648167

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United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Keryx Biopharmaceuticals
Collaborative Study Group (CSG)
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Study Chair: Julia B Lewis, MD Collaborative Study Group at the Nephrology Clinical Trials Center, Vanderbilt University Medical Center
Additional Information:
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Responsible Party: Keryx Biopharmaceuticals Identifier: NCT00648167    
Other Study ID Numbers: KRX-0502-201
First Posted: April 1, 2008    Key Record Dates
Results First Posted: October 9, 2014
Last Update Posted: April 4, 2017
Last Verified: March 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Keryx Biopharmaceuticals:
end-stage renal disease
end stage renal disease
kidney failure
renal failure
phosphate binder
Additional relevant MeSH terms:
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Kidney Diseases
Kidney Failure, Chronic
Urologic Diseases
Renal Insufficiency, Chronic
Renal Insufficiency
Phosphorus Metabolism Disorders
Metabolic Diseases