Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

A 4-Week Dose-Ranging and Efficacy Trial of KRX-0502 (Ferric Citrate) in Patients With End-Stage Renal Disease

This study has been completed.
Collaborative Study Group (CSG)
Information provided by (Responsible Party):
Keryx Biopharmaceuticals Identifier:
First received: February 17, 2010
Last updated: December 3, 2014
Last verified: December 2014
This is a research study for people with high blood phosphorus levels who are on dialysis. This medical condition can cause weakening of the bones and damage other organs. This can lead to many health problems, and sometimes death. Phosphorus is in much of the food we eat, and is helpful to us in small amounts. Patients with kidney failure have trouble getting rid of the phosphorus eaten in food. Dialysis can help remove some of the phosphorus, but often patients must take a phosphate binder like PhosLo®, Renagel®, or Renvela® to bring the blood phosphorus levels back to normal. The purpose of this study is to see if KRX-0502 (ferric citrate) is safe and effective as a phosphate binder.

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

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A 4-Week Dose-Ranging and Efficacy Trial of KRX-0502 (Ferric Citrate) in Patients With End-Stage Renal Disease (ESRD) Following a Two-Week Washout Period

Resource links provided by NLM:

Further study details as provided by Keryx Biopharmaceuticals:

Primary Outcome Measures:
  • Change in Serum Phosphorus From Baseline to End of Treatment [ Time Frame: Baseline and day 28 ]
    Mean change from baseline was calculated separately for each treatment arm (LOCF)

Secondary Outcome Measures:
  • Pairwise Comparison of the Mean Change in Serum Phosphorus From Baseline to the End of Treatment [ Time Frame: Baseline and day 28 ]
    Mean change from baseline was calculated separately for each treatment arm. Only subjects that have both baseline and end of treatment serum phosphorus scores were analyzed for this outcome.

  • Proportion of Patient With a Serum Phosphorus ≤5.5 mg/dL at the End of Treatment [ Time Frame: Baseline and day 28 ]
    proportion was calculated separately for each treatment arm

Enrollment: 154
Study Start Date: May 2010
Study Completion Date: November 2010
Primary Completion Date: November 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1 g/day
1 g/day KRX-0502 (ferric citrate)
Drug: ferric citrate
1, 6, or 8 g/day taken within 1 hour of meals or snacks daily for 28 days
Other Name: KRX-0502
Experimental: 6 g/day
6 g/day KRX-0502 (ferric citrate)
Drug: ferric citrate
1, 6, or 8 g/day taken within 1 hour of meals or snacks daily for 28 days
Other Name: KRX-0502
Experimental: 8 g/day
8 g/day KRX-0502 (ferric citrate)
Drug: ferric citrate
1, 6, or 8 g/day taken within 1 hour of meals or snacks daily for 28 days
Other Name: KRX-0502

Detailed Description:
There will be a screening visit about 4 weeks receiving study drug. Upon qualifying for the study after the screening visit, patients will then be asked to stop taking their current phosphate binder for about 2 weeks. Then, if patients continue to qualify for the study, they will be entered in the study that lasts about 28 days. Study visits will happen every week during the patient's usual dialysis appointments. There will be a total of up to 9 visits for this study, and total participation time could last up to 8 weeks.

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

Inclusion Criteria:

  • Males or non-pregnant, non-lactating females
  • Age > 18 years
  • On thrice weekly hemodialysis or peritoneal dialysis for at least the previous three months prior to Screening Visit (Visit 0)
  • Serum phosphorus levels ≥ 3.5 mg/dL and < 8.0 mg/dL at Screening Visit (Visit 0)
  • Serum phosphorus levels > 6.0 mg/dL during the washout period (Visits 2 or 3)
  • Taking 3 to 15 tablets/capsules per day of 667mg calcium acetate or 800 mg sevelamer (hydrochloride or carbonate), or any combination of these agents as reported by the patient at Screening Visit (Visit 0)
  • Serum ferritin <1000micrograms/L and Transferrin Saturation (TSAT) <50% at the Screening Visit (Visit 0)
  • Willingness to be discontinued from current phosphate binder(s) and initiated on KRX-0502 (ferric citrate)
  • Willing and able to give informed consent
  • Willing and able to stay on a constant dose of Vitamin D (or its analogs) and Sensipar (cinacalcet) for the treatment period, if applicable.

Exclusion Criteria:

  • Parathyroidectomy within six months prior to Screening Visit (Visit 0)
  • Actively symptomatic gastrointestinal bleeding or inflammatory bowel disease
  • Serum phosphorus levels >10.0 mg/dL documented in all of the three monthly laboratories (done routinely in the dialysis unit) in the three months prior to the Screening Visit (Visit 0)
  • History of multiple drug allergies or intolerances
  • History of malignancy in the last five years (treated cervical or non-melanomatous 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 [Nephrocaps, 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 trial (scheduled outpatient access surgery allowed)
  • Any other medical condition that renders the patient unable to or unlikely to complete the trial or that would interfere with optimal participation in the trial or produce significant risk to the patient
  • Receipt of any investigational drug within 30 days of Screening Visit (Visit 0)
  • Inability to cooperate with study personnel or history of noncompliance
  • Unsuitable for this trial per Principal Investigator's 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: NCT01074125

United States, Colorado
Western Nephrology
Westminster, Colorado, United States, 80031
United States, Florida
Pines Clinical Research, Inc.
Pembroke Pines, Florida, United States, 33028
United States, Georgia
Kidney Care Associates, LLC
Augusta, Georgia, United States, 30901
United States, Illinois
Circle Medical Management
Chicago, Illinois, United States, 60607
United States, Massachusetts
Western New England Renal & Transplant Associates
Springfield, Massachusetts, United States, 01107
United States, New York
Brookdale Physician's Dialysis Associates
Brooklyn, New York, United States, 11212
United States, Ohio
Cincinnati, Ohio, United States, 45206
Cleveland Clinical Foundation Fresenius East (Fairhill)
Cleveland, Ohio, United States, 44104
The Ohio State University Cramblett Medical Clinic
Columbus, Ohio, United States, 43210
United States, Tennessee
Southeast Renal Research Institute
Chattanooga, Tennessee, United States, 37404
Nephrology Associates, PC
Nashville, Tennessee, United States, 37205
Meharry Medical College Clinical Research Center
Nashville, Tennessee, United States, 37208
Vanderbilt University Medical Center Clinical Trials Center
Nashville, Tennessee, United States, 37232-1371
United States, Texas
Kidney Associates
Houston, Texas, United States, 77030
United States, Wisconsin
Centre Point Dialysis
West Allis, Wisconsin, United States, 53214
Puerto Rico
RCMI- Clinical Research Center Medical Sciences Campus University of Puerto Rico
Rio Piedras, Puerto Rico, 00936-5067
Sponsors and Collaborators
Keryx Biopharmaceuticals
Collaborative Study Group (CSG)
Study Chair: Julia B Lewis, MD Collaborative Study Group (CSG)
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Keryx Biopharmaceuticals Identifier: NCT01074125     History of Changes
Other Study ID Numbers: KRX-0502-305
Study First Received: February 17, 2010
Results First Received: October 4, 2014
Last Updated: December 3, 2014

Keywords provided by Keryx Biopharmaceuticals:
End Stage Renal Disease

Additional relevant MeSH terms:
Kidney Diseases
Kidney Failure, Chronic
Renal Insufficiency, Chronic
Urologic Diseases
Renal Insufficiency
Phosphorus Metabolism Disorders
Metabolic Diseases
Ferric Compounds
Citric Acid
Calcium Chelating Agents
Chelating Agents
Sequestering Agents
Molecular Mechanisms of Pharmacological Action processed this record on April 28, 2017