HyperphosphatemiaPhase 3NCT01191255

A 58-Week Safety and Efficacy Trial of Ferric Citrate in Patients With ESRD on Dialysis

A Phase 3 study of Hyperphosphatemia and Kidney Failure, run by Keryx Biopharmaceuticals at 56 sites in 3 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Trial summary

This is up to a 58 week study comparing ferric citrate to active control for 52 weeks in ESRD dialysis patients, and subsequently comparing ferric citrate to placebo for 4 weeks. Read more about this study

Who is it for?: Ages 18 years and older
Conditions the study is for: Hyperphosphatemia, Kidney Failure
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 441 participants
Where: 56 sitesin 3 countries
Study dates: Oct 2010to Feb 2013
Phase: Phase 3
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Males or non-pregnant, non-breast-feeding females
Age ≥18 years
On thrice-weekly hemodialysis or on peritoneal dialysis for at least the previous three months prior to Screening
Serum phosphorus ≥6.0 mg/dL for study entry
Taking less than 3-18 pills/day of current phosphate binder
Willing to be discontinued from current phosphate binder(s) and initiated on ferric citrate
Willing and able to give informed consent
Life expectancy >1 year

Who cannot join

Parathyroidectomy within six months prior to Screening
Actively symptomatic gastrointestinal bleeding or inflammatory bowel disease
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
Intolerance to oral iron-containing products

Show all 13Show fewer

Psychiatric disorder that interferes with the patient's ability to comply with the study protocol
Inability to tolerate oral drug intake
Intolerance to calcium acetate and sevelamer carbonate
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 Investigator's clinical judgment.

Trial locations and contacts

56 sites in 3 countries.

Country

City, postcode or hospital

56 sites in 3 countries

United States52 sites

Mountain Kidney and Hypertension Associates, PA
Asheville, North Carolina, 28801
Kidney Care Associates, LLC
Augusta, Georgia, 30901
University of Colorado Denver
Aurora, Colorado, 80045
Tufts Medical Center
Boston, Massachusetts, 02111
PAB Clinical Research
Brandon, Florida, 33511
Brookdale Physician's Dialysis Associates
Brooklyn, New York, 11212
University of Vermont/ Fletcher Allen Health Care; Renal Services
Burlington, Vermont, 05401
Clinical Research Limited
Canton, Ohio, 44718
Metrolina Nephrology Associates, PA
Charlotte, North Carolina, 28207
Nephrology Clinical Research Center
Charlottesville, Virginia, 22908
Southeast Renal Research Institute Nephrology Associates
Chattanooga, Tennessee, 37404
Circle Medical Management
Chicago, Illinois, 60607
Division of Nephrology and Hypertension Department of Internal Medicine University of Cincinnati College of Medicine
Cincinnati, Ohio, 45267
Cleveland Clinic Foundation Q7-150 Nephrology
Cleveland, Ohio, 44195
The Ohio State University Division of Nephrology
Columbus, Ohio, 43210
UT Southwestern Medical Center at Dallas
Dallas, Texas, 75390
Atlanta Nephrology Referral Center
Decatur, Georgia, 30030
Henry Ford Hospital
Detroit, Michigan, 48202
Duke University Medical Center Division of Nephrology
Durham, North Carolina, 27705
Clinical Research & Consulting Center, LLC
Fairfax, Virginia, 22030
Nephrology Associates of Northern Virginia, Inc.
Fairfax, Virginia, 22033
Peninsula Kidney Associates
Hampton, Virginia, 23666
Pioneer Valley Nephrology
Holyoke, Massachusetts, 01040
Kidney Associates
Houston, Texas, 77030
Nephrology, PA
Houston, Texas, 77030
Mayo Clinic
Jacksonville, Florida, 32216
ASA Clinical Research, LLC
Jupiter, Florida, 33458
Kansas City VA Medical Center
Kansas City, Missouri, 64128
Tower Nephrology Medical Group
Los Angeles, California, 90048
Veterans Administration Greater Los Angeles Healthcare System, West Los Angeles
Los Angeles, California, 90073
Nephrology Specialists, PC
Michigan City, Indiana, 46360
Medical College of Wisconsin Froedert Memorial Lutheran Hospital Division of Nephrology
Milwaukee, Wisconsin, 53226
Nephrology Associates, PC
Nashville, Tennessee, 37205
Vanderbilt University Medical Center Clinical Trials Center
Nashville, Tennessee, 37232-1371
LSU Health Sciences Center Section of Nephrology and Hypertension Department of Internal Medicine
New Orleans, Louisiana, 70112
Ocala Kidney Group
Ocala, Florida, 34471
DaVita
Oklahoma City, Oklahoma, 73116
Pines Clinical Research, Inc.
Pembroke Pines, Florida, 33028
University of Pennsylvania Health System
Philadelphia, Pennsylvania, 19104
Michigan Kidney Consultants, PC
Pontiac, Michigan, 48341
McGuire VA Medical Center
Richmond, Virginia, 23249
Apex Research of Riverside
Riverside, California, 92505
Rockville Dialysis Center
Rockville, Maryland, 20850
University of Utah Health Sciences Center
Salt Lake City, Utah, 84132
Nephrology Hypertension Clinic
Southgate, Michigan, 48195
Western New England Renal & Transplant Associates
Springfield, Massachusetts, 01107
Southwest Clinical Research Institute, LLC
Tempe, Arizona, 85284
Kidney Specialists of North Houston, PLLC
The Woodlands, Texas, 77384
Western Nephrology
Westminster, Colorado, 80031
American Institute of Research
Whittier, California, 90603
Trial Management Associates
Wilmington, North Carolina, 28401
Wake Forest University School of Medicine
Winston-Salem, North Carolina, 27157

Other trials in United States

Israel2 sites

Department of Nephrology and Hypertension Brazilai Medical Center
Ashkelon
Tel Aviv Sourasky Medical Center Nephrology Department
Tel Aviv

Other trials in Israel

Puerto Rico2 sites

RCMI-Clinical Research Center Medical Sciences Campus University of Puerto Rico
Rio Piedras, PR, 00936-5067
Puerto Rico Renal Health & Research Center, Inc/ Atlantic Healthcare Group, Inc
Trujillo Alto, PR, 00976

Other trials in Puerto Rico

About this study

Official title: A Three-Period, 58-Week Safety and Efficacy Trial of KRX-0502 (Ferric Citrate) in Patients With End-Stage Renal Disease (ESRD) on Dialysis

This is up to a 58 week study comparing ferric citrate to active control for 52 weeks in ESRD dialysis patients, and subsequently comparing ferric citrate to placebo for 4 weeks.

Read the detailed description

This trial is a three-period, multicenter, safety and efficacy clinical trial. The first period is a two-week Washout Period, the second period is a 52-week randomized, open-label, active control Safety Assessment Period, and the third period is a four-week, randomized, open-label, placebo-controlled Efficacy Assessment Period in only the patients who were randomized to treatment with ferric citrate during the Safety Assessment Period. The primary objectives of this trial are to determine the long-term safety over 52 weeks of up to twelve (12) caplets/day of KRX-0502 (ferric citrate) in patients with ESRD undergoing either hemodialysis or peritoneal dialysis and to determine the efficacy of KRX-0502 (ferric citrate) in the four-week, randomized, open-label, placebo-controlled Efficacy Assessment Period.

Conditions: Hyperphosphatemia, Kidney Failure
Being tested: ferric citrate, ca acetate, sevelamer carbonate, placebo
Keywords: ESRD, end-stage renal disease, dialysis, hemodialysis, peritoneal dialysis, hemodialysis (HD), peritoneal dialysis (PD), chronic renal insufficiency, phosphate binder, kidney failure, renal failure
Medical subject headings: Hyperphosphatemia, Renal Insufficiency, Kidney Failure, Chronic, Renal Insufficiency, Chronic

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

ferric citrate, ca acetate, sevelamer carbonate, placeboDrug
Also called PhosLo, Renvela, KRX-0502, Zerenex
All intervention doses will be based on serum phosphorus levels and/or drug label requirements

Study groups in NCT01191255
Study group	Role	What they receive
Active Control	Active comparator	PhosLo (calcium acetate) Renvela (sevelamer carbonate) Receives: Drug: ferric citrate, ca acetate, sevelamer carbonate, placebo
Placebo	Placebo comparator	Placebo Receives: Drug: ferric citrate, ca acetate, sevelamer carbonate, placebo
KRX-0502 (Ferric Citrate)	Experimental	ferric citrate Receives: Drug: ferric citrate, ca acetate, sevelamer carbonate, placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

Change in Mean Serum Phosphorus From Baseline (Week 52) to the End of the Efficacy Assessment Period (EAP; Week 56)
Patients who completed the 52-week Safety Assessment Period (SAP) on KRX-0502 (ferric citrate) were randomized in a 1:1 ratio to receive either KRX-0502 (ferric citrate) or Placebo for 4 weeks.
Measured: 4 weeks

Secondary outcomes (4)

Change in Mean Serum Ferritin From Baseline to Week 52
Measured: 52 weeks
Change in Mean Serum Transferrin Saturation (TSAT) From Baseline to the End of the Safety Assessment Period (Week 52)
Measured: 52 weeks
IV Iron Analysis
Full Analysis Population, cumulative IV Iron administration from Baseline to the end of the Safety Assessment Period (Week 52)
Measured: 52 weeks
ESA Analysis
Full analysis population, cumulative Erythropoiesis-stimulating agent (ESA) administration from baseline to the end of the Safety Assessment Period (Week 52)
Measured: 52 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

Oct 2010Feb 2013

First posted30 Aug 2010 (estimated)
Study startOct 2010
Primary completionJan 2013
Study completionFeb 2013

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (2)Papers the sponsor has linked to this study.
Other trials for HyperphosphatemiaStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 3
Primary purpose: Prevention
Allocation: Randomised
Intervention model: Factorial
Masking: None (open label)
Enrolment: 441 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT01191255
Sponsor's protocol ID: KRX-0502-304
Status last verified: Dec 2014
First submitted: 26 Aug 2010
Last updated: 10 Dec 2014
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes

Publications

Natale P, Green SC, Ruospo M, Craig JC, Vecchio M, Elder GJ, Strippoli GF. Phosphate binders for preventing and treating chronic kidney disease-mineral and bone disorder (CKD-MBD). Cochrane Database Syst Rev. 2025 Jun 27;6(6):CD006023. doi: 10.1002/14651858.CD006023.pub4.
PubMed 40576086
Rodby RA, Umanath K, Niecestro R, Bond TC, Sika M, Lewis J, Dwyer JP; Collaborative Study Group. Ferric Citrate, an Iron-Based Phosphate Binder, Reduces Health Care Costs in Patients on Dialysis Based on Randomized Clinical Trial Data. Drugs R D. 2015 Sep;15(3):271-9. doi: 10.1007/s40268-015-0103-y.
PubMed 26239948

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Not yet recruitingObservational study
Tenapanor in Maintenance Hemodialysis Patients
Hyperphosphatemia, Maintenance Hemodialysis
Active, not recruitingPhase 3
A Clinical Study of TS-172 in Hyperphosphatemia Patients on Hemodialysis
Hyperphosphatemia Patients on Hemodialysis
RecruitingObservational study
Multicenter, Open, Prospective, 48 Weeks, Observational Study ,Evaluate the Safety and Efficacy of Nephoxil Capsule
Hyperphosphatemia
Recruiting
Pragmatic Randomised Trial of High Or Standard PHosphAte Targets in End-stage Kidney Disease (PHOSPHATE)
Kidney Failure, Chronic, Hyperphosphatemia
RecruitingPhase 2
Phosphate in Acute Pancreatitis
Pancreatitis

All Hyperphosphatemia trials

Study at a glance

From the registry record, last updated by the sponsor on 10 Dec 2014. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Three-Period, 58-Week Safety and Efficacy Trial of KRX-0502 (Ferric Citrate) in Patients With End-Stage Renal Disease (ESRD) on Dialysis
ClinicalTrials.gov ID: NCT01191255
Acronym / sponsor ID: KRX-0502-304
Conditions: Hyperphosphatemia, Kidney Failure
Keywords: ESRD, end-stage renal disease, dialysis, hemodialysis, peritoneal dialysis, hemodialysis (HD), peritoneal dialysis (PD), chronic renal insufficiency
Phase: Phase 3
Study type: Interventional
Recruitment status: Completed
Enrolment: 441 participants (actual)
Lead sponsor: Keryx BiopharmaceuticalsIndustry (pharma, biotech, devices)
Study start: Oct 2010
Primary completion: Jan 2013 (actual)
Study completion: Feb 2013 (actual)
First posted: 30 Aug 2010 (estimated)
Results: Posted 10 Dec 2014

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

This is up to a 58 week study comparing ferric citrate to active control for 52 weeks in ESRD dialysis patients, and subsequently comparing ferric citrate to placebo for 4 weeks.

Detailed description

Study design

Primary purpose: Prevention
Allocation: Randomised
Intervention model: Factorial
Masking: None (open label)
Number of arms: 3

Arm	Type	Receives
Active Control	Active comparator	Drug: ferric citrate, ca acetate, sevelamer carbonate, placeboPhosLo (calcium acetate) Renvela (sevelamer carbonate)
Placebo	Placebo comparator	Drug: ferric citrate, ca acetate, sevelamer carbonate, placeboPlacebo
KRX-0502 (Ferric Citrate)	Experimental	Drug: ferric citrate, ca acetate, sevelamer carbonate, placeboferric citrate

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (8 listed)

Males or non-pregnant, non-breast-feeding females
Age ≥18 years
On thrice-weekly hemodialysis or on peritoneal dialysis for at least the previous three months prior to Screening
Serum phosphorus ≥6.0 mg/dL for study entry
Taking less than 3-18 pills/day of current phosphate binder

Key exclusion criteria (13 listed)

Parathyroidectomy within six months prior to Screening
Actively symptomatic gastrointestinal bleeding or inflammatory bowel disease
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

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
ferric citrate, ca acetate, sevelamer carbonate, placeboAlso: PhosLo, Renvela, KRX-0502, ZerenexAll intervention doses will be based on serum phosphorus levels and/or drug label requirements	Drug	Active Control, KRX-0502 (Ferric Citrate), Placebo

Primary outcome

Change in Mean Serum Phosphorus From Baseline (Week 52) to the End of the Efficacy Assessment Period (EAP; Week 56)
Time frame: 4 weeks
Patients who completed the 52-week Safety Assessment Period (SAP) on KRX-0502 (ferric citrate) were randomized in a 1:1 ratio to receive either KRX-0502 (ferric citrate) or Placebo for 4 weeks.

4 secondary outcomes

Change in Mean Serum Ferritin From Baseline to Week 52
Time frame: 52 weeks
Change in Mean Serum Transferrin Saturation (TSAT) From Baseline to the End of the Safety Assessment Period (Week 52)
Time frame: 52 weeks
IV Iron Analysis
Time frame: 52 weeks
ESA Analysis
Time frame: 52 weeks

Results and safety

Results posted to the registry on 10 Dec 2014, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Active Control-SAP	149	111
KRX-0502 (Ferric Citrate)-SAP	292	193
Placebo-EAP	0	0
KRX-0502 (Ferric Citrate)-EAP	0	0

Primary outcome: Change in Mean Serum Phosphorus From Baseline (Week 52) to the End of the Efficacy Assessment Period (EAP; Week 56)

Time frame: 4 weeks. Mean (Standard Deviation). Unit: mg/dL

Measure	Active Control-SAP n = 0	KRX-0502 (Ferric Citrate)-SAP n = 0	Placebo-EAP n = 91	KRX-0502 (Ferric Citrate)-EAP n = 91
Baseline (Week 52)	–	–	5.44 (1.459)	5.12 (1.189)
End of EAP (Week 56)	–	–	7.23 (1.784)	4.89 (1.291)

Placebo-EAP vs KRX-0502 (Ferric Citrate)-EAP: p <0.0001, ANCOVA

Population analysed: Full Analysis Population (LOCF)

4 secondary outcomes are reported in the full results.

Adverse events

Time frame: Serious treatement emergent adverse events (TEAEs) up to 56 weeks. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
KRX-0502 (SAP)	114 of 289 (39.4%)	211 of 289 (73%)	Not reported
Active Control (SAP)	73 of 149 (49%)	88 of 149 (59.1%)	Not reported
KRX-0502 (EAP)	11 of 95 (11.6%)	5 of 95 (5.3%)	Not reported
Placebo (EAP)	17 of 95 (17.9%)	0 of 95 (0%)	Not reported

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 10 Dec 2014.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 40576086Natale P, Green SC, Ruospo M, Craig JC, Vecchio M, Elder GJ, Strippoli GF. Phosphate binders for preventing and treating chronic kidney disease-mineral and bone disorder (CKD-MBD). Cochrane Database Syst Rev. 2025 Jun 27;6(6):CD006023. doi: 10.1002/14651858.CD006023.pub4.
Derived from this study: PubMed 26239948Rodby RA, Umanath K, Niecestro R, Bond TC, Sika M, Lewis J, Dwyer JP; Collaborative Study Group. Ferric Citrate, an Iron-Based Phosphate Binder, Reduces Health Care Costs in Patients on Dialysis Based on Randomized Clinical Trial Data. Drugs R D. 2015 Sep;15(3):271-9. doi: 10.1007/s40268-015-0103-y.

Related trials for Hyperphosphatemia

Not yet recruitingObservational study
Tenapanor in Maintenance Hemodialysis Patients
Hyperphosphatemia, Maintenance Hemodialysis
Active, not recruitingPhase 3
A Clinical Study of TS-172 in Hyperphosphatemia Patients on Hemodialysis
Hyperphosphatemia Patients on Hemodialysis
RecruitingObservational study
Multicenter, Open, Prospective, 48 Weeks, Observational Study ,Evaluate the Safety and Efficacy of Nephoxil Capsule
Hyperphosphatemia
Recruiting
Pragmatic Randomised Trial of High Or Standard PHosphAte Targets in End-stage Kidney Disease (PHOSPHATE)
Kidney Failure, Chronic, Hyperphosphatemia
RecruitingPhase 2
Phosphate in Acute Pancreatitis
Pancreatitis

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Julia B Lewis, MD study chair

Collaborative Study Group

Samuel Blumenthal, MD study chair

Collaborative Study Group

56 sites in 3 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study of Hyperphosphatemia and Kidney Failure, run by Keryx Biopharmaceuticals at 56 sites in 3 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 10 Dec 2014. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 56 sites in United States, Israel, Puerto Rico. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 10 Dec 2014). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Mean Serum Phosphorus From Baseline (Week 52) to the End of the Efficacy Assessment Period (EAP; Week 56) (time frame: 4 weeks). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01191255, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Dec 2014.