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

A Long-Term Safety Extension Trial of KRX-0502 (Ferric Citrate) in Patients With End-Stage Renal Disease (ESRD) on Dialysis

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01554982
Enrollment
168
Registered
2012-03-15
Start date
2012-08-31
Completion date
2014-08-31
Last updated
2016-07-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

End Stage Renal Disease, ESRD, Hyperphosphatemia, Kidney Failure, Renal Failure

Keywords

Participation Limited, Long Term, Safety Extension

Brief summary

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.

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.

Interventions

DRUGferric citrate

Dose based on monthly serum phosphorus levels with goal of 3.5-5.5 mg/dL for all patients.

Sponsors

Keryx Biopharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
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.

Design outcomes

Primary

MeasureTime frameDescription
Safety Parameters48 WeeksSafety 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

MeasureTime frameDescription
Serum Phosphorus- Week 4848 weeks—
Ferritin- BaselineBaseline—
Ferritin- Week 4848 weeks—
Transferrin Saturation (TSAT) - BaselineBaseline—
Serum Phosphorus- BaselineBaseline—
Hemoglobin- BaselineBaseline—
Hemoglobin- Week 4848 weeks—
IV Iron Use48 weeksPercent of subjects with No IV iron intake from first dose of study drug to Week 48
TSAT- Week 4848 weeks—

Countries

Puerto Rico, United States

Participant flow

Participants by arm

ArmCount
Ferric Citrate
ferric citrate: Dose based on monthly serum phosphorus levels with goal of 3.5-5.5 mg/dL for all patients.
166
Total166

Baseline characteristics

CharacteristicFerric Citrate
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
31 Participants
Age, Categorical
Between 18 and 65 years
135 Participants
Age, Continuous55.1 years
STANDARD_DEVIATION 11.06
Region of Enrollment
Puerto Rico
2 participants
Region of Enrollment
United States
164 participants
Sex: Female, Male
Female
63 Participants
Sex: Female, Male
Male
103 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
142 / 166
serious
Total, serious adverse events
75 / 166

Outcome results

Primary

Safety Parameters

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).

Time frame: 48 Weeks

Population: Safety Population; Treatment Emergent Adverse Events (TEAEs), not including SAEs, reported include only those occurring at a frequency \>5%

ArmMeasureGroupValue (NUMBER)
Ferric CitrateSafety ParametersSubjects with at least 1 TEAE142 participants
Ferric CitrateSafety ParametersSubjects with at least 1 related TEAE35 participants
Ferric CitrateSafety ParametersSubjects with at least 1 serious TEAE75 participants
Ferric CitrateSafety ParametersSubjects with at least 1 related, serious TEAEa0 participants
Ferric CitrateSafety ParametersTotal # of deaths10 participants
Other Pre-specified

Ferritin- Baseline

Time frame: Baseline

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateFerritin- Baseline709.7 ng/mLStandard Deviation 385.11
Other Pre-specified

Ferritin- Week 48

Time frame: 48 weeks

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateFerritin- Week 48821.0 ng/mLStandard Deviation 411.54
Other Pre-specified

Hemoglobin- Baseline

Time frame: Baseline

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateHemoglobin- Baseline11.1 g/dLStandard Deviation 1.36
Other Pre-specified

Hemoglobin- Week 48

Time frame: 48 weeks

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateHemoglobin- Week 4811.3 g/dLStandard Deviation 1.38
Other Pre-specified

IV Iron Use

Percent of subjects with No IV iron intake from first dose of study drug to Week 48

Time frame: 48 weeks

ArmMeasureValue (NUMBER)
Ferric CitrateIV Iron Use59.0 percentage of participants
Other Pre-specified

Serum Phosphorus- Baseline

Time frame: Baseline

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateSerum Phosphorus- Baseline5.7 mg/dLStandard Deviation 1.66
Other Pre-specified

Serum Phosphorus- Week 48

Time frame: 48 weeks

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateSerum Phosphorus- Week 485.2 mg/dLStandard Deviation 1.34
Other Pre-specified

Transferrin Saturation (TSAT) - Baseline

Time frame: Baseline

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateTransferrin Saturation (TSAT) - Baseline32.4 percentage of saturationStandard Deviation 13.51
Other Pre-specified

TSAT- Week 48

Time frame: 48 weeks

ArmMeasureValue (MEAN)Dispersion
Ferric CitrateTSAT- Week 4840.3 percentage of saturationStandard Deviation 19.12

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026