A Phase 3 interventional study of Ferric Citrate 1 GM Oral Tablet [AURYXIA] and Placebo in Anemia, Iron Deficiency, Hyperphosphatemia and Renal Insufficiency, Chronic, sponsored by USRC Kidney Research. Completed at 23 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-08-29.
Sponsored by USRC Kidney Research · Phase 3, Interventional, and Treatment
A 9-month randomized, double-blind, placebo-controlled study to compare the effect of fixed dose ferric citrate versus placebo in patients with advanced chronic kidney disease (eGFR ≤20 ml/min/1.73m2) on the composite endpoint of time to initiation of maintenance dialysis or all-cause mortality.
This multicenter, randomized, double-blind, placebo-controlled clinical trial is being conducted to determine the effect of ferric citrate on the time to a composite endpoint of initiation of maintenance dialysis or all-cause mortality in patients with non-dialysis dependent, advanced CKD. Up to 400 subjects will be randomized in 1:1 ratio to receive either ferric citrate or matching placebo. All subjects will initiate dosing at 2 tablets per meal or snacks, up to 3 times per day (maximum of 6 tablets per day). The dose of ferric citrate/placebo will only be adjusted based on safety and/or tolerability. Given the double-blind design of this trial, investigators will be instructed to not prescribe commercial Auryxia to either study arm. Study visits during the treatment period are to be conducted as part of routine scheduled clinical encounters. Standard of care local laboratory results will be collected however no study specific laboratory tests other than a pregnancy test in women of child-bearing potential will be required.
600 studies on the registry are indexed under Anemia, Iron-Deficiency; 95 are open to participants now.
This study's enrollment of 289 is above the median of 100 across 459 interventional studies indexed under Anemia, Iron-Deficiency.
Browse Anemia, Iron-Deficiency studies →USRC Kidney Research is the lead sponsor of 4 studies on the registry; none are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Supplied as tablets for oral administration containing 1 gram ferric citrate (210 milligrams of ferric iron). Administered orally with meals or snacks.
Drug: Ferric Citrate 1 GM Oral Tablet [AURYXIA]
Tablets, matching in color and size to ferric citrate.
Drug: Placebo
All subjects will be instructed to take study drug (ferric citrate or placebo) at a fixed dose of 2 tablets per meal or snacks, up to three times per day. The maximum dose is 6 tablets per day. No additional tablets (beyond a total of 6 per day) should be taken. Tablets should not be crushed or chewed.
Also known as: Auryxia
All subjects will be instructed to take study drug (ferric citrate or placebo) at a fixed dose of 2 tablets per meal or snacks, up to three times per day. The maximum dose is 6 tablets per day. No additional tablets (beyond a total of 6 per day) should be taken. Tablets should not be crushed or chewed.
Number of Participants Achieving a Composite Endpoint of Initiation of Maintenance Dialysis or All-cause Mortality
Number of participants achieving a composite endpoint of initiation of maintenance dialysis or all-cause mortality
Time frame: 9 months
Hospitalization Events Reported as a Serious Adverse Event (SAE) (Excluding Disease-related Hospitalization [e.g., Dialysis Access Placement, Dialysis Initiation, Kidney Transplant] and Elective Procedures)
Number of hospitalization events reported as a serious adverse event (SAE) (excluding disease-related hospitalization \[e.g., dialysis access placement, dialysis initiation, kidney transplant\] and elective procedures)
Time frame: 9 months
Component of Primary - Initiation of Maintenance Dialysis
Component of Primary - Number of participants initiating maintenance dialysis
Time frame: 9 months
Component of Primary - All-Cause Mortality
Component of Primary - Number of patients reaching endpoint of all-cause mortality.
Time frame: 9 months
This was a randomized, double-blind, placebo-controlled clinical trial to assess the effect of ferric citrate on the time to a composite endpoint of initiation of maintenance dialysis or all-cause mortality compared with placebo in adults with advanced chronic kidney disease.
| Milestone | Ferric Citrate | Placebo |
|---|---|---|
| Started | 144 | 145 |
| Received day 1 dose | 138 | 136 |
| Completed | 88 | 77 |
| Not completed | 56 | 68 |
Number of participants achieving a composite endpoint of initiation of maintenance dialysis or all-cause mortality
| Participants | Ferric Citrate | Placebo |
|---|---|---|
| Number of Participants Achieving a Composite Endpoint of Initiation of Maintenance Dialysis or All-cause Mortality | 35 | 46 |
Number of hospitalization events reported as a serious adverse event (SAE) (excluding disease-related hospitalization \[e.g., dialysis access placement, dialysis initiation, kidney transplant\] and elective procedures)
| Number of hospitalizations per patient | Ferric Citrate | Placebo |
|---|---|---|
| Hospitalization Events Reported as a Serious Adverse Event (SAE) (Excluding Disease-related Hospitalization [e.g., Dialysis Access Placement, Dialysis Initiation, Kidney Transplant] and Elective Procedures) | 1.1 ± 2.4 | 2.5 ± 9.4 |
Component of Primary - Number of participants initiating maintenance dialysis
| Participants | Ferric Citrate | Placebo |
|---|---|---|
| Component of Primary - Initiation of Maintenance Dialysis | 24 | 29 |
Component of Primary - Number of patients reaching endpoint of all-cause mortality.
| Participants | Ferric Citrate | Placebo |
|---|---|---|
| Component of Primary - All-Cause Mortality | 1 | 4 |
Collected over Serious Adverse Events and Adverse Events of Special Interest were collected from initiation of study drug treatment through the 10 months.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Ferric Citrate | 2/138 (1.4%) | 33/138 (23.9%) | 0/138 (0%) |
| Placebo | 6/136 (4.4%) | 43/136 (31.6%) | 0/136 (0%) |
| Event | Ferric Citrate | Placebo |
|---|---|---|
| Cardiac failure congestiveCardiac disorders | 6/138 | 6/136 |
| Acute kidney injuryRenal and urinary disorders | 3/138 | 5/136 |
| AnaemiaBlood and lymphatic system disorders | 1/138 | 4/136 |
| Cardiac arrestCardiac disorders | 1/138 | 4/136 |
| PneumoniaInfections and infestations | 1/138 | 3/136 |
| SyncopeNervous system disorders | 0/138 | 3/136 |
| SepsisInfections and infestations | 3/138 | 1/136 |
| Respiratory syncytial virus infectionInfections and infestations | 0/138 | 2/136 |
| Hip fractureInjury, poisoning and procedural complications | 1/138 | 2/136 |
| Fluid overloadMetabolism and nutrition disorders | 1/138 | 2/136 |
This patient population includes those patients that were consented, eligible to be enrolled, randomized, and received a Day 1 dose.
| Age, Continuous(years) | Ferric Citrate | Placebo | Total |
|---|---|---|---|
| Mean | 66.3 ± 13.1 | 68.2 ± 12.9 | 67 ± 13 |
| Sex: Female, Male(Participants) | Ferric Citrate | Placebo | Total |
|---|---|---|---|
| Female | 79 | 71 | 150 |
| Male | 59 | 65 | 124 |
| Race (NIH/OMB)(Participants) | Ferric Citrate | Placebo | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 0 | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 24 | 21 | 45 |
| White | 94 | 97 | 191 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 20 | 18 | 38 |
| Comorbid conditions at baseline(Participants) | Ferric Citrate | Placebo | Total |
|---|---|---|---|
| Atherosclerotic cardiovascular disease | 41 | 55 | 96 |
| Congestive heart failure | 20 | 30 | 50 |
| Diabetes | 92 | 86 | 178 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Ran from Mar 2022 to primary completion in Jan 2024, 21 months.
Results were first posted in Aug 2025, 1 year 7 months after primary completion.
Of 48 phase 3 interventional studies under Anemia, Iron-Deficiency, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 14 and three quarters within 41. This study's 21 months is close to that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Apr 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Tetraferric tricitrate decahydrate
USRC Kidney Research