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

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.

Age

18–any

Sex

ALL

Healthy volunteers

Not accepted

You may be eligible if

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.

You may not be if

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

What this study is about