Please select the eligibility criteria that correspond to the clinical trial below.
Title: An Open-label, Randomised, Active-controlled, Parallel Group, Multicentre Phase 3 Study to Investigate the Long-term Safety, Tolerability and Efficacy of PA21 Compared With Sevelamer Carbonate in Dialysis Patients With Hyperphosphataemia. Extension Study for Protocol PA-CL-05A (NCT01324128)
Brief Summary: This is a Phase 3, randomised, active controlled, multicentre extension study to investigate the long-term safety and efficacy of PA21, a phosphate binder, for control of hyperphosphataemia in dialysis patients. This is an extension study to PA-CL-05A (NCT01324128), subjects have already been enrolled and have been treated with study medication for at least 24 weeks.


Options:
A: 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
B: Inclusion Criteria:

* Age \> 18 years
* Evidence of CKD Stages II, III or IV
* Stage II CKD; eGFR 60-89 ml/min
* Stage III CKD: eGFR 30-59 ml/min
* Stage IV CKD: eGFR 15-29 ml/min
* Proteinuria (\>200 mg/day or 300 mg/gm creatinine on a spot urine) on urinalysis on two occasions within 18 months of recruitment
* Diagnosis of diabetes and receiving at least one medication for diabetes mellitus
* HbA1c\>6.5%

Exclusion criteria:

* Age \<18
* Patients receiving active treatment for hyperphosphatemia
* Biopsy proven renal disease other than diabetic nephropathy
* Hypophosphatemia
* Hypercalcemia
* Any history of significant gastrointestinal disorders
* Any history of significant gastrointestinal surgery such as ileostomy, colostomy and colectomy.
C: Inclusion Criteria:

* age \>18 years,
* CKD stage 3-5

Exclusion Criteria:

* Existing or previous treatment within the last 1 year with a phosphate binder;
* hyperphosphatemia (\>5.6 mg/dL);
* hypophosphatemia (\<2.5 mg/dL);
* malnutrition,
* malignant neoplasms,
* current history of gastrointestinal and/or endocrine diseases.
D: Inclusion Criteria:

* Subjects who have completed treatment in Protocol PA-CL-05A
* Written Informed Consent

Exclusion Criteria:

* Hyper/hypo calcemia; hyper intact parathyroid hormone (iPTH)
* Other significant medical conditions
* Pregnancy

Answer: D