Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Double Blind, Randomized, Placebo Controlled Trial to Evaluate the Efficacy and Safety of FOSTRAP Chewing Gum in Patients With Chronic Kidney Disease and Hyperphosphatemia.
Brief Summary: The phosphorus content in saliva is increased in chronic kidney disease. We hypothesize that a chewing gum that binds salivary phosphorus would be a novel, effective agent to reduce serum levels of phosphorus in patients with chronic kidney disease. We are testing this hypothesis using a chewing gum called FOSTRAP which has been shown to be effective in a small, non-randomized study in patients with chronic kidney disease on hemodialysis.


Options:
A: Inclusion Criteria:

* Stable CKD patients who are currently on hemodialysis three times a week for at least 12 weeks prior to the acquisition of informed consent
* Patients on stable dose(s) of phosphate binder(s) for at least 28 days prior to the acquisition of informed consent.
* Patients on stable dose(s) of Vitamin D or calcitonin agent for at least 28 days prior to the acquisition of informed consent, in case patients are treated by those agents

Exclusion Criteria:

* History of major gastrointestinal surgery, or swallowing disorders, bowel obstruction, hemorrhagic gastrointestinal lesion
* Continuous severe constipation/diarrhea.
* History of parathyroid intervention \[parathyroidectomy（PTx），percutaneous ethanol injection therapy（PEIT）etc.\] within 1 year of the acquisition of informed consent
* Diet restriction such as fasting and/or excessive dieting
* Uncontrolled hypertension
B: Inclusion Criteria:

1. Men or women \> 18 years of age;
2. The subject has voluntarily signed and dated the most recent informed consent form approved by an Institutional Review Board (IRB);
3. The subject will, in the opinion of the investigator, be compliant with prescribed therapy;
4. Subject must be able to communicate and be able to understand and comply with the requirements of the study;
5. For subjects with CKD not on dialysis- kidney function at any stage that in the opinion of the investigator is stable and not expected to initiate dialysis within 3 months;
6. For subjects with CKD not on dialysis- a screening serum phosphorus value greater than or equal to 4.5 mg/dL;
7. For subjects with ESRD - a screening serum phosphorus value greater than or equal to 4.6 mg/dL and less than or equal to 9.0 mg/dL and one of the two conditions: A mean historical value of the most recent 2 phosphorus measurements ≥ 4.6 and less than or equal to 9.0 mg/dL at the time of written informed consent or A second screening serum phosphorus value greater than or equal to 4.6 mg/dL and less than or equal to 9.0 mg/dL performed not less than 7 days from the date of the previous screening;
8. In the opinion of the investigator, subjects with ESRD must be prescribed a stable dialysis regimen (3x/week) for ≥ 4 weeks prior to baseline and must have a stable dialysis access;
9. Subjects with ESRD must have an historical URR ≥ 65% for at least 4 weeks prior to baseline;
10. All subjects must have NO change in prescribed dose or frequency of any of the following medications ≥ 14 days prior to baseline:

    1. Phosphate binding products including prescribed and over-the counter
    2. Oral or injectable active vitamin D
    3. Oral nutritional vitamin D
    4. Calcimimetics
    5. Calcium supplements
    6. Anti-osteoporotic medication (e.g. bisphosphonates)
11. Subject must be prescribed a diet appropriate for patients with their stage of kidney disease, and must be willing to avoid intentional changes in diet; and
12. Subjects must have a screening salivary flow rate by Saxon test ≥ 1 g/2 min.

Exclusion criteria:

1. Receiving or has received an investigational product (or is currently using an investigational device) within 28 days prior to baseline;
2. Known sensitivity to chitin or allergy to shellfish;
3. Clinical evidence of active malignancy and/or receiving systemic chemotherapy/radiotherapy with the exception of basal cell or squamous carcinoma of the skin;
4. Clinically significant infection requiring treatment with antibiotics (within 7 days prior to baseline);
5. Inpatient hospitalization within 14 days prior to baseline with the exception of hospitalizations related to vascular access procedures;
6. Planned surgical intervention for secondary hyperparathyroidism;
7. In the opinion of the investigator, inability to chew gum for 60 minutes;
8. Planned relocation to another area within the next 4 months;
9. Subject has a known history of immunodeficiency diseases, including a positive HIV (ELISA and Western blot) test result;
10. Active drug or alcohol dependence or abuse (excluding tobacco use) in the opinion of the principal investigator;
11. Unstable medical condition which in the opinion of the investigator would compromise successful completion of the study;
12. Known active liver disease with AST or ALT levels greater than 3X the upper limit of normal; and
13. Subject has had a major cardiovascular event within 90 days of screening. The investigator should be guided by evidence of any of the following;

    1. Acute myocardial infarction
    2. Acute cerebral vascular event
    3. Vascular surgical intervention
    4. Coronary Revascularization
    5. Decompensated congestive heart failure
C: Inclusion Criteria:

* Non-dialyzed male or female patients with CKD, with a GFR of less than 30mL/min/1.73m² who have elevated serum phosphorus or who develop elevated serum phosphorus following washout from phosphorus-binding therapy.
* Patients must have written informed consent
* Negative serum pregnancy test if appropriate
* Expected to be able to comply with protocol procedures and schedule

Exclusion Criteria:

* Unstable angina pectoris
* Severe congestive heart failure
* Severe liver dysfunction
* Severe malnutrition
* Severe hyperparathyroidism
* AIDS (HIV positive subjects without AIDS are not excluded)
* Active malignancy for which the subject is receiving chemotherapy or radiation
* Subject unlikely to complete the study
* History of obstructed bowels or hypersensitivity to any of the study medications or their components
* History of swallowing disorders such as dysphagia (that would prevent the subject from taking the study drug) severe gastrointestinal motility disorders, or major GI tract surgery
* Participation in an investigational drug or device trial within 30 days of randomization
* Subjects on Vitamin D therapy
* Subjects with acute symptoms, in the last month, or current radiographic evidence of kidney stones
* Subjects who have undergone renal transplant or receiving dialysis
* Or any condition with makes patient participation not in the patients best interest
D: Inclusion Criteria:

* Stage III to V Chronic Kidney Disease
* Serum Phosphorus 4.0-6.0 mg/dL prior to Randomization
* Ferritin 300 ng/mL or less
* Transferrin Saturation (TSAT) 30% or less
* Hemoglobin \>9.0 and \<12.0 g/dL
* Must consume a minimum of 2 meals per day

Exclusion Criteria:

* Parathyroidectomy within 24 weeks of study
* gastrointestinal bleed or inflammatory bowel disease within 12 weeks of study
* Requirement for dialysis or kidney injury within 8 weeks of study
* Absolute requirement for oral iron, intravenous iron, Erythropoiesis-Stimulating Agent, blood transfusions, and Sensipar during the study
* Absolute requirement for calcium-, magnesium-, or aluminum-containing drugs with meals
* Absolute requirement for vitamin C, niacin, or nicotinamide outside of multivitamins
* History of hemochromatosis
* Allergy to iron products
* History of malignancy in last 5 years

Answer: B