Inclusion:

Subjects will be considered eligible for entry in the study if they meet all of the following criteria.

1. Male or female, aged ≥18 years.
2. Able to comply with the study procedures and medication.
3. Written informed consent given.
4. On a stable hemodialysis regimen (at least 3x per week) for ≥12 weeks prior to screening.
5. (a) Subject receiving phosphate binder medication(s) at screening, must have been on a stable regimen (dose and medication) for at least 1 month prior to screening and will remain on this regimen until entry into the washout period OR(b) Subjects (i) is not currently receiving any phosphate binding medication at screening (or medication likely to act as a phosphate binder) and (ii) must not have done so for at least one month and (iii) has sustained hyperphosphatemia.
6. Willing to abstain from taking any phosphate binder or oral magnesium-, oral aluminum- or oral iron-containing products and preparations other than the study medication.

7. If required to take >6000 mg/day of fermagate, the subject will be willing to have at least three meals per day.

   Specifically, for randomization and inclusion into the treatment period, one of the following criteria must be fulfilled:

8. (a) Is not receiving phosphate binding medication at screen and has a screen serum phosphate value above 3.0 mmol/L (9.3 mg/dL)OR(b) Has a serum phosphate value of ≥1.94 mmol/L (≥6.0 mg/dL) at Washout Visit 2 to 4 or above 3.0 mmol/L (9.3 mg/dL) at visit 1 during washout.

Exclusion:

Subjects will not be considered eligible for entry in the study if they meet one or more of the following criteria.

1. Participation in any clinical trial using an investigational product or device during the 30 days preceding the Screening Visit.
2. Previous experience of fermagate treatment.
3. A significant history of alcohol, drug or solvent abuse in the opinion of the investigator.
4. Any disease or condition, physical or psychological that, in the opinion of the investigator, would compromise the safety of the subject or the likelihood of achieving reliable results or increase the likelihood of the subject being withdrawn.
5. Laboratory findings at screening which, in the opinion of the investigator, are clinically significant for this subject population.
6. A screen serum magnesium concentration of >3.0 mg/dL (>1.25 mmol/L).
7. A known history of hemochromatosis.
8. Subjects receiving either tetracycline or lithium treatment.
9. Subjects receiving nicotinamide (niacinamide) or niacin (nicotinic acid) alone (i.e. not as a constituent of a multivitamin supplementation).
10. A serum ferritin level of ≥1500 ng/mL (≥3370 pmol/L).
11. Non-elective hospitalization in the 4 weeks prior to screening.
12. Female subjects who are of childbearing potential and who are neither surgically sterilized nor using reliable contraceptive methods (hormonal, barrier methods or intrauterine device) or who are lactating or pregnant.
13. Current hypophosphatemia at screening (last 2 consecutive phosphate values of <2.2 mg/dL [<0.7 mmol/L]).
14. Known history of colorectal malignancy, familial polyposis coli and/or strong family history (in 2 or more first degree relatives) of these terms
15. A QTcF interval of >560 ms at screen.
16. Known persistent (>1 month) non compliance (<70%) with prescribed medication regimens at screen.
17. Current clinically significant intestinal motility disorder.
18. Intestinal motility disorder with current or previous use of lanthanum carbonate.
19. Known intolerance to lanthanum carbonate or any excipients of fermagate or Fosrenol medication.
20. Subjects with inflammatory bowel disease that, in the investigator's opinion, is poorly controlled.
21. Subjects placed under guardianship or tutelage.
22. Subjects previously withdrawn from the study.

The above inclusion and exclusion criteria would be the same for all countries except the exclusion criteria of the QTc interval would be different for Germany (QTc interval of >470ms at screen).