Dose Ranging Study of Magnesium Iron Hydroxycarbonate in Haemodialysis Subjects With Hyperphosphataemia

Inclusion Criteria: * Male or female subjects on active haemodialysis, aged 18 years or over who are able to comply with study procedures * Written informed consent given * On a stable haemodialysis regimen (three times per week) for at least 3 months and be unlikely to change their dialysis prescription during the study period * On a stable dose of phosphate binder for at least 1 month prior to screening * Willing to abstain from taking any phosphate binder or oral magnesium-, aluminium- or iron-containing products and preparations, other than the study medication * Willing to avoid any intentional changes in diet such as fasting, dieting or overeating * On a dialysate magnesium ion concentration of ≤1.0 mmol/L for at least 1 month prior to screening Exclusion Criteria: * Received a cardiac transplant * Heart failure according to New York Heart Association (NYHA) Functional IV Classification * Participation in any other clinical trial using an investigational product or device within the previous 4 weeks * A significant history of alcohol, drug or solvent abuse in the opinion of the investigator * Any disease or condition, physical or psychological, which in the opinion of the investigator would compromise the safety of the subject or increase the likelihood of the subject being withdrawn * Clinically significant laboratory findings (at screening for this subject population) in the opinion of the investigator * Any history of recent clinically significant malignancy * A significant illness (excluding renal disease) in the 4 weeks before screening * A history of poorly controlled epilepsy * Female subjects who are lactating or pregnant. Women of childbearing potential (pre-menopausal and not surgically sterilised) unless they are using a reliable contraceptive method, that is, barrier methods, hormones or intrauterine device * Allergy to magnesium iron hydroxycarbonate or sevelamer or any component of the formulations * Any condition that affects the reliability of measuring QT interval, for example, an irregular heart rhythm such as atrial fibrillation or frequent ectopic activity