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

High levels of phosphate in the blood are linked with serious effects, due to calcium imbalances (high levels of parathyroid hormone (PTH), bone disease, formation of calcium deposits in the body, and blood-vessel disease.

Current guidelines indicate that blood phosphorus levels should be maintained between 1.13 to 1.78 mmol/L in patients who receive hemodialysis.

The purpose of this study is to determine the range of dosages which are tolerated by patients with hyperphosphatemia, undergoing haemodialysis.

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opinion of the investigator would compromise the safety of the subject or increase the likelihood of the subject being withdrawn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