Approximately 207 patients with chronic kidney disease (CKD) on hemodialysis will be entered into this study at approximately 26 centers in the United States. This study aims to evaluate the safety and efficacy of sevelamer carbonate powder dosed once-a-day (QD) with the largest meal compared to sevelamer hydrochloride tablets dosed three-times-per-day (TID) with meals. The total length of participation is approximately 24 weeks.

Inclusion Criteria:

• On three times per week hemodialysis for three months or longer
• Currently on a phosphate binder(s)
• Considered compliant with phosphate binders and hemodialysis therapy
• Willing to avoid any intentional changes in diet such as fasting or dieting
• Have the following documented local laboratory measurements:a.Two most recent consecutive serum phosphorus measurements that are ≥ 3.0 and ≤ 6.5 (6.5) mg/dL within 60 days of screening; b.A most recent intact parathyroid hormone (iPTH) measurement ≤ 800 pg/mL within 90 days of screening
• Have the following central laboratory measurements: a.A serum phosphorus measurement > 5.5 mg/dL at randomization (Week 0);b.A serum iPTH measurement ≤ 800 pg/mL at screening
• Have not participated in any other investigational drug studies within 30 days prior to enrollment
• Level of understanding and willingness to cooperate with all visits and procedures as described by the study personnel
• Willing and able to take sevelamer alone as a phosphate binder for the duration of the study
• Willing and able to maintain screening doses of lipid medication for the duration of the study, except for safety reasons
• Willing and able to avoid antacids and phosphate binders containing aluminum, magnesium, calcium or lanthanum for the duration of the study unless prescribed as an evening calcium supplement
• If female and of childbearing potential (pre-menopausal and not surgically sterile), willing to use an effective contraceptive method throughout the study, which includes barrier methods, hormones, or intrauterine devices (IUDs)
• Life expectancy of 12 months or greater
• Willing and able to provide informed consent

Exclusion Criteria:

• Active bowel obstruction, dysphagia, swallowing disorder, or severe gastrointestinal (GI) motility disorders
• Active ethanol or drug abuse, excluding tobacco use
• In the opinion of the Investigator, subject has poorly controlled diabetes mellitus, poorly controlled hypertension, active vasculitis, HIV infection, or any clinically significant unstable medical condition
• Use of anti-arrhythmic or anti-seizure medications for the use of arrhythmia or seizure disorders
• Known hypersensitivity to sevelamer or any constituents of the study drug
• Pregnant or breast-feeding
• Evidence of active malignancy except for basal cell carcinoma of the skin
• Unable to comply with the requirements of the study
• Any other condition which, in the opinion of the Investigator, will prohibit the subject's inclusion in the study