To assess the effect on reduction of serum phosphate and the safety of BAY77-1931 (Lanthanum Carbonate) in patients with hyperphosphatemia undergoing hemodialysis in a randomized, double-blind, parallel group study in comparison with Calcium carbonate.

Inclusion Criteria:

• Pre-dialysis serum phosphate levels: ≧5.6 mg/dL and <11.0 mg/dL at 1 week after the initiation of the washout period.
• Out-patient
• Undergoing hemodialysis three times per week for at least previous 3 consecutive months

Exclusion Criteria:

• Pre-dialysis serum phosphate levels of ≧10.0 mg/dL at the start of the washout period or ≧11.0 mg/dL at 1 week after
• Corrected serum calcium level of <7.0 mg/dL or ≧11.0 mg/dL at the start of the washout period and/or 1 week after
• Serum intact PTH (Parathyroid) of ≧1000 pg/mL at the start of the washout period
• Pregnant woman, or lactating mother
• Significant gastrointestinal disorders including known acute peptic ulcer
• Liver dysfunction
• History of cardiovascular or cerebrovascular diseases
• Requiring treatment for hypothyroidism