A Phase 3 Study of TS-172 in Hyperphosphatemia Patients on Hemodialysis

Inclusion Criteria:

1. Hyperphosphatemia patients (outpatients) with chronic kidney disease receivinghemodialysis (HD or HDF) 3 times a week for at least 12 weeks prior to Visit 1 (Week -4)

2. Patients aged >=18 years at the time of obtaining informed consent

3. Patients with a serum phosphorus concentration of >= 3.5 mg/dL and < 5.5 mg/dL atVisit 1 (Week -4)

4. Patients whose serum phosphorus concentration at Visit 3 (Week -2) or Visit 4 (Week -1) has increased by at least 1.0 mg/dL compared with the value at Visit 1 (Week -4)and is >= 5.5 mg/dL and < 10.0 mg/dL.

Exclusion Criteria:

1. Patients with confirmed serum intact PTH concentration >500 pg/mL from Visit 1 (Week -4) to Visit 5 (Week 0)

2. Patients with serum phosphorus concentration >= 10.0 mg/dL from Visit 2 (Week -3) toVisit 4 (Week -1)

3. Patients who have undergone previous parathyroid intervention (PTx, PEIT, etc.)