A Phase 2 Study of TS-172 in Hyperphosphatemia Patients on Hemodialysis With Phosphate Binders

Inclusion Criteria: 1. Hyperphosphatemia patients (outpatients) with chronic kidney disease receiving hemodialysis (HD or HDF) 3 times a week for at least 12 weeks prior to Visit 1 (Week -3) 2. Patients aged \>= 18 years at the time of obtaining informed consent 3. Patients with a serum phosphorus concentration of \>= 5.5 mg/dL and \< 10.0 mg/dL at Visit 1 (Week -3) 4. Patients who have been prescribed at least one phosphate binder within the approved dosage, and the prescribed drug and dosage regimen should have been unchanged during the last 2 weeks prior to Visit 1 (Week -3) Exclusion Criteria: 1. Patients with confirmed serum intact PTH concentration \>500 pg/mL from Visit 1 (Week -3) to Visit 4 (Week 0) 2. Patients who have undergone previous parathyroid intervention (PTx, PEIT, etc.)