Study to Evaluate the Use of Tenapanor as Core Therapy in the Treatment of Hyperphosphatemia

This is a randomized, open-label study to evaluate different methods of initiating tenapanor therapy in CKD patients on dialysis with hyperphosphatemia, when they are either phosphate binder naïve or on phosphate binder therapy. The objective to evaluate the effect of tenapanor alone or in combination with phosphate binders to achieve target serum phosphorus (s-P) levels of ≤5.5 mg/dL when tenapanor is administered as the core therapy (alone or in combination with phosphate binders) for the treatment of hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis.