Randomized Study of Tenapanor Added to Phosphate Binders for Patients With Refractory Hyperphosphatemia

IntroductionSerum phosphorus management is important for patients with chronic kidney disease on dialysis to reduce the risk of hyperparathyroidism and ectopic vascular calcification. Phosphate binders (PBs) control serum phosphorus levels; however, some patients do not achieve adequate control with existing PBs. The similar mechanisms of action of each PB may limit their ability to lower serum phosphorus levels. Therefore, drugs with novel mechanisms of action that can be added to existing PBs to further lower serum phosphorus levels are desired. Tenapanor, a novel selective inhibitor of intestinal sodium/hydrogen exchanger 3 transporters, decreases passive phosphate absorption in the intestine, thereby decreasing serum phosphorus levels.MethodsThis study evaluated the efficacy and safety of tenapanor treatment with up-titration when added to PBs among Japanese hemodialysis patients with hyperphosphatemia poorly controlled by PBs alone. In total, 169 patients taking PBs whose serum phosphorus level was ≥6.1 and