Tenapanor: A Phosphate Absorption Inhibitor for the Management of Hyperphosphatemia in Patients With Kidney Failure.

Because of increased risks of cardiovascular disease and death, patients with hyperphosphatemia receiving maintenance dialysis are advised to limit phosphorus consumption and are prescribed phosphate binders in an effort to better control serum phosphate concentrations. Because of large pill size, pill burden, and tolerability issues, phosphate binder adherence is relatively poor. On ingestion, phosphate is absorbed from the intestine via transcellular or paracellular transport. Data show that inhibiting sodium-hydrogen exchanger 3 modulates paracellular phosphate absorption (the predominant pathway in humans). Tenapanor is a first-in-class, minimally absorbed, phosphate absorption inhibitor that selectively inhibits sodium-hydrogen exchanger 3, with a mechanism distinct from, and complementary to, that of phosphate binders. In phase 3 and postregistrational studies, tenapanor conferred statistically significant and clinically meaningful reductions in serum phosphate in patients receiving maintenance dialysis with hyperphosphatemia. Here, we review the available preclinical and clinical data on the effects of tenapanor on controlling intestinal phosphate absorption.