Tenapanor reduces phosphate binder pill burden among hemodialysis patients in a post hoc phase 3 analysis

Using phosphate binders (PBs) to control hyperphosphatemia in patients undergoing hemodialysis is associated with substantial pill burden. In this post hoc phase 3 analysis, we evaluated the benefit of the selective sodium/hydrogen exchanger isoform 3 inhibitor, tenapanor, in reducing pill burden in these patients. Patients received oral tenapanor starting at 5 mg twice daily and PBs. Dose adjustments of PBs and tenapanor were based on serum phosphorus levels. Changes in daily PB pill count, daily equivalent dose of PBs, number of combined PBs used, PB dose frequency, and tenapanor dose at Week 50 were analyzed according to patient background factors. The analysis comprised 204 patients (followed up for Week 50: 154 patients). Factors affecting the tenapanor dose at Week 50 were sex (P = 0.029), age (< 65 vs. ≥ 65 years; P = 0.008), normalized protein catabolic rate (< 0.80 vs. ≥ 1.00; P = 0.019), presence of diabetic nephropathy (P = 0.038), constipation (P = 0.015), and the occurrence of diarrhea as an adverse event (P = 0.009). Tenapanor consistently reduced the daily PB pill count and equivalent dose of PBs from baseline to Week 50 across all patient background factors evaluated (all P < 0.001 vs. baseline), thus demonstrating the clinical benefit of tenapanor regardless of patient background characteristics.Clinical Trial Registration ClinicalTrials.Gov (NCT04771780).