Abstract: TH-PO0223
Tenapanor Improves Bowel Movements in Patients with ESKD and Mild to Severe Constipation
Session Information
- Bone and Mineral Metabolism: Clinical Reports and Practice
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 502 Bone and Mineral Metabolism: Clinical
Authors
- Fishbane, Steven, Zucker School of Medicine at Hofstra & Northwell Health, Great Neck, New York, United States
- Zhao, Suling, Ardelyx, Inc., Waltham, Massachusetts, United States
- Yang, Yang, Ardelyx, Inc., Waltham, Massachusetts, United States
- Edelstein, Susan A., Ardelyx, Inc., Waltham, Massachusetts, United States
- Spiegel, David M., Ardelyx, Inc., Waltham, Massachusetts, United States
Background
Tenapanor (TEN) is approved to reduce serum phosphorus in adults with chronic kidney disease on dialysis as add-on therapy in patients (pts) who have an inadequate response to phosphate binders (PBs) or who are intolerant of any dose of PB therapy. Constipation occurs in 30%-40% of pts with end-stage kidney disease (ESKD) receiving dialysis, and while uncomfortable for all, it often impairs the effectiveness of peritoneal dialysis. This study examines the effects of TEN on stool frequency and consistency in pts with ESKD who experienced constipation at baseline.
Methods
In this post hoc analysis of the phase 3 BLOCK study (NCT02675998), pts on hemodialysis with ESKD and hyperphosphatemia were randomized to receive 3 mg, 10 mg, or 30 mg TEN twice daily for 8 weeks. Daily eDiary entries tracked stool frequency and consistency via the Bristol Stool Form Scale (BSFS). Pts were categorized into 2 groups based on baseline weekly stool frequency (BWSF): ≤6 (constipation) and ≤3 (severe constipation).
Results
After the 8-week randomized treatment period (RTP), similar reductions in serum phosphate (mean [SE]) were observed in both groups (BWSF ≤6, 1.0 [0.2 mg/dL]); BWSF ≤3, 1.1 [0.7]). In pts with BWSF ≤6, weekly stool frequency increased from a mean (SE) of 4.7 (0.2) at baseline to 8.2 (0.7), and weekly stool consistency score improved from a mean (SE) of 2.7 (0.1) to 4.0 (0.2) during the End of Treatment (EOT) week of the RTP (P<0.001 for both; Figure). In pts with BWSF ≤3, weekly stool frequency increased from constipation at baseline (mean [SE] of 2.3 [0.3]) to within the normal range (6.3 [1.9]; P<0.05); weekly stool consistency score also normalized from constipation (BSFS 1.4 [0.1]) to 3.3 (0.7) during the EOT week of the RTP (P=0.02). No unexpected safety signals were observed in this study.
Conclusion
Improved weekly stool frequency and stool consistency were observed in pts with ESKD who experienced constipation at baseline and were taking TEN to reduce serum phosphate.
Funding
- Commercial Support – Ardelyx, Inc.