Adults 18 to 80, any sex, with Hyperphosphatemia. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Change in Serum Phosphorus Levels During Placebo Controlled Randomized Withdrawal Period in the Responder PopulationPrimary· 12 weeks (randomized withdrawal period)
Patients with at least a 1.2 mg/dL decrease in serum phosphorus during the first 26 weeks of the study were defined as the responder population.
Group
Value
95% CI
Tenapanor 10 mg, 20 mg, 30 mg BID
0.43
± 0.199
Placebo
1.80
± 0.196
Change in Serum Phosphorus Levels During Placebo Controlled Randomized Withdrawal Period in the ITT PopulationSecondary· 12 weeks (randomized withdrawal period)
Placebo Adjusted Change in Serum Phosphorus from the beginning to the end of the Randomized Withdrawal Period in all patients
Group
Value
95% CI
Tenapanor 10 mg, 20 mg, 30 mg BID
0.22
± 0.149
Placebo
0.88
± 0.150
Serum Phosphorus From BaselineSecondary· 26 weeks (open label treatment period)
Serum Phosphorus from baseline (post washout) to end of 26 week period
Baseline Serum Phosphorus
Group
Value
95% CI
Tenapanor 10 mg, 20 mg, 30 mg BID
7.44
± 1.439
End of Period serum Phosphorus
Group
Value
95% CI
Tenapanor 10 mg, 20 mg, 30 mg BID
5.88
± 1,455
Adverse events — posted to ClinicalTrials.gov
Time frame: 1 year.
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
This Phase 3, 26-week, open label study with a 12-week, placebo-controlled, randomized withdrawal period followed by an open label long term safety extension will evaluate the safety and efficacy of tenapanor to treat hyperphosphatemia in end-stage renal disease (ESRD) on hemodialysis and peritoneal dialysis.
Publications & conference data
7 peer-reviewed publications reference this trial (live from Europe PMC):
NCT06810167 — Assessing Tenapanor as a Treatment of CF-related Constipation.
· Phase 3
· recruiting
NCT06481150 — A Novel Approach for Reducing Hyperoxaluria and Kidney Stone Risk.
· Phase 4
· completed
NCT05995899 — Effect of Tenapanor on the Metagenomics and Metabolomics of Patients With Irritable Bowel Syndrome With Constipation
· Phase 4
· completed
NCT06203444 — An Open-label Study to Evaluate the Pharmacokinetics of Oral Tenapanor in Breast Milk of Lactating Females
· Phase 1
· completed
NCT04549597 — Study to Evaluate the Use of Tenapanor as Core Therapy in the Treatment of Hyperphosphatemia
· Phase 4
· completed
Other recruiting trials for Hyperphosphatemia
Currently open trials in the same condition.
NCT06933472 — A Study of a Novel Iron-based Phosphate Binder AP301 in Patients With Hyperphosphatemia in the U.S. and China
· Phase 3
· recruiting
NCT06664125 — Evaluate the Efficacy and Safety of JMKX003002 in End-Stage Renal Disease Patients on Hemodialysis with Hyperphosphatemi
· Phase 2
· recruiting
NCT06206135 — Multicenter, Open, Prospective, 48 Weeks, Observational Study ,Evaluate the Safety and Efficacy of Nephoxil Capsule
· recruiting
NCT06186934 — Post Marketing Surveillance Study to Observe Safety and Effectiveness of NEPHOXIL ® in S. Korea Patients
· recruiting
NCT03573089 — Pragmatic Randomised Trial of High Or Standard PHosphAte Targets in End-stage Kidney Disease (PHOSPHATE)
· NA
· recruiting
Other Ardelyx trials
Trials by the same sponsor.
NCT07382167 — A 26-Wk Study to Assess Safety & Efficacy of Tenapanor for T/t of Chronic Idiopathic Constipation in Adults
· Phase 3
· recruiting
NCT06203444 — An Open-label Study to Evaluate the Pharmacokinetics of Oral Tenapanor in Breast Milk of Lactating Females
· Phase 1
· completed
NCT05643534 — Study to Assess Safety and Efficacy of Tenapanor for Treatment of IBS-C in Pediatric Patients 12 to Less Than 18 Years
· Phase 3
· recruiting
NCT04780841 — A Study Evaluating the Safety and Efficacy of RDX013 for the Treatment of Hyperkalemia
· Phase 2
· completed
NCT04549597 — Study to Evaluate the Use of Tenapanor as Core Therapy in the Treatment of Hyperphosphatemia
· Phase 4
· completed
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Ardelyx
Last refreshed: 29 June 2023
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03427125.