Ardelyx, Inc. shared positive data on the use of XPHOZAH®? (tenapanor) in poster presentations at the American Society of Nephrology (ASN) Kidney Week 2023 meeting, currently being held in Philadelphia, Pennsylvania, and will showcase XPHOZAH in an Exhibitor Spotlight event. Ardelyx's presence at Kidney Week 2023 will honor the memory of Derek Forfang, Chair of the Ardelyx Patient Advisory Council and a passionate advocate for patients with kidney disease.

XPHOZAH, the first and only phosphate absorption inhibitor, was approved by the U.S. Food and Drug Administration on October 17, 2023 to reduce serum phosphorus in adults with chronic kidney disease (CKD) on dialysis as add-on therapy in patients who have an inadequate response to phosphate binders or who are intolerant of any dose of phosphate binder therapy. XPHOZAH offers a different mechanism of action that blocks phosphate absorption at the primary pathway and is administered as a single tablet taken twice daily. The first poster, titled Optimal Initiation of Tenapanor Treatment Analyzed by Baseline Phosphate Binder Dose: A Sub-analysis of the OPTIMIZE Study, looked at serum phosphate (sP) control across two cohorts of patients by phosphate lowering pill burden.

In OPTIMIZE, Cohort 1 added tenapanor 30 mg twice a day and stopped using phosphate binders, while Cohort 2 added tenapanor 30 u mg twice a day and reduced their phosphate binder dose by 50%. The OPTIMIZE study showed that both cohorts experienced improved sP control and improved patient reported quality of life, as well as a reduction in pill burden. This analysis suggests that patients on high phosphate binder dosage (more than six pills per day) may have better early sP control by initiating tenapanor with a 50% reduction in phosphate binder dosage, while patients on lower dosage of phosphate binders had similar early sP control regardless of the tenapanor initiation strategy.

In a poster titled Patient Education Improves Adherence to Tenapanor Treatment in OPTIMIZE Study, researchers looked at the effect of patient education on adherence, using data from the OPTIMIZE study compared to data from two phase 3 clinical studies of tenapanor, BLOCK and PHREEDOM. In the OPTIMIZE study, patients were provided with a patient brochure including information on how to take tenapanor, what they might experience while on the medication, which medications should be discontinued and ways to mitigate potential onset of loose stools or diarrhea. The study found that this educational information improved adherence, and may have specifically reduced medication discontinuation due to changes in bowel habits.

XPHOZah, discovered and developed by Ardelyx, is a first-in-class, phosphate absorption inhibitor with a differentiated mechanism of action that acts locally in the gut to inhibit the sodium hydrogen exchanger 3 (NHE3), thereby reducing phosphate absorption through the paracellular pathway, the primary pathway of phosphate absorption. XPHOZAH is a single tablet, taken twice daily. Diarrhea was the most common side effect experienced by patients taking XPHOZAH in clinical trials.