WALTHAM, Mass., April 27, 2026 (GLOBE NEWSWIRE) -- Ardelyx, Inc. (NASDAQ:ARDX), a commercial-stage biopharmaceutical company focused on the development and commercialization of innovative medicines that meet significant unmet medical needs, today announced an abstract accepted for poster presentation, sharing data on the long-term impact of XPHOZAH® (tenapanor) on serum electrolytes and select nutrition biomarkers, at the National Kidney Foundation's (NKF) Spring Clinical Meetings, to be held May 7-10, 2026, in New Orleans.

XPHOZAH, the first and only phosphate absorption inhibitor (PAI), is approved by the U.S. Food and Drug Administration 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.

Information regarding NKF Spring Clinical Meetings, including the presentation abstract, can be found here.

Tenapanor Decreases Serum Phosphate Without Altering Other Serum Electrolytes in Patients with Chronic Kidney Disease with Hyperphosphatemia on Dialysis

Authors: Pablo E. Pergola, Yang Yang, Suling Zhao, Elizabeth Stremke, Susan Edelstein, David M. Spiegel

Poster: G-353

Display time: May 7, 2026, 5:15 - 7:30 PM CT

In addition to the poster presentation during NKF Spring Clinical Meetings, Ardelyx is sponsoring a Peer Exchange, titled "Treating Hyperphosphatemia and Side Effect Management," on May 8 at 12:15 PM CT, where Lisa Gutekunst, MSEd, RD, CSR, CDN, will facilitate a peer exchange session discussing first-in-class PAI XPHOZAH. The session will review the XPHOZAH mechanism of action, efficacy and safety data, and practical considerations for XPHOZAH as add-on therapy for the many dialysis patients on a phosphate binder with serum phosphorus levels above guideline-established targets.

About XPHOZAH® (tenapanor)

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. Please see additional full Prescribing Information.

About Hyperphosphatemia

Hyperphosphatemia is a serious condition, defined as elevated levels of phosphate in the blood, which affects the vast majority of the 550,000 patients in the United States with chronic kidney disease (CKD) on maintenance dialysis. The kidneys are responsible for eliminating excess phosphate and as kidney function declines, phosphate is not adequately eliminated from the body. As a result, hyperphosphatemia is a nearly universal condition among people with CKD on maintenance dialysis, with internationally recognized KDIGO treatment guidelines that recommend lowering elevated phosphate levels toward the normal range (2.5-4.5mg/dL).

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

XPHOZAH is contraindicated in:

Pediatric patients under 6 years of age
Patients with known or suspected mechanical gastrointestinal obstruction

WARNINGS AND PRECAUTIONS

Diarrhea

Patients may experience severe diarrhea. Treatment with XPHOZAH should be discontinued in patients who develop severe diarrhea.

MOST COMMON ADVERSE REACTIONS

Diarrhea, which occurred in 43-53% of patients, was the only adverse reaction reported in at least 5% of XPHOZAH-treated patients with CKD on dialysis across trials. The majority of diarrhea events in the XPHOZAH-treated patients were reported to be mild-to-moderate in severity and resolved over time, or with dose reduction. Diarrhea was typically reported soon after initiation but could occur at any time during treatment with XPHOZAH. Severe diarrhea was reported in 5% of XPHOZAH-treated patients in these trials.

INDICATION

XPHOZAH (tenapanor), 30 mg BID, is indicated 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.

For additional safety information, please see full Prescribing Information.

About Ardelyx

Ardelyx is a commercial-stage biopharmaceutical company focused on the development and commercialization of innovative medicines that meet significant unmet medical needs. Ardelyx has two commercial products approved in the United States, IBSRELA® (tenapanor) and XPHOZAH® (tenapanor). The company's pipeline includes the Phase 3 development of IBSRELA for chronic idiopathic constipation (CIC) and RDX10531, a next-generation NHE3 inhibitor with potential application across multiple therapeutic areas. Ardelyx works with its partners to develop and commercialize its products outside of the United States. For more information, please visit https://ardelyx.com/ and connect with us on X (formerly known as Twitter), LinkedIn and Facebook.

Investor Contact:

Lisa Caperelli

SVP, Investor Relations & Corporate Communications

lcaperelli@ardelyx.com

Media Contact:

Lindsey Manuel

Associate Director, Corporate Communications

lmanuel@ardelyx.com

Ardelyx Announces Abstract Accepted for Poster Presentation at the NKF's Spring Clinical Meetings