Ardelyx Inc (NASDAQ: ARDX) is a commercial-stage biopharmaceutical company that develops and sells prescription medicines targeting gastrointestinal and renal conditions. Revenue comes from U.S. product sales of two approved drugs: IBSRELA (tenapanor), approved for irritable bowel syndrome with constipation (IBS-C), and XPHOZAH (tenapanor), FDA-approved in October 2023 to reduce serum phosphorus in adults with chronic kidney disease (CKD) on dialysis. Both products share the same active compound, tenapanor, a sodium-hydrogen exchanger isoform 3 (NHE3) inhibitor. Ardelyx commercializes both products in the U.S. through its own sales organization and has executed collaboration agreements with external partners for ex-U.S. territories. The company was founded in October 2007 and has incurred losses in every year since inception, funding operations through product sales, equity issuances, loan agreements with SLR, collaboration partnerships, and the sale of future royalties and commercialization milestones to HCR. A Phase 3 trial for an IBSRELA label extension into chronic idiopathic constipation (CIC) began in January 2026, with topline data expected in the second half of 2027.

Revenue model

Product sales of two FDA-approved prescription drugs, IBSRELA and XPHOZAH, in the U.S. market. Supplementary funding has come from collaboration partnerships, equity offerings under at-the-market programs, loan agreements with SLR, and the sale of future royalties and commercialization milestones to HCR.

Products and services

IBSRELA (tenapanor): approved for IBS-C in adults. XPHOZAH (tenapanor): FDA-approved October 2023 as a first-in-class phosphate absorption inhibitor for adults with CKD on dialysis. Both products use tenapanor as the active ingredient, acting locally in the gut to inhibit NHE3. A next-generation NHE3 inhibitor is in discovery-stage development.

Customers and end markets

Adult patients in the U.S. with IBS-C (IBSRELA) and adults with CKD on dialysis who have inadequate response to or intolerance of phosphate binders (XPHOZAH). The estimated U.S. dialysis patient population exceeds 550,000 adults, with approximately 80% receiving phosphate-lowering therapy as of the FY2025 10-K filing. Prescribers are primarily gastroenterologists and nephrologists. Medicare beneficiaries represent a significant payer segment; XPHOZAH moved into the ESRD Prospective Payment System (ESRD PPS) on January 1, 2025, removing Medicare Part D coverage and materially reducing XPHOZAH revenue in FY2025.

Value-chain role

Commercial-stage drug developer and seller. Ardelyx handles drug discovery, clinical development, regulatory affairs, and U.S. commercialization directly. Manufacturing is outsourced to third-party contract manufacturers, including single-source suppliers. Ex-U.S. commercialization is handled through collaboration partners.

Geographic exposure

Primarily U.S. commercial operations. Ex-U.S. territories for IBSRELA and XPHOZAH are covered through collaboration agreements. Patents for tenapanor have been issued in the U.S., Europe, Japan, China, Australia, and other countries.

Source: SEC 10-K, filed 2026-02-19

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