Ardelyx (NASDAQ:ARDX) executives outlined commercial momentum for IBSRELA and XPHOZAH, key investment priorities for 2026, and development plans for a chronic idiopathic constipation (CIC) expansion at a Global Healthcare Conference, highlighting what management characterized as improving execution and increasing confidence in long-term growth targets.
Commercial update: IBSRELA growth and 2026 priorities
Chief Commercial Officer Eric Foster said IBSRELA delivered 73% growth in 2025, which he said strengthened the company’s confidence entering 2026. Foster described 2025 as a year focused on execution, noting the company “beat and raised” guidance for IBSRELA multiple times during the year.
Foster also pointed to additional growth drivers the company is emphasizing in 2026, including reimbursement support, distribution strategy, and patient engagement.
- Field access/reimbursement expansion: Ardelyx expanded its field access team in 2025 and plans to continue investing in that group in 2026 to help “pull through” prescriptions once patients are identified.
- Distribution network focus: Foster said the company’s “IBSRELA Pharmacy Network” is intended to improve fulfillment and refill performance versus retail, citing higher fulfillment rates and, on average, more refills when prescriptions go through that limited distribution network.
- Patient engagement: Management described the IBS-C patient population as highly motivated and said engagement efforts can help drive patients to discuss IBSRELA with physicians.
Path to the company’s 2029 IBSRELA target and prescribing mix
Management reiterated prior commentary that IBSRELA is expected to exceed $1 billion in revenue in 2029. Foster said the investments being made in 2026 are intended to support performance beyond the year, including toward the 2029 outlook and potentially beyond it, particularly if the company adds a CIC indication.
Chief Financial Officer Sue Hohenleitner reiterated 2026 IBSRELA guidance of $410 million to $430 million, noting that the low end implies roughly 50% growth following the 73% increase in 2025. Foster added that, in his view, the market for IBS-C treatments has been growing at double-digit rates in recent years and argued the company’s target patient penetration is relatively modest compared with the overall addressable population discussed on the call.
On prescription dynamics, Foster said refills remain important, but new prescriptions are also necessary to drive growth. He said the company’s distribution strategy can lift refills, while sales force investments are intended to expand the top of the funnel for new prescriptions.
Asked about the split between primary care and gastroenterology prescribers, Foster said primary care is already contributing. He said the company’s targeting approach aims to cover roughly 50% of the total prescription market through high-prescribing primary care physicians, gastroenterologists, and advanced practice providers (nurse practitioners and physician assistants).
CIC expansion: EXCEL Phase III design, timing, and commercial implications
Ardelyx discussed its ongoing EXCEL Phase III trial evaluating tenapanor in CIC, emphasizing that adding a CIC indication could broaden prescriber flexibility and expand the overall opportunity. Management described CIC as a condition on a continuum with IBS-C and said having both indications could reduce “friction points” for physicians.
On trial design, the company said EXCEL is a single Phase III, double-blind, placebo-controlled study enrolling about 700 patients. Management said it was powered at approximately 95% to detect a 14% difference between tenapanor and placebo. The treatment period is 26 weeks, with a primary endpoint assessed at week 12 and designed to evaluate a durable response, requiring improvement in bowel movement function in nine of 12 weeks.
Executives said the first patient was dosed after an investigator meeting held in January, and the company’s goal is to complete enrollment by the end of the year, with data analysis in the second half of the following year to support an NDA submission. They also cited operational momentum, saying more than 90% of approximately 110 sites were up and running.
On commercialization, Foster said entering CIC would likely require additional sales force expansion, particularly into primary care, because the broader prescriber universe is larger than the current IBS-C focus. However, he also said there should be overlap and synergies between CIC and IBS-C investments rather than a one-for-one buildout.
XPHOZAH: non-Medicare growth, access metrics, and 2026 outlook
Management also addressed XPHOZAH performance following Medicare-related transition dynamics discussed by investors in 2025. Executives said the business “bottomed out” early in the year and emphasized growth in non-Medicare segments.
Foster said Ardelyx delivered 41% growth in its non-Medicare revenue-generating business in 2025 (excluding temporary Medicare transition scripts seen in the first quarter) and reported 9% growth in total dispenses, including the patient assistance program. He also said access improved and is higher than it was in 2024, citing that as a key indicator supporting the company’s strategy and the potential to grow the business going forward.
Regarding Medicare access, management said the “base case” should be the current status quo while the company continues to monitor potential developments. Executives emphasized focus on execution within the non-Medicare segment and said they are tracking return on investment across both IBSRELA and XPHOZAH programs, noting in their experience field sales can provide the highest return.
IP and next-generation NHE3 inhibitor plans
On intellectual property, management said the company’s strongest protection includes a composition of matter patent through 2033 and a method of use patent through 2034. Executives also discussed a formulation patent (referred to as the “299 patent”), which they said is Orange Book listed and part of an evolving portfolio intended to support future discussions with potential generic entrants. Management argued that each incremental year beyond loss of exclusivity could be materially valuable.
Ardelyx also discussed a next-generation NHE3 inhibitor program (referred to during the event as “531”), describing increased solubility and potency versus tenapanor as potentially enabling improved efficacy, possible once-daily dosing in current areas, and optionality for additional indications. Management said IND-enabling studies are underway with a plan to submit an IND by year-end, followed by a typical Phase I first-in-human safety program, alongside additional preclinical work to explore other opportunities.
In the financial discussion, executives reiterated 2026 operating expense guidance of $520 million and said spending is expected to run at a relatively steady pace through the year. They attributed incremental investment to advancing the CIC program and the 531 program. Management also emphasized that, based on the guidance discussed, top-line growth is expected to outpace expense growth and noted the company generated cash during the last two quarters of the prior year.
About Ardelyx (NASDAQ:ARDX)
Ardelyx, Inc (NASDAQ: ARDX) is a clinical‐stage biopharmaceutical company focused on discovering, developing and commercializing targeted small molecule drugs for cardio‐renal and gastrointestinal diseases. The company’s lead marketed product, tenapanor (sold under the brand name XPHOZAH in the United States), is approved for the treatment of hyperphosphatemia in patients with chronic kidney disease on dialysis. Ardelyx’s proprietary approach targets epithelial transporters in the gastrointestinal tract, offering localized activity with limited systemic exposure.
Beyond tenapanor, Ardelyx’s development pipeline includes treatments designed to address other complications in kidney disease and related metabolic disorders.
