Ardelyx Reiterates Lower IBSRELA Outlook After Slower Growth

The Tip Desk · November 10, 2026 · 3 min read

Third-quarter product revenue was $125.5 million as IBSRELA rose 23% and the company kept 2026 IBSRELA guidance at $350 million to $370 million.

Ardelyx Inc. (ARDX), a commercial-stage biopharmaceutical company, reported third-quarter 2026 total product revenue of $125.5 million, up 19% from a year earlier, as year-over-year growth slowed for a second consecutive quarter.

IBSRELA (tenapanor), the company’s irritable bowel syndrome with constipation product, generated $96.3 million, up 23% from a year earlier. That followed 33% growth in the second quarter and about 58% in the first quarter. Ardelyx said the increase was driven by higher total writers and total prescriptions.

XPHOZAH (tenapanor), used to reduce serum phosphorus in adults with chronic kidney disease on dialysis, contributed $29.2 million, up 7% from a year earlier after 27% growth in the second quarter.

The company reiterated full-year 2026 IBSRELA revenue guidance of $350 million to $370 million, the range it set after cutting the prior $410 million to $430 million outlook in August. XPHOZAH full-year guidance remained $110 million to $120 million, and operating-expense guidance remained below $500 million. Ardelyx said IBSRELA long-term guidance of achieving $1 billion in annual revenue remains. In the second quarter it had said it was evaluating evolving market dynamics and their impact on the timing of that achievement; the third-quarter release restated the $1 billion target without that timing caveat. XPHOZAH long-term guidance, pulled in the second quarter, was not restated.

President and Chief Executive Officer Mike Raab said IBSRELA year-over-year growth of 23% was the engine driving total product revenue of over $125 million for the quarter.

Net loss narrowed to $0.7 million, or $(0.00) a share, from $1.0 million, or $(0.00) a share, in the year-ago quarter. The third-quarter net loss included $15.1 million of share-based compensation. Gross profit margin was above 95%.

Research and development expenses were $25.2 million, compared with $18.1 million a year earlier. Ardelyx said the increase was primarily related to investments in the ACCEL Phase 3 trial for chronic idiopathic constipation. Selling, general and administrative expenses were $93.9 million, compared with $83.6 million a year earlier, which the company attributed to deliberate investments to address access barriers and drive future adoption of IBSRELA.

Cash, cash equivalents and short-term investments were $285.3 million as of September 30, 2026, compared with $281.8 million as of June 30, 2026.

Ardelyx said it completed enrollment ahead of schedule in ACCEL, a 26-week Phase 3 trial of tenapanor for chronic idiopathic constipation in about 700 patients across 110 U.S. sites. In the second quarter it had said it was on track to complete enrollment by the end of 2026. The company is on track to announce topline data in the second half of 2027.

The U.S. Patent and Trademark Office notified the company that on November 10, 2026, it will issue U.S. Patent No. 12,788,750, “Oral Formulation of a Therapeutic Compound,” with an expiration date of December 6, 2041, covering commercial formulations of both IBSRELA and XPHOZAH.

In October, at the American College of Gastroenterology meeting, Ardelyx presented real-world data showing gastrointestinal-related healthcare resource utilization dropped after adults with IBS-C started IBSRELA. At the American Society of Nephrology Kidney meeting it presented real-world data showing reductions in serum phosphate following XPHOZAH initiation in adults on dialysis.

Ardelyx said IBSRELA’s growth supports full-year guidance and reinforces its long-term view of achieving $1 billion in annual revenue.