Ardelyx has dosed the first patient in the ACCEL (ten-03-301) Phase III clinical trial evaluating Ibsrela (tenapanor) to treat chronic idiopathic constipation (CIC) in adults.

The multicentre, randomised, double-blind, placebo-controlled trial is designed to evaluate the efficacy and safety of tenapanor for treating CIC with twice-daily administration over 26 consecutive weeks.

It plans to enrol around 700 adults with CIC, with the primary endpoint assessing patient-reported constipation outcomes.

Patient enrolment for ACCEL is expected to continue through 2026, and Ardelyx anticipates top line data from the trial in the second half of 2027.

The Phase III clinical trial represents progress in Ardelyx’s objective to expand Ibsrela’s potential beyond its existing indication for irritable bowel syndrome with constipation. Previous studies have demonstrated Ibsrela’s efficacy, tolerability, and safety through a comprehensive clinical development plan.

Ardelyx chief patient officer and interim chief medical officer Laura Williams said: “Today marks an important milestone for our team and the patients we are committed to serving. We are pleased to announce that the first patient has been dosed in the ACCEL Phase III clinical trial, an integral step to bringing Ibsrela and its differentiated mechanism of action to patients with chronic idiopathic constipation.

“This achievement reflects the dedication of our investigators, clinical staff, internal team, and most importantly, the patients and families who entrust us with their care.

“We remain focused on conducting this study with the highest standards of safety, integrity and scientific rigour, and we look forward to the insights it will provide for the future health of our patients.”