Ardelyx has reported positive results from the Phase III clinical trial of tenapanor to treat hyperphosphatemia in patients with end-stage renal disease (ESRD) who are on dialysis.
The eight-week, double-blind, randomised Phase III trial with a four-week placebo-controlled randomised withdrawal period, evaluated the efficacy and safety of the drug in 219 patients.
The results indicated that the drug has met its primary endpoint, which is to measure the difference in a change in serum phosphorus within patients from the end of the eight-week treatment period to the end of the four-week randomised withdrawal period.
Ardelyx president and chief executive officer Mike Raab said: "We are very pleased with the overall efficacy and improved tolerability profile of tenapanor in this study.
"The magnitude of the reduction of serum phosphorus in a large percentage of patients treated with tenapanor in this trial surpassed our expectations.
"We are highly confident in tenapanor and look forward to further establishing its clinical and commercial value in the next Phase III trial."
The results showed that the drug was well-tolerated, with the only adverse events being diarrhea. The treatment discontinuations due to diarrhea for patients treated with tenapanor were found to be 7.8%, while there were no discontinuations in the withdrawal period.
The firm intends to commence a second Phase III trial of the drug to treat hyperphosphatemia in ESRD patients on dialysis this year.
This 26-week, open-label treatment period Phase III trial will include a randomised withdrawal period and an additional 26-week long-term safety extension.
Image: Micrograph of an end-stage kidney disease. Photo: courtesy of Nephron/Wikipedia.