High rates of diarrhoea in Phase IIb study of tenapanor inHyperphosphatemia in Chronic Kidney Disease- Ardelyx+ AstraZeneca

Ardelyx, Inc. has announced that AstraZeneca's 161-patient Phase IIb clinical trial evaluating tenapanor in hyperphosphatemic patients with chronic kidney disease on haemodialysis met its primary endpoint by demonstrating a statistically significant dose-related decrease in serum phosphate levels for tenapanor-treated patients compared to patients receiving placebo (p=0.012). It was noted, however, that the rate of diarrhea was distinctly higher than expected. The overall safety profile remains consistent with that observed in previous tenapanor trials. In October 2012, Ardelyx entered into a partnership with AstraZeneca for the worldwide development and commercialization of tenapanor.

Comment: Diarrhoea can be an issue in this population because fluid levels are important for these patients. Ardelyx said it would now work with AstraZeneca, which licensed tenapanor in October 2012, to evaluate the future development plans for the drug.