Ardelyx Stock Collapses After FDA Rejects Its Kidney Disease Candidate Pitch

Three months after revealing that the FDA had asked for more information to support tenapanor application for a chronic kidney disease drug, the FDA issued a letter to Ardelyx Inc ARDX identifying deficiencies in its application ahead of its PDUFA date next week (July 29).
The Company, which got word from the FDA on July 13, said they asked for a meeting with the agency to discuss the rejection and fix any shortcomings but were turned down.
The agency noted that a key issue is the size of the treatment effect and the clinical relevance of tenapanor for controlling serum phosphorus in adult patients with chronic kidney disease on dialysis.
CEO Mike Raab expressed surprise at the decision, noting that the drug had hit its primary endpoint in three pivotal trials across 1,000 patients.
The FDA in 2019 approved 50 mg, twice-daily oral tenapanor to increase bowel movements and decrease abdominal pain for patients with irritable bowel syndrome with constipation.
In April, FDA had asked Ardelyx to provide information on how the drug’s mechanism of action works.
Price Action: ARDX shares cratered 67.1% at $2.53 during the premarket session on the last check Tuesday.
Related content: Benzinga's Full FDA Calendar.