FDA Issues Letter to Ardelyx Detailing Deficiencies in Application for Tenapanor

While tenapanor has already received approval for treatment of abdominal pain in patients with IBS, the US FDA issued a letter to Ardelyx noting deficiencies in their NDA for an indication related to controlling serum phosphorus in adult patients with CKD on dialysis “preclude discussion” related to labeling and post-marketing requirements.

This article was originally published on HCPLive.com.

Within a week of the PDUFA data, the US Food and Drug Administration (FDA) issued a letter to biopharmaceutical company Ardelyx, Inc, citing issues in the company’s New Drug Application (NDA) for tenapanor.

The letter, received on July 13, stated the deficiencies of the NDA “preclude discussion” around the would-be labeling and post-marketing requirements for tenapanor as a drug for controlling serum phosphorus in adult patients with chronic kidney disease (CKD) on dialysis.

The FDA noted key issues in the NDA for tenapanor include size and clinical relevance of the treatment effect.

Though the letter stated the notification did not reflect a final decision on the NDA, a meeting requested by the company on the matters of the letter was denied by the FDA.

In a release accompanying the news, Ardelyx president and chief executive officer Mike Raab expressed disappointment with the communication.

"This is an extremely disheartening and disappointing communication from the FDA, particularly following the weeks of label discussions that occurred in early April, the fact that our NDA submission included three pivotal trials across 1,000 patients, all which met their primary and key secondary endpoints, as well as the additional data analyses we submitted in late April in response to the FDA's requests," Raab said.

He stressed the company plans to work with FDA going forward to interpret the highlighted NDA deficiencies “and will seek to resolve them as quickly as possible.”

The FDA previously approved 50 mg, twice-daily oral tenapanor to increase bowel movements and decrease abdominal pain for patients with IBS-C.