FDA Issues Letter to Ardelyx for Submission of Tenapanor for Chronic Kidney Disease

The US Food and Drug Administration (FDA) has issued a letter to biopharmaceutical company Ardelyx, Inc, identifying deficiencies in the company’s New Drug Application (NDA) for investigative drug tenapanor, ahead of its PDUFA date next week.

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 statement 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.