FDA approves tenapanor for lowering serum phosphorous levels in CKD patients on dialysis

The US Food and Drug Administration (FDA) has approved tenapanor (Xphozah) for lowering serum phosphorous levels in patients with CKD on dialysis.  The agency has accepted Ardelyx’s resubmission of a New Drug Application (NDA) for tenapanor as the agent to reduce serum phosphorus in adults with CKD on dialysis as add-on therapy in patients who have an inadequate response to phosphate binders or who are intolerant of any dose of phosphate binder therapy.

The FDA has determined that the NDA is a class 2 review, which results in a six-month review period from the date of resubmission. The FDA has set a user fee goal date of October 17, 2023. The company expects XPHOZAH to be commercially available in the fourth quarter of 2023, as soon as possible following an approval from the FDA.

“The acceptance of our NDA is a significant milestone in our journey to bring XPHOZAH to patients. We are excited about the prospect of working collaboratively with the FDA to finalize this review over the next few months,” said Mike Raab, president and chief executive officer of Ardelyx. “We are now in full preparation mode and intend to launch XPHOZAH to the physician and patient communities who have patiently waited for access to this novel therapy as soon as possible after we receive an approval notification from the FDA, finally bringing this much-needed treatment to patients.”

The NDA is supported by a comprehensive development program that included more than 1,200 patients in three Phase 3 clinical trials evaluating the safety and efficacy of XPHOZAH, all of which met their primary and key secondary endpoints (PHREEDOM, BLOCK and AMPLIFY), as well as two additional Phase 4 open-label clinical trials (OPTIMIZE and NORMALIZE).

About XPHOZAH® (tenapanor)

XPHOZAH, discovered and developed by Ardelyx, is a first-in-class, phosphate absorption inhibitor that has a novel mechanism of action and acts locally in the gut to inhibit the sodium hydrogen exchanger 3 (NHE3), reducing phosphate absorption through the paracellular pathway, the primary pathway of phosphate absorption. This novel blocking mechanism enables a one 30mg tablet twice daily dosing regimen. The most common side effect with XPHOZAH in clinical trials was diarrhea.

About Hyperphosphatemia

Hyperphosphatemia is a serious condition resulting in an abnormally elevated level of phosphate in the blood that is estimated to affect the vast majority of the 550,000 patients in the United States with chronic kidney disease (CKD) on maintenance dialysis. The kidney is the organ responsible for regulating phosphate, but when kidney function is significantly impaired, phosphate is not adequately eliminated from the body. As a result, hyperphosphatemia is a nearly universal condition among people with CKD on maintenance dialysis with internationally recognized KDIGO treatment guidelines that recommend lowering elevated phosphate levels toward the normal range (2.5-4.5mg/dL).