Ardelyx stock drops 70% after setback with FDA over phosphorus drug
Pharmaceutical company Ardelyx Inc. saw a 70% drop in its stock value on Monday after announcing that the FDA had “identified deficiencies” in the company’s new drug application for its serum phosphorus drug tenapanor.
"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 [new drug application (NDA)] submission included three pivotal trials across 1,000 patients, all of 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," Mike Raab, president and CEO of Ardelyx, said in a press release. "We plan to work with the FDA to learn more about the identified deficiencies and will seek to resolve them as quickly as possible."
Tenapanor is being investigated to control serum phosphorus in adult patients with chronic kidney disease on dialysis.
Ardelyx submitted an NDA for tenapanor in June 2020. In April 2021, the company said the FDA extended the Prescription Drug User Fee Act date to July 29, following the submission of additional analyses.
Ardelyx shares, which closed at $7.70 in the regular session on Monday, dropped to $2.50 in after-hours trading.
FDA letter
Ardelyx said it received a letter from the FDA on July 13 stating that, as part of its ongoing review of the company's NDA for tenapanor, the agency “has identified deficiencies that preclude discussion of labeling and postmarketing requirements/commitments at this time,” Ardelyx said.
The company said it immediately requested a meeting to discuss the deficiencies and was notified by the FDA that the request for a meeting was denied, the release said.
“While the FDA has not provided specific details regarding the deficiencies, the FDA noted that a key issue is the size of the treatment effect and its clinical relevance,” the company said.
PHREEDOM study
Ardelyx announced in December 2019 that phase 3 results from its PHREEDOM study demonstrated treatment with tenapanor safely and effectively decreased serum phosphorous in patients with CKD on dialysis.
“These results are very exciting and represent a capstone to our tenapanor clinical development program, which is focused on the development of a new and important therapy for patients with hyperphosphatemia," Raab said at the time.
The FDA action is the second time over the past week that the agency has impacted an NDA for a drug treatment for kidney disease. On July 15, the agency’s Cardiovascular and Renal Drugs Advisory Committee voted against approval of roxadustat for the treatment of anemia in patients with CKD, citing safety concerns.
- References:
- www.healio.com/news/nephrology/20210716/fda-panel-does-not-recommend-approval-of-roxadustat-for-anemia
- www.healio.com/news/nephrology/20191204/phreedom-study-tenapanor-effective-for-hyperphosphatemia-in-patients-on-dialysis