Unicycive Therapeutics resubmits oxylanthanum carbonate NDA to FDA
The package includes 12 months of stability data from a new manufacturer after two manufacturing-related FDA letters.
Adrian Kessler
A new FDA action date could be set after Unicycive Therapeutics, Inc. NASDAQUNCY resubmitted its oxylanthanum carbonate application on Tuesday with production data from a new manufacturer. Unicycive anticipates the agency will accept the package within 30 days of Sept. 29 and assign an action date six months from resubmission.
The Sept. 29 company release says the package includes 12 months of drug-product stability data from the new vendor. It also includes laboratory bridging data comparing material from the old and new suppliers, following the FDA's recommendation in earlier discussions.
Unicycive is a Mountain View, California, small-cap developer of medicines for kidney disease. Oxylanthanum carbonate is an investigational oral phosphate binder for people on dialysis whose chronic kidney disease leaves them with elevated blood phosphorus.
Unicycive shares closed at US$4.64 on Sept. 28 at 4 p.m. ET, according to the NASDAQUNCY quote page, before the resubmission announcement. That close provides a trading baseline; it does not show the market's reaction to Tuesday's news.
A New Vendor Addresses the Manufacturing Deficiencies
In a June 30 announcement, Unicycive said it had received an FDA complete response letter citing repeated deficiencies at its original third-party manufacturer. Those deficiencies had also been cited in a June 2025 letter, and the FDA had not reinspected that facility during the intervening review, according to the company's account.
Unicycive said the FDA raised no concerns about clinical efficacy or safety data in the June 2026 letter and requested no additional data. That does not resolve the manufacturing issue: a complete response letter means the agency has declined to approve the application in its existing form.
The company said the replacement facility last underwent an FDA inspection in March 2024 and received a "No Action Indicated" classification. Unicycive has submitted specifications and additional laboratory comparisons from the new supplier, but FDA acceptance of the resubmission and approval of the drug remain separate steps.
The application draws on a healthy-volunteer Phase 1 study, a healthy-volunteer bioequivalence study and a tolerability study in patients with chronic kidney disease on dialysis. The new package described on Sept. 29 centres on production controls and stability rather than a new clinical readout.
"By adding an alternative primary manufacturing vendor, we are positioning the NDA for expedient review and potential approval," Unicycive chief executive Shalabh Gupta said in the Sept. 29 release.
The original vendor has been assigned an FDA inspection, Unicycive said, although it had not taken place as of Sept. 29. If the original vendor is inspected in the near term and deemed cGMP-compliant, Unicycive plans to ask the agency about a shorter approval timetable. Any change would require FDA agreement.
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Approved Products Set the Dialysis Market
Unicycive would enter a market with drugs already approved to lower phosphorus in adults on dialysis. Ardelyx, Inc. NASDAQARDX says its Xphozah is a phosphate absorption inhibitor approved as an add-on for patients who respond inadequately to binders or cannot tolerate them.
Akebia Therapeutics, Inc. NASDAQAKBA says its Auryxia, a ferric-citrate phosphate binder, is approved to control serum phosphorus in adults with chronic kidney disease on dialysis.
As a dated price reference for the dialysis-drug peer set, Ardelyx closed at US$3.41 on Sept. 28 at 4 p.m. ET, according to the NASDAQARDX quote page. Unicycive's Sept. 29 release reported US$61.4 million in unaudited cash, cash equivalents and marketable securities on June 30. The company expects that amount to fund operations into the second half of 2027.
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Unicycive anticipates the FDA will accept its Sept. 29 resubmission by Oct. 29. Acceptance would put the new manufacturing package into review; a later FDA action would decide whether oxylanthanum carbonate can be marketed in the United States.
