Unicycive Therapeutics Receives FDA Complete Response Letter On Its Application For Oxylanthanum Carbonate For Hyperphosphatemia In Patients

Unicycive Therapeutics, Inc. (NASDAQ: UNCY ), a clinical-stage biotechnology company developing therapies for patients with kidney disease, today announced that it has received a Complete Response Letter (CRL) from the U.S.

Food and Drug Administration (FDA) regarding the resubmitted New Drug Application (NDA) for oxylanthanum carbonate (OLC) for the treatment of hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis.

The FDA has not raised any concerns regarding clinical efficacy or safety data, and no additional data was requested from Unicycive.

The CRL is based on the same third-party manufacturing deficiencies that were identified in the previous CRL issued in June 2025.

Unicycive understands that the FDA has not yet conducted its inspection of that third-party manufacturing vendor as part of the review process of the resubmitted NDA.

The NDA for OLC had been resubmitted based on Unicycive’s belief of continued progress by the original third-party manufacturing vendor in resolving FDA-cited deficiencies and demonstrating inspection readiness.

Unicycive previously discussed these milestones during a Type A meeting with the FDA in September 2025, which was held to obtain feedback and alignment on resolving the deficiencies identified in the Company’s CRL related to the compliance status of the vendor.

The FDA did not express any concerns about the third-party manufacturer’s progress and no additional issues were raised by the FDA at the Type A meeting. "We remain confident in the efficacy and safety of OLC," said Shalabh Gupta, M.D., Chief Executive Officer of Unicycive. "We are in active and ongoing discussion with the FDA regarding label and packaging, and we are optimistic that there will be a successful inspection of the third-party manufacturing vendor and that we will be able to expeditiously resubmit the NDA." The OLC NDA is supported by data from three clinical studies: a Phase 1 study in healthy volunteers, a bioequivalence study in healthy volunteers, and a tolerability study of OLC in chronic kidney disease (CKD) patients on dialysis, multiple preclinical studies, as well as chemistry, manufacturing and controls (CMC) data.