Unicycive Therapeutics, Inc. (Nasdaq: UNCY) received a second Complete Response Letter from the US FDA for the resubmitted New Drug Application for oxylanthanum carbonate (OLC), its investigational oral phosphate binder for hyperphosphatemia in chronic kidney disease patients on dialysis. The Unicycive oxylanthanum carbonate FDA review has now been blocked twice by the same third-party manufacturing deficiencies, with the agency indicating it has not yet conducted an inspection of the relevant vendor — extending the approval timeline by an indeterminate period while the manufacturing compliance issue remains unresolved.
The CRL cited the same third-party manufacturing deficiencies identified in the prior CRL issued in June 2025. Unicycive stated the FDA had not conducted its pre-approval inspection of the third-party manufacturing vendor during the resubmission review cycle. The company had resubmitted the NDA based on its assessment that the vendor had made sufficient progress toward resolving the previously cited deficiencies and had demonstrated inspection readiness. No new clinical studies were requested, and the FDA raised no concerns regarding the clinical efficacy or safety data supporting the OLC NDA.
A Type A meeting held in September 2025 between Unicycive and the FDA — convened to obtain alignment on resolving the original manufacturing compliance findings — produced no additional concerns from the agency about the vendor’s remediation progress. Despite this, the FDA did not proceed to inspect the facility during the subsequent six-month review period, which carried a Prescription Drug User Fee Act target date of June 29, 2026.
The nature of the OLC manufacturing deficiencies — residing entirely with a third-party contract manufacturer rather than Unicycive’s own operations — means the timing of approval now depends in part on the FDA’s inspection of the third-party manufacturing facility.. Labeling discussions were ongoing at the time of the CRL, with the company noting it received FDA communication on June 29 regarding carton and container labeling.