Objective:

To report on the FDA's Complete Response Letter regarding Unicycive Therapeutics' New Drug Application for oxylanthanum carbonate.

Approach:

• FDA Response: The FDA issued a Complete Response Letter (CRL) for the resubmitted New Drug Application (NDA) for oxylanthanum carbonate.
• Deficiencies Identified: The CRL relates to deficiencies at a third-party manufacturing vendor, previously noted in a prior CRL from June 2025.
• Clinical Data: The FDA did not identify concerns regarding clinical efficacy or safety data and did not request additional data.
• Manufacturing Inspection: The FDA did not inspect the third-party manufacturing facility during the review of the resubmitted NDA.
• Company's Belief: Unicycive believed that the third-party vendor had made progress in resolving deficiencies and demonstrated inspection readiness.
• Ongoing Discussions: Labeling discussions with the FDA are ongoing, with the most recent communication received on June 29 regarding carton and container labeling.
• NDA Support: The NDA is supported by data from various studies, including a phase 1 study and a tolerability study in patients with chronic kidney disease.

Key Findings:

• The CRL is based on manufacturing deficiencies, not clinical efficacy or safety concerns.
• The FDA did not inspect the third-party manufacturing facility during the review.
• Labeling discussions with the FDA are still ongoing.

Interpretation:

The FDA's concerns are focused on manufacturing processes rather than the drug's clinical data.

Limitations:

• The CRL does not address the clinical efficacy or safety of oxylanthanum carbonate.
• The third-party manufacturing vendor's readiness remains unverified by an FDA inspection.

Conclusion:

Unicycive Therapeutics continues to seek FDA approval for oxylanthanum carbonate through the 505(b)(2) regulatory pathway.

Sources:

• Unicycive Therapeutics Inc.