Shares of Unicycive Therapeutics tumbled in morning trading after the U.S. Food and Drug Administration delivered a second Complete Response Letter (CRL) for the company’s resubmitted New Drug Application for oxylanthanum carbonate (OLC). The drug, intended as a phosphate-binding therapy for patients with hyperphosphatemia on dialysis, was again rejected on the product’s PDUFA target action date of June 29, 2026.
The FDA’s decision pointed to third-party manufacturing deficiencies as the cause for denial - the same vendor-related issues that prevented approval in June 2025. Regulators also confirmed that they had not inspected the implicated contract manufacturer during the period in which Unicycive’s resubmission was under review.
Importantly, the agency did not raise questions about OLC’s clinical efficacy or its safety profile, nor did it request additional clinical data from the company. That leaves the underlying scientific evidence for the product intact while keeping the regulatory pathway blocked by a supply-chain compliance matter that lies outside Unicycive’s direct operational control.
Company leadership reiterated confidence in the drug. CEO Shalabh Gupta said the firm remains confident in OLC’s efficacy and safety and noted that conversations with the FDA on labeling and packaging continue. Despite that stance, the repeated manufacturing-related CRL has increased uncertainty about the timing of any eventual approval.
Analysts maintained differing degrees of conviction heading into the decision. H.C. Wainwright had reiterated a Buy rating and a $22 price target prior to the PDUFA date and kept its positive view after the agency’s response. Nonetheless, two consecutive rejections centered on the same manufacturing issues in as many years have materially heightened timeline uncertainty for investors and other stakeholders.
Market moves were overwhelmingly company-specific. The broader indices moved higher during the session, with the S&P 500 up 0.3%, the Dow Jones Industrial Average edging 0.1% higher, and the Nasdaq gaining 0.8%, indicating that the sharp drop in Unicycive shares was not driven by broader market weakness.
Peers in the phosphate-binding and hyperphosphatemia treatment space were not cited as contributing factors to the selloff. The report noted that key competitors, including Ardelyx and Akebia Therapeutics - makers of Xphozah and Auryxia, respectively - were not identified as catalysts for the stock’s move.
The confluence of factors - a second consecutive CRL tied to manufacturing, the FDA’s lack of an inspection of the relevant vendor during the resubmission review, and already elevated investor expectations ahead of the PDUFA date - set the stage for today’s steep decline. Shares fell as much as 46.1% in morning trading, hitting a session low of $3.99, near the 52-week low of $3.71, before recovering modestly to trade around $4.15.
Key context and takeaways
- Regulatory blockage is focused on third-party manufacturing compliance rather than clinical product concerns.
- The FDA did not request additional safety or efficacy data in this CRL.
- Market reaction was isolated to the company, with major indexes finishing the session higher.
What remains uncertain
- The timing and scope of any future FDA inspection of the third-party vendor were not specified in the communication.
- While labeling and packaging discussions are ongoing, the company did not disclose a revised timeline for addressing the manufacturing deficiencies.