Unicycive hits another hurdle with hyperphosphataemia drug
Unicycive Therapeutics' hopes of getting FDA approval of its drug for hyperphosphataemia in patients with chronic kidney disease (CKD) who need dialysis have been knocked back again.
The US regulator has sent a second complete response letter (CRL) to the Mountain View, California-based biotech for oxylanthanum carbonate (OLC), which was first filed for approval in 2024 and refiled last December.
In both CRLs, the FDA has taken issue with deficiencies at a third-party manufacturer of the drug, which is being developed as a more patient-friendly alternative to current phosphate binder therapies for dialysis-related hyperphosphataemia, such as Takeda's Fosrenol (lanthanum carbonate).
In a statement, Unicycive said the FDA had not raised any concerns regarding the efficacy or safety of OLC, and has asked for no additional clinical data, so it remains confident of the drug's prospects.
"The CRL is based on the same third-party manufacturing deficiencies that were identified in the previous CRL issued in June 2025," said the company. "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 [new drug application]."
Chief executive Shalabh Gupta said Unicycive is 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."
Despite the optimistic comments, shares in Nasdaq-listed Unicycive had plummeted nearly 49% in pre-market trading at the time of writing, trading at less than $4 and approaching a year-long low.
Current phosphate binder drugs require patients to take a large number of pills per day – as many as a dozen for some products – and in some cases are formulated as large, chewable tablets. In contrast, OLC requires fewer and smaller pills to be taken and can be swallowed whole with water – just one aspirin-sized pill three times a day.
In a survey commissioned by Unicycive that was reported in 2022, kidney disease specialists said that the greatest unmet need in the treatment of hyperphosphataemia with phosphate binders is a lower pill burden and better patient compliance.
A high phosphate level in the blood is a common complication of CKD, particularly affecting patients on dialysis. In severe cases, it can cause bone and muscle problems, as well as increase the risk of heart attacks and strokes.
Despite the availability of several FDA-approved phosphate binders, it is estimated that around 75% of patients fail to achieve serum phosphorus targets.
Photo by Kai Pilger on Unsplash
