FDA Issues Complete Response Letter for Unicycive's Oxylanthanum Carbonate NDA Resubmission

Unicycive Therapeutics (Nasdaq: UNCY) 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), the company's investigational oral phosphate binder for the treatment of hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis. The CRL, issued on June 30, 2026, cites previously identified third-party manufacturing deficiencies, while the FDA raised no concerns regarding the clinical efficacy or safety data of OLC and requested no additional data.

The FDA had accepted the NDA resubmission on January 29, 2026, deeming it a Class II complete response with a six-month review period and setting a Prescription Drug User Fee Act (PDUFA) target action date of June 29, 2026. The Agency had not conducted its inspection of the third-party manufacturing facility during the NDA resubmission review period.

Labeling and packaging discussions with the FDA are ongoing, with the latest communication received by the company from the FDA on June 29 regarding carton and container labels.

The NDA for OLC 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 CKD patients on dialysis), multiple preclinical studies, as well as chemistry, manufacturing and controls (CMC) data. The FDA did not raise any concerns regarding OLC's preclinical, clinical, or safety data included in the original NDA submission.

The NDA was originally resubmitted in December 2025 based on continued progress by the original third-party manufacturing vendor in resolving FDA-cited deficiencies and demonstrating inspection readiness. The company had 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 single deficiency identified in the company's initial CRL related to the compliance status of the vendor. Following receipt of the initial CRL in June 2025, European Union regulatory authorities inspected the original third-party manufacturing vendor and identified no deficiencies.

OLC is an investigational oral phosphate binder that leverages proprietary nanoparticle technology to deliver high phosphate binding potency, reducing the number and size of pills that patients must take. Unicycive is seeking FDA approval of OLC via the 505(b)(2) regulatory pathway. OLC is protected by a global patent portfolio including issued patents on composition of matter with exclusivity until 2031, and with the potential for patent term extension until 2035.

The company ended 2025 with an unaudited position of $41.3 million in cash, cash equivalents, and short-term investments, which permits continued advancement of OLC commercial launch activities and a cash runway into 2027. The company also has an effective Form S-3 shelf registering up to $150,000,000 of securities, including up to $50,000,000 under an at-the-market program.

Unicycive Therapeutics is a clinical-stage biotechnology company developing therapies for patients with kidney disease. Its second investigational treatment, UNI-494, is intended for the treatment of conditions related to acute kidney injury and has been granted orphan drug designation by the FDA for the prevention of Delayed Graft Function in kidney transplant patients, and has completed a Phase 1 dose-ranging safety study in healthy volunteers.