Sentynl Therapeutics gets FDA complete response letter for CUTX-101 NDA

Sentynl Therapeutics, a U.S.-based biopharmaceutical company wholly-owned by Zydus Lifesciences, announced that the USFDA issued a Complete Response Letter (CRL) for its New Drug Application (NDA) for copper histidinate (CUTX-101). CUTX-101 is intended to treat Menkes disease in pediatric patients.

The CRL cited the need to address findings related to a CGMP inspection of the manufacturing facility for CUTX-101. Zydus recently provided responses to the USFDA's September 2025 re-inspection regarding the facility's CGMP compliance and is awaiting the Establishment Inspection Report (EIR). Sentynl plans to request a meeting with the USFDA to discuss the CRL and resubmission of the NDA.

The CRL did not raise concerns about approvability beyond the CGMP inspection or identify deficiencies in CUTX-101's efficacy and safety data. CUTX-101 is a subcutaneous injectable formulation designed to restore copper homeostasis in patients with Menkes disease, a rare X-linked recessive pediatric genetic disease.