US FDA Issues Response Letter for Zydus’ CUTX-101 Drug for Menkes Disease

Zydus Lifesciences Ltd. said on Wednesday that the US Food and Drug Administration has issued a Complete Response Letter to its wholly owned subsidiary, Sentynl Therapeutics Inc., regarding its New Drug Application for copper histidinate – CUTX-101 – for treating Menkes disease in paediatric patients.

A Complete Response Letter indicates the FDA has completed its review but cannot approve the product in its current form. The company must carry out additional steps, which may include a site inspection or resubmission of the application.
Menkes disease is a rare, severe recessive genetic disorder affecting copper metabolism due to specific gene mutations. CUTX-101 is an injectable therapy that restores and maintains copper levels in patients.

Zydus Lifesciences said it recognises the FDA’s decision and remains committed to working with the agency on next steps. Sentynl Chief Executive Officer Matt Heck emphasised that the company remains dedicated to patients and intends to address feedback promptly to pursue resubmission.

The US regulator requested a current good manufacturing practices (CGMP) inspection at the facility producing CUTX-101. The plant was reinspected in September, demonstrating CGMP compliance, and the company is awaiting the Establishment Inspection Report.

Sentynl will request a meeting with the FDA to discuss the Complete Response Letter and resubmission. CUTX-101 had initially received priority review and is supported by positive topline clinical results, showing significant improvement in overall survival for patients receiving early treatment.