FDA Alert

FDA Approves First Treatment for Children with Menkes Disease in the United States

Edited by:
Ashton L. Stahl

Key Highlights

  • The FDA approved the first treatment specifically indicated for children with Menkes disease in the United States.
  • The therapy is intended for patients with early-diagnosed Menkes disease, a rare genetic copper transport disorder that usually leads to early mortality.
  • Approval was based on two open-label, single-arm clinical trials.

The FDA approved Zycubo (copper histidinate), the first treatment for children with Menkes disease, a neurodegenerative disorder caused by a genetic defect that impairs a child’s ability to absorb copper.

Menkes disease is a rare X-linked genetic disorder caused by mutations affecting copper transport in the body. According to the FDA, the condition leads to copper deficiency in critical tissues, resulting in progressive neurological deterioration, connective tissue abnormalities, and failure to thrive.

The approval applies to a copper replacement therapy designed for pediatric patients diagnosed early. The FDA noted that early intervention is essential in Menkes disease.

The FDA’s decision was supported by data from two open-label, single-arm clinical trials in pediatric patients treated for up to 3 years. The agency emphasized the rarity of Menkes disease and the challenges associated with conducting large, randomized clinical trials in this population.

Among children who initiated treatment within 4 weeks of birth, copper histidinate was associated with a 78% reduction in mortality risk. Additionally, nearly half of early-treated patients survived beyond 6 years, with some surviving more than 12 years. No patients in the untreated control group survived beyond 6 years. Survival benefits were also observed in children who began treatment later.

The most common adverse events included infections, respiratory complications, seizures, gastrointestinal symptoms, anemia, and injection site reactions. Because of the risk of copper accumulation, patients receiving copper histidinate require close monitoring.

Reference

US Food and Drug Administration. FDA approves first treatment for children with Menkes disease. US Food and Drug Administration. Published January 12, 2026. Accessed January 13, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-children-menkes-disease