What Was Approved?
On January 12, 2026, the U.S. Food and Drug Administration approved Zycubo (copper histidinate) for the treatment of Menkes disease in pediatric patients.
Zycubo is the first FDA-approved treatment specifically for Menkes disease.
What Is Menkes Disease?
Menkes disease is a rare inherited disorder that interferes with the body’s ability to properly absorb and distribute copper.
The condition can affect the brain and other organs and may cause problems such as:
- Seizures
- Poor growth
- Developmental delay
- Neurologic deterioration
Without treatment, the disease can be life-threatening.
How Does Zycubo Work?
Zycubo is a copper replacement therapy.
It provides copper in the form of copper histidinate to help address the copper deficiency associated with Menkes disease.
How Is Zycubo Given?
Zycubo is given by subcutaneous injection.
The FDA-approved dosing depends on age:
- Younger than 1 year: 1.45 mg twice daily, with 8 to 12 hours between injections
- Age 1 year to younger than 17 years: 1.45 mg once daily
Laboratory monitoring is required during treatment.
What Monitoring Is Needed?
Before starting treatment, the FDA label recommends checking:
- Serum copper
- Ceruloplasmin
- Electrolytes
- Kidney function
- Liver function
- Complete blood count
These tests are also monitored during treatment.
What Is the Main Safety Concern?
The FDA prescribing information warns about copper accumulation and toxicity.
Because copper can build up in the body, careful laboratory monitoring and dose adjustment are important.
Is Zycubo Used for Occipital Horn Syndrome?
No.
The FDA-approved label specifically states that Zycubo is not indicated for the treatment of Occipital Horn Syndrome.
Why Is Early Treatment Important?
Clinical evidence reviewed by the FDA suggested that children who started copper histidinate treatment very early in life had better survival outcomes than untreated patients.
However, individual outcomes can vary, and treatment decisions should be made by specialists experienced in Menkes disease.
Bottom Line
Zycubo (copper histidinate) is the first FDA-approved treatment for pediatric patients with Menkes disease.
It is given by subcutaneous injection and requires regular monitoring because excessive copper accumulation can cause toxicity.
Sources
- U.S. Food and Drug Administration (FDA) — FDA Approves First Treatment for Children With Menkes Disease, January 12, 2026.
- U.S. Food and Drug Administration (FDA) — Zycubo (copper histidinate) Prescribing Information, January 2026.
- U.S. Food and Drug Administration (FDA) — Drug Trials Snapshot: Zycubo.
- U.S. Food and Drug Administration (FDA) — Novel Drug Approvals for 2026.