FDA

FDA OKs first treatment for Menkes disease

January 14, 2026

Brand name: Zycubo

Generic name: copper histidinate

Manufacturer: Sentynl Therapeutics

Approval date: January 13, 2026

FDA has approved the Zycubo (copper histidinate) injection for the treatment of Menkes disease in pediatric patients.

Menkes disease is a rare X-linked recessive pediatric disease caused by mutations of the copper transporter ATP7A encoded by the ATP7A gene.

Zycubo is a bioavailable copper replacement therapy that’s administered as a SC injection to bypass the impaired GI absorption in patients with Menkes disease.

Efficacy

Efficacy was evaluated in two open-label, single-arm clinical trials (trial 1 [NCT00001262] and trial 2 [NCT00811785]) in pediatric patients treated for up to three years. Overall survival was assessed by comparing treated patients with untreated patients from contemporaneous external control groups. The analysis included 66 treated patients and 17 untreated patients, most of whom were from the U.S.

Children who began treatment within four weeks of birth had a 78% reduction in mortality risk compared with untreated patients. Nearly half of early-treated patients survived beyond six years, and some survived more than 12 years. No patients in the untreated control group survived beyond six years. Children who started treatment later than four weeks after birth also experienced a substantial survival benefit.

Safety

The most common adverse reactions (≥7%) reported with treatment were pneumonia, viral infection, respiratory failure, seizure, bacterial infection, hemorrhage, hypotension, vomiting, tachycardia, pyrexia, volume depletion, fracture, dyspnea, elevated transaminases, diarrhea, fungal infection, anemia, and local administration reaction.

Because copper can accumulate in the body, patients receiving Zycubo should be closely monitored for potential toxicity.

Sources:

FDA Approves First Treatment for Children With Menkes Disease. [News release]. 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-children-menkes-disease

Zycubo (copper histidinate) [package insert]. Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/211241s000lbl.pdf Revised January 2026. Accessed January 13, 2026.