FDA Approves First Treatment for Devastating Menkes Disease in Children
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A groundbreaking new therapy, Zycubo, offers hope for infants diagnosed with the rare and fatal genetic disorder, Menkes disease.
The U.S. Food and Drug Management approved zycubo (copper histidinate) injection on January 12, 2026, marking the first-ever treatment option for pediatric patients battling Menkes disease. This approval represents a meaningful advancement in the treatment of ultra-rare genetic conditions and offers a potential lifeline to children who previously faced a severely limited prognosis.
Understanding Menkes Disease
Menkes disease is a progressive neurodegenerative disorder stemming from a genetic defect that prevents the proper absorption of copper. This deficiency leads to a cascade of debilitating symptoms, including seizures, stunted growth and weight gain, developmental delays, and intellectual disability. The disease impacts multiple organ systems, affecting the vascular system, bladder, bowel, bones, muscles, and nervous system. Approximately one in every 100,000-250,000 live births are affected globally, with a higher prevalence among boys. Without treatment, children with the classical form of Menkes disease – representing 90% of cases – typically do not survive past the age of three.
How Zycubo Works
Zycubo is a copper replacement therapy administered via subcutaneous injection. Unlike conventional copper supplements, Zycubo delivers copper in a specialized form – copper histidinate – designed to bypass the genetic roadblock in intestinal absorption. This allows the body to effectively utilize the essential mineral, addressing the underlying cause of the disease.
Clinical Trial results Demonstrate Dramatic Enhancement
The FDA’s decision was based on data from two open-label, single-arm clinical trials involving pediatric patients treated with Zycubo for up to three years. Researchers assessed overall survival by comparing treated patients to a contemporaneous external control group of untreated individuals, primarily from the United States. The analysis included 66 patients receiving Zycubo and 17 untreated patients.
The results were compelling. Children who initiated treatment within the first four weeks of life experienced a remarkable 78% reduction in the risk of death compared to those who did not receive the therapy. Furthermore,nearly half of the early-treated patients survived beyond six years,with some exceeding 12 years of age – a previously unheard-of outcome for children with classical Menkes disease. Even children who began treatment later than four weeks after birth demonstrated a substantial survival benefit.
Safety and Monitoring
While Zycubo offers significant promise, it is indeed not without potential side effects.The most commonly reported adverse reactions included infections,respiratory problems,seizures,vomiting,fever,anemia,and reactions at the injection site. Due to the potential for copper accumulation in the body, patients receiving Zycubo will require close monitoring for signs of toxicity.
A Milestone for Rare Disease Treatment
“This approval marks an unprecedented advance for children with Menkes disease,” stated Tracy Beth Hoeg, M.D., Ph.D., Acting Director of the FDA’s Center for Drug Evaluation and Research (CDER). “The company demonstrated a large improvement in overall survival compared with untreated patients, using an innovative trial design that addressed the challenges of studying an ultra-rare disease.”
The progress of Zycubo was expedited thru the FDA’s Priority Review, Fast Track Designation, Breakthrough Therapy Designation, and Orphan Drug Designation programs, highlighting the agency’s commitment to accelerating the development of treatments for rare and life-threatening conditions. Zycubo is approved for use by Sentynl Therapeutics.
the FDA remains dedicated to collaborating with the rare disease community to foster further advancements in drug development for Menkes disease and other challenging conditions.
