The U.S. Food and Drug Administration approved Zycubo (copper histidinate, CUTX‑101) as the first approved treatment for Menkes disease, a rare pediatric disorder of copper absorption that causes severe neurodegeneration and early mortality. Sentynl Therapeutics, which took over development and commercialization duties, secured the approval ahead of the PDUFA date after addressing prior manufacturing concerns. The approval generates a pediatric rare disease priority review voucher (PRV) that will be transferred to the asset’s original developer under existing commercial agreements. Regulators’ clearance follows clinical data demonstrating biochemical correction with copper histidinate and safety readouts sufficient for approval in this desperate, unmet population. Sponsors noted the approval will enable immediate commercialization planning and underscored the continued value of targeted development for orphan pediatric disorders.