The U.S. Food and Drug Administration approved Zycubo (copper histidinate, CUTX‑101) as the first therapy for Menkes disease, granting a rare pediatric disease priority review voucher to the sponsor. Sentynl Therapeutics will commercialize the drug after earlier development work by Cyprium/Fortress Biotech. The approval addresses a fatal pediatric disorder of copper absorption that causes seizures and failure to thrive; FDA cleared the application two days before the PDUFA date after the sponsor resolved prior manufacturing questions. The decision includes transfer provisions for the PRV and potential milestone and royalty arrangements disclosed in company filings. For clinicians treating this ultra‑rare pediatric population, the approval provides the first disease‑specific therapy. For biotech investors and rare‑disease developers, the approval highlights regulatory pathways for high‑impact orphan medicines and the commercial value of PRVs.