Ultragenyx reported that its gene therapy hit a co‑primary endpoint in the mid‑point analysis of a Phase 3 study for a rare urea cycle disorder, producing a statistically significant reduction in ammonia levels. The announcement signals a potential regulatory path forward and positions the program for a potential filing depending on final data. Ultragenyx framed the result as a validation of its delivery and expression strategy for hepatic metabolic diseases; investors and partners will watch the full dataset, durability, and safety profile as the company prepares next regulatory steps.