Ultragenyx Pharmaceutical Inc. received accelerated approval from the U.S. Food and Drug Administration for GENGLYCOS (pariglasgene brecaparvovec-opnr, also known as DTX401) in adult and pediatric patients aged 8 years and older with glycogen storage disease type Ia (GSDIa), or Von Gierke disease. It is the first FDA-approved treatment for the ultra-rare inherited metabolic disorder and Ultragenyx’s first gene therapy approval and fifth FDA approval overall. The therapy is intended to reduce daily cornstarch requirements as an adjunct to nutritional management. The approval was supported by the 48-week Phase 3 GlucoGene study, which treated 46 participants with DTX401 at 1.0 x 10^13 GC/kg or placebo and showed a reduction in cornstarch requirements in the treated group. As a condition of accelerated approval, Ultragenyx will provide two years of safety and efficacy data from open-label commercial treatment of 50 patients and 20 controls through an enhanced GSDIa Disease Monitoring Program, which will follow previously treated trial participants and new commercial patients for a total of 10 years. William Blair cited a $2.7 million wholesale acquisition cost per patient, while analyst Sami Corwin resumed coverage with an Outperform rating and modeled $362 million in peak GENGLYCOS sales. Ultragenyx shares rose 11.28% to $29.20 in Thursday premarket trading, according to Benzinga Pro data.