Ultragenyx (RARE) Status update summary

FDA approval and clinical impact

• GENGLYCOS (DTX401) received accelerated FDA approval as the first gene therapy for glycogen storage disease type Ia (GSDIa), targeting the underlying cause in patients aged eight and older.

• Approval was based on Phase 3 data showing statistically significant reduction in daily cornstarch intake, improved glucose regulation, and positive secondary endpoints, with a well-tolerated and manageable safety profile.

• The FDA granted accelerated approval, requiring two years of additional data from 50 commercially treated patients and 20 untreated controls to confirm clinical benefit.

• Post-marketing requirements include a 10-year Disease Monitoring Program, with the first two years focused on endpoints like cornstarch intake and time to hypoglycemia.

• GENGLYCOS is the fifth FDA approval for the company and comes with a Priority Review Voucher.

Safety, risks, and patient management

• GENGLYCOS is contraindicated in patients with severe hepatic fibrosis or cirrhosis and requires monitoring for hypersensitivity, hepatotoxicity, and adrenal insufficiency.

• Serious adverse events include anaphylaxis, adrenal insufficiency, high lactate, and hypoglycemia; common side effects are elevated liver enzymes, nausea, headache, and hypertriglyceridemia.

• Patients must be monitored for vector shedding and advised on hygiene for three months post-infusion.

• Vaccinations should be avoided one month prior to administration, and strict contraception guidelines apply for both men and women post-treatment.

• There is a theoretical risk of tumorigenicity due to AAV vector integration, and any tumors must be reported.

Commercial launch and patient access

• GENGLYCOS will be available within 30-60 days, with a U.S. wholesale acquisition cost of $2.7 million per patient.

• A national network of qualified treatment centers (QTCs) is being rapidly expanded, with sufficient capacity to meet initial demand and plans to double the number of centers by year-end.

• Access will initially proceed through single-case agreements, leveraging established relationships with payers and providers.

• The UltraCare program and new Gene Therapy Guides will support patients through insurance, treatment navigation, and education.

• GENGLYCOS will be distributed through a network of Qualified Treatment Centers and supported by the UltraCare program.