The company applied for approval of the gene therapy in the treatment of Glycogen Storage Disease Type Ia or Von Gierke disease.
- The FDA is now expected to decide on the application by Aug. 23.
- The company intends to manufacture the therapy at its new gene therapy manufacturing facility in Bedford, Massachusetts, if approved.
- The application comes on the heels of an FDA rejection for the company’s UX111 gene therapy.
Ultragenyx Pharmaceutical Inc. (RARE) said on Monday that the U.S. Food and Drug Administration (FDA) has granted priority review to its application seeking approval of DTX401 gene therapy.
The company applied for approval of the gene therapy in the treatment of Glycogen Storage Disease Type Ia or Von Gierke disease, a rare metabolic disorder caused by a deficiency in the enzyme glucose-6-phosphatase. It causes glycogen and fat to build up in the liver and kidneys, typically leading to severely low blood sugar, enlarged liver, and growth retardation in infants.
The FDA is now expected to decide on the application by Aug. 23. The company intends to manufacture the therapy at its new gene therapy manufacturing facility in Bedford, Massachusetts, if approved.
Leadership Take
“Current dietary approaches to managing GSDIa place an extraordinary burden on individuals and families while still leaving patients with significant medical needs, including the risk of potentially life-threatening episodes of acute hypoglycemia and accumulation of long-term complications over their lifetime,” said Eric Crombez, chief medical officer at Ultragenyx.
“If approved, DTX401 would be the first treatment to address the disease at its root cause,” Crombez added.
The company’s application includes data from a late-stage trial where patients treated with DTX401 experienced several clinical benefits translating to meaningful improvements in patient-reported quality of life.
Ultragenyx’s Recent Setbacks
The application comes on the heels of an FDA rejection for the company’s UX111 gene therapy. The company submitted an application seeking approval for UX111 for Sanfilippo syndrome type A in January after it was denied approval in 2025.
Earlier this month, the company said that the FDA had once again refused approval for the gene therapy and sought additional supportive documentation which the company expects to provide in a resubmission. Ultragenyx did not detail the FDA’s concerns for the repeated rejection.
Ultragenyx also said last week that it is continuing to evaluate the study data for UX143. In December, the company said that its late-stage studies of Setrusumab (UX143) in osteogenesis imperfecta did not meet the primary endpoint of reducing annualized fracture rates, though both trials showed improvements in bone mineral density. The company said last week that it is continuing to study the data, without providing more details.
How Did Stocktwits Users React?
On Stocktwits, retail sentiment around RARE stock stayed within the ‘extremely bullish’ territory over the past 24 hours while message volume remained at ‘high’ levels.
RARE stock has lost 45% over the past 12 months.
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