Updated Aug 20, 2026
/FDA grants Ultragenyx accelerated approval for GENGLYCOS in glycogen storage disease type Ia/Systematic funds post worst day since 2023 on momentum-driven selloff/Tim Walz blocks Minnesota mining permits near Boundary Waters, defying Trump energy law/UK Home Office nine-page guide tells asylum seekers rape is a crime and women need no male permission/Beam Global Posts 174% Sequential Revenue Jump, European Sales Near Half of Total/SHF Holdings amends retention plan, removes directors from incentive eligibility/FDA grants Ultragenyx accelerated approval for GENGLYCOS in glycogen storage disease type Ia/Systematic funds post worst day since 2023 on momentum-driven selloff/Tim Walz blocks Minnesota mining permits near Boundary Waters, defying Trump energy law/UK Home Office nine-page guide tells asylum seekers rape is a crime and women need no male permission/Beam Global Posts 174% Sequential Revenue Jump, European Sales Near Half of Total/SHF Holdings amends retention plan, removes directors from incentive eligibility

FDA grants Ultragenyx accelerated approval for GENGLYCOS in glycogen storage disease type Ia

NOVATO, August 19. A U.S. Food and Drug Administration accelerated approval for GENGLYCOS (pariglasgene brecaparvovec-opnr) arrived Tuesday for Ultragenyx Pharmaceutical Inc. (Nasdaq Global Select Market: RARE), the company disclosed in an 8-K. The therapy, also designated DTX401, is cleared for adult and pediatric patients eight years of age and older with glycogen storage disease type Ia.

By Ines Ferreira2 min readRARE
Share

Key takeaways

  • The FDA granted Ultragenyx accelerated approval for GENGLYCOS (pariglasgene brecaparvovec-opnr, also designated DTX401) for adult and pediatric patients eight years and older with glycogen storage disease type Ia.
  • The approval rests on the Phase 3 GlucoGene study, a 48-week randomized, double-blind, placebo-controlled trial of 46 participants, in which treated patients' cornstarch requirements fell with statistical significance versus placebo (p<0.001).
  • Efficacy data came from 44 participants in the modified intention-to-treat population, with 20 in the DTX401 arm and 24 in the placebo group.
  • The accelerated pathway requires two years of open-label commercial safety and efficacy data from 50 treated patients and 20 controls who cannot receive GENGLYCOS due to anti-AAV8 antibodies.
  • Ultragenyx will expand its GSDIa Disease Monitoring Program to track both new commercial patients and prior clinical trial participants over a combined 10-year period.

NOVATO, August 19. A U.S. Food and Drug Administration accelerated approval for GENGLYCOS (pariglasgene brecaparvovec-opnr) arrived Tuesday for Ultragenyx Pharmaceutical Inc. (Nasdaq Global Select Market: RARE), the company disclosed in an 8-K. The therapy, also designated DTX401, is cleared for adult and pediatric patients eight years of age and older with glycogen storage disease type Ia.

The FDA decision rests on the Phase 3 GlucoGene study, a 48-week randomized, double-blind, placebo-controlled trial enrolling 46 participants. Patients received DTX401 at a dose of 1.0 x 10^13 genome copies per kilogram or placebo. In the treated group, cornstarch requirements fell at a level that cleared statistical significance against placebo (p<0.001), the filing shows.

Efficacy data came from 44 participants in the modified intention-to-treat population: 20 in the DTX401 arm, 24 in the placebo group. At Week 48, eligible participants crossed over and received the alternate treatment, then continued to be followed. Analyses were conducted at Week 96 and Week 144.

Post-marketing obligations

The accelerated pathway requires two years of open-label commercial safety and efficacy data. Ultragenyx agreed to provide that through 50 treated patients and 20 controls. The control group consists of patients who sought commercial treatment but cannot receive GENGLYCOS because they carry anti-AAV8 antibodies, the 8-K states.

The post-marketing study will cover reductions in cornstarch clinical burden, fasting tolerance, and other measures, according to the company. In the commercial setting, patients can track their glucose levels in real time, and physicians can adjust cornstarch intake and diet more immediately than in the trial context, the filing notes.

Ultragenyx's existing GSDIa Disease Monitoring Program will be expanded to follow both new commercial patients and previously treated clinical trial participants. The combined cohort will be tracked for 10 years. Howard Horn, Executive Vice President, Chief Financial Officer, and Corporate Strategy officer, signed the 8-K on behalf of the Novato, California company.

Related reading

Frequently asked

What is GENGLYCOS approved to treat?

GENGLYCOS is approved for adult and pediatric patients eight years of age and older with glycogen storage disease type Ia.

What dose of DTX401 was used in the trial?

Patients in the treated group received DTX401 at a dose of 1.0 x 10^13 genome copies per kilogram, compared with placebo.

How did the trial measure success?

The treated group showed a reduction in cornstarch requirements that cleared statistical significance against placebo (p<0.001).

What are the post-marketing requirements for the accelerated approval?

Ultragenyx must provide two years of open-label commercial safety and efficacy data through 50 treated patients and 20 controls, with analyses covering cornstarch clinical burden, fasting tolerance, and other measures.

How long will patients be monitored after treatment?

The combined cohort of new commercial patients and previously treated clinical trial participants will be tracked for 10 years through the expanded GSDIa Disease Monitoring Program.