The FDA has approved Genglycos ... gene therapy, to reduce cornstarch dependence in patients eight and older with GSDIa, the first approved treatment to target the disease's underlying genetic cause. ... The FDA has granted accelerated approval to pariglasgene brecaparvovec-opnr (Genglycos) for adults and pediatric patients eight years of age and older with glycogen storage disease type Ia (GSDIa), a rare inherited disorder caused by ... The FDA has approved Genglycos (pariglasgene brecaparvovec-opnr), a one-time AAV8 gene therapy, to reduce cornstarch dependence in patients eight and older with GSDIa, the first approved treatment to target the disease's underlying genetic cause. ... The FDA has granted accelerated approval to pariglasgene brecaparvovec-opnr (Genglycos) for adults and pediatric patients eight years of age and older with glycogen storage disease type Ia (GSDIa), a rare inherited disorder caused by deficiency of the enzyme glucose-6-phosphatase.¹ Genglycos, formerly known in development as DTX401, is indicated to reduce daily cornstarch intake as an adjunct to nutritional management and is the first approved therapy for the condition.¹,² Ultragenyx announces U.S. FDA approval of Genglycos gene therapy, the first-ever FDA-approved treatment designed to treat the underlying cause of glycogen storage disease type Ia (GSDIa). News release. Ultragenyx Pharmaceutical Inc. Published August 19, 2026. Accessed August 20, 2026. RARE rises on completion of rolling submission for AAV gene therapy. "This accelerated approval reflects our confidence in the clinical evidence to date and our commitment to bringing innovative treatments to patients with rare genetic diseases while we continue to gather data to confirm long-term benefit." — Megha Kaushal, MD, MSc, acting deputy director, CBER Office of Therapeutic Products, US Food and Drug Administration · Genglycos is a one-time, AAV8-based gene therapy administered as a single intravenous infusion, designed to deliver a functional G6PC gene to liver cells to restore glucose-6-phosphatase activity and stabilize blood sugar during fasting Serious adverse reactions reported across two clinical studies included anaphylaxis, adrenal insufficiency, elevated lactate levels, and hypoglycemia, and the most common adverse reactions were increased liver transaminases, nausea, headache, constipation, and hyperglycemia.¹ Genglycos-treated patients also showed a higher rate of hypertriglyceridemia than placebo-treated patients (29% versus 8%).¹ The prescribing information carries warnings for anaphylaxis, liver toxicity, adrenal insufficiency, and tumorigenicity risk, and the therapy should not be used during pregnancy.¹ "Today's approval is a great milestone in using a gene therapy to treat this disease and improve the quality of life for people with this condition," said Karim Mikhail, B Pharm, MS, acting director of the FDA's Center for Biologics Evaluation and Research.¹

Duchenne Cell Therapy Decision Slips to November After FDA Labels New Arm Function Data a Major Amendment · Hunter Syndrome Gene Therapy Halted by FDA After Spine Scans Show Small Masses in Five Children · Gene Therapy for Glycogen Storage Disease Type Ia Wins Accelerated Approval Priced at 2.7 Million Dollars · What are inborn errors of immunity? A group of more than 500 rare genetic disorders... Duchenne Cell Therapy Decision Slips to November After FDA Labels New Arm Function Data a Major Amendment · Hunter Syndrome Gene Therapy Halted by FDA After Spine Scans Show Small Masses in Five Children · Gene Therapy for Glycogen Storage Disease Type Ia Wins Accelerated Approval Priced at 2.7 Million Dollars · What are inborn errors of immunity? A group of more than 500 rare genetic disorders, also called primary immunodeficiencies, in which a faulty gene leaves the immune system unable to work properly. Mayo Clinic joined the federal AEGIS project to build CRISPR treatments for children with inherited immune disorders. Here is what is real. Mayo Clinic has signed on as one of three clinical sites for a federally funded project that aims to do something no gene therapy program has managed yet: build a single, reusable system to treat children with rare inherited immune disorders, rather than developing an expensive therapy for each mutation one at a time. The project is called AEGIS, short for Affordable Gene Editing Therapies for Immune System Diseases of Children. It is funded by an award of up to $27.7 million from the Advanced Research Projects Agency for Health, the federal agency created to pursue high-risk medical research, and it is part of the agency's THRIVE program, which targets hereditary rare diseases with in vivo genetic medicines.

The FDA approved Genglycos (pariglasgene brecaparvovec-opnr) to reduce daily cornstarch intake in patients aged 8 years and older with glycogen storage disease type Ia. Known as Von Gierke disease, GSDIa is a rare metabolic disorder caused by a mutation in the G6PC gene. This genetic variation leads to a deficiency in glucose-6-phosphatase (G6Pase), an enzyme needed to release glucose into the bloodstream. Without this enzyme, the body cannot properly maintain blood glucose levels, causing severe hypoglycemia and other serious metabolic complications · Pariglasgene brecaparvovec is an adeno-associated virus (AAV) serotype 8 based gene therapy that delivers a functional copy of the G6PC gene into liver cells, enabling the production of normally functioning G6Pase. Ultragenyx stated that as part of its postmarketing commitments to the FDA, the Company will provide 2 years of clinical data from open-label commercial treatment of 50 patients and 20 control patients through its existing GSDIa Disease Monitoring Program. ... Ultragenyx announces US FDA approval of Genglycos™ gene therapy, the first-ever FDA-approved treatment designed to treat the underlying cause of glycogen storage disease type Ia (GSDIa). “The reduced reliance on cornstarch, experienced by patients in our clinical studies, demonstrates this gene therapy’s ability to establish the normal breakdown of glycogen to produce glucose during fasting or episodes of metabolic stress. This ability to regulate glucose has alleviated the disease burden and has the potential to mitigate the risk of severe or life-threatening hypoglycemia for these patients.” Close more info about First Gene Therapy Approved for Glycogen Storage Disease Type la

The clearance of Genglycos for a rare glycogen storage disease gives Ultragenyx a sellable voucher and momentum ahead of an eagerly anticipated study readout.

The accelerated greenlight for Ultragenyx’s gene therapy for glycogen storage disease has raised analyst expectations for approval of UX111, which the FDA rejected last summer and is currently reviewing for a second time. A decision is expected by mid-September.