The US Food and Drug Administration (FDA) granted accelerated approval for Ultragenyx Pharmaceutical’s Genglycos (pariglasgene brecaparvovec-opnr), also known as DTX401, in adult and paediatric patients eight years and older with glycogen storage disease type Ia (GSDIa). 

Dr Eric Crombez, Chief Medical Officer at Ultragenyx, commented: “As our first gene therapy approval, Genglycos represents an important achievement for our company and the realisation of the promise of a powerful new tool to deliver transformative medicines for people living with rare diseases.” 

GSDIa is an ultra-rare genetic metabolic disorder caused by a deficiency of the enzyme needed to release glucose from the liver to the bloodstream. The deficiency reduces the liver’s ability to control glucose levels and is associated with potentially life-threatening hypoglycaemia episodes and other serious complications. 

“Day-to-day management of GSDIa requires a relentless regimen of raw cornstarch and strict dietary management that can be extraordinarily demanding for patients and families. Even with meticulous adherence to this regimen, patients must be perfect. Any missed cornstarch puts patients at risk of severe hypoglycaemia, seizures, and even death,” said Dr David Weinstein, one of the world’s leading GSDIa experts. “The approval of Genglycos represents a major step forward for the GSDIa community and reflects almost 30 years of work and scientific progress aimed at improving safety and the quality of life of people living with this disease.” 

The approval of Genglycos is based on positive data from the 48-week randomised, double-blind, placebo-controlled Phase III GlucoGene study which treated 46 participants aged eight years and older. 

As part of accelerated approval, Ultragenyx has agreed to provide two years of safety and efficacy clinical data from open-label commercial treatment of 50 patients and 20 control patients through enhancement of its existing GSDIa Disease Monitoring Program (DMP).