GENGYLCOS (pariglasgene brecaparvovec-opnr; DTX401)
Reduction of daily cornstarch intake as an adjunct to nutritional management of glycogen storage disease type Ia · Adults and pediatric patients aged 8 years and older with glycogen storage disease type Ia
RARE · Ultragenyx Pharmaceutical
Regulatory designations
Full timeline
8 milestonesOriginal PDUFA date superseded by early approval
FDA had assigned August 23 as the PDUFA target action date for the DTX401 BLA. The agency granted accelerated approval on August 19, four days before the goal date.
Ultragenyx — BLA acceptance and August 23 action date↗FDA granted accelerated approval to GENGYLCOS
FDA granted accelerated approval to GENGYLCOS (pariglasgene brecaparvovec-opnr), the first approved therapy for glycogen storage disease type Ia. The gene therapy is indicated to reduce daily cornstarch intake as an adjunct to nutritional management in adults and pediatric patients aged 8 years and older. In the randomized study, patients treated with GENGYLCOS had a 31% mean reduction from baseline in daily cornstarch intake compared with placebo.
FDA — Accelerated approval of GENGYLCOS for GSDIa↗FDA did not anticipate an advisory committee meeting
Ultragenyx reported that FDA did not anticipate convening an advisory committee for the DTX401 application at that time.
Ultragenyx — First-quarter 2026 regulatory update↗FDA accepted the BLA with Priority Review
FDA accepted the application, granted Priority Review and assigned the August 23, 2026 action date.
Ultragenyx — FDA acceptance and Priority Review↗Related News
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Oct 2, 2026Ultragenyx Announces Marketing Authorisation Application (MAA) Submission to the European Medicines Agency (EMA) for the First Investigational Gene Therapy for MPS IIIA (Sanfilippo Syndrome Type A)
Sep 17, 2026Ultragenyx Announces Approval of FAYUVI™ Gene Therapy, the First-Ever FDA-Approved Treatment for Sanfilippo Syndrome Type A (MPS IIIA)
Sep 2, 2026Ultragenyx Announces Phase 3 Aspire results in Angelman Syndrome
Sep 1, 2026Ultragenyx Announces the Publication of a Successful 96-Week Randomized, Placebo-Controlled Trial with Crossover Treatment of GENGLYCOS™ (also known as DTX401) AAV Gene Therapy in GSDIa in The Journal of Inherited Metabolic Disease