# GENGYLCOS (pariglasgene brecaparvovec-opnr; DTX401) PDUFA Event: Reduction of daily cornstarch intake as an adjunct to nutritional management of glycogen storage disease type Ia Canonical URL: https://biopharmsignal.com/pdufa-calendar/RARE/dtx401-glycogen-storage-disease-type-ia Ticker: RARE Company: Ultragenyx Pharmaceutical Event date: 2026-08-23 Event type: FDA Decision Stage: PDUFA Result: Approved Result date: 2026-08-19 Application type: BLA Original PDUFA date superseded by early approval. FDA had assigned August 23 as the PDUFA target action date for the DTX401 BLA. The agency granted accelerat... ## Event Timeline ### August 23, 2026 — Original PDUFA date superseded by early approval FDA had assigned August 23 as the PDUFA target action date for the DTX401 BLA.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](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-us-fda-acceptance-and-priority-review) ### August 19, 2026 — 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](https://www.fda.gov/news-events/press-announcements/fda-approves-first-therapy-patients-aged-8-years-and-older-glycogen-storage-disease-type-ia) ### May 5, 2026 — 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](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-reports-first-quarter-2026-financial-results-and) ### February 23, 2026 — 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](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-us-fda-acceptance-and-priority-review) ### December 30, 2025 — Rolling BLA submission completed Ultragenyx completed the rolling submission seeking approval of DTX401 as a treatment for GSDIa. [Ultragenyx — DTX401 rolling BLA completed](https://ir.ultragenyx.com/node/18251/pdf) ### August 18, 2025 — Rolling BLA submission initiated Ultragenyx submitted the nonclinical and clinical modules and planned to complete the chemistry, manufacturing and controls module in the fourth quarter of 2025. [Ultragenyx — DTX401 rolling BLA initiated](https://ir.ultragenyx.com/node/17976) ### May 30, 2024 — Phase 3 GlucoGene study met its primary endpoint DTX401 produced a statistically significant and clinically meaningful reduction in daily cornstarch intake versus placebo at Week 48 while maintaining glucose control. [Ultragenyx — Positive Phase 3 GlucoGene topline results](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-positive-top-line-results-phase-3-study) ### November 8, 2021 — Phase 3 GlucoGene study started The randomized pivotal study began enrolling patients with glycogen storage disease type Ia to evaluate DTX401 against placebo. [ClinicalTrials.gov — GlucoGene study record (NCT05139316)](https://clinicaltrials.gov/study/NCT05139316) ## Regulatory Designations - Priority Review FDA: [Ultragenyx — FDA acceptance and Priority Review](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-us-fda-acceptance-and-priority-review) - Fast Track FDA: [Ultragenyx — DTX401 regulatory designations](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-us-fda-acceptance-and-priority-review) - Orphan Drug FDA: [Ultragenyx — DTX401 regulatory designations](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-us-fda-acceptance-and-priority-review) - Regenerative Medicine Advanced Therapy FDA: [Ultragenyx — DTX401 regulatory designations](https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-us-fda-acceptance-and-priority-review) ## Related Pages - RARE PDUFA calendar: https://biopharmsignal.com/pdufa-calendar/RARE.md - RARE company profile: https://biopharmsignal.com/company/RARE.md - PDUFA calendar: https://biopharmsignal.com/pdufa-calendar.md ## Related News - 2026-09-02 — Ultragenyx Announces Phase 3 Aspire results in Angelman Syndrome: https://biopharmsignal.com/news/RARE/ultragenyx-announces-phase-3-aspire-results-in-angelman-syndrome-6f1182c3.md - 2026-09-01 — Ultragenyx 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: https://biopharmsignal.com/news/RARE/ultragenyx-announces-the-publication-of-a-successful-96-week-randomized-placebo--0f6d355a.md - 2026-08-25 — Ultragenyx Reports Inducement Grant Under Nasdaq Listing Rule 5635(c)(4): https://biopharmsignal.com/news/RARE/ultragenyx-reports-inducement-grant-under-nasdaq-listing-rule-5635-c-4-d47cbbd9.md - 2026-08-19 — 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): https://biopharmsignal.com/news/RARE/ultragenyx-announces-u-s-fda-approval-of-genglycos-gene-therapy-the-first-ever-f-da638102.md - 2026-08-04 — Ultragenyx Reports Second Quarter 2026 Financial Results and Corporate Update: https://biopharmsignal.com/news/RARE/ultragenyx-reports-second-quarter-2026-financial-results-and-corporate-update-629023e6.md