GENGLYCOS (pariglasgene brecaparvovec-opnr), an AAV8 gene therapy for glycogen storage disease type Ia, granted accelerated approval on August 19, 2026 - four days ahead of its August 23 PDUFA goal date.
Run-up into the decision (T-120 → T+5)
Daily close, T-120 (2/26/26) through T+0. Run-up high $35.87 on 7/7/26, low $18.5 on 3/24/26 (T-120 to T-1). FDA decision 8/19/26. Historical price action, not a forecast.
Key facts
FDA decision date2026-08-19
OutcomeApproved
Drug / candidateGENGLYCOS (pariglasgene brecaparvovec-opnr, DTX401)
IndicationGlycogen storage disease type Ia (GSDIa) in adult and pediatric patients eight years of age and older
CompanyUltragenyx Pharmaceutical Inc.
Market-cap tierMid
120-day run-up (T-120→T-1)+10.6%
Cohort decision-day move (history)2.1% median (n=230)
The PDUFA target action date was August 23, 2026; the FDA granted accelerated approval on August 19 and Ultragenyx announced it after the market close that day. GENGLYCOS is the first FDA-approved treatment designed to treat the underlying cause of GSDIa, and Ultragenyx's first approved gene therapy. It is a single intravenous AAV8 gene therapy delivering G6Pase expression under the native promoter; patients in clinical studies reduced their reliance on round-the-clock cornstarch dosing. As a condition of accelerated approval, Ultragenyx will provide two years of safety and efficacy data from open-label commercial treatment of 50 patients and 20 control patients. The BLA held Priority Review, and the approval earned Ultragenyx a rare pediatric disease Priority Review Voucher.
Run-up figures are the stock's own daily closing path over the 120 trading days before the decision, from our price history. Cohort move is the historical median absolute decision-day move for this market-cap tier. History, not a prediction.
Was GENGLYCOS (pariglasgene brecaparvovec-opnr, DTX401) approved by the FDA?
Yes. The FDA approved the application for GENGLYCOS (pariglasgene brecaparvovec-opnr, DTX401) on August 19, 2026. The primary source is linked on this page.
Which company is behind GENGLYCOS (pariglasgene brecaparvovec-opnr, DTX401)?
GENGLYCOS (pariglasgene brecaparvovec-opnr, DTX401) is a Ultragenyx Pharmaceutical Inc. (RARE) program. The FDA decision came on August 19, 2026; the company's own announcement is linked on this page.
How did RARE stock trade into the FDA decision?
Measured over the 120 trading days before the decision (T-120 to T-1), RARE moved +10.6%. That is the recorded price path into this specific event -- historical measurement, not a prediction, and not investment advice.
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