Ultragenyx to Sell Rare Pediatric Disease Voucher for $210 Million

Ultragenyx Pharmaceutical has entered a definitive agreement to sell a rare pediatric disease priority review voucher (PRV) for $210 million, the company announced October 7, 2026.¹ Ultragenyx received the voucher following FDA approval of pariglasgene brecaparvovec-opnr (Genglycos), also known as DTX401, the first treatment designed to address the underlying cause of glycogen storage disease type Ia (GSDIa).¹

“Monetizing this PRV provides significant non-dilutive capital to advance our efforts to bring forward first-ever therapies for rare and ultra-rare diseases, and supports our path to profitability,” said Howard Horn, chief financial officer and executive vice president, corporate strategy, Ultragenyx, in a company press release.¹ “GENGLYCOS itself benefited from capital generated from a previous PRV sale, demonstrating the important role the PRV program plays in helping companies develop transformative therapies for rare disease patients.”

How did Ultragenyx earn this voucher?

FDA granted Genglycos accelerated approval on August 19, 2026, as an adjunct to nutritional management for reducing daily cornstarch intake in patients 8 years and older with GSDIa, a rare metabolic disorder caused by G6Pase enzyme deficiency.²^,³ The one-time gene therapy met its primary endpoint in the phase 3 GlucoGene study, showing a statistically significant reduction in cornstarch requirements versus placebo, and also carries regenerative medicine advanced therapy and fast track designations.²^,³ Because the approval rests on a surrogate endpoint, Ultragenyx must still complete confirmatory trials to verify clinical benefit.²

What does the rare pediatric disease priority review voucher program do?

Under the FDA program, a sponsor that wins approval for a drug or biologic treating a rare pediatric disease may qualify for a PRV redeemable for priority review of a later, unrelated marketing application.¹ Vouchers can be used internally or sold or transferred to another company, and Ultragenyx said the program played a direct role in Genglycos's own path to market, since capital from an earlier voucher sale helped fund its development.¹

What are the deal terms?

The transaction remains subject to customary closing conditions, including expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act.¹ Jefferies LLC is serving as exclusive financial advisor and Gibson, Dunn and Crutcher LLP as legal counsel to Ultragenyx.¹

Why does the PRV program matter for rare disease financing?

This sale reflects a broader financing pattern across the rare disease sector, where priority review vouchers have become a recurring source of non-dilutive capital for companies with thin patient populations and high development costs. “The US dominates because the PRV program creates a highly valuable and, more importantly, tradable asset,” said Dan Williams, PhD, CEO of UK-based SynaptixBio, rare disease biotech company. Dr Williams discussed why the voucher program has drawn growing interest from rare disease drug developers and investors in a previous company statement.⁴ Dr Williams has noted that biotechs outside the United States, lacking an equivalent mechanism, must rely on public markets, private investment, or acquisition instead, underscoring the PRV's distinct financial value for sponsors like Ultragenyx.⁴

What are the limitations?

The Ultragenyx transaction has not yet closed as of the date of the company’s announcement and remains contingent on standard regulatory clearance. A definitive agreement does not necessarily guarantee completion, the company noted in its release.¹ The release does not disclose the voucher buyer or specify how Ultragenyx will allocate the proceeds beyond general rare disease development and corporate strategy goals.

Separately, Genglycos's accelerated approval rests on a surrogate cornstarch-reduction endpoint rather than confirmed clinical outcomes, so its continued approval depends on verification in confirmatory trials. The rare pediatric disease PRV program itself has previously lapsed and required congressional reauthorization. While reauthorization has reportedly restored financial certainty for rare disease investors, the program's long-term availability as a financing tool still depends on future legislative action.⁴

References

1. Ultragenyx Pharmaceutical. Ultragenyx enters into agreement to sell rare pediatric disease priority review voucher for $210 million. Press release. Published October 7, 2026. Accessed October 8, 2026. https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-enters-agreement-sell-rare-pediatric-disease-priority
2. Ultragenyx Pharmaceutical. 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). Press release. Published August 19, 2026. Accessed October 8, 2026. https://ir.ultragenyx.com/node/19181
3. FDA. FDA approves first therapy for patients aged 8 years and older with glycogen storage disease type Ia. Press release. Published August 19, 2026. Accessed October 8, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-therapy-patients-aged-8-years-and-older-glycogen-storage-disease-type-ia
4. Schoenthaler E. SynaptixBio: rare disease biotech investment rising in US after PRV renewal, UK lagging behind. BioPharm International. Published August 11, 2026. Accessed October 8, 2026. https://www.biopharminternational.com/view/synaptixbio-rare-disease-biotech-investment-rising-in-us-after-prv-renewal-uk-lagging-behind