TheTechno Optimist.

Ultragenyx—Ultragenyx's Angelman drug apazunersen fails Phase 3 Aspire trial on primary and key secondary endpointsFayuvi (UX111)Ultragenyx—FDA approves Fayuvi, the first treatment for Sanfilippo syndrome type A, at $3.95M per patientGenglycos (DTX401)Ultragenyx—FDA grants accelerated approval to Genglycos, the first gene therapy for glycogen storage disease type Ia

Ultragenyx

Rare-disease gene therapies and medicines

USpublic~1,371 staffest. 2010Checked 11 Oct

The brief

Analyst view
  • Two AAV gene therapies approved in 2026: Genglycos (Aug) and Fayuvi (Sep), each earning a priority review voucher.
  • Sales come mostly from Crysvita; 2026 revenue guidance is $730-760M, with profit targeted for 2027.
  • Setbacks: setrusumab missed its main goal in two Phase 3 bone trials (late 2025), and its Angelman drug failed Phase 3 in Sep 2026.

Technical approach

As reported
Vectors

Harmless viruses carry the gene

Its gene therapies pack a working gene into an AAV shell, a virus that causes no disease, given once by IV drip.

Targets

Pick the right tissue

Different AAV types home to different organs: AAV8 for the liver (Genglycos), AAV9 to reach the brain (Fayuvi).

Manufacturing

Making its own virus

Ultragenyx makes AAV in its own Bedford, Massachusetts plant, with Andelyn Biosciences as a second manufacturer.

Portfolio

Many tiny markets

Each disease has a few thousand patients, so it runs many programs and sells through specialist treatment centres.

Primer