The FDA has approved Ultragenyx’s Fayuvi, the first treatment for Sanfilippo syndrome type A, a fatal inherited brain disease in children.
Fayuvi (rebisufligene etisparvovec-hopf) is a one-time gene therapy. It is the first FDA-approved treatment of any kind for MPS IIIA, as the condition is also known.
The approval at a glance
- Drug: Fayuvi (rebisufligene etisparvovec-hopf)
- Company: Ultragenyx Pharmaceutical
- Indication: Paediatric patients with Sanfilippo syndrome type A (MPS IIIA)
- Type: One-time intravenous gene therapy
- Designations: Orphan drug, fast track and breakthrough therapy
How it works
Children with Sanfilippo syndrome type A lack a working SGSH gene. Without it, they cannot make an enzyme called sulfamidase, so a substance called heparan sulfate builds up in cells and damages the brain. Fayuvi uses a modified, non-infectious virus (AAV9) to deliver a working copy of the gene, allowing cells to make the missing enzyme.
What the trial showed
The open-label trial enrolled children aged 2 to 5. Treated children maintained or improved their cognitive scores. Untreated children in a historical comparison group typically plateaued and then declined.
Safety and administration
Common side effects included raised liver enzymes, nausea and vomiting, fever, reduced appetite and lower blood cell counts. The therapy must be given in a setting able to manage infusion reactions, with corticosteroids started the day before and continued for at least eight weeks afterwards.
Why it matters
- A first for families. Until now, there was no approved treatment for Sanfilippo syndrome type A.
- Gene therapy momentum. The approval adds to the growing number of one-time genetic treatments for rare diseases.
- Early treatment matters. Because the disease damages the brain progressively, timing of diagnosis and treatment is likely to be critical.
What it means for the supply chain
Gene therapies have specialised supply chains. Each dose is high value, must be stored and shipped under strict temperature control, and is given at specialist treatment centres. Hospitals preparing to offer Fayuvi will need cold chain handling, trained staff and arrangements for steroid pre-treatment and follow-up.
The bottom line
Fayuvi gives families of children with Sanfilippo syndrome type A their first approved treatment. Watch for pricing and the number of centres able to give it.
Frequently Asked Questions
What is Fayuvi? A one-time gene therapy from Ultragenyx for children with Sanfilippo syndrome type A.
Is it the first treatment for this condition? Yes. It is the first FDA-approved treatment for MPS IIIA.
How is it given? As a single intravenous infusion, with corticosteroids before and for at least eight weeks after.
What did the trial show? Treated children maintained or improved cognitive scores, unlike untreated children in a historical comparison group.
Sources
| Source | Used for |
|---|---|
| Pharmaceutical Executive | Approval details, mechanism, trial results, safety and administration |
| US Food and Drug Administration (FDA) press announcement | Approval date |
| CGTLive | Approval coverage |
Additional Resources
| Resource | What you’ll find |
|---|---|
| National Organization for Rare Disorders (NORD) | Information on Sanfilippo syndrome |
| Cure Sanfilippo Foundation | Patient and family resources |
| US Food and Drug Administration (FDA) | Cellular and gene therapy approvals |
| Ultragenyx investor relations | Launch updates |
Data note: Pricing and the exact approved age range were not stated in available reporting, so they are not included.