What is Fayuvi, the first treatment for Sanfilippo syndrome?

We have folded our coverage of this story into one complete guide: Is there really a first FDA-approved treatment for Sanfilippo syndrome?

The short version: Fayuvi (rebisufligene etisparvovec) is a one-time gene therapy for Sanfilippo syndrome type A — the first FDA-approved treatment for a disease that previously had no treatment at all. For the full picture — how the therapy works, what FDA approval actually means, what families usually do next, and what to watch from here — read the complete guide.

Why this approval is a landmark for families

Sanfilippo syndrome type A previously had no approved treatment at all, so a first approval changes the landscape even while many questions remain. Fayuvi is described in the coverage as a one-time gene therapy, and the full guide linked above explains how it works and what the approval does and does not mean. Keeping both ideas together — a genuine first, and a story still unfolding — is the honest reading.

What to do, step by step

1. Read the complete guide linked above for how the therapy works and what approval means.
2. Keep the scope precise: the approval concerns Sanfilippo syndrome type A.
3. Note that this is presented as a one-time gene therapy, not an ongoing medicine.
4. Bring any questions about an individual child to their specialist care team.
5. Follow reporting from regulators for what happens after approval.