Ultragenyx wins FDA greenlight for first Sanfilippo therapy, priced at nearly $4M

September 18, 2026
8:40 pm

The FDA has given the go-ahead to Ultragenyx’s rebisufligene etisparvovec—now to be marketed under the brand name Fayuvi—for the treatment of Sanfilippo syndrome type A, an ulta-rare, progressive neurological condition in children.

Fayuvi is the first-ever FDA-approved therapy for the fatal condition, according to a company news release on Thursday afternoon. Sanfilippo syndrome type A causes children to gradually lose cognitive and other developmental abilities, with Ultragenyx’s new therapy indicated for patients with preserved neurodevelopmental function.

The approval represents a comeback for the one-time gene therapy, which was initially rejected in July 2025 due to manufacturing issues.

Ultragenyx wins FDA greenlight for first Sanfilippo therapy, priced at nearly $4M

The FDA has given the go-ahead to Ultragenyx’s rebisufligene etisparvovec—now to be marketed under the brand name Fayuvi—for the treatment of Sanfilippo syndrome type A, an ulta-rare, progressive neurological condition in children.

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