On September 22, Ultragenyx Pharmaceutical rose 9.39% in regular trading, trading at $16.025/share with turnover of approximately $64.94 million, extending upward momentum following last week's landmark FDA approval.

The rally stems from the continued market repricing of the FDA's approval of Fayuvi, the first-ever treatment for children with Sanfilippo syndrome type A, a rare genetic condition that progressively damages the brain and nervous system. Delivered as a one-time intravenous infusion, Fayuvi uses a modified virus to deliver a healthy gene replacing the enzyme patients lack. Clinical trials demonstrated that treated children aged 2 to 5 maintained or improved cognitive abilities compared to historical outcomes. The wholesale acquisition cost per patient is set at $3.95 million. Fayuvi represents the company's sixth FDA approval and second approved gene therapy.

The initial approval on September 17 sent shares surging approximately 12.6%, and the stock has continued to attract buying interest as investors digest the commercial potential of this high-value orphan drug.

(The above content is based on publicly available market information, generated by a program or algorithm, and is intended solely as a stock movement alert. It does not constitute investment advice or a basis for trading decisions.)