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FDA Fully Approves Ultragenyx’s Fayuvi for Sanfilippo A

By Drooid · Sep 18, 2026, 10:42 PM UTC · How we work

Summary

Story summary

The U.S. FDA granted full approval to Ultragenyx’s gene therapy Fayuvi for Sanfilippo syndrome type A.
Fayuvi’s U.S. list price is $3.95 million, making it among the world’s most expensive drugs.
In the pivotal Transpher A trial, treated children scored 23.5 points higher on cognitive assessments.
The FDA estimated 3,000-5,000 patients could benefit.
The FDA granted a second Priority Review Voucher.

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Story summary

The U.S. FDA granted full approval to Ultragenyx’s gene therapy Fayuvi for Sanfilippo syndrome type A.
Fayuvi’s U.S. list price is $3.95 million, making it among the world’s most expensive drugs.
In the pivotal Transpher A trial, treated children scored 23.5 points higher on cognitive assessments.
The FDA estimated 3,000-5,000 patients could benefit.
The FDA granted a second Priority Review Voucher.