FAYUVI (rebisufligene etisparvovec-hopf; UX111 / ABO-102) was approved by the FDA on September 17, 2026 for sanfilippo syndrome type A (MPS IIIA).
Verified against: FDA action day September 17, 2026 (CBER approval letter) · Announcement September 17, 2026 (Ultragenyx 8-K) · Goal date September 19, 2026 (Ultragenyx 8-K).
FAYUVI (rebisufligene etisparvovec-hopf, UX111) approved as the first treatment for pediatric patients with Sanfilippo syndrome type A, a standard full approval with a Priority Review Voucher (Sep 17 2026).
The PDUFA action date was September 19, 2026 and the FDA approved on September 17, two days early. That goal date came from Ultragenyx's own 8-K of April 2, 2026 ("The FDA set a Prescription Drug User Fee Act (PDUFA) action date of September 19, 2026"), which is why the margin is quoted as a measurement. The BLA was a resubmission after an earlier Complete Response Letter; UX111 was licensed from Abeona Therapeutics.
Run-up figures are the stock's own daily closing path over the 120 trading days before the decision, from our price history. Cohort move is the historical median absolute decision-day move for this market-cap tier. History, not a prediction.
Primary source: Ultragenyx 8-K, September 17, 2026 (Item 8.01)
FDA record of the action: the FDA approved on September 17, 2026, per CBER approval letter (FAYUVI) (FDA letter). The sponsor announced it the same day. Action dates on pdufa.bio come from the FDA's own record, not the press release. Every FDA action we hold, by FDA date: FDA approval letters.
| Fund | Shares | Value at quarter end | Filing |
|---|---|---|---|
| RTW Investments | 7,796,895 | $260.3 million | filed August 14, 2026 |
13F reports list long positions in common stock at quarter end, are due 45 days later, and show no short positions or later trades. Notes, warrants and other instruments are not counted as shares.
Yes. The FDA approved the application for FAYUVI (rebisufligene etisparvovec-hopf; UX111) on September 17, 2026, per the FDA's own record. The primary source is linked on this page.
FAYUVI (rebisufligene etisparvovec-hopf; UX111) is an Ultragenyx Pharmaceutical Inc. (RARE) program. The FDA decision came on September 17, 2026; the FDA's own record of the decision is linked on this page.
Measured over the 120 trading days before the decision (T-120 to T-1), RARE moved -35.6%. That is the recorded price path into this specific event. Historical measurement, not a prediction, and not investment advice.