$RARE: Ultragenyx Lost Its Biggest Program Overnight. The Next FDA Decision Is 16 Days Away.
A clean Phase 3 miss in Angelman syndrome deleted $1.2 billion from Ultragenyx overnight, leaving a growing $745M revenue base priced below 2x sales sixteen days before its next FDA decision. Scenario zones inside.
Ultragenyx ($RARE) went into Tuesday night worth $2.6 billion. It came out of the overnight session worth roughly $1.4 billion, trading in the premarket around $14, down 46% and below its prior 52-week low of $18.29. Financial media are calling it a run at the lowest price in the company's history.
The cause is unambiguous. After the close on September 2, Ultragenyx reported topline results from Aspire, its Phase 3 study of apazunersen (GTX-102) in Angelman syndrome. The trial did not achieve its primary endpoint, change from baseline in the Bayley-4 cognitive raw score. It also missed the key secondary endpoint, net response on the Multidomain Responder Index. And this was not a near-miss the company can argue with: per the release, there were no differences between treated and control groups on cognition scores, on net MDRI response, or on the mean changes of any of the five individual MDRI components. In a 129-patient study randomized one-to-one against sham, the drug simply did not separate.
Why this program carried so much of the stock
Angelman syndrome is a rare neurogenetic disorder with an estimated 60,000 patients in commercially accessible geographies and no approved therapy of any kind. GTX-102 was one of the most advanced programs in the field, carrying Breakthrough Therapy, Orphan Drug, Rare Pediatric Disease, and Fast Track designations from the FDA plus PRIME status in Europe. A first-in-disease drug for a lifelong condition requiring continuous care was, by a wide margin, the largest single opportunity in the Ultragenyx pipeline.
The sell side confirmed the math this morning by deleting it. JPMorgan cut its price target from $80 to $36 and downgraded to Neutral. Baird went from $40 to $16, Evercore ISI from $34 to $16, and William Blair pulled its Outperform rating entirely. The spread between those targets, $16 to $36, is itself the story: nobody agrees yet on what the leftover company is worth.
Ultragenyx says it will now evaluate what to do with the apazunersen program and, more importantly for the financial picture, will implement what it calls significant expense reductions while supporting the commercial business.
The part the overnight tape ignores
Here is what makes this a more interesting setup than a standard Phase 3 blowup. The company that just lost its lead program is not a one-asset biotech running on hope and a cash pile.
Three weeks before this failure, on August 19, the FDA approved GENGLYCOS (DTX401), Ultragenyx's gene therapy for glycogen storage disease type Ia, the first approved treatment ever for that disease. Sixteen days from now, on September 19, the FDA is due to decide on a second gene therapy, UX111 for Sanfilippo syndrome type A, under a PDUFA date the agency set when it accepted the resubmitted application in April.
And the base business underneath is growing. Second-quarter revenue of $214 million was the highest in company history, up 28% year over year, and management reaffirmed full-year 2026 guidance of $730 to $760 million, a figure that excludes anything from the new launches. The company has been publicly guiding to profitability in 2027, with combined R&D and SG&A expenses contracted at least 15% next year, and that was before last night's promise of deeper cuts.
So the question the premarket price is asking is brutally simple. The market just repriced Ultragenyx at roughly two times this year's guided revenue, a multiple normally reserved for broken businesses, sixteen days before a binary FDA decision. Either the entire investment case was the drug that just died, or the overnight tape has mispriced what survived. The answer runs through the real share count, the cash runway math, and what each September 19 outcome does to the valuation.
The rest of this briefing is for paid members: the share-count math on exactly how much value was deleted overnight, the product-by-product revenue base that survives the failure, the $436 million cash runway clock against the promised expense cuts, the September 19 PDUFA setup, and scenario-by-scenario price zones for where $RARE trades from here.
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