NOVATO, California, September 2, 2026, 19:50 (EDT) – Shares in Ultragenyx fell 44% after the company’s Phase 3 trial failure erased $1.14 billion from its market value.
- Ultragenyx was last changing hands at $14.95 at 19:48 EDT, down 43.7% from its close in the regular session.
- Phase 3 Aspire did not achieve its main Bayley-4 endpoint or its key MDRI secondary endpoint.
- Revenue for the June quarter totaled $214 million, while cash and marketable securities were reported at $436 million.
Ultragenyx Pharmaceutical Inc. NASDAQ:RARE stock dropped 43.7% in after-hours trading on Wednesday. The decline came after the company reported its Phase 3 study of apazunersen in Angelman syndrome did not meet its primary endpoints Ultragenyx statement.
The change wiped out about $1.14 billion from the company’s market capitalization. It also redirected focus from a key asset towards sales activities and available cash.
RARE traded at $14.95 as of 19:48 EDT, down from its regular session closing price of $26.53 Yahoo Finance.
RARE repriced within minutes of the closing bell
U.S. dollars per share, selected one-minute observations
As of . Source: Yahoo Finance one-minute quote history. Extended-hours prices can be thin. Values are rounded.
Aspire registered 129 participants, all with a complete maternal UBE3A gene deletion. Subjects were evenly assigned to either apazunersen treatment or a sham procedure.
The study did not achieve its Bayley-4 cognition endpoint or its MDRI response goal. Ultragenyx observed no difference supporting efficacy across all five MDRI components. Safety findings were in line with those reported in Phase 1/2.
The company intends to assess apazunersen’s prospects and implement major cost cuts. This approach is significant, as the core business continues to generate substantial revenue.
The commercial base is concentrated but growing
Second-quarter 2026 revenue mix; total revenue was $214 million
Rounded shares may not sum to 100%. Source: Ultragenyx Q2 2026 results, August 4, 2026.
Revenue for the second quarter increased by 28% to $214 million, compared with $167 million. Crysvita contributed $156 million, accounting for around 73% of the total quarterly results.
As of June 30, cash and marketable securities stood at $436 million. The company used $97 million in operating cash in the quarter. The current cash balance represents roughly 30% of the lowered equity value.
Chief Executive Emil Kakkis stated, “We are disappointed by the Aspire result.” He added that the commercial base will back the pipeline. The company has yet to specify the extent of its planned reductions.
William Blair analyst Sami Corwin identified spillover risks for the distinct Aurora study. She noted that even if Aurora achieves its primary endpoint, commercialization may still face challenges Reuters.
One failure, four remaining decision points
- GENGLYCOS approvedFDA accelerated approval in GSDIa
- Aspire missesPrimary and key secondary endpoints fail
- UX111 decisionFDA action date for Sanfilippo syndrome
- UX701 dataWilson disease dose-finding update
- DTX301 endpointOTC deficiency treatment-burden result
Sources: FDA, Aspire release and Ultragenyx catalyst guidance.
GENGLYCOS gained FDA approval for GSDIa on August 19, marking Ultragenyx’s fifth therapy to receive authorisation through the accelerated approval pathway FDA.
Coming up, the FDA decision on UX111 is set for September 19. The gene therapy is designed for Sanfilippo syndrome type A. Data for UX701 is anticipated in the fourth quarter.
Ultragenyx’s $14.95 share price implied an equity value of roughly $1.47 billion, which is nearly double the midpoint of its 2026 revenue projection of $730 million to $760 million. Based on 98.59 million outstanding shares, the ratio at the close was 3.5 times.
Risks: Trading outside standard hours can intensify price fluctuations. Reducing expenses may help retain cash but could delay other initiatives. Outcomes of regulatory reviews and launch performance are still unclear.
Investors are looking for two key figures. One concerns the extent of cost savings. The other focuses on initial GENGLYCOS demand ahead of the upcoming regulatory ruling.
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