secwatch.observer — SEC 8-K summary
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Issuer:     Ultragenyx Pharmaceutical Inc. (RARE)
CIK:        0001515673
Form:       8-K
Filed at:   2026-09-02T20:04:05+00:00
Accession:  0001193125-26-380165
Event type: other_material
Sentiment:  negative
Materiality: 1.00
Item codes: 8.01
LLM model:  deepseek-v4-flash:cloud@v2

Ultragenyx Phase 3 Aspire fails primary and key secondary endpoints in Angelman syndrome
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- Apazunersen (GTX-102) did not meet primary endpoint (Bayley-4 cognitive raw score change) nor key secondary (MDRI net response).
- No differences vs control on Bayley Cognition raw scores or MDRI mean changes across five individual endpoints.
- Safety profile in Aspire consistent with Phase 1/2; randomized groups comparable at baseline.
- Company will evaluate apazunersen program disposition and implement significant expense reductions while supporting commercial business.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/1515673/000119312526380165/0001193125-26-380165-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/1515673/000119312526380165/rare-20260902.htm
  HTML page:      https://secwatch.observer/filing/0001193125-26-380165

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer