{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-26-380165","form_type":"8-K","ticker":"RARE","cik":"0001515673","company_name":"Ultragenyx Pharmaceutical Inc.","filed_at":"2026-09-02T20:04:05+00:00","discovered_at":"2026-09-02T20:06:00.415380+00:00","generated_at":"2026-09-02T20:06:37.238772+00:00","sec_items":["8.01"],"event_type":"other_material","sentiment":"negative","materiality_score":1.0,"calibrated_materiality_score":1.0,"confidence":"high","headline":"Ultragenyx Phase 3 Aspire fails primary and key secondary endpoints in Angelman syndrome","bullets":["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."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-26-380165","json":"https://secwatch.observer/filing/0001193125-26-380165.json","markdown":"https://secwatch.observer/filing/0001193125-26-380165.md","text":"https://secwatch.observer/filing/0001193125-26-380165.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1515673/000119312526380165/0001193125-26-380165-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1515673/000119312526380165/rare-20260902.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-09-02T20:06:37.238772+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}