{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-26-130498","form_type":"8-K","ticker":"RARE","cik":"0001515673","company_name":"Ultragenyx Pharmaceutical Inc.","filed_at":"2026-03-30T23:59:59+00:00","discovered_at":"2026-05-14T18:02:35.290173+00:00","generated_at":"2026-05-15T08:22:08.251207+00:00","sec_items":["8.01"],"event_type":"regulatory","sentiment":"positive","materiality_score":0.55,"calibrated_materiality_score":0.55,"confidence":"high","headline":"Ultragenyx receives FDA IND clearance for UX016 in GNE myopathy; Phase 1/2 to start H2 2026","bullets":["FDA cleared IND for UX016, a prodrug of sialic acid for GNE myopathy, a rare inherited neuromuscular disorder.","UX016 is a small molecule prodrug designed to enhance sialic acid delivery to muscle cells.","Phase 1/2 study planned for H2 2026, enrolling ~24 adults aged 18–55 in the US; externally funded by a patient group.","Study will evaluate safety, pharmacokinetics, and efficacy including muscle strength and functional measures through 48 weeks."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-26-130498","json":"https://secwatch.observer/filing/0001193125-26-130498.json","markdown":"https://secwatch.observer/filing/0001193125-26-130498.md","text":"https://secwatch.observer/filing/0001193125-26-130498.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1515673/000119312526130498/0001193125-26-130498-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1515673/000119312526130498/rare-20260330.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-15T08:22:08.251207+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"}