{"schema_version":"secwatch.filing_event.v1","accession":"0000950170-24-138250","form_type":"8-K","ticker":"RARE","cik":"0001515673","company_name":"Ultragenyx Pharmaceutical Inc.","filed_at":"2024-12-19T23:59:59+00:00","discovered_at":"2026-05-14T18:03:08.652936+00:00","generated_at":"2026-05-29T01:34:13.287821+00:00","sec_items":["8.01"],"event_type":"regulatory","sentiment":"positive","materiality_score":0.7,"calibrated_materiality_score":0.7,"confidence":"high","headline":"Ultragenyx submits BLA to FDA for UX111 gene therapy in Sanfilippo syndrome type A","bullets":["Submitted BLA to FDA seeking accelerated approval for UX111 (AAV gene therapy) in Sanfilippo syndrome type A (MPS IIIA).","BLA supported by Transpher A study: rapid, sustained CSF heparan sulfate reduction correlated with improved cognitive development vs. natural history.","Most common adverse events were liver enzyme elevations; majority mild/moderate (Grade 1/2), all resolved.","In 2024, FDA agreed CSF heparan sulfate can serve as surrogate endpoint for accelerated approval."],"urls":{"canonical":"https://secwatch.observer/filing/0000950170-24-138250","json":"https://secwatch.observer/filing/0000950170-24-138250.json","markdown":"https://secwatch.observer/filing/0000950170-24-138250.md","text":"https://secwatch.observer/filing/0000950170-24-138250.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1515673/000095017024138250/0000950170-24-138250-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1515673/000095017024138250/rare-20241219.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-29T01:34:13.287821+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"}