{"schema_version":"secwatch.filing_event.v1","accession":"0000950123-24-003302","form_type":"8-K","ticker":"RARE","cik":"0001515673","company_name":"Ultragenyx Pharmaceutical Inc.","filed_at":"2024-04-15T23:59:59+00:00","discovered_at":"2026-05-14T18:03:18.772123+00:00","generated_at":"2026-06-03T22:54:04.609467+00:00","sec_items":["8.01","9.01"],"event_type":"other_material","sentiment":"positive","materiality_score":0.85,"calibrated_materiality_score":0.85,"confidence":"high","headline":"Ultragenyx reports positive Phase 1/2 GTX-102 data in Angelman syndrome with rapid, sustained improvements","bullets":["Expansion Cohorts A&B (24 patients) at Day 170 showed clinically meaningful improvements across cognition, behavior, sleep, motor, and communication domains vs natural history.","Multi-domain responder index (MDRI) net response of +2.0 (p<0.0001) at Day 170; majority of patients achieved +2 to +4 domain improvement.","Dose-escalation Cohorts 4-7 (15 patients) at Day 758 showed sustained long-term benefit; MDRI net response +2.0 (p=0.0007) at Day 338.","No unexpected serious adverse events; three patients had mild-moderate lower extremity weakness (resolved, no recurrence on re-dosing).","FDA notified of safety events; no issues raised or additional actions required; data to be presented at AAN 2024."],"urls":{"canonical":"https://secwatch.observer/filing/0000950123-24-003302","json":"https://secwatch.observer/filing/0000950123-24-003302.json","markdown":"https://secwatch.observer/filing/0000950123-24-003302.md","text":"https://secwatch.observer/filing/0000950123-24-003302.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1515673/000095012324003302/0000950123-24-003302-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1515673/000095012324003302/rare-20240415.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-03T22:54:04.609467+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"}