{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-26-377485","form_type":"8-K","ticker":"UPB","cik":"0002022626","company_name":"Upstream Bio, Inc.","filed_at":"2026-09-01T11:05:15+00:00","discovered_at":"2026-09-01T11:10:03.443692+00:00","generated_at":"2026-09-01T11:10:07.909598+00:00","sec_items":["7.01","8.01","9.01"],"event_type":"other_material","sentiment":"positive","materiality_score":0.8,"calibrated_materiality_score":0.8,"confidence":"high","headline":"Upstream Bio announces Phase 3 plans for verekitug in severe asthma and CRSwNP","bullets":["Phase 3: 400mg verekitug SC every 12 weeks vs placebo; one trial each in severe asthma and CRSwNP.","~1,500 patients total across both trials; broad populations, no biomarker restriction.","Primary endpoints: asthma AAER over 48 weeks; CRSwNP co-primary NPS and NCS at 48 weeks.","Trials to start Q1 2027; BLA submission expected with supportive results; potential launch as early as 2030.","Based on productive End-of-Phase 2 FDA meetings; data from 500+ treated patients."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-26-377485","json":"https://secwatch.observer/filing/0001193125-26-377485.json","markdown":"https://secwatch.observer/filing/0001193125-26-377485.md","text":"https://secwatch.observer/filing/0001193125-26-377485.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/2022626/000119312526377485/0001193125-26-377485-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/2022626/000119312526377485/upb-20260901.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-09-01T11:10:07.909598+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"}