{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-25-125881","form_type":"8-K","ticker":"PRTA","cik":"0001559053","company_name":"PROTHENA CORP PUBLIC LTD CO","filed_at":"2025-05-23T23:59:59+00:00","discovered_at":"2026-05-14T18:02:48.756468+00:00","generated_at":"2026-05-20T14:15:47.947725+00:00","sec_items":["8.01","9.01"],"event_type":"other_material","sentiment":"negative","materiality_score":0.9,"calibrated_materiality_score":0.9,"confidence":"high","headline":"Prothena's Phase 3 AFFIRM-AL trial for birtamimab fails; development halted; workforce reduction planned","bullets":["Phase 3 AFFIRM-AL did not meet primary endpoint of all-cause mortality (HR=0.915, p=0.7680); secondary endpoints also missed.","Birtamimab development discontinued; open-label extension stopped.","Company to substantially reduce workforce and operating expenses; further update expected in June 2025.","Birtamimab was generally safe and well-tolerated, consistent with prior safety profile.","Upcoming data: PRX012 Phase 1 ASCENT (Alzheimer's) in August; partner updates from Roche, Novo Nordisk, BMS in 2025-2026."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-25-125881","json":"https://secwatch.observer/filing/0001193125-25-125881.json","markdown":"https://secwatch.observer/filing/0001193125-25-125881.md","text":"https://secwatch.observer/filing/0001193125-25-125881.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1559053/000119312525125881/0001193125-25-125881-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1559053/000119312525125881/d891971d8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-20T14:15:47.947725+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"}