{"schema_version":"secwatch.filing_event.v1","accession":"0000950170-25-009225","form_type":"8-K","ticker":"ATRA","cik":"0001604464","company_name":"Atara Biotherapeutics, Inc.","filed_at":"2025-01-27T23:59:59+00:00","discovered_at":"2026-05-14T18:03:04.165367+00:00","generated_at":"2026-05-27T09:16:30.409264+00:00","sec_items":["2.05","9.01"],"event_type":"other_material","sentiment":"negative","materiality_score":0.75,"calibrated_materiality_score":0.75,"confidence":"high","headline":"Atara Biotherapeutics cuts workforce by ~50%; expects $7.5M severance costs","bullets":["Workforce reduction impacts ~50% of current employees; completion expected by June 2025.","Estimated severance and related benefits of approximately $7.5 million, primarily one-time cash charges.","Additional details to be disclosed in Q1 2025 Form 10-Q.","Company may incur other charges not currently contemplated from the reduction."],"urls":{"canonical":"https://secwatch.observer/filing/0000950170-25-009225","json":"https://secwatch.observer/filing/0000950170-25-009225.json","markdown":"https://secwatch.observer/filing/0000950170-25-009225.md","text":"https://secwatch.observer/filing/0000950170-25-009225.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1604464/000095017025009225/0000950170-25-009225-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1604464/000095017025009225/atra-20250127.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-27T09:16:30.409264+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":[{"claim_id":"084152ee8a92821dd8a18444ec887f1d7d602eae","claim":"Atara Biotherapeutics, Inc. announced a restructuring with charges of approximately $7.5 million in total for severance and related benefits affecting workforce (approximately 50% of its current employees).","evidence_excerpt":"On January 27, 2025, Atara Biotherapeutics, Inc. (the “Company”) announced a reduction in its workforce that will impact approximately 50% of its current employees. The Company expects to substantially complete the workforce reduction by June 2025. The Company expects to recognize approximately $7.5 million in total for severance and related benefits for employees laid off under the reduction in force.","evidence_source":"SEC 8-K Item 2.05/2.06","evidence_url":"https://www.sec.gov/Archives/edgar/data/1604464/000095017025009225/0000950170-25-009225-index.htm","confidence":0.95,"family_label":"Restructurings & Charges","details":[{"label":"Type","value":"restructuring"},{"label":"Charge","value":"approximately $7.5 million in total for severance and related benefits"},{"label":"Affected area","value":"workforce"},{"label":"Headcount","value":"approximately 50% of its current employees"}],"fact_type":"restructuring_charge"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}