{"schema_version":"secwatch.filing_event.v1","accession":"0000950170-23-026351","form_type":"8-K","ticker":"ATRA","cik":"0001604464","company_name":"Atara Biotherapeutics, Inc.","filed_at":"2023-06-05T23:59:59+00:00","discovered_at":"2026-05-14T18:03:39.625546+00:00","generated_at":"2026-06-14T07:22:51.649405+00:00","sec_items":["5.02","5.07"],"event_type":"other_material","sentiment":"neutral","materiality_score":0.3,"calibrated_materiality_score":0.3,"confidence":"high","headline":"Director Beth Seidenberg resigns; shareholders reject officer exculpation amendment at annual meeting","bullets":["Director Beth Seidenberg resigned from Board effective June 1, 2023, to pursue other activities.","Board reduced from eight to seven directors.","At annual meeting, stockholders elected Pascal Touchon, Carol Gallagher, and Maria Grazia Roncarolo as directors.","Advisory vote on executive compensation approved (71.8M for, 2.2M against).","Proposal to amend Certificate of Incorporation to exculpate officers was not approved (38.6M for, 35.4M against)."],"urls":{"canonical":"https://secwatch.observer/filing/0000950170-23-026351","json":"https://secwatch.observer/filing/0000950170-23-026351.json","markdown":"https://secwatch.observer/filing/0000950170-23-026351.md","text":"https://secwatch.observer/filing/0000950170-23-026351.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023026351/0000950170-23-026351-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023026351/atra-20230531.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-14T07:22:51.649405+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":"aebb20aab3","claim":"Beth Seidenberg resigned as Director at Atara Biotherapeutics, Inc..","evidence_excerpt":"On June 1, 2023, Beth Seidenberg, M.D., notified Atara Biotherapeutics, Inc. (the “ Company ”), of her resignation from the Board of Directors of the Company (the “ Board ”), effective immediately.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023026351/0000950170-23-026351-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"resigned"},{"label":"Role","value":"Director"}],"fact_type":"executive_change"},{"claim_id":"24bd87ed5b322a75db55e62bace36c3a1faedca7","claim":"Atara Biotherapeutics, Inc. shareholders approved Election of Directors at the 2023-05-31 meeting.","evidence_excerpt":"Each of the three nominees for director was elected to serve until the 2026 annual meeting of stockholders and until their respective successors are elected.","evidence_source":"SEC 8-K Item 5.07","evidence_url":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023026351/0000950170-23-026351-index.htm","confidence":0.9,"family_label":"Shareholder Votes","details":[{"label":"Proposal","value":"director election"},{"label":"Outcome","value":"passed"},{"label":"Meeting","value":"2023-05-31"}],"fact_type":"shareholder_vote"},{"claim_id":"254147d58852997fcbb233a630b80afcb241423f","claim":"Atara Biotherapeutics, Inc. shareholders approved Advisory vote to approve on the compensation of the Company’s named executive officers at the 2023-05-31 meeting.","evidence_excerpt":"The stockholders approved, on an advisory basis, the compensation awarded to the Company’s named executive officers, as disclosed in the Proxy Statement.","evidence_source":"SEC 8-K Item 5.07","evidence_url":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023026351/0000950170-23-026351-index.htm","confidence":0.9,"family_label":"Shareholder Votes","details":[{"label":"Proposal","value":"say on pay"},{"label":"Outcome","value":"passed"},{"label":"Meeting","value":"2023-05-31"}],"fact_type":"shareholder_vote"},{"claim_id":"28c7a190ef433498077a7caa22d6136d9a0ea645","claim":"Atara Biotherapeutics, Inc. shareholders rejected Approval of an amendment to Company’s Certificate of Incorporation at the 2023-05-31 meeting.","evidence_excerpt":"The stockholders did not approve an amendment of the Company’s Certificate of Incorporation to provide for the exculpation of officers as permitted by Delaware law.","evidence_source":"SEC 8-K Item 5.07","evidence_url":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023026351/0000950170-23-026351-index.htm","confidence":0.9,"family_label":"Shareholder Votes","details":[{"label":"Proposal","value":"charter amendment"},{"label":"Outcome","value":"failed"},{"label":"Meeting","value":"2023-05-31"}],"fact_type":"shareholder_vote"},{"claim_id":"93a84bcb8f59d33cf407ed4cccfac8e3d94dc03b","claim":"Atara Biotherapeutics, Inc. shareholders approved Ratification of appointment of independent registered public accounting firm at the 2023-05-31 meeting.","evidence_excerpt":"The stockholders ratified the appointment of Deloitte & Touche LLP as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2023.","evidence_source":"SEC 8-K Item 5.07","evidence_url":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023026351/0000950170-23-026351-index.htm","confidence":0.9,"family_label":"Shareholder Votes","details":[{"label":"Proposal","value":"auditor ratification"},{"label":"Outcome","value":"passed"},{"label":"Meeting","value":"2023-05-31"}],"fact_type":"shareholder_vote"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}