{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-26-394360","form_type":"8-K","ticker":"SNSE","cik":"0001829802","company_name":"Sensei Biotherapeutics, Inc.","filed_at":"2026-09-17T20:15:12+00:00","discovered_at":"2026-09-17T20:16:00.519561+00:00","generated_at":"2026-09-17T20:16:19.678877+00:00","sec_items":["5.02"],"event_type":"leadership","sentiment":"neutral","materiality_score":0.2,"calibrated_materiality_score":0.2,"confidence":"high","headline":"Faeth appoints co-founder Karen Vousden to board as Class II director","bullets":["Board expanded from 5 to 6 directors; Vousden appointed effective Sept 11, 2026, serving until 2029 annual meeting.","Vousden, 68, is a cancer biologist, co-founded Faeth in April 2019, and leads at Francis Crick Institute since 2017.","Also appointed to Compensation Committee; receives standard director cash retainer and option for 25,000 shares under 2026 Equity Plan.","Option vests monthly over 3 years, with full vesting upon change in control; no family or 404(a) transactions disclosed."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-26-394360","json":"https://secwatch.observer/filing/0001193125-26-394360.json","markdown":"https://secwatch.observer/filing/0001193125-26-394360.md","text":"https://secwatch.observer/filing/0001193125-26-394360.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1829802/000119312526394360/0001193125-26-394360-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1829802/000119312526394360/d174402d8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-09-17T20:16:19.678877+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":"c2a5f80eb1","claim":"Karen Vousden was appointed as Class II Director at Sensei Biotherapeutics, Inc..","evidence_excerpt":"On September 11, 2026, the Board of Directors (the “Board”) of Faeth Therapeutics, Inc. (the “Company”) increased the size of the Board from five to six directors and appointed Karen Vousden, Ph.D. to serve as a Class II director, effective immediately.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1829802/000119312526394360/0001193125-26-394360-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"appointed"},{"label":"Role","value":"Class II Director"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}