{"schema_version":"secwatch.filing_event.v1","accession":"0001724521-26-000021","form_type":"8-K","ticker":"RCUS","cik":"0001724521","company_name":"Arcus Biosciences, Inc.","filed_at":"2026-04-20T23:59:59+00:00","discovered_at":"2026-05-14T18:02:32.812212+00:00","generated_at":"2026-05-15T05:20:48.427862+00:00","sec_items":["8.01"],"event_type":"other_material","sentiment":"negative","materiality_score":0.75,"calibrated_materiality_score":0.75,"confidence":"high","headline":"Arcus discontinues Phase 3 STAR-121 NSCLC trial; Gilead lets option rights lapse","bullets":["STAR-121 evaluating domvanalimab + zimberelimab + chemo vs pembro + chemo in 1L metastatic NSCLC stopped by IDMC for futility.","Zimberelimab + chemo showed comparable overall survival vs pembro + chemo; trial discontinued despite that.","Gilead declines option continuation payment; option period ends July 14, 2026; loses rights to CCR6, CD89, CD40L programs.","Gilead retains time-limited options for AB801 (AXL inhibitor), AB598 (anti-CD39), AB102 (MRGPRX2 antagonist), and TNF small molecule.","Arcus retains full rights to casdatifan program except Taiho territories (Japan and certain Asian countries)."],"urls":{"canonical":"https://secwatch.observer/filing/0001724521-26-000021","json":"https://secwatch.observer/filing/0001724521-26-000021.json","markdown":"https://secwatch.observer/filing/0001724521-26-000021.md","text":"https://secwatch.observer/filing/0001724521-26-000021.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1724521/000172452126000021/0001724521-26-000021-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1724521/000172452126000021/rcus-20260420.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-15T05:20:48.427862+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"}