secwatch.observer — SEC 8-K summary
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Issuer:     Arcus Biosciences, Inc. (RCUS)
CIK:        0001724521
Form:       8-K
Filed at:   2026-10-20T12:33:25+00:00
Accession:  0001724521-26-000047
Event type: other_material
Sentiment:  positive
Materiality: 0.70
Item codes: 8.01
LLM model:  deepseek-v4.1-flash:cloud@v2

Arcus reports ARC-20 casdatifan data: 1L PFS 69% at 12 months, 2L median PFS 14.5 months
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- First-line casdatifan + zimberelimab (n=30): 50% confirmed ORR, 86%/69% landmark PFS at 6/12 months, 6.7% primary progression; median follow-up 11.5 months.
- Second-line casdatifan + cabozantinib (n=43): median PFS 14.5 months, 18-month OS 77%, cORR 44%, primary progression 5%; median follow-up 21.3 months.
- Late-line casdatifan monotherapy (n=121): median OS 35 months, median PFS 13 months, cORR 36% across four pooled cohorts with 28 months median follow-up.
- Casdatifan + ipilimumab + zimberelimab: 1 of 24 scanned patients (4%) had primary progression at 3 months; 31 dosed, no unexpected safety signals.
- Data cutoff Sept 4, 2026; presented Oct 20, 2026. No unexpected safety signals in any cohort; Grade 3+ immune-mediated AEs consistent with ipilimumab/nivolumab.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/1724521/000172452126000047/0001724521-26-000047-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/1724521/000172452126000047/rcus-20261020.htm
  HTML page:      https://secwatch.observer/filing/0001724521-26-000047

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer