---
schema_version: "secwatch.filing_event.v1"
accession: "0001724521-26-000047"
form_type: "8-K"
ticker: "RCUS"
cik: "0001724521"
company_name: "Arcus Biosciences, Inc."
filed_at: "2026-10-20T12:33:25+00:00"
generated_at: "2026-10-20T12:35:06.675993+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Arcus reports ARC-20 casdatifan data: 1L PFS 69% at 12 months, 2L median PFS 14.5 months

## Summary
- 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.

## SEC filing metadata
- accession: 0001724521-26-000047
- form_type: 8-K
- ticker: RCUS
- cik: 0001724521
- company_name: Arcus Biosciences, Inc.
- filed_at: 2026-10-20T12:33:25+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1724521/000172452126000047/0001724521-26-000047-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1724521/000172452126000047/rcus-20261020.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001724521-26-000047
- JSON: https://secwatch.observer/filing/0001724521-26-000047.json
- Plain text: https://secwatch.observer/filing/0001724521-26-000047.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.