---
schema_version: "secwatch.filing_event.v1"
accession: "0001558370-25-000291"
form_type: "8-K"
ticker: "XLO"
cik: "0001840233"
company_name: "Xilio Therapeutics, Inc."
filed_at: "2025-01-21T23:59:59+00:00"
generated_at: "2026-05-27T22:24:55.494131+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Xilio reports 27% response rate for vilastobart + atezolizumab in MSS CRC Phase 2 trial

## Summary
- 27% preliminary ORR (3 PRs, 2 confirmed) in MSS CRC patients without liver metastases as of Jan 13, 2025 cutoff.
- Responses accompanied by decreases in CEA and ctDNA levels and clinical symptom improvement.
- Safety: well-tolerated; 5% colitis, low Grade 3/4 irAEs, no treatment-related deaths.
- Heavily pre-treated population: 70% had ≥3 prior lines of therapy.
- Company plans to seek partnerships; expects to report updated Phase 2 data mid-2025.

## SEC filing metadata
- accession: 0001558370-25-000291
- form_type: 8-K
- ticker: XLO
- cik: 0001840233
- company_name: Xilio Therapeutics, Inc.
- filed_at: 2025-01-21T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1840233/000155837025000291/0001558370-25-000291-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1840233/000155837025000291/xlo-20250121x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001558370-25-000291
- JSON: https://secwatch.observer/filing/0001558370-25-000291.json
- Plain text: https://secwatch.observer/filing/0001558370-25-000291.txt

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