---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-138481"
form_type: "8-K"
ticker: "STRO"
cik: "0001382101"
company_name: "SUTRO BIOPHARMA, INC."
filed_at: "2025-06-10T23:59:59+00:00"
generated_at: "2026-05-19T15:24:37.103049+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Sutro Biopharma stockholders approve reverse stock split at 1:5 to 1:25 ratio

## Summary
- Reverse stock split authorized at ratio between 1:5 and 1:25, board to set exact ratio.
- Three Class I directors elected: Heidi Hunter, Jon Wigginton, Michael Dybbs for three-year terms.
- Ernst & Young LLP ratified as independent auditor for fiscal year ending Dec 2025 with 99.1% for.
- Non-binding advisory vote on named executive officer compensation passed with 42.99M for.
- All proposals passed at June 6, 2025 annual meeting; broker non-votes ranged from 12.5M on director elections.

## SEC filing metadata
- accession: 0001193125-25-138481
- form_type: 8-K
- ticker: STRO
- cik: 0001382101
- company_name: SUTRO BIOPHARMA, INC.
- filed_at: 2025-06-10T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 5.07
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1382101/000119312525138481/0001193125-25-138481-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1382101/000119312525138481/d859738d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-138481
- JSON: https://secwatch.observer/filing/0001193125-25-138481.json
- Plain text: https://secwatch.observer/filing/0001193125-25-138481.txt

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