---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-085374"
form_type: "8-K"
ticker: "UPB"
cik: "0002022626"
company_name: "Upstream Bio, Inc."
filed_at: "2025-06-12T23:59:59+00:00"
generated_at: "2026-05-19T11:36:57.726915+00:00"
event_type: "other"
sentiment: "neutral"
materiality_score: 0.3
calibrated_materiality_score: 0.15
confidence: "high"
source: SEC EDGAR
---

# Upstream Bio shareholders elect two Class I directors, ratify PwC as auditor

## Summary
- Erez Chimovits received 42,089,191 votes for, 241,430 withheld; Marcella Kuhlman Ruddy received 41,993,308 for, 337,313 withheld.
- Ratification of PwC as independent auditor for FY2025 approved with 43,600,758 for, 996 against, 25,541 abstain.
- Meeting held June 10, 2025; 53,688,703 shares outstanding and entitled to vote.

## SEC filing metadata
- accession: 0000950170-25-085374
- form_type: 8-K
- ticker: UPB
- cik: 0002022626
- company_name: Upstream Bio, Inc.
- filed_at: 2025-06-12T23:59:59+00:00
- event_type: other
- sentiment: neutral
- materiality_score: 0.3
- calibrated_materiality_score: 0.15
- confidence: high
- sec_items: 5.07
- EDGAR index: https://www.sec.gov/Archives/edgar/data/2022626/000095017025085374/0000950170-25-085374-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/2022626/000095017025085374/upb-20250610.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-085374
- JSON: https://secwatch.observer/filing/0000950170-25-085374.json
- Plain text: https://secwatch.observer/filing/0000950170-25-085374.txt

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