---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-076911"
form_type: "8-K"
ticker: "BOLD"
cik: "0001782303"
company_name: "Boundless Bio, Inc."
filed_at: "2025-05-23T23:59:59+00:00"
generated_at: "2026-05-20T14:55:34.359839+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Boundless Bio restructures pipeline, cuts workforce 33%, discontinues BBI-355 monotherapy

## Summary
- Workforce reduction of ~1/3; expects $1.2M one-time costs, substantially completed in Q2 2025.
- Discontinues current POTENTIATE trial arms for BBI-355 due to narrow therapeutic index and poor tolerability.
- Plans to develop BBI-355/BBI-825 combination; initial clinical data expected within extended cash runway.
- Selects BBI-940 as Kinesin program candidate; IND submission expected first half 2026.
- Cash, equivalents & investments $138.3M as of March 31, 2025; operating runway extended into first half 2028.

## SEC filing metadata
- accession: 0000950170-25-076911
- form_type: 8-K
- ticker: BOLD
- cik: 0001782303
- company_name: Boundless Bio, Inc.
- filed_at: 2025-05-23T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 2.05, 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1782303/000095017025076911/0000950170-25-076911-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1782303/000095017025076911/bold-20250523.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-076911
- JSON: https://secwatch.observer/filing/0000950170-25-076911.json
- Plain text: https://secwatch.observer/filing/0000950170-25-076911.txt

## Key facts
- Restructurings & Charges
  Boundless Bio, Inc. announced a restructuring with charges of approximately $1.2 million (approximately one-third of the Company’s workforce).
  - Type: restructuring
  - Charge: approximately $1.2 million
  - Headcount: approximately one-third of the Company’s workforce
  source text: On May 23, 2025, Boundless Bio, Inc. (the Company), in connection with the portfolio prioritization described below, announced a workforce reduction of approximately one-third of the Company’s workforce. The Company expects to incur one-time costs of approximately $1.2 million in connection with the workforce reduction primarily related to one-time termination benefits (some of which are contractual), including severance and healthcare related benefits.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1782303/000095017025076911/0000950170-25-076911-index.htm

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