---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-221704"
form_type: "8-K"
ticker: "IOBTQ"
cik: "0001865494"
company_name: "IO Biotech, Inc."
filed_at: "2025-09-29T23:59:59+00:00"
generated_at: "2026-05-17T05:26:53.401037+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# FDA advises IO Biotech not to submit BLA for Cylembio; workforce cut by ~50%

## Summary
- FDA recommends against BLA submission based on IOB-013 trial data (PFS improved but missed statistical significance).
- Company plans new registrational study for first-line advanced melanoma; also engaging European regulators.
- Restructuring reduces workforce ~50%; expects $1.0-1.5M severance charges in Q3 2025.
- Cash runway extended into Q1 2026 to focus on regulatory path for Cylembio.

## SEC filing metadata
- accession: 0001193125-25-221704
- form_type: 8-K
- ticker: IOBTQ
- cik: 0001865494
- company_name: IO Biotech, Inc.
- filed_at: 2025-09-29T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 2.05, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1865494/000119312525221704/0001193125-25-221704-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1865494/000119312525221704/d940102d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-221704
- JSON: https://secwatch.observer/filing/0001193125-25-221704.json
- Plain text: https://secwatch.observer/filing/0001193125-25-221704.txt

## Key facts
- Restructurings & Charges
  IO Biotech, Inc. announced a restructuring with charges of approximately $1.0 million to $1.5 million (approximately 50% of the Company’s workforce globally).
  - Type: restructuring
  - Charge: approximately $1.0 million to $1.5 million
  - Headcount: approximately 50% of the Company’s workforce globally
  source text: On September 25, 2025, the Board of Directors of IO Biotech, Inc. (the “Company”) approved a restructuring and workforce reduction plan (the “Plan”) to conserve capital to align the Company’s operations with its primary focus of advancing development of Cylembio ® (imsapepimut and etimupepimut, adjuvanted). The Plan is expected to result in a reduction of approximately 50% of the Company’s workforce globally. In connection with the implementation of the Plan, the Company expects to incur one-time charges and cash expenditures in a range of approximately $1.0 million to $1.5 million, primarily related to employee wages and severance payments, healthcare continuation, earned vacation time and related termination costs.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1865494/000119312525221704/0001193125-25-221704-index.htm

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