---
schema_version: "secwatch.filing_event.v1"
accession: "0001641172-25-003620"
form_type: "8-K"
ticker: "PULM"
cik: "0001574235"
company_name: "Pulmatrix, Inc."
filed_at: "2025-04-10T23:59:59+00:00"
generated_at: "2026-05-23T17:16:39.343831+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Pulmatrix and Cullgen amend merger agreement to one-step merger; Second Merger Sub removed

## Summary
- Amendment No. 1 dated April 7, 2025 changes transaction from two-step to one-step merger, eliminating Second Merger Sub.
- Clarifies fractional shares provision; Cullgen will survive as wholly owned subsidiary of Pulmatrix.
- Boards of both companies approved the amendment; all other terms of original November 13, 2024 agreement remain.
- Transaction remains subject to stockholder approval, regulatory clearances, and Nasdaq listing; consideration unchanged.

## SEC filing metadata
- accession: 0001641172-25-003620
- form_type: 8-K
- ticker: PULM
- cik: 0001574235
- company_name: Pulmatrix, Inc.
- filed_at: 2025-04-10T23:59:59+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 1.01, 5.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1574235/000164117225003620/0001641172-25-003620-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1574235/000164117225003620/form8-k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001641172-25-003620
- JSON: https://secwatch.observer/filing/0001641172-25-003620.json
- Plain text: https://secwatch.observer/filing/0001641172-25-003620.txt

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