---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-069818"
form_type: "8-K"
ticker: "ATOS"
cik: "0001488039"
company_name: "ATOSSA THERAPEUTICS, INC."
filed_at: "2025-05-13T23:59:59+00:00"
generated_at: "2026-05-21T14:56:56.177499+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Atossa Q1 cash $65.1M; pivots (Z)-endoxifen to metastatic breast cancer

## Summary
- Ended Q1 2025 with $65.1M cash, no debt; no revenue reported.
- Strategic shift to metastatic breast cancer as lead indication for (Z)-endoxifen.
- Added 3 new US patents, expanding IP portfolio to over 200 claims related to (Z)-endoxifen.
- Operating expenses $7.4M (up $0.4M YoY) with R&D $4.2M, G&A $3.3M.
- Interest income $0.7M, down from $1.1M due to lower money market balance.

## SEC filing metadata
- accession: 0000950170-25-069818
- form_type: 8-K
- ticker: ATOS
- cik: 0001488039
- company_name: ATOSSA THERAPEUTICS, INC.
- filed_at: 2025-05-13T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1488039/000095017025069818/0000950170-25-069818-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1488039/000095017025069818/atos-20250513.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-069818
- JSON: https://secwatch.observer/filing/0000950170-25-069818.json
- Plain text: https://secwatch.observer/filing/0000950170-25-069818.txt

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