---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-044098"
form_type: "8-K"
ticker: "ATOS"
cik: "0001488039"
company_name: "ATOSSA THERAPEUTICS, INC."
filed_at: "2025-03-25T23:59:59+00:00"
generated_at: "2026-05-24T05:39:36.543929+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Atossa Therapeutics ends 2024 with $71.1M cash; advances (Z)-endoxifen for metastatic breast cancer

## Summary
- Cash and equivalents $71.1M, no debt; operating expenses fell to $27.6M from $31.4M in 2023.
- Strategic pivot to pursue metastatic breast cancer indication for (Z)-endoxifen, citing streamlined regulatory path.
- Phase 2 EVANGELINE trial of (Z)-endoxifen showed Ki-67 ≤10% response rate >85% across doses; amended protocol to compare 40mg + OFS vs exemestane + OFS.
- Phase 2 KARISMA-Endoxifen: 1mg and 2mg doses reduced mammographic breast density by 17.3 and 23.5 percentage points (p<0.01) vs placebo 0.27 pts.
- R&D expenses down 19% to $14.1M; G&A expenses down 4% to $13.5M.

## SEC filing metadata
- accession: 0000950170-25-044098
- form_type: 8-K
- ticker: ATOS
- cik: 0001488039
- company_name: ATOSSA THERAPEUTICS, INC.
- filed_at: 2025-03-25T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1488039/000095017025044098/0000950170-25-044098-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1488039/000095017025044098/atos-20250325.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-044098
- JSON: https://secwatch.observer/filing/0000950170-25-044098.json
- Plain text: https://secwatch.observer/filing/0000950170-25-044098.txt

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