---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-106944"
form_type: "8-K"
ticker: "ATOS"
cik: "0001488039"
company_name: "ATOSSA THERAPEUTICS, INC."
filed_at: "2025-08-12T23:59:59+00:00"
generated_at: "2026-05-17T14:26:08.819047+00:00"
event_type: "earnings"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Atossa Q2 operating expenses $9M; FDA clears IND path for (Z)-endoxifen in metastatic breast cancer

## Summary
- Total operating expenses $9.0M in Q2 2025, up 27% YoY from $7.1M; R&D spend rose 55% to $5.5M.
- FDA feedback July 2025: no additional toxicity studies needed; Atossa plans IND submission in Q4 2025 for (Z)-endoxifen in metastatic breast cancer.
- I-SPY2 pilot (20 patients): 95% completed ≥75% dosing; median Ki-67 dropped from 10.5% to 5%; functional tumor volume decreased 77.7% by MRI.
- Issued U.S. Patent 12,281,056 with 58 claims covering (Z)-endoxifen enteric formulations; two other patents under post-grant challenge.

## SEC filing metadata
- accession: 0000950170-25-106944
- form_type: 8-K
- ticker: ATOS
- cik: 0001488039
- company_name: ATOSSA THERAPEUTICS, INC.
- filed_at: 2025-08-12T23:59:59+00:00
- event_type: earnings
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1488039/000095017025106944/0000950170-25-106944-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1488039/000095017025106944/atos-20250812.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-106944
- JSON: https://secwatch.observer/filing/0000950170-25-106944.json
- Plain text: https://secwatch.observer/filing/0000950170-25-106944.txt

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