---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-307516"
form_type: "8-K"
ticker: "ATOS"
cik: "0001488039"
company_name: "ATOSSA THERAPEUTICS, INC."
filed_at: "2025-12-04T23:59:59+00:00"
generated_at: "2026-05-16T14:37:03.285365+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Atossa completes FDA Type C meeting; gains clarity on accelerated (Z)-endoxifen development

## Summary
- FDA provided feedback on regulatory pathways for (Z)-endoxifen across metastatic, neoadjuvant, and risk-reduction settings.
- Company submitted IND for metastatic breast cancer program and awaits FDA feedback.
- Phase 2 EVANGELINE trial continuing in neoadjuvant ER+/HER2- breast cancer.
- Nearly 800 participants in completed trials; no MTD identified up to 360 mg/day.
- Additional IND submissions planned in 2026 for combination strategies beyond monotherapy and breast cancer.

## SEC filing metadata
- accession: 0001193125-25-307516
- form_type: 8-K
- ticker: ATOS
- cik: 0001488039
- company_name: ATOSSA THERAPEUTICS, INC.
- filed_at: 2025-12-04T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1488039/000119312525307516/0001193125-25-307516-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1488039/000119312525307516/atos-20251204.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-307516
- JSON: https://secwatch.observer/filing/0001193125-25-307516.json
- Plain text: https://secwatch.observer/filing/0001193125-25-307516.txt

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