---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-24-134779"
form_type: "8-K"
ticker: "ATOS"
cik: "0001488039"
company_name: "ATOSSA THERAPEUTICS, INC."
filed_at: "2024-12-10T23:59:59+00:00"
generated_at: "2026-05-29T05:08:52.569223+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Atossa presents positive PK/tolerability data from Phase 2 EVANGELINE trial of (Z)-endoxifen

## Summary
- 50% of patients on 80 mg (Z)-endoxifen + goserelin met target plasma Css of 500-1,000 ng/mL.
- Tissue Css levels >2x plasma; >90% of patients achieved target tissue levels >500 ng/g.
- Ki-67 ≤10% response rate >85% across doses after 4 weeks, indicating antitumor activity.
- (Z)-endoxifen well tolerated with no Grade 3-4 toxicities; four gynecologic events in 80 mg groups.
- Randomized trial to compare 40 mg + OFS vs exemestane + OFS; recruitment expected to start 2025.

## SEC filing metadata
- accession: 0000950170-24-134779
- form_type: 8-K
- ticker: ATOS
- cik: 0001488039
- company_name: ATOSSA THERAPEUTICS, INC.
- filed_at: 2024-12-10T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1488039/000095017024134779/0000950170-24-134779-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1488039/000095017024134779/atos-20241210.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-24-134779
- JSON: https://secwatch.observer/filing/0000950170-24-134779.json
- Plain text: https://secwatch.observer/filing/0000950170-24-134779.txt

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