ATOSSA THERAPEUTICS, INC.
ATOS evidence brief
What we can confirm
What it means
What to watch
Prepared research question
What matters most for ATOS—catalysts, financial risk and supporting evidence?
Traceable citations · Unknowns marked
BioSniper AI · ATOS
Atossa Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing (Z)-endoxifen, a selective estrogen receptor modulator/degarder, primarily for breast cancer and other breast conditions.
Key risk: Going concern uncertainty
BioSniper Score
Based on 4 of 6 signals
Financial data as of Jun 30, 2026.
Tracking 1 pipeline candidate · 2 clinical trials for ATOSSA THERAPEUTICS, INC..
Atossa Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing (Z)-endoxifen, a selective estrogen receptor modulator/degarder, primarily for breast cancer and other breast conditions.
- Lead drug candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator (SERM)/selective estrogen receptor degrader (SERM/D) [sec_mda · as of 2026-03-25].
- Cash and equivalents of $26.1 million as of 2026-06-30 [sec].
- Net loss of $8.5 million for the quarter ended 2026-06-30 [sec].
- Shareholders' equity of $57.7 million as of 2026-06-30 [sec].
- Expects existing resources will be insufficient to fund planned operations for the next twelve months, raising substantial doubt about going concern [sec_mda · as of 2026-08-07].
What works
- (Z)-endoxifen is the most active metabolite of Tamoxifen, an FDA-approved drug for breast cancer, and is substantially more potent [sec_mda · as of 2026-08-07].
- Patent protection for (Z)-endoxifen extends through at least November 2038 in key areas [sec_mda · as of 2026-08-07].
- Company has completed a Phase 2 trial of (Z)-endoxifen for mammographic density reduction (NCT05068388) [catalyst].
What to weigh
- Company has no revenue and expects to incur ongoing operating losses for the foreseeable future [sec_mda · as of 2026-08-07].
- Existing cash is likely insufficient to fund operations for the next twelve months, creating substantial doubt about going concern [sec_mda · as of 2026-08-07].
- Additional capital may not be available on acceptable terms or at all, and the company could be forced to cease or curtail operations [sec_mda · as of 2026-08-07].
From the filings
Quoted directly from source documents.
Lead drug candidate is (Z)-endoxifen, a SERM/SERD for breast cancer.
“Our lead drug candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator (SERM)/ selective estrogen receptor degrader (SERM/D)”
SEC MD&A · March 25, 2026
Company expects existing resources will be insufficient for the next twelve months.
“As of the date of filing this Quarterly Report, we expect our existing resources will likely be insufficient to fund our planned operations for the next twelve months, and additional capital resources will be needed to fund operations longer-term.”
SEC MD&A · August 7, 2026
(Z)-endoxifen is the most active metabolite of Tamoxifen and is substantially more potent.
“(Z)-endoxifen is the most active metabolite of Tamoxifen, an FDA approved drug to treat and prevent breast cancer in high-risk women, and it is substantially more pot”
SEC MD&A · August 7, 2026
Catalyst timeline
- 2021-12-21 · Phase 2 Start: A Phase 2, Randomized, Double-blinded, Placebo-controlled, Dose-Response Study of Oral (Z)-Endoxifen - NCT: NCT05068388 — This Phase 2 trial of (Z)-endoxifen for mammographic density reduction has been completed.
- 2023-02-14 · Phase 2 Start: A Phase 2 Trial of (Z)-Endoxifen + Goserelin as Neoadjuvant Treatment for Premenopausal Women With E - NCT: NCT05607004 — This Phase 2 trial of (Z)-endoxifen in combination with goserelin is active but not recruiting.
Risks & what to watch (3)›
Key risks
- Going concern uncertainty — Existing cash likely insufficient for 12 months; may need to cease or curtail operations [sec_mda · as of 2026-08-07].
- No revenue or profitability — No revenue anticipated until regulatory approval and commercialization; ongoing operating losses [sec_mda · as of 2026-08-07].
- Capital access risk — Additional funding may not be available on acceptable terms due to market conditions [sec_mda · as of 2026-08-07].
What to watch
- Ability to raise additional capital to fund operations beyond the next twelve months [sec_mda · as of 2026-08-07].
- Progress of ongoing Phase 2 trial of (Z)-endoxifen + goserelin in premenopausal women (NCT05607004) [catalyst].
- Any new clinical data or regulatory milestones for (Z)-endoxifen [sec_mda · as of 2026-08-07].
Sources: Catalysts · SEC filings · SEC MD&A · Generated August 27, 2026 · How we verify sources →
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Evidence & data
Score breakdownBased on 4 of 6 signals · derived from public data
8.6 months
D/E 0.20 · 0% dilution
Lead: Phase 2
1 candidate
No upcoming catalysts tracked
No insider transactions in the last 180 days
Runway
Pipeline
Regulatory
Financials
Institutional Holdings
Source: SEC Form 13F · as of Mar 2026Institutional holders
31
Total value held
$8.2M
| Holder | Shares | Value |
|---|---|---|
| vanguard capital management llc | 698,192 | $3.7M |
| ameriprise financial inc | 255,134 | $1.3M |
| blackrock, inc. | 133,169 | $700K |
| renaissance technologies llc | 109,007 | $573K |
| geode capital management, llc | 97,061 | $511K |
| millennium management llc | 66,739 | $351K |
| susquehanna international group, llp | 55,000 | $289K |
| vanguard fiduciary trust co | 52,235 | $275K |
| state street corp | 39,761 | $209K |
| northern trust corp | 19,224 | $101K |
Showing top 10 of 31 institutional holders of ATOSSA THERAPEUTICS, INC.. Open the full 13F history after sign-in.
Short Interest
as of May 20, 2026- % of float
- 3.9%
- Days to cover
- 6.2
- Shares short
- 337,509
- Daily short volume
- -
Short percent of float and days-to-cover reflect reported short positioning. Daily short volume is the exchange-reported short share of a single day's trading volume and is noisier. See the most-shorted biotech ranking →
ATOS short interestGovernance
Frequently asked questions
What is the AI investment thesis for ATOSSA THERAPEUTICS, INC.?
Atossa Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing (Z)-endoxifen, a selective estrogen receptor modulator/degarder, primarily for breast cancer and other breast conditions.
What is ATOSSA THERAPEUTICS, INC.'s lead drug candidate?
ATOSSA THERAPEUTICS, INC.'s most advanced tracked candidate is -endoxifen (Phase 2) for Breast Neoplasms.
Who is the CEO of ATOSSA THERAPEUTICS, INC.?
Dr. Steven C. Quay FCAP, M.D., Ph.D. is the chief executive officer of ATOSSA THERAPEUTICS, INC. (ATOS).
Where is ATOSSA THERAPEUTICS, INC. headquartered?
ATOSSA THERAPEUTICS, INC. (ATOS) is headquartered in Seattle, WA, United States.
What therapeutic areas does ATOSSA THERAPEUTICS, INC. focus on?
ATOSSA THERAPEUTICS, INC. develops therapies across Oncology, Reproductive.
The AI overview and BioSniper Score are neutral, data-derived signals built from public SEC filings, ClinicalTrials.gov and FDA records — not investment advice.