ATOSSA THERAPEUTICS, INC.
ATOS evidence brief
What we can confirm
- BioSniper Score:
- 5.5 / 10
- Market Cap:
- $19.6M
- Lead Asset:
- -endoxifen (Phase 2)
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 is a clinical-stage biopharmaceutical company developing oral (Z)-endoxifen, a selective estrogen receptor modulator/degrader, for breast cancer and other oncology indications, with two fully enrolled Phase 2 programs expected to yield data by year-end 2026.
Key risk: Cash runway concern
BioSniper Score
Based on 4 of 6 signals
Financial data as of Jun 30, 2026.
Tracking 1 pipeline candidate · 3 clinical trials · 1 catalyst for ATOSSA THERAPEUTICS, INC..
Atossa Therapeutics is a clinical-stage biopharmaceutical company developing oral (Z)-endoxifen, a selective estrogen receptor modulator/degrader, for breast cancer and other oncology indications, with two fully enrolled Phase 2 programs expected to yield data by year-end 2026.
- Lead drug candidate is oral (Z)-endoxifen, a SERM/SERM/D currently in Phase 2 clinical development [sec_mda · as of 2026-03-25].
- Two most advanced clinical programs are fully enrolled and expected to generate data by year-end 2026 [news · published 2026-08-14].
- Cash & equivalents of $26.1M as of 2026-06-30 [sec].
- Net income of -$8.5M for the period ending 2026-06-30 [sec].
- Shareholders' equity of $26.8M as of 2026-06-30 [sec].
What works
- Two advanced clinical programs are fully enrolled, with data expected by year-end 2026, indicating progress toward potential inflection points [news · published 2026-08-14].
- The company holds seven U.S. and 16 international patents covering its proprietary (Z)-endoxifen, with protection expected through at least November 17, 2038 [sec_mda · as of 2026-03-25].
- Atossa has a cash position of $26.1M as of 2026-06-30, providing near-term operational runway [sec].
What to weigh
- The company expects existing resources will likely be insufficient to fund planned operations for the next twelve months, raising substantial doubt about its ability to continue as a going concern [sec_mda · as of 2026-08-07].
- Atossa does not anticipate any revenue until its pharmaceutical programs are developed, receive regulatory approvals, and are successfully commercialized [sec_mda · as of 2026-08-07].
- The company expects to incur ongoing operating losses for the foreseeable future as it continues development [sec_mda · as of 2026-08-07].
From the filings
Quoted directly from source documents.
Two advanced clinical programs are fully enrolled and data expected by year-end 2026.
“Atossa Therapeutics, Inc. (NASDAQ: ATOS) is approaching a potentially important inflection point as its two most advanced clinical programs are now fully enrolled and expected to generate data by year-end.”
News · August 14, 2026
Lead drug candidate is oral (Z)-endoxifen, a SERM/SERM/D in Phase 2.
“Our lead drug candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator (SERM)/ selective estrogen receptor degrader (SERM/D) currently in Phase 2 clinical development.”
SEC MD&A · March 25, 2026
Existing resources likely insufficient to fund operations for 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
Catalyst timeline
- 2021-12-21 · Phase 2 start: (Z)-Endoxifen in premenopausal women with breast density — A Phase 2, randomized, double-blinded, placebo-controlled, dose-response study of oral (Z)-endoxifen in premenopausal women with measurable breast density.
- 2023-02-14 · Phase 2 start: (Z)-Endoxifen + Goserelin as neoadjuvant treatment — A Phase 2 trial of (Z)-endoxifen + goserelin as neoadjuvant treatment for premenopausal women with ER+, HER2-, breast cancer.
- 2027-03-01 · Phase 2 start: (Z)-Endoxifen for McCune-Albright syndrome — A Phase 2 open-label, safety, tolerability and exposure study of oral (Z)-endoxifen for the treatment of gonadotropin-independent precocious puberty in girls with McCune-Albright syndrome.
Risks & what to watch (3)›
Key risks
- Cash runway concern — Existing resources likely insufficient to fund operations for next twelve months; additional capital needed [sec_mda · as of 2026-08-07].
- No revenue until commercialization — No anticipated revenue until programs are developed, approved, and commercialized [sec_mda · as of 2026-08-07].
- Ongoing operating losses — Company expects to incur ongoing operating losses for the foreseeable future [sec_mda · as of 2026-08-07].
What to watch
- Data from the two fully enrolled Phase 2 programs expected by year-end 2026 [news · published 2026-08-14].
- Company's ability to secure additional capital to extend runway beyond twelve months [sec_mda · as of 2026-08-07].
- Progress of the Phase 2 open-label study of (Z)-endoxifen for McCune-Albright syndrome, starting 2027-03-01 [catalyst].
Sources: Catalysts · News · SEC MD&A · Generated October 9, 2026 · How we verify sources →
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Evidence & data
Score breakdownBased on 4 of 6 signals · derived from public data
Cash runway data unavailable
D/E 0.20 · 0% dilution
Lead: Phase 2
1 candidate
1 upcoming, next in ~138d
No insider transactions in the last 180 days
Catalysts
Pipeline
Regulatory
Financials
Institutional Holdings
Source: SEC Form 13F · as of Mar 2026Institutional holders
31
Total value held
$6.5M
| Holder | Shares | Value |
|---|---|---|
| vanguard capital management llc | 349,096 | $1.8M |
| 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 |
| ubs group ag | 92,034 | $484K |
| millennium management llc | 66,739 | $351K |
| 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 is a clinical-stage biopharmaceutical company developing oral (Z)-endoxifen, a selective estrogen receptor modulator/degrader, for breast cancer and other oncology indications, with two fully enrolled Phase 2 programs expected to yield data by year-end 2026.
What is ATOSSA THERAPEUTICS, INC.'s lead drug candidate?
ATOSSA THERAPEUTICS, INC.'s most advanced tracked candidate is -endoxifen (Phase 2) for Breast Neoplasms; Precocious Puberty, Gonadotropin-dependent.
What is ATOSSA THERAPEUTICS, INC.'s next catalyst?
ATOSSA THERAPEUTICS, INC.'s next tracked catalyst is a Phase2_Start event — "Phase2_Start: A Phase 2 Open-Label, Safety, Tolerability and Exposure Study of Oral (Z)-Endoxifen for the Treatment of Gonadotropin-Independent Precocious Puberty in Girls With McCune-Albright Syndrome" — expected March 1, 2027.
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.
The AI overview and BioSniper Score are neutral, data-derived signals built from public SEC filings, ClinicalTrials.gov and FDA records — not investment advice.