Atossa Therapeutics, Inc.
Atossa Therapeutics, Inc. (Nasdaq: ATOS) is a clinical-stage biopharmaceutical company developing medicines for oncology and other areas of unmet medical need, with a focus on breast cancer and related conditions. Its lead candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator and degrader in Phase 2… From the company’s description.
In fiscal 2025, Atossa Therapeutics, Inc. reported a net loss of $34.77M. Operations used $29.76M in cash.
Margins and return on equity change in ; everything else in percent. Fewer shares and less debt are shown plainly, not as bad news — it depends what you make of buybacks. Dotted labels explain each measure. is shown separately from the annual figures.
What Atossa Therapeutics, Inc. does
In the company’s own words
Atossa Therapeutics, Inc. (Nasdaq: ATOS) is a clinical-stage biopharmaceutical company developing medicines for oncology and other areas of unmet medical need, with a focus on breast cancer and related conditions. Its lead candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator and degrader in Phase 2 development. The company is studying it in estrogen receptor-positive breast cancer, including neoadjuvant treatment, ductal carcinoma in situ and breast-density reduction, and is exploring potential uses in Duchenne muscular dystrophy, McCune-Albright syndrome and other conditions. Atossa also supports collaborative and investigator-sponsored studies of (Z)-endoxifen; it has no reportable business segments described here. The company is in the research and development phase and does not market products. In 2025, it recorded $21.2 million in research and development expenses, and had $41.3 million in cash and cash equivalents at December 31, 2025. Atossa’s portfolio includes patent rights and applications relating to (Z)-endoxifen, immunotherapies and other therapies. Its website is www.atossatherapeutics.com.
Company details
- Sector
- Health Care
- Industry (SIC)
- Pharmaceutical Preparations
- Headquarters
- SEATTLE, WA
- Fiscal year end
- December
- CIK
- 1488039
- SIC
- 2834
Financial performance, year by year
Fiscal 2012–2025 · USDThe full income statement, balance sheet and cash flow for each of these years — every figure traceable to its filing — is on the Financials tab with a free account.
Who owns Atossa Therapeutics, Inc. — and what changed
Funds as of 2026Q2 · superinvestors as of 2026-06-30
Largest fund holders · Atossa Therapeutics, Inc.’s weight in each
Fund ownership is a floor, not a census — pensions, insurers and people holding shares directly are not visible here.
Fund ownership counts N-PORT filers only, so it is a floor rather than a census — pensions, insurers and direct holders are not visible here, and the remainder is not “held by individuals”.
Every fund and institutional holder, quarter by quarter, is on the Ownership tab with a free account.
Recent filings
All filings →Each filing opens into its own statements and disclosures here.
Put this business in context.
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