Atossa Therapeutics Reports Fourth Quarter and Year-End 2025 Financial Results and Provides a Corporate Update
SEATTLE, March 25, 2026 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) (Atossa or the Company), a clinical-stage biopharmaceutical company developing novel therapies in oncology and other areas of high unmet clinical need, today announces its financial results for the fourth quarter and year ended December 31, 2025 and provides an update on recent corporate developments.
"While we have consistently made meaningful and measurable progress across our (Z)-endoxifen development strategy in oncology over the last 12 months, we continue to explore the best opportunities to leverage the technology where it may help to address serious health conditions and unmet medical needs. As we continue to keep a careful eye on opportunities in the breast cancer space, we are also diligently working to advance (Z)-endoxifen in certain rare disease indications, such as Duchenne Muscular Dystrophy (DMD) and McCune-Albright Syndrome (MAS)," stated Dr. Steven Quay, M.D., Ph.D., Atossa Therapeutics' President and Chief Executive Officer. "To date, we have published work that identifies the opportunity for (Z)-endoxifen, while achieving both FDA Rare Pediatric Disease and Orphan Drug designations. We believe these FDA designations are important for future development as they both help to speed the FDA review process as well as provide potential financial benefits in the future."
"In the meantime, we are consciously aligning our resources with the demands of potential commercialization, even as we have added new professionals to our team to help drive both our rare disease and breast cancer programs forward. With a strong balance sheet and a strategically focused team, we believe we are well-positioned to execute and advance our clinical programs toward key value-creating milestones," concluded Dr. Quay.
Clinical & Regulatory Progress & Announcements
Atossa Announces Additions to Management Team
Comparison of Years-Ended December 31, 2025 and 2024
Operating Expenses. Total operating expenses were $37.1 million for the year ended December 31, 2025, which was an increase of $9.5 million, from the year ended December 31, 2024 of $27.6 million. Factors contributing to the increased operating expenses in the year ended December 31, 2025 are explained below.
Research & Development Expenses. The following table provides a breakdown of major categories within R&D expenses for the years ended December 31, 2025 and 2024, together with the dollar change in those categories (dollars in thousands):
For the Year Ended December 31,
2025
2024
Increase
Increase (%)
Research and Development Expense
Clinical and non-clinical trials
$16,204
$10,107
$6,097
60 %
Compensation
3,206
2,928
278
9 %
Professional fees and other
1,775
1,082
693
64 %
Research and Development Expense Total
$21,185
$14,117
$7,068
50 %
As (Z)-endoxifen is our only product candidate for which we currently incur R&D expenses, we have not further disaggregated R&D expenses by product candidate:
General and Administrative (G&A) Expenses. The following table provides a breakdown of major categories within G&A expenses for the years ended December 31, 2025 and 2024, together with the dollar change in those categories (dollars in thousands):
For the Year Ended December 31,
2025
2024
Increase
(Decrease)
Increase (%)
(Decrease)
General and Administrative Expense
Compensation
$6,062
$5,458
$604
11 %
Professional fees and other
9,191
7,164
2,027
28 %
Insurance
703
882
(179)
(20) %
General and Administrative Expense Total
$15,956
$13,504
$2,452
18 %
Interest Income. Interest income of $2.4 million for the year ended December 31, 2025 represented a decrease of $1.7 million compared to the prior year, and was due primarily to a decrease in the average funds invested in our money market account.
Impairment Charge on Investment in Equity Securities. For the year ended December 31, 2024, we wrote down our Investment in equity securities by $1.7 million due to impairment of our investment in Dynamic Cell Therapies, Inc.
About (Z)-Endoxifen
(Z)-Endoxifen is a potent Selective Estrogen Receptor Modulator/Degrader (SERM/D) with demonstrated activity across multiple mechanisms of interest. Atossa is evaluating its potential applications in oncology and rare diseases. The Company's proprietary oral formulation has shown a favorable safety profile and pharmacology distinct from tamoxifen, including ER-targeted effects and PKC inhibition. Atossa's (Z)-endoxifen is not approved for any indication.
Atossa's (Z)-endoxifen program is supported by a growing global intellectual property portfolio, including multiple recently issued U.S. patents and numerous pending applications worldwide.
About Atossa Therapeutics
Atossa Therapeutics, Inc. (Nasdaq: ATOS) is a clinical-stage biopharmaceutical company developing innovative medicines in oncology and other areas of significant unmet need. The Company's lead product candidate, (Z)-endoxifen, is currently in development across several clinical settings. More information is available at https://atossatherapeutics.com.
Forward Looking Statements
This press release contains certain "forward-looking statements" within the meaning of applicable securities laws, including but not limited to, our 2026 outlook and our expectations regarding the Company's development and regulatory strategy and related milestones, including potential Investigational New Drug submissions, the potential indications that the Company may pursue for (Z)-endoxifen, the potential for (Z)-endoxifen to receive regulatory approval and the timing thereof, the Company's progress across its pipeline and potential commercialization, the strength of the Company's patent portfolio, the Company's potential eligibility for the Rare Pediatric Disease Priority Review Voucher (PRV) program and the value of a PRV, and the potential market and growth opportunities for the Company. Words such as "expect," "potential," "continue," "may," "will," "should," "could," "would," "seek," "intend," "plan," "estimate," "anticipate," "believe," "design," "predict," "future," or other similar expressions or statements regarding intent, belief or current expectations, are forward-looking statements.
Forward-looking statements in this press release are subject to risks and uncertainties that may cause actual results, outcomes, or the timing of actual results or outcomes to differ materially from those projected or anticipated, including, without limitation, risks and uncertainties associated with: our ability to successfully execute our strategy to shorten our clinical development timelines and pursue a DMD indication or other indications for our lead program, (Z)-endoxifen; expected timing, completion and results of our preclinical studies, clinical trials and research and development programs; the unpredictable relationship between preclinical study results and clinical study results; the timing or likelihood of regulatory filings and approvals; the outcome or timing of necessary regulatory approvals; our ability to receive orphan-drug exclusivity for (Z)-endoxifen for DMD; our ability to maintain compliance with Nasdaq listing requirements; our ability to establish and maintain intellectual property rights covering our products; the impact of general macroeconomic conditions on our business; our ability to raise capital; and other risks and uncertainties detailed from time to time in Atossa's filings with the SEC, including, without limitation, its Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q.
Forward-looking statements are presented as of the date of this press release. Except as required by law, we do not intend to update any forward-looking statements.
ATOSSA THERAPEUTICS, INC.
CONSOLIDATED BALANCE SHEETS
(amounts in thousands, except share and per share data)
December 31, 2025
December 31, 2024
Assets
Current assets
Cash and cash equivalents
$
41,299
$
71,084
Restricted cash
110
110
Prepaid materials
3,081
2,098
Prepaid expenses and other current assets
1,128
1,165
Total current assets
45,618
74,457
Other assets
1,990
1,987
Total assets
$
47,608
$
76,444
Liabilities and stockholders' equity
Current liabilities
Accounts payable
$
4,293
$
679
Accrued expenses
1,307
919
Payroll liabilities
1,558
1,862
Other current liabilities
1,097
1,507
Total current liabilities
8,225
4,967
Total liabilities
8,225
4,967
Commitments and contingencies
Stockholders' equity
Convertible preferred stock - $0.001 par value; 10,000,000 shares authorized;
577 and 582 shares issued and outstanding as of December 31, 2025 and
December 31, 2024, respectively
—
—
Common stock - $0.18 par value; 350,000,000 shares authorized; 8,611,361
and 8,611,266 shares issued and outstanding as of December 31, 2025 and
December 31, 2024, respectively
1,550
1,550
Additional paid-in capital
285,840
283,194
Treasury stock, at cost; 88,003 shares of common stock at December 31, 2025
and December 31, 2024
(1,475)
(1,475)
Accumulated deficit
(246,562)
(211,792)
Total stockholders' equity
39,353
71,477
Total liabilities and stockholders' equity
$
47,608
$
76,444
ATOSSA THERAPEUTICS, INC.
CONSOLIDATED STATEMENTS OF OPERATIONS
(amounts in thousands, except share and per share data)
For the Year Ended December 31,
2025
2024
Operating expenses
Research and development
$ 21,185
$ 14,117
General and administrative
15,956
13,504
Total operating expenses
37,141
27,621
Operating loss
(37,141)
(27,621)
Impairment charge on investment in equity securities
—
(1,710)
Interest income
2,377
4,050
Other expense, net
(6)
(223)
Loss before income taxes
(34,770)
(25,504)
Income tax benefit
—
—
Net loss
$ (34,770)
$ (25,504)
Net loss per share of common stock - basic and diluted
$ (4.04)
$ (3.04)
Weighted average shares outstanding used to compute
net loss per share - basic and diluted
8,611,321
8,6390,618
SOURCE Atossa Therapeutics Inc