ATOSSA THERAPEUTICS, INC.

NOTE 1: NATURE OF OPERATIONS

Atossa Therapeutics, Inc. (the Company) was incorporated on April 30, 2009, in the State of Delaware to develop and market medical devices, laboratory tests and therapeutics to address breast health conditions. The Company is focused on developing proprietary innovative medicines in areas of significant unmet medical need in oncology, with a focus on breast cancer and other breast conditions.

NOTE 2: LIQUIDITY AND CAPITAL RESOURCES

The Company has incurred net losses and negative operating cash flows since inception. For the six months ended June 30, 2025, the Company recorded a net loss of $15.1 million and used $13.2 million of cash in operating activities. As of June 30, 2025, the Company had $57.9 million in cash and cash equivalents and working capital of $55.7 million. The Company has not yet established an ongoing source of revenue sufficient to cover its operating costs, and it believes it will need to continue to raise substantial additional capital to accomplish its business plan over the next several years. Management believes its currently available cash and cash equivalents will be sufficient to finance the Company’s operations for at least one year from the date these Condensed Consolidated Financial Statements are issued. The Company plans to continue to fund its losses from operations and capital funding needs through a combination of public or private equity offerings, debt financings or other sources, including potential corporate collaborations, licenses and other similar arrangements. There can be no assurance as to the availability or terms upon which such financing and capital might be available in the future. If the Company is unable to secure additional funding, it may be forced to curtail or suspend its business plans.

NOTE 3: SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

The accompanying Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. They do not include all information and notes required by GAAP for complete financial statements. However, except as disclosed herein, there have been no material changes in the information disclosed in the Notes to Consolidated Financial Statements included in the Annual Report on Form 10-K of the Company for the year ended December 31, 2024. The year-end Condensed Consolidated Balance Sheet presented in this report was derived from audited consolidated financial statements but does not include all annual disclosures required by GAAP.

In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation have been included and have been prepared on the same basis as the annual consolidated financial statements. Operating results for the six months ended June 30, 2025 are not necessarily indicative of the results that may be expected for the year ending December 31, 2025.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these financial statements include stock-based compensation expense and prepaid or accrued clinical trial balances at the end of any reporting period. Actual results could differ materially from the Company’s estimates.

Cash and Cash Equivalents

Cash and cash equivalents include unrestricted cash and all highly liquid instruments with original maturities of three months or less at the date of purchase. Cash equivalents consist primarily of amounts invested in money market accounts.

Restricted Cash

The Company’s restricted cash balance as of June 30, 2025 and December 31, 2024 consisted entirely of cash pledged as security for the Company’s issued commercial credit cards.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of deposits of cash and cash equivalents, including those deposited in money market deposit accounts. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any material losses in such accounts and believes it is not exposed to significant risk. The Company has invested its excess cash primarily in money market funds.

Clinical Trial and Preclinical Study Accruals

The Company makes estimates of its accrued expenses for clinical trial and preclinical study activities as of each balance sheet date in its financial statements based on the facts and circumstances known to the Company at that time. These accruals are based upon estimates of costs incurred and fees that may be associated with services provided by clinical trial investigational sites and Contract Research Organizations (CROs), and for other clinical trial-related activities. Payments under certain contracts with such parties depend on factors such as successful enrollment of patients, site initiation and progression through the various stages of the Company's clinical trials. In accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If possible, the Company obtains information regarding unbilled services directly from these service providers. However, the Company may be required to estimate these services based on other information available to it. If the Company underestimates or overestimates the activities or fees associated with a study or service at a given point in time, adjustments to research and development expenses may be necessary in future periods. Historically, the Company’s estimated accrued liabilities have approximated actual expense incurred. Subsequent changes in estimates may result in a material change in the Company's accruals.

Prepaid Materials

The Company capitalizes its purchase of certain raw materials, active pharmaceutical ingredients and related supplies for use in the manufacturing of drug products for use in its preclinical and clinical development programs, as it has determined that these materials have alternative future use. The Company can use these raw materials and related supplies in multiple clinical drug products, and they therefore have future use independent of the development status of any particular drug program until they are utilized in the manufacturing process. The Company expenses the cost of materials when used. The Company periodically reviews these capitalized materials for continued alternative future use and writes down the assets to their net realizable value in the period in which an impairment is identified. Prepaid materials not expected to be used within 12 months of the balance sheet date are presented in Other assets on the Condensed Consolidated Balance Sheets.

Other Assets

Other assets consist of property and equipment, prepaid materials and clinical deposits.

Fair Value Measurements

The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements.

The fair value hierarchy is broken down into the three input levels summarized below:

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Level 1: Quoted market prices in active markets for identical assets or liabilities;

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Level 2: Other observable market-based inputs or unobservable inputs that are corroborated by market data; and

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Level 3: Unobservable inputs that cannot be corroborated by market data that reflects the reporting entity's own assumptions.

The carrying amounts reflected in the accompanying Condensed Consolidated Balance Sheets for cash and cash equivalents, restricted cash, and accounts payable approximate their fair values due to their short-term nature. Refer to Note 8 of these Condensed Consolidated Financial Statements.

Research and Development

Research and development (R&D) costs are expensed as incurred and consist of costs associated with research activities. R&D expenses include, for example, manufacturing expenses for the Company's drugs under development, expenses associated with preclinical studies, clinical trials and associated salaries, bonuses, stock-based compensation and benefits. R&D expenses also include an allocation of the CEO's salary and related benefits, including bonus and non-cash stock-based compensation expense, based on an estimate of his total hours spent on R&D activities. The Company's CEO is involved in the development of the Company's drug candidates and oversight of the related clinical trial activities and also acts as the Company's Chief Medical Officer.

Stock-based Compensation

The Company measures and recognizes compensation expense for all stock-based awards made to employees, officers, non-employee directors, and other key persons providing services to the Company, currently limited to stock options. Stock-based compensation is measured using the estimated grant date fair value and is recognized as an expense over the requisite service period, generally the vesting period. The Company has made a policy election to recognize forfeitures when they occur.

The fair value of each stock option grant is estimated using the Black-Scholes option-pricing model, which requires assumptions regarding the expected volatility of the price of the Company’s common stock, the expected life of the options, an expectation regarding future dividends on the Company’s common stock, and a risk-free interest rate. The Company’s expected common stock price volatility assumption is based upon the historical volatility of its stock price. The Company has elected the simplified method for the expected life assumption for stock option grants, which averages the contractual term of the options of 10 years with the vesting term, typicallyone tofour years, as the Company does not have sufficient option exercise experience. The dividend yield assumption ofzero is based upon the fact that the Company has never paid cash dividends and presently has no intention of paying cash dividends in the future. The risk-free interest rate assumption is based upon prevailing short-term interest rates over the expected life of the options as of the grant date.

Income Taxes

The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using enacted tax rates and laws that are expected to be in effect when the differences are expected to be recovered or settled. Realization of deferred tax assets is dependent upon future taxable income. A valuation allowance is recognized if it is more likely than not that some portion or all of a deferred tax asset will not be realized based on the weight of available evidence, including expected future earnings. The Company recognizes an uncertain tax position in its financial statements when it concludes that a tax position is more likely than not to be sustained upon examination based solely on its technical merits. Only after a tax position passes the first step of recognition will measurement be required. Under the measurement step, the tax benefit is measured as the largest amount of benefit that is more likely than not to be realized upon effective settlement. This is determined on a cumulative probability basis. The full impact of any change in recognition or measurement is reflected in the period in which such change occurs. The Company records any interest or penalties related to income taxes in income tax benefit in the Condensed Consolidated Statements of Operations.

Recently Issued Accounting Pronouncements

In November 2024, the Financial Accounting Standards Board (the FASB) issued Accounting Standards Update (ASU) No. 2024-03, Disaggregation of Income Statement Expenses (Topic 220-40). This standard requires business entities to disclose in a tabular format, on an annual and interim basis, purchases of inventory, employee compensation, depreciation, intangible asset amortization and depletion for each income statement line item that contains those expenses. The guidance is effective for public business entities in annual reporting periods beginning after December 15, 2026, and in interim periods within annual reporting periods beginning after December 15, 2027. Entities may apply the guidance prospectively or retrospectively. The Company is currently assessing the potential impact of this ASU.

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes: Improvements to Income Tax Disclosures (Topic 740). This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. This ASU is effective for annual periods beginning after December 15, 2024. The Company is currently assessing the potential impact of this ASU.

The Company does not expect the adoption of any other recently issued accounting pronouncements to have a material impact on its financial statements.

NOTE 4: PREPAID EXPENSES AND OTHER CURRENT ASSETS

Prepaid expenses and other current assets consisted of the following (in thousands):

NOTE 5: ACCRUED EXPENSES

Accrued expenses consisted of the following (in thousands):

NOTE 6: PAYROLL LIABILITIES

Payroll liabilities consisted of the following (in thousands):

NOTE 7: OTHER CURRENT LIABILITIES

In 2017, the Company formed a wholly owned subsidiary in Australia called Atossa Genetics AUS Pty Ltd. The purpose of this subsidiary is to perform R&D activities, including some of the Company’s clinical trials. Australia offers R&D cash rebates on qualified R&D activities incurred in the country. The Australian R&D tax incentive program is a self-assessment program, and as such, the Australian Taxation Office (ATO) has the right to review the Company’s program and related expenditures for a period of four years following the tax return filing date. If a review were to occur, a qualified program and related expenditures could be disqualified by the ATO with interest and penalties. Based on the Company’s evaluation of the ATO's taxpayer alert in December 2023, the Company believes that it is no longer reasonably assured that the full tax position would be sustained under audit. Accordingly, as of June 30, 2025 and December 31, 2024, a liability of $1.5 million was included in Other current liabilities in the Condensed Consolidated Balance Sheets.

NOTE 8: FAIR VALUE OF FINANCIAL INSTRUMENTS

The following tables present the Company’s fair value hierarchy for all its financial assets and liabilities, by major security type, that are measured at fair value on a recurring basis (in thousands):

NOTE 9: STOCKHOLDERS’ EQUITY

Common Stock

The Company is authorized to issue 350,000,000 shares of common stock, par value $0.18 per share. The Company may offer, from time to time, to sell, in an "at the market offering", shares of our common stock up to an aggregate offering price of up to $100.0 million. We didnot make any sales under the at the market offering facility during the year ended December 31, 2024 or during the three and six months ended June 30, 2025.

Preferred Stock

The Company is authorized to issue a total of 10,000,000 shares of preferred stock, par value $0.001 per share. The Company has designated 750,000 shares of Series A junior participating preferred stock, par value $0.001 per share,4,000 shares of Series A convertible preferred stock, par value $0.001 per share,25,000 shares of Series B convertible preferred stock, par value $0.001 per share, and 20,000 shares of Series C convertible preferred stock, par value $0.001 per share, through the filings of certificates of designation with the Delaware Secretary of State. No shares of Series A junior participating preferred stock, Series A convertible preferred stock, or Series C convertible preferred stock, were outstanding as of June 30, 2025 and December 31, 2024.

Series B Convertible Preferred Stock

Conversion. Each share of Series B convertible preferred stock is convertible at the Company’s option at any time, or at the option of the holder at any time, into the number of shares of the Company’s common stock determined by dividing the $1,000 stated value per share of the Series B convertible preferred stock by a conversion price of $3.52 per share. In addition, the conversion price per share is subject to adjustment for stock dividends, distributions, subdivisions, combinations, or reclassifications. Subject to limited exceptions, a holder of the Series B convertible preferred stock will not have the right to convert any portion of the Series B convertible preferred stock to the extent that, after giving effect to the conversion, the holder, together with its affiliates, would beneficially own in excess of 9.99% of the number of shares of the Company’s common stock outstanding immediately after giving effect to its conversion.

During the three and six months ended June 30, 2025, certain holders of the Series B convertible preferred stock exercised their conversion option and converted an aggregate of 5 shares of Series B convertible preferred stock into 1,420 shares of the Company’s common stock. No cash was exchanged in connection with the conversion. During the three and six months ended June 30, 2024, there wereno conversions of Series B convertible preferred stock.

Fundamental Transactions. In the event the Company effects certain mergers, consolidations, sales of substantially all of its assets, tender or exchange offers, reclassifications, or share exchanges in which its common stock is effectively converted into or exchanged for other securities, cash or property, the Company consummates a business combination in which another person acquires 50% of the outstanding shares of its common stock, or any person or group becomes the beneficial owner of 50% of the aggregate ordinary voting power represented by its issued and outstanding common stock, then, upon any subsequent conversion of the Series B convertible preferred stock, the holders of the Series B convertible preferred stock will have the right to receive any shares of the acquiring corporation or other consideration it would have been entitled to receive if it had been a holder of the number of shares of common stock then issuable upon conversion in full of the Series B convertible preferred stock.

Dividends. Holders of Series B convertible preferred stock shall be entitled to receive dividends (on an as-if-converted-to-common-stock basis) in the same form as dividends actually paid on shares of the common stock when, as and if such dividends are paid on shares of common stock. The Company’s preferred stock contractually entitles the holders of such securities to participate in dividends but do not contractually require the holders of such securities to participate in losses of the Company.

Voting Rights. Except as otherwise provided in the certificate of designation or as otherwise required by law, the Series B convertible preferred stock has no voting rights.

Liquidation Preference. Upon the Company’s liquidation, dissolution or winding-up, whether voluntary or involuntary, holders of Series B convertible preferred stock will be entitled to receive out of the Company’s assets, whether capital or surplus, the same amount that a holder of common stock would receive if the Series B convertible preferred stock were fully converted (disregarding for such purpose any conversion limitations under the certificate of designation) to common stock, which amounts shall be paid pari passu with all holders of common stock.

Redemption Rights. The Company is not obligated to redeem or repurchase any shares of Series B convertible preferred stock. Shares of Series B convertible preferred stock are not otherwise entitled to any redemption rights, or mandatory sinking fund or analogous provisions.

2021 Warrants

The warrants were issued to institutional and accredited investors as a part of certain financing transactions, which closed on January 8, 2021 and March 23, 2021. The terms and conditions of the warrants are as follows:

Exercisability. Each warrant is exercisable at any time and will expire 4.5 years from the date of issuance. The warrants are exercisable, at the option of each holder, in whole or in part by delivering to the Company a duly executed exercise notice and payment in full for the number of shares of the Company’s common stock purchased upon such exercise, except in the case of a cashless exercise as discussed below. The number of shares of common stock issuable upon exercise of the warrants is subject to adjustment in certain circumstances, including a stock split or, stock dividend on, or a subdivision, combination or recapitalization of the common stock. Upon the merger, consolidation, sale of substantially all of the Company’s assets, or other similar transaction, the holders of warrants shall, at the option of the Company, be required to exercise the warrants immediately prior to the closing of the transaction, or such warrants shall automatically expire. Upon such exercise, the holders of warrants shall participate on the same basis as the holders of common stock in connection with the transaction.

Cashless Exercise. If at any time there is no effective registration statement registering, or the prospectus contained therein is not available for issuance of, the shares issuable upon exercise of the warrant, the holder may exercise the warrant on a cashless basis. When exercised on a cashless basis, a portion of the warrant is cancelled in payment of the purchase price payable in respect of the number of shares of the Company’s common stock purchasable upon such exercise.

Exercise Price. Each warrant represents the right to purchaseone share of common stock. In addition, the exercise price per share is subject to adjustment for stock dividends, distributions, subdivisions, combinations or reclassifications, and for certain dilutive issuances. Subject to limited exceptions, a holder of warrants will not have the right to exercise any portion of the warrant to the extent that, after giving effect to the exercise, the holder, together with its affiliates, and any other person acting as a group together with the holder or any of its affiliates, would beneficially own in excess of 4.99% of the number of shares of the Company’s common stock outstanding immediately after giving effect to its exercise. The holder, upon notice to the Company, may increase or decrease the beneficial ownership limitation provisions of the warrant, provided that in no event shall the limitation exceed 9.99% of the number of shares of the Company’s common stock outstanding immediately after giving effect to the exercise of the warrant.

Transferability. Subject to applicable laws and restrictions, a holder may transfer a warrant upon surrender of the warrant to us with a completed and signed assignment in the form attached to the warrant. The transferring holder will be responsible for any tax liability that may arise as a result of the transfer.

Exchange Listing. The Company does not intend to apply to list the warrants on any securities exchange or recognized trading system.

Rights as Stockholder. Except as set forth in the warrant, the holder of a warrant, solely in such holder’s capacity as a holder of a warrant, will not be entitled to vote, to receive dividends or to any of the other rights of the Company's stockholders. The Company’s warrants contractually entitle the holders of such securities to participate in dividends but do not contractually require the holders of such securities to participate in losses of the Company.

Warrants Outstanding

As of June 30, 2025, the following warrants to purchase shares of the Company’s common stock were outstanding:

Warrant Activity

There wereno warrant exercises during the three and six months ended June 30, 2025. During the three and six months ended June 30, 2024, the Company received approximately $0.1 million and $0.3 million, respectively from the exercises of warrants, resulting in the issuance of 100,000 and 303,750, respectively, shares of common stock. On June 21, 2025,2,812,500 warrants granted in December 2020 expired.

NOTE 10: NET LOSS PER SHARE

Basic net loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding. Diluted net loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock that would have been outstanding during the period assuming the issuance of shares of common stock for all potentially dilutive shares of common stock outstanding. Potentially dilutive shares of common stock consist of outstanding stock options, convertible preferred stock and common stock warrants. Because the inclusion of potential shares of common stock would be anti-dilutive for all periods presented, they have been excluded from the calculation.

The following table sets forth the weighted average number of shares of common stock excluded from the calculation of diluted net loss per share, because including them would be anti-dilutive:

NOTE 11: INCOME TAXES

Deferred income tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial reporting and tax bases of assets and liabilities and are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. A valuation allowance is provided for the amount of deferred tax assets that, based on available evidence, are not expected to be realized.

As a result of the Company’s cumulative losses, management has concluded that a full valuation allowance against the Company’s net deferred tax assets is appropriate. Therefore, no income tax provision was recorded for the three and six months ended June 30, 2025 and 2024.

NOTE 12: COMMITMENTS AND CONTINGENCIES

Litigation and Contingencies

On April 3, 2025, Intas Pharmaceuticals Ltd. (Intas) filed a Petition for Post Grant Review (PGR) with the U.S. Patent and Trademark Office’s (USPTO) Patent Trial and Appeal Board (PTAB) (the 391 PGR Petition) seeking to invalidate one of the Company’s issued patents (U.S. Patent No. 12,071,391) titled “Methods for Making and Using Endoxifen,” on the alleged grounds of anticipation, obviousness, lack of written description, and lack of enablement. On July 7, 2025, the Company filed its Patent Owner’s Request for Discretionary Denial of Institution in response to the 391 PGR Petition, and a decision regarding this request is expected from the PTAB by September 8, 2025. The Company’s Patent Owner Preliminary Response Brief was filed on August 5, 2025.

On April 3, 2025, Intas also filed a Petition for Inter Partes Review (IPR) with the USPTO’s PTAB (the 151 IPR Petition) seeking to invalidate one of the Company’s issued patents (U.S. Patent No. 11,261,151) titled “Methods for Making and Using Endoxifen” (together with U.S. Patent No. 12,071,391, the Patents) on the alleged grounds of anticipation and obviousness. On July 7, 2025, the Company filed its Patent Owner’s Request for Discretionary Denial of Institution in response to the 151 IPR Petition, and a decision regarding this request is expected from the PTAB by September 8, 2025. The Company’s Patent Owner Preliminary Response Brief was filed on August 5, 2025.

The Company intends to vigorously contest the 391 PGR Petition and the 151 IPR Petition and believes that the Patents were properly granted and include valid and enforceable claims. However, there can be no assurance that the Company will prevail in contesting either the 391 PGR Petition or the 151 IPR Petition.

From time to time, the Company is subject to other legal proceedings and claims that arise in the ordinary course of its business. The Company believes that these matters do not have a material effect, individually or in the aggregate, on its financial position, results of operations or cash flows.

Contractual Obligations

Contractual obligations represent the Company’s future cash commitments and liabilities under agreements with third party clinical trial service providers. Apart from contracts with one third-party clinical trial service provider, such agreements are cancellable upon written notice by the Company. The non-cancellable contracts expire upon completion of the clinical trial and release of the final report, or the contracts may be terminated by the clinical trial service provider, by the FDA or another governmental agency. As of June 30, 2025, the Company's estimated non-cancellable commitment was $7.9 million.

NOTE 13: STOCK BASED COMPENSATION

On May 15, 2020, the stockholders of the Company approved the 2020 Stock Incentive Plan (the 2020 Plan) to provide for the grants of equity-based awards to employees, officers, non-employee directors and other key persons providing services to the Company. No awards may be granted under the 2020 Plan after June 27, 2034. An aggregate of 30,000,000 shares of common stock is reserved for issuance in connection with awards granted under the 2020 Plan. As of June 30, 2025,9,170,778 shares were available for future grants under the 2020 Plan.

The Company recognized stock-based compensation expense in the Condensed Consolidated Statements of Operations as follows (in thousands):

The following table shows a summary of all stock option activity for the six months ended June 30, 2025:

The Company granted 4,242,547 options to purchase shares of common stock to employees and directors during the three months ended June 30, 2025. The weighted average grant date fair value of options granted during the six months ended June 30, 2025 was $0.75.

As of June 30, 2025, the unrecognized compensation cost associated with unvested options was $4.7 million. This expense is expected to be recognized over a weighted-average period of 1.7 years.

NOTE 14: DEFINED CONTRIBUTION PLAN

The Company has a defined contribution plan to which employees of the Company may defer contributions for income tax purposes. Participants are eligible to receive employer matching contributions up to 6% of deferrals. Employees may also be eligible for a discretionary match over 6%. Defined contribution plan employer matching contributions for the three and six months ended June 30, 2025 were $63 thousand and $138 thousand, respectively, and $37 thousand and $114 thousand, respectively, for the same periods in 2024.

NOTE 15: SEGMENTS

The Company operates as asingle segment. Operating segments are identified as the components of an enterprise of which separate discrete financial information is available for evaluation by the Chief Operating Decision Maker (the CODM) in making decisions regarding resource allocation and in assessing performance. The measure of segment assets is reported on the balance sheets as total assets. To date, the Company's CODM has made such decisions and assessed performance at the Company-level as a single segment using information at the condensed consolidated financial statement level.

The CODM is Steven C. Quay, M.D., Ph D. Chairman, President and CEO. The CODM utilizes Net Loss from the Condensed Consolidated Statement of Operations for the measure of segment loss.