Aptevo Therapeutics Inc.

Note 1. Nature of Business and Significant Accounting Policies

Organization and Liquidity

Aptevo Therapeutics Inc. (Aptevo, we, us, or the Company) is a clinical-stage, research and development biotechnology company focused on developing novel immunotherapy candidates for the treatment of different forms of cancer. We have developedtwo versatile and enabling platform technologies for rational design of precision immune modulatory drugs and have two clinical candidates and six preclinical candidates currently in development. Clinical candidate mipletamig is a CD123xCD3 T cell engager that is currently being evaluated in the RAINIER study, a Phase 1b/2 program evaluating mipletamig in combination with standard of care venetoclax + azacitidine for the treatment of frontline acute myelogenous leukemia (AML) patients who are unfit for intensive chemotherapy. The ongoing Phase 1b trial was initiated in August 2024. Clinical candidate ALG.APV-527 targets 4-1BB (co-stimulatory receptor) and 5T4 (tumor antigen). The compound is designed to reactivate antigen-primed T cells to specifically kill tumor cells and was most recently evaluated in a Phase 1 clinical trial for the treatment of multiple solid tumor types likely to express 5T4.

We are currently trading on the Nasdaq Capital Market under the symbol “APVO.”

The accompanying consolidated financial statements have been prepared on a basis that assumes we will continue as a going concern and which contemplates the realization of assets, and satisfaction of liabilities, and commitments in the normal course of business. For the year ended December 31, 2025, we had net loss of $26.0 million. We had an accumulated deficit of $275.1 million as of December 31, 2025. For the year ended December 31, 2025, net cash used in our operating activities was $25.6 million. We have suffered recurring losses from operations and negative cash flows from operating activities. When considered in aggregate, these factors raise substantial doubt about our ability to continue as a going concern for the one-year period from the date of issuance of these financial statements. For the year ended December 31, 2025, we received $38.5 million in proceeds through various equity offerings. In addition, during the subsequent events period, we sold 0.09 million shares under the First SEPA at an average price of $6.56 per share and raised $0.6 million in net proceeds. We sold 0.1 million shares under the Second SEPA at an average price of $5.85 per share and raised $0.6 million net proceeds. We will need to raise additional funds to support our operating and capital needs in addition to our existing cash resources, cash to be generated from future milestones related to IXINITY sales and regulatory approvals achieved by Medexus Pharmaceuticals (Medexus), sale of common stock under the First SEPA and the Second SEPA, and exercise of warrants. We may choose to raise additional funds to support our operating and capital needs in the future.

We continue to face significant challenges and uncertainties and, as a result, our available capital resources may be consumed more rapidly than currently expected due to: (a) changes we may make to the business that affect ongoing operating expenses; (b) changes we may make in our business strategy; (c) changes we may make in our research and development spending plans; (d) whether and to what extent potential milestones are received from Medexus with respect to IXINITY; (e) macroeconomic conditions such as rising inflation, potential trade war, and other costs as well as political events such as a U.S. federal government shutdown, evolving healthcare policies, and military actions; and (f) other items affecting our forecasted level of expenditures and use of cash resources. We may attempt to obtain other public or private financing, collaborative or licensing arrangements with strategic partners, or through credit lines or other debt financing sources to increase the funds available to fund operations. However, we may not be able to secure such funding in a timely manner or on favorable terms, if at all. Furthermore, if we issue equity or debt securities to raise additional funds, our existing stockholders may experience dilution, and the new equity or debt securities may have rights, preferences, and privileges senior to those of our existing stockholders. If we raise additional funds through collaboration, licensing, or other similar arrangements, it may be necessary to relinquish valuable rights to our potential products or proprietary technologies, or grant licenses on terms that are not favorable to us. Without additional funds, we may be forced to delay, scale back, or eliminate some of our research and development activities or other operations and potentially delay product development in an effort to provide sufficient funds to continue our operations. If any of these events occur, our ability to achieve our development goals may be adversely affected. Given the continuing global economic and geopolitical climate, including stock market volatility and potential trade war, we may experience delays or difficulties in the financing environment and raising capital due to economic uncertainty.

Basis of Presentation

The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). These consolidated financial statements include all adjustments, which include normal recurring adjustments, necessary for the fair presentation of the Company’s financial position.

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 at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and changes in these estimates are recorded when known.

The consolidated financial statements include the accounts of the Company and our wholly owned subsidiary, Aptevo Research and Development LLC. All intercompany balances and transactions have been eliminated.

Reclassification

Certain amounts in the accompanying consolidated financial statements were reclassified to conform to the current period presentation. There has been no impact on previously reported net loss or stockholders' equity from such reclassification.

Significant Accounting Policies

Use of Estimates

The preparation of financial statements in conformity with GAAP requires estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses, and related disclosures of contingent liabilities in the consolidated financial statements and accompanying notes. Estimates are used for, but not limited to, clinical accruals, useful lives of equipment, commitments and contingencies, stock-based compensation, fair value used for common warrant valuation and incremental borrowing rate (IBR) used for our lease. Given the global economic and geopolitical climate, these estimates are becoming more challenging, and actual results could differ materially from those estimates.

Cash Equivalents

Cash equivalents are highly liquid investments with a maturity of 90 days or less at the date of purchase and include time deposits and investments in money market funds with commercial banks and financial institutions.

Prepaid Expenses and Other Current Assets

We record prepaid expenses and other current assets made in advance for goods or services to be received in the future. Our prepaid expenses primarily relate to prepaid clinical deposits and other corporate deposits. Such amounts are expensed over the period in which the related goods or services are received. Management applies judgment in determining the appropriate period over which prepaid expenses are expensed, based on the expected pattern of benefit.

Concentrations of Credit Risk

Financial instruments that potentially subject Aptevo to concentrations of credit risk consist primarily of cash and cash equivalents. Aptevo places its cash and cash equivalents with high quality financial institutions and may maintain cash balances in excess of insured limits. Management believes that the financial risks associated with its cash and cash equivalents are minimal.

Property and Equipment

Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the following estimated useful lives:

Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is credited or charged to operations. Repairs and maintenance costs are expensed as incurred.

Leases

We determine if an arrangement is a lease at inception date. Leases are to be classified as finance or operating leases at the lease commencement date, which affects the classification of expense recognition in the consolidated statement of operations. Right-of-use assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments, as agreed to in the lease. Operating lease liabilities and the corresponding right-of-use assets are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. An operating right-of-use asset is measured as the amount of the initial measurement of the lease liability, adjusted for prepaid or accrued lease payments, the remaining balance of any lease incentive received, unamortized initial direct costs, and any impairment of the right-of-use asset. The initial measurement of the lease liabilities and right-to-use assets of finance leases is the same as for operating leases. We include options to extend the lease and certain termination options in our lease liability and right-of-use asset when it is reasonably certain that we will exercise those options.

As our existing leases do not contain an implicit interest rate, we estimate our IBR based on information available at commencement date in determining the present value of future payments. Due to the significant judgment involved and the complex analysis needed to determine this discount rate, we engaged a third-party valuation specialist to advise us in our determination of our IBR for the initial adoption of the standard and subsequent amendment of our office lease.

Lease expense for operating leases is recognized on a straight-line basis over the lease term as part of our selling, general and administrative expenses and our research and development expenses on our consolidated statements of operations. Lease expense for financing leases consists of amortization of the right-of-use asset and interest on the lease liability as part of our research and development expenses on our consolidated statements of operations.

Accrued Expenses and Other Current Liabilities

We record clinical accruals for estimated costs of research, preclinical studies, and preclinical trials, which are a significant component of our research and development expenses. Management uses judgment and estimates when determining these costs. Completed patient visits and other invoiceable costs are accrued monthly after review and validation by the appropriate internal teams. The process involves reviewing respective agreements, documentation provided by the CRO, data provided by the clinical sites, along with the timing of the clinical activities, and payment history from prior periods. Depending on the time of payments and the status of documentation, our clinical accruals may vary from one period to the next.

Fair Value of Financial Instruments

We measure and record cash equivalents at fair value in the accompanying financial statements. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, an exit price, in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs.

The carrying amounts of our short-term financial instruments, which include cash and cash equivalents and accounts payable, approximate their fair value due to their short maturities.

Research and development expenses are expensed as incurred. Research and development costs primarily consist of internal labor costs, fees paid to outside service providers,50% shared costs incurred under the Collaboration Agreement with Alligator Bioscience, and the costs of materials used in clinical trials and research and development. Other research and development expenses include facility, maintenance, and related support expenses.

A substantial portion of Aptevo’s preclinical studies and all of its clinical studies have been performed by third-party CROs. The Company reviews the activities performed by the CROs each period. For preclinical studies, the significant factors used in estimating accruals include the percentage of work completed to date and contract milestones achieved. For clinical study expenses, the significant factors used in estimating accruals include the number of patients enrolled and services provided but not yet invoiced. The Company’s estimates are highly dependent upon the timeliness and accuracy of the data provided by its CROs clinical sites regarding the status of each program and total program spending and adjustments are made when deemed necessary.

Collaborative Agreements

We analyze our collaboration arrangements to assess whether they are within the scope of ASC Topic 808, Collaborative Arrangements (ASC 808), to determine whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards that are dependent on the commercial success of such activities. To the extent the arrangement is within the scope of ASC 808, we assess whether aspects of the arrangement between us and our collaboration partner are within the scope of other accounting literature, including ASC Topic 606, Revenue from Contracts with Customers (ASC 606). If it is concluded that some or all aspects of the arrangement represent a transaction with a customer, we will account for those aspects of the arrangement within the scope of ASC 606.

ASC 808 provides guidance for the presentation and disclosure of transactions in collaborative arrangements, but it does not provide recognition or measurement guidance. Therefore, if we conclude a counterparty to a transaction is not a customer or otherwise not within the scope of ASC 606, we consider the guidance in other accounting literature as applicable or by analogy to account for such transaction. The classification of transactions under our arrangements is determined based on the nature and contractual terms of the arrangement along with the nature of the operations of the participants.

General and Administrative Expenses

General and administrative expenses consist primarily of personnel-related costs and professional fees in support of our executive, business development, finance, accounting, investor relations, information technology, legal and human resource functions. Other costs include facility costs not otherwise included in research and development expense.

Stock-Based Compensation

We measure and recognize compensation expense for restricted stock units (RSUs), and stock options granted to our employees and directors based on the fair value of the awards as of the date of grant. The fair value of stock options is estimated at the date of grant using the Black-Scholes option pricing model that requires management to apply judgment and make estimates, including:

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the expected term of the stock option award;

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the expected volatility of our underlying common stock, which we estimate based on the historical volatility of the historical and implied future volatility of our common stock;

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the risk-free interest rate, which we based on the yield curve of U.S. Treasury securities with periods commensurate with the expected term of the options being valued;

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the expected dividend yield, which we estimate to bezero based on the fact that we have never paid cash dividends and have no present intention to pay cash dividends; and

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the fair value of our common stock on the date of grant.

Stock-based compensation expense for RSUs is recognized on a straight-line basis over the vesting period of the respective award. Stock-based compensation expense for our stock options, both converted and Aptevo granted, is recognized on a straight-line basis over the vesting period of the respective award.

We routinely evaluate the appropriateness of the forfeiture rate based on actual forfeiture experience, analysis of employee turnover, and expectations of future option exercise behavior.

Income Taxes

Income taxes are accounted for using the liability method. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between financial statement carrying amounts of existing assets and liabilities and their respective tax bases and net operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which those temporary differences are expected to be recovered or settled.

Aptevo’s ability to realize deferred tax assets depends upon future taxable income, as well as the limitations discussed below. For financial reporting purposes, a deferred tax asset must be reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax assets will not be realized prior to expiration. Aptevo considers historical and future taxable income, future reversals of existing taxable temporary differences, taxable income in prior carryback years, and ongoing tax planning strategies in assessing the need for valuation allowances. In general, if Aptevo determines that it is more likely than not to realize more than the recorded amounts of net deferred tax assets in the future, Aptevo will reverse all or a portion of the valuation allowance established against its deferred tax assets, resulting in a decrease to the provision for income taxes in the period in which the determination is made. Likewise, if Aptevo determines that it is not more likely than not to realize all or part of the net deferred tax asset in the future, Aptevo will establish a valuation allowance against deferred tax assets, with an offsetting increase to the provision for income taxes, in the period in which the determination is made.

Because tax laws are complex and subject to different interpretations, significant judgment is required. As a result, Aptevo makes certain estimates and assumptions, in (1) calculating Aptevo’s income tax expense, deferred tax assets and deferred tax liabilities, (2) determining any valuation allowance recorded against deferred tax assets and (3) evaluating the amount of unrecognized tax benefits, as well as the interest and penalties related to such uncertain tax positions. Aptevo’s estimates and assumptions may differ significantly from tax benefits ultimately realized.

Segment Reporting

Operating segments are identified as components of an entity about which separate discrete financial information is available for evaluation by the chief operating decision maker (CODM), or decision-making group, in making decisions on how to allocate resources and assess performance. The Company's CODM is the Chief Executive Officer, who views the Company's operations as one operating segment, which is discovery and development of novel oncology therapeutics.

Recently Adopted Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-09, Income Taxes (Topic 740): Improvement to Income Tax Disclosures. The purpose of ASU 2023-09 is to enhance disclosures around income taxes, including a tabular rate reconciliation and separate disclosures for any reconciling items within certain categories that fall under a specified quantitative threshold. This ASU is effective and has been adopted for our fiscal year ended December 31, 2025.

Accounting Pronouncements Pending Adoption

In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses (DISE). The purpose of ASU 2024-03 is to enhance expense disclosures by requiring additional disaggregated information about specified categories of expenses included in certain expense captions presented on the face of the income statement. This ASU is effective for fiscal years beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027. The amendments may be applied either prospectively to financial statements issued for reporting periods after the effective date of this ASU or retrospectively to all prior periods presented in the financial statements. The Company is currently assessing the impact this ASU will have on its financial statements.

Note 2. Collaboration Agreements

Alligator Bioscience AB

On July 20, 2017, our wholly owned subsidiary Aptevo Research and Development LLC (Aptevo R&D), entered into a collaboration and option agreement (the Collaboration Agreement) with Alligator Bioscience AB (Alligator), pursuant to which Aptevo and Alligator have been collaboratively developing ALG.APV-527.

We assessed the arrangement in accordance with ASC 606 –Revenue Recognition (ASC 606) and concluded that the contract counterparty, Alligator, is not a customer. As such the arrangement is not in the scope of ASC 606 and is instead treated as a collaborative agreement under ASC 808 –Collaborative Arrangements (ASC 808). Both Aptevo and Alligator are active participants in the development of ALG.APV-527 and are exposed to significant risks and rewards under the Collaboration Agreement. Amounts owed to us for Alligator's share of development costs incurred by the Company are recorded as a reduction of research and development expense under ASC 730 –Research and Developmentin the period the costs are incurred. For the years ended December 31, 2025 and 2024, we recorded approximately $0.3 million and $2.2 million, which represent our 50% cost share, in our research and development expense related to the Collaboration Agreement, respectively.

Note 3. Fair Value Measurements

The Company’s estimates of fair value for financial assets and financial liabilities are based on the framework established in the fair value accounting guidance. The framework is based on the inputs used in valuation, gives the highest priority to quoted prices in active markets and requires that observable inputs be used in the valuations when available. The disclosure of fair value estimates in the fair value accounting guidance hierarchy is based on whether the significant inputs into the valuation are observable. In determining the level of the hierarchy in which the estimate is disclosed, the highest priority is given to unadjusted quoted prices in active markets and the lowest priority to unobservable inputs that reflect the Company’s significant market assumptions. The level in the fair value hierarchy within which the fair value measurement is reported is based on the lowest level input that is significant to the measurement in its entirety. The three levels of the hierarchy are as follows:

Level 1— Quoted prices in active markets for identical assets and liabilities;

Level 2— Inputs other than quoted prices in active markets, that are either directly or indirectly observable; and,

Level 3— Unobservable inputs that are supported by little or no market activity, and that are significant to the fair value of the assets or liabilities.

As of December 31, 2025 and 2024, we had $20.5 million and $7.5 million in money market funds, respectively, which are classified as Level 1 investments. The carrying amounts of our money market funds approximate their fair value. As of December 31,2025 and 2024, we didnot have any Level 2 or Level 3 assets or liabilities.

Note 4. Cash and Cash Equivalents

The Company’s cash equivalents are highly liquid investments with a maturity of 90 days or less at the date of purchase and investments in money market funds.

The following table shows our cash and cash equivalents as of December 31,2025 and 2024:

Note 5. Property and equipment, net

Property and equipment consist of the following:

Depreciation expense for the years ended December 31, 2025 and 2024 was $0.2 million and $0.4 million, respectively.

Note 6. Leases and Contingencies

Office Space Lease – Operating

We have an operating lease related to our office and laboratory space in Seattle, Washington. This lease was amended in March 2019 to extend the term through April 2030 and providetwo options toextend the lease term, each byfive years, as well as a one-time option to terminate the lease in April 2023, with nine months’ notice. We had previously determined at lease inception and as of the May 26, 2022, amendment date thatwe should not include any periods after the termination option when evaluating this amendment as we were not reasonably certain to not exercise the option, therefore we recorded our liability through April 30, 2023.

As of December 31, 2025, we are not reasonably certain to exercise the two options to extend the lease term. Therefore, pursuant to our May 26, 2022 amendment, we recorded our lease liability through April 30, 2030.

For the years ended December 31, 2025 and 2024, we recorded $0.9 million for both years related to variable expenses due to true ups of operating costs or real estate taxes.

Equipment Leases - Operating and Financing

As of December 31, 2025, we didnot have any operating or financing leases for equipment. We recorded $1.2 million in operating lease cost for the years ended December 31, 2025 and 2024.

Components of lease expense:

Right-of-use assets acquired under operating leases:

Lease payments:

Future minimum payments as of December 31, 2025 are as follows:

As of December 31, 2025, thelong-term andcurrent portion of the lease liabilities were $3.8 million and $0.9 million, respectively. As of December 31, 2024, thelong-term andcurrent portion of the lease liabilities were $4.6 million and $0.8 million, respectively.

As of December 31, 2025, the weighted-average remaining lease term and weighted discount rate for operating leases was 4.3 years and 12.03%, respectively. As of December 31, 2024, the weighted-average remaining lease term and weighted discount rate for operating leases was 5.3 years and 12.03%, respectively.

Note 7. Prepaid Expenses, Other Current Assets, Accrued Expenses, and Other Current Liabilities

Prepaid expenses and other current assets consisted of the following as of December 31, 2025 and December 31, 2024.

Accrued expenses and other current liabilities consisted of the following as of December 31, 2025 and December 31, 2024.

Note 8. Reverse Stock Split

On May 14 and July 24, 2025, weheld Special Meetings of the Stockholders (together, the "Special Meetings") at which our stockholders approved a series of alternate amendments to the Amended and Restated Certificate of Incorporation to effect, at the option of our Board of Directors (the Board), a reverse split of Aptevo's common stock, respectively, with the effectiveness of one of such amendments and the abandonment of the other amendments, or the abandonment of all amendments, to be determined by the Board in its sole discretion following the Special Meetings.

Thespecific 1-for-20 and 1-for-18 reverse split ratios were approved by the Board on May 21 and December 17, 2025, respectively. On May 23 and December 29, 2025, the Company filed a Certificate of Amendment of Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware to effect a 1-for-20 and 1-for-18, respectively, reverse stock split of the Company's outstanding common stock (together, the "Reverse Stock Splits"). The Reverse Stock Splits became effective on May 23 and December 29, 2025, respectively, at 5:01 p.m. Eastern Time, and our common stock began trading on the Nasdaq Capital Market, on a split-adjusted basis, at market open on May 27 and December 30, 2025, respectively.

In the year ended December 31, 2024, the Company effected two reverse stock splits on March 5 and December 3, 2024 at the ratios of 1-for-44 and 1-for-37, respectively.

No fractional shares were issued as a result of the Reverse Stock Splits. Stockholders of record who would otherwise be entitled to receive a fractional share received a cash payment in lieu thereof.

We have adjusted all common stock and stock equivalent figures retroactively in this Form 10-K for all periods presented to reflect the Reverse Stock Splits.

Note 9. Net Loss per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period. The weighted-average number of common shares outstanding includes the shares held in abeyance resulting from the exercise of warrants because there is no consideration required for delivery of shares. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period using the as-if converted method. For the purpose of this calculation, warrants, stock options and RSUs are only included in the calculation of diluted net loss per share when their effect is dilutive.

We utilize the control number concept in the computation of diluted earnings per share to determine whether potential common stock instruments are dilutive. The control number used is loss from continuing operations or income from discontinued operations. The control number concept requires that the same number of potentially dilutive securities applied in computing diluted earnings per share from continuing operations be applied to all other categories of income or loss, regardless of their anti-dilutive effect on such categories.

Common stock equivalents include warrants, stock options and unvested RSUs.

The following table presents the computation of basic and diluted net loss per share (in thousands, except share and per share amounts):

The following table represents all potentially dilutive shares:

We use the treasury stock method when determining dilutive shares. For the year ended December 31, 2025 and 2024, the Company was in a net loss position, therefore the share number used to calculate diluted earnings per share is the same as the basic earnings per share.

Note 10. Equity

2023 Equity Offerings and Common Warrants

As of December 31, 2025, there were 1 outstanding warrant issued in August 2023 with an exercise price $363,369.30 and an aggregate of 2 outstanding warrants issued in November 2023 with an exercise price of $136,555.20 per share (collectively, the “2023 Warrants”). If such warrants are exercised, we will receive up to an additional $0.6 million in gross proceeds.

2024 Equity Offerings and Common Warrants

On April 15, 2024, we completed a public offering of common stock and warrants, in which we received gross proceeds of $4.6 million, less total issuance costs of $0.6 million, which included 255 shares of common stock (or pre-funded warrants in lieu thereof, all of which have been exercised as of December 31, 2025) and accompanying common warrants to purchase up to 510 shares of common stock at an exercise price of $17,982.00 per share for a combined offering price of $17,982.00 per share and accompanying common warrants. The common warrants were exercisable immediately following the date of issuance and will expire in April 2029. As of December 31, 2025, we have 23 common warrants outstanding with an amended exercise price of $3,096.00 per share and 11 common warrants outstanding with an amended exercise price of $17,982.00 per share that were issued in connection with the April 2024 public offering (the April 2024 Warrants). The common warrants were exercisable immediately following the date of issuance and will expire in April 2029.

On July 1, 2024, we completed a registered direct offering (the July 2024 Registered Direct Offering) in which we issued 400 shares of common stock (or pre-funded warrants in lieu thereof, all of which have been exercised as of December 31, 2025) and accompanying common warrants to purchase up to 801 shares of common stock at an exercise price of $6,861.60 per share for a combined offering price of $6,861.60 per share and accompanying common warrants. The common warrants became exercisable immediately following the date of stockholder approval on August 6, 2024, and will expire in August 2029. We received approximately $2.7 million in gross proceeds less total issuance costs of $0.8 million. Issuance costs include placement agent fees and legal fees of $0.4 million and non-cash warrant modification costs of $0.4 million. The Company recognized the $0.4 million modification date incremental value of the modified warrants as compared to the original warrants as a non-cash issuance cost of the July 2024 Registered Direct Offering. As of December 31, 2025, we have 33 common warrants outstanding at an amended exercise price of $3,096.00 per share that were issued in connection with the July 2024 Registered Direct Offering (the July 2024 Warrants).

On December 12, 2024, we entered into a warrant inducement agreement (the December 2024 Inducement Agreement)with certain holders of our 2023 Warrants, April 2024 Warrants, July 2024 Warrants and warrants issued on September 18, 2024 (together, the "Existing Warrants") to exercise for cash 2,287 Existing Warrants at a reduced exercise price of $2,700.00 per share(such transaction, the “December 2024 Warrant Inducement”). Additionally, pursuant to the December 2024 Inducement Agreement, we issued 4,575 common warrants (the December 2024 Warrants, and, together with the remaining April 2024 Warrants and July 2024 Warrants, the 2024 Warrants) with an exercise price of $3,430.80 per share which are exercisable immediately following the date of issuance and will expire in December 2029. We received $6.2 million in gross proceeds from the exercise of these warrants less total issuance costs of $0.6 million, which includes placement agent fees and legal fees. The common warrants issued in connection with the December 2024 Warrant Inducement were equity classified as they are indexed to the Company's stock and do not contain any exercise contingency. The fair value of Existing Warrants immediately before and after the December 2024 Warrant Inducement were $3.5 million and $3.6 million, respectively. The fair value of the December 2024 Warrants was $7.3 million. Given the common warrants were equity classified, the modified fair value of Existing Warrants and the December 2024 Warrants to purchase common stock has been accounted for in additional paid-in capital as an equity cost because the modification was done in order to raise equity by inducing the exercise of warrants. As of December 31, 2025, there were 4,578 December 2024 Warrants outstanding with an amended exercise price of $428.40 per share.

2025 Equity Offerings and Common Warrants

On April 4, 2025, we completed a registered direct offering and a concurrent private placement (the April 4, 2025 Offering), in which we issued 4,901 shares of common stock and accompanying common warrants to purchase up to an aggregate of 9,803 shares of common stock at an exercise price of $428.40 per share for a combined offering price of $428.40 per share and accompanying common warrants. The common warrants became immediately exercisable following the date of stockholder approval on May 14, 2025 and will expire in May 2030. We received $2.1 million in gross proceeds less total issuance costs of $0.2 million. In connection with the April 4, 2025 Offering, we also agreed to amend certain existing warrants that were previously issued on December 12, 2024 to purchase up to 4,575 shares of common stock and had an exercise price of $3,430.80 per share, and reduced the exercise price of these warrants to $428.40 per share. The Company recognized the $0.6 million modification date incremental value of the modified warrants as compared to the original warrants as a non-cash issuance cost of the April 4, 2025 Offering. Given the common warrants were equity classified, the modified fair value of existing common warrants to purchase common stock has been accounted for in additional paid-in capital as an equity cost because the modification was done in order to raise equity in conjunction with the April 4, 2025 Offering. As of December 31, 2025, we have 9,812 common warrants outstanding in connection with the April 4, 2025 Offering.

On April 22, 2025, we completed a registered direct offering (the April 22, 2025 Offering and together with the April 4, 2025 Offering, the April 2025 Offerings), in which we issued 6,455 shares of common stock at a purchase price of $310.32 per share. We received $2.0 million in gross proceeds less total issuance costs of $0.2 million. We did not issue any common warrants in connection with the April 22, 2025 Offering.

On June 20, 2025, we completed an offering priced at-the-market (the June 2025 Offering) with certain institutional investors, in which we received gross proceeds $8.0 million, which included 136,944 shares of common stock (or pre-funded warrants in lieu thereof, all of which have been exercised as of June 30, 2025) and accompanying common warrants to purchase up to 684,722 shares of common stock at an exercise price of $58.50 per share for a combined purchase price of $58.50 per share and accompanying common warrants. The common warrants became immediately exercisable following the date of stockholder approval on July 24, 2025 and will expire in July 2030. We received $8.0 million in gross proceeds less total issuance costs of $0.7 million. During the fourth quarter of 2025,22,223 shares common warrants were exercised. As of December 31, 2025, we have 662,508 common warrants outstanding in connection with the June 2025 Offering.

The exercise price of the June 2025 warrants was reset to $11.70 per share during the subsequent events period as a result of issuing shares of common stock pursuant to our First SEPA. The exercise price of $11.70 represents the floor price of these warrants. If the warrants issued in connection with the 2025 offerings are exercised at their current exercise price, we will receive up to an additional $12.0 million in proceeds.

The following is a summary of common warrant activity for the year ended December 31, 2025:

The warrants are classified as an equity instrument because they are both indexed to the Company's own stock and classified in stockholders' equity, are recorded at fair value on the date of issuance and have no exercise contingency. For the years ended December 31, 2025, and 2024, thevaluation assumptions for warrants issued were estimated on the measurement date using the Black-Scholes option-pricing model with the following weighted-average assumptions:

Additionally, the common warrants issued in our June 2025 Offering include a down-round feature. On September 16, 2025, in connection with the sales of common warrants and common stock, the exercise price of the common warrants issued in connection with the June 2025 Offering was lowered to $25.10 per share. Upon the trigger of the down round provision of these common warrants, on September 16, 2025, the Company recorded a deemed dividend of $1.5 million which represents the fair value transferred to the warrant holders from the down round feature being triggered. On December 17, 2025, the down-round feature was triggered again, the common warrants issued in connection with the June 2025 Offering was lowered to $19.01 per share. The Company calculated the difference between the common warrants' fair value on September 16, 2025 and December 17, 2025, the dates the down round feature were triggered, using the current exercise prices and the newly established prices after the trigger events occurred. The deemed dividend increased net loss attributable to common equity by $1.6 million in the condensed consolidated statement of operations for the year ended December 31, 2025. The fair value of the common warrants prior to and immediately after the exercise price adjustment, were estimated using the Black-Scholes option-pricing model with the following assumptions:

Standby Equity Purchase Agreement

June 2025 SEPA

On June 16, 2025, we entered into a Standby Equity Purchase Agreement with Yorkville. Pursuant to the First SEPA, the Company has the right, but not the obligation, to issue and sell to Yorkville from time to time up to $25.0 million of the Company’s common stock during the 36 months following the execution of the First SEPA, subject to market conditions, restrictions, and satisfaction of the conditions in the First SEPA. As consideration for Yorkville’s irrevocable commitment to purchase the shares of common stock up to the First Commitment Amount, the Company paid a structuring fee in the amount of $25,000 to Yorkville, and the Company has agreed to pay a commitment fee to Yorkville in an amount equal to 2.00% of the First Commitment Amount in five equal installments. We accounted for the structuring and the commitment fee as deferred issuance cost. As of December 31, 2025, the remaining availability under the First SEPA is $8.7 million. On July 24, 2025, we received shareholder approval for the potential issuance of 19.99% or more of the aggregate number of shares of outstanding common stock pursuant to our First SEPA.

January 2026 SEPA

On January 8, 2026, we entered into the Second SEPA, the Company has the right, but not the obligation, to issue and sell to Yorkville from time to time up to $60.0 million of our common stock during the 36 months following the execution of the Second SEPA, subject to the restrictions and satisfaction of the conditions in the Second SEPA. The Company paid a structuring fee in the amount of $25,000 to Yorkville, and the Company has agreed to pay a commitment fee to Yorkville in an amount equal to 2.00% of the Second Commitment Amount in five equal installments. Pursuant to the Second SEPA, we will not sell shares of our common stock to Yorkville that would result in the beneficial ownership of Yorkville and its affiliates (on an aggregated basis) exceeding 9.99%of our then outstanding common stock. On February 18, 2026, we received shareholder approval for the potential issuance of 19.99% or more of the aggregate number of shares of outstanding common stock pursuant to our Second SEPA.

At The Market Offering Agreement

On April 28, 2025, we entered into an At The Market Offering Agreement with Roth for an aggregate offering price of $50.0 million, pursuant to which we may offer and sell shares of our common stock from time to time through Roth. The compensation to Roth for the shares sold pursuant to the ATM Agreement will be an amount equal to 3.0% of the gross sales price of the shares sold under the ATM Agreement. The sale of such shares of common stock by Roth will be effected under the Company’s existing shelf Registration Statement on Form S-3, which was declared effective on February 26, 2025 (the Registration Statement). On June 20, 2025, we filed the latest amendment to the prospectus supplement to our Registration Statement on Form S-3 filed on February 14, 2025 pursuant to General Instruction I.B.6 of Form S-3 (General Instruction I.B.6), which updates the amount of shares that we are eligible to sell under the ATM Agreement to an aggregate of $8.0 million. There is currentlyno remaining availability under the ATM Agreement due to limitations of General Instruction I.B.6.

Rights Plan

On November 8, 2020, our Board of Directors (the Board) approved and adopted a Rights Agreement (the Rights Agreement), dated as of November 8, 2020, by and between the Company and Broadridge Corporate Issuer Solutions, Inc., as rights agent, pursuant to which the Board declared a dividend ofone preferred share purchase right (each, a "Right") for each outstanding share of the Company’s common stock held by stockholders as of the close of business on November 23, 2020. One Right also will be issued together with each Common Share issued by the Company after November 23, 2020, but before the Distribution Date (as defined below) (or the earlier redemption or expiration of the Rights) and, in certain circumstances, after the Distribution Date. When exercisable, each Right initially would represent the right to purchase from the Company one one-thousandth of a share of a newly-designated series of preferred stock, Series A Junior Participating Preferred Stock, par value $0.001 per share, of the Company. Subject to various exceptions, the Rights become exercisable in the event any person (excluding certain exempted or grandfathered persons) becomes the beneficial owner of ten percent (10%) or more of the Company’s common stock without the approval of the Board. On October 30, 2025, we entered into Amendment No. 5 to the Rights Agreement and extended the expiration of such agreement to October 29, 2026. We have evaluated the rights agreement and determined that it does not represent a derivative or a liability.

2018 Stock Incentive Plan

On June 7, 2024, at the 2024 annual meeting of the stockholders, our stockholders approved the Second Amended and Restated 2018 SIP (the Second Amended 2018 SIP) to increase the number of shares authorized for issuance under the Second Amended 2018 SIP by 12 shares of common stock (adjusted for 1-for-37 reverse stock split effective December 3, 2024, 1-for-20 reverse stock split effective May 23, 2025, and 1-for-18 reverse stock split effective December 29, 2025). As of December 31, 2024, there were 7 shares available to be granted under the Second Amended 2018 SIP.

On July 24, 2025, at the 2025 annual meeting of the stockholders, our stockholders approved the Third Amended and Restated 2018 SIP (the Third Amended 2018 SIP) to increase the number of shares authorized for issuance under the Amended 2018 SIP by 13,888 shares of common stock (adjusted for 1-for-18 reverse stock split effective as of December 29, 2025). As of December 31, 2025, there are 7,353 shares available to be granted under the Third Amended 2018 SIP.

Stock options and RSUs under the Third Amended and Restated 2018 SIP generally vest pro rata over aone-year or three-year period. Stock options terminateten years from the grant date, though the specific terms of each grant are determined individually. The Company’s executive officers, members of our board of directors, and certain other employees and consultants may be awarded options and/or RSUs with different vesting criteria, and awards granted to non-employee directors will vest over aone-year period. Option exercise and RSU grant prices for new awards granted by the Company equal the closing price of the Company’s common stock on the Nasdaq Capital Market on the date of grant.

Stock-Based Compensation Expense

Stock-based compensation expense includes amortization of stock options and RSUs granted to employees and non-employees and has been reported in our consolidated statements of operations as follows:

The Company accounts for stock-based compensation by measuring the cost of employee services received in exchange for all equity awards granted based on the fair value of the award as of the grant date. The Company recognizes the compensation expense over the vesting period. All assumptions used to calculate the grant date fair value of non-employee equity awards are generally consistent with the assumptions used for equity awards granted to employees. In the event the Company terminates any of its consulting agreements, the unvested equity underlying the agreements would also be forfeited.

Stock Options

As of December 31, 2025, we had $0 unrecognized compensation expense. The Company didnot issue options and hadno outstanding options during the year ended December 31, 2025. The total fair value of stock options vested for the year ended December 31, 2024 was $1.0 million.

Restricted Stock Units

The following is a summary of restricted stock activity for the year ended December 31, 2025:

As of December 31, 2025, we had $0.2 million of unrecognized stock-based compensation expense related to RSUs expected to vest over a weighted-average period of 0.6 years. As of December 31, 2024, we had $0.2 million of unrecognized stock-based compensation expense related to RSUs expected to vest over a weighted-average period of 1.2 years.

The fair value of each RSU has been determined to be the closing trading price of the Company’s common stock on the date of grant as quoted on the Nasdaq Capital Market.

Note 11. 401(k) Savings Plan

Aptevo has established a defined contribution savings plan under Section 401(k) of the Internal Revenue Code, as amended. The 401(k) Plan covers all employees. Under the 401(k) Plan, employees may make elective salary deferrals. Aptevo currently provides for matching of qualified deferrals up to 50% of 401(k) employee deferral contributions, based on a maximum employee deferral rate of 6% of compensation. During the years ended December 31, 2025 and 2024, Aptevo’s related share of matching contributions was approximately $0.2 million.

Note 12. Income Taxes

We didnot have an income tax benefit or income tax expense from continuing operations in the years ended December 31,2025 and 2024.

The components of loss before income taxes were as follows (in thousands):

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are presented below:

The Company evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. Based on the Company’s history of operating losses, including a three-year cumulative loss position as of December 31, 2025, the Company has concluded that it is more likely than not that the benefit of its deferred tax assets will not be realized. Accordingly, the Company provided a full valuation allowance for its net deferred tax assets as of December 31, 2025 and 2024. The valuation allowance increased by $5.1 million during the year ended December 31, 2025. The increase in the valuation allowance during the year ended December 31, 2025 was due primarily to an increase in deferred tax assets resulting from operating losses and tax credits generated in the current year. This is partially offset by a decrease in unamortized Section 174 capitalization from prior years without additional capitalization in the current year as the Company elects to fully expense current year R&D expenditures under Section 174A.

As of December 31, 2025 and 2024, we have recorded gross federal net operating losses (NOL) carryforwards of approximately $207.9 million and $173.9 million, respectively, gross state NOL carryforwards of approximately

$70.8 million and $70.8 million, respectively, and tax credit carryforwards of $0.8 million and $0 million, respectively. Approximately $2.0 million of federal losses and credits would begin to expire in 2037, while $205.9 million of federal losses may be carried forward indefinitely. The state net operating losses will begin to expire in varying periods.

The Company is in the process of completing an IRC Section 382/383 study through December 31, 2025 on its federal and state tax attributes. Based on the study, potential historical ownership changes have been identified, including a potential ownership change in June 2025. As a result of the potential June 2025 ownership change, there may be an additional permanent limitation on our ability to use approximately $0.8 million tax credits solely due to the IRC 382/383 limitations, assuming sufficient future taxable income. We may experience ownership changes in the future as a result of subsequent shifts in our stock ownership, some of which may be outside of our control. If an ownership change occurs in the future, our ability to use our net operating loss carryforwards and credits could be further limited.

The Company files income tax returns in the U.S. and several state jurisdictions and are open to review by taxing authorities for the 2020 tax filings and thereafter.

We are subject to the accounting guidance for uncertain income tax positions. We believe that our income tax positions and deductions will be sustained on audit and do not anticipate any adjustments that will result in a material adverse effect on our financial condition, results of operations, or cash flow. Our policy for recording interest and penalties associated with audits and uncertain tax positions is to record such items as a component of income tax expense, and amounts recognized to date are insignificant. No uncertain income tax positions are recorded, and we do not expect our uncertain tax position to change during the next twelve months.

We adopted ASU 2023-09 on a prospective basis beginning with the year ended December 31, 2025. The following table presents required disclosure pursuant to ASU 2023-09 and reconciles the U.S. federal statutory tax amount and rate to our actual effective amount and rate for the year ended December 31, 2025:

The following table presents the required disclosures prior to our adoption of ASU 2023-09 and reconciles the U.S. federal statutory income tax rate to the effective income tax rate for the year ended December 31, 2024:

The amount of cash income taxes paid by the Company during the years ended December 31, 2025 and December 31, 2024 was $0.

Note 13. Segment Information

Operating segments are identified as components of an entity about which separate discrete financial information is available for evaluation by the chief operating decision maker (CODM), or decision-making group, in making decisions on how to allocate resources and assess performance. The Company's CODM, the Chief Executive Officer, views the Company's operations asone operating segment, which is discovery and development of novel oncology therapeutics. The discovery and development of novel oncology therapeutics segment develops novel immunotherapy candidates for the treatment of different forms of cancer. Our clinical and preclinical candidates were developed using two versatile and enabling platform technologies, ADAPTIR and ADAPTIR-FLEX. The Company does not have revenue in the current comparative period, incurs expenses primarily in North America and manages the business activities on a consolidated basis.

The accounting policies of the novel oncology therapeutics segment are the same as those described in the summary of significant accounting policies.

The CODM assesses performance for the novel oncology therapeutics segment and decides how to allocate resources based on net loss that also is reported on the income statement as consolidated net loss. The measure of segment assets is reported on the balance sheet as cash and cash equivalents.

The Company has not generated any product revenue in the current period and expects to continue to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates through all stages of development and clinical trials.

As such, the CODM uses cash forecast models in deciding how to invest into the novel oncology therapeutics segment. Such cash forecast models are reviewed to assess the entity-wide operating results and performance. Net loss is used to monitor budget versus actual results. Monitoring budgeted versus actual results, net cash used in operating activities for the period and cash on hand are used in assessing performance of the segment.

The table below summarizes the significant expense categories regularly reviewed by the CODM for the years ended December 31, 2025, and 2024.

(a) Other segment items included in segment loss includes interest income, interest expense, rental income and FOREX gain/loss.

(b) The Company is a single operating segment and therefore the measure of segment net loss is the same as consolidated net loss and does not require reconciliation.

For the year ended December 31, 2025, and 2024, the net cash used in operating activities was $25.6 million and $23.8 million, respectively. The table below summarizes the significant asset categories regularly reviewed by the CODM for the years ended December 31, 2025, and 2024.

Note 14. Subsequent Events

On January 8, 2026, we entered into the Second SEPA with Yorkville. Pursuant to the Second SEPA, the Company has the right, but not the obligation, to issue and sell to Yorkville from time to time up to $60.0 million of the Company’s common stock during the 36 months following the execution of the Second SEPA, subject to market conditions, restrictions, and satisfaction of the conditions in the Second SEPA. As consideration for Yorkville’s irrevocable commitment to purchase the shares of common stock up to the Second Commitment Amount, the Company paid a structuring fee in the amount of $25,000 to Yorkville, and the Company has agreed to pay a commitment fee to Yorkville in an amount equal to 2.00% of the Second Commitment Amount in five equal installments. We accounted for the structuring and the commitment fee as deferred issuance cost. We filed Form S-1 for 7.1 million shares under the Second SEPA on January 28, 2026.

We sold 0.09 million shares under the First SEPA at an average price of $6.56 per share and raised $0.6 million in net proceeds, and sold 0.1 million shares under the Second SEPA at an average price of $5.85 per share and raised $0.6 million net proceeds. The down-round feature was triggered and further lowered the exercise price of the June 2025 warrantsto $11.70, which represents the floor price of the June 2025 warrants.