Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following Management’s Discussion and Analysis of Financial Condition and Results of Operations (MD&A) together with the consolidated financial statements and the related notes thereto included in this Annual Report on Form 10-K. MD&A contains forward-looking statements that are subject to risks and uncertainties, such as those set forth in the sections of this Annual Report on Form 10-K captioned “Cautionary Note Regarding Forward-Looking Statements,” “Risk Factors” and elsewhere. As a result, our actual results may differ materially from those anticipated in these forward-looking statements.

Overview

We are a clinical-stage, research and development biotechnology company focused on developing novel immunotherapy candidates for the treatment of different forms of cancer. We have developed two 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 currently being clinically evaluated in the RAINIER trail, part one of a Phase 1b/2 program initiated in August 2024 for the treatment of frontline acute myelogenous leukemia (AML) in combination with standard of care venetoclax + azacitidine. 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 is currently being evaluated for the treatment of multiple solid tumor types.

Along with our clinical candidates, the preclinical candidates, APVO603 and APVO711, were also developed using our ADAPTIR® protein technology platform. Our preclinical candidates APVO442, APVO455, APVO451 and APVO452 were developed using our ADAPTIR-FLEX® protein technology platform. We wholly own both platforms which enable us to efficiently design and create new molecules, supporting our pipeline growth. Based on the safety and tolerability results from mipletamig, which utilizes a unique CRIS-7 binding domain, the Company has built out its CD3 engaging portfolio to five molecules.

Our ADAPTIR and ADAPTIR-FLEX platforms are designed to generate monospecific and multi-specific antibody candidates capable of enhancing the human immune system against cancer cells. Both are modular platforms, which gives us the flexibility to potentially generate immunotherapeutic candidates with a variety of mechanisms of action. This flexibility in design allows us to generate novel therapeutic candidates that may provide effective strategies against difficult to treat, as well as advanced forms of cancer. We have successfully designed and constructed numerous clinical-stage product candidates based on our ADAPTIR platform, which is designed to generate monospecific and bispecific immunotherapeutic proteins that specifically bind to one or more targets. This allows for the development of therapeutic molecules which may have structural and functional advantages over monoclonal antibodies. We have also developed a preclinical candidate based on the ADAPTIR-FLEX platform which is advancing in our pipeline. The structural differences of ADAPTIR and ADAPTIR FLEX molecules over monoclonal antibodies allow for the development of immunotherapies that are designed to engage immune effector cells and disease targets to produce signaling responses that modulate the immune system to kill tumor cells. We believe we are skilled at candidate generation, validation, and subsequent preclinical and clinical development.

Recent Developments

•

Mipletamig Clinical Performance: Mipletaming in triplet combination therapy continues to outperform standard of care ven/aza1 in unfit frontline patients with acute myeloid leukemia (AML). This further validates a differentiated safety profile, including no cytokine release syndrome in frontline patients; suggesting it is additive to the current standard of care.

•

Expanded CD3 portfolio: the addition of three new multispecific candidates, leveraging the Company’s proprietary application of its differentiated CRIS7-derived CD3 binding domain, including the introduction of its first two trispecific assets:

These additions emphasize the breadth and modularity of the ADAPTIR and ADAPTIR-FLEX platforms and position the Company to address a wider range of tumor targets and combination strategies across immune-oncology.

•

Strengthened Financial Capacity: In 2026, the Company established a $60 million equity line facility, providing additional access to capital, subject to market conditions and the Company’s capital deployment strategy. If fully utilized, this facility, together with current resources, is expected to support operations into 2029.

Results of Operations

Year Ended December 31, 2025 Compared to Year Ended December 31, 2024

For the year ended December 31, 2025, we had net loss of $26.0 million compared to $24.1 million net loss for the same period in 2024. As of December 31, 2025, we had $21.6 million in cash and cash equivalents.

Research and Development Expenses

We expense research and development costs as incurred. These expenses relate primarily to conducting non-clinical studies and clinical trials, fees to professional service providers for analytical testing, independent monitoring or other administration of our clinical trials and obtaining and evaluating data from our clinical trials and non-clinical studies. Our research and development expenses include:

•

employee salaries and related expenses, including stock-based compensation and benefits for our employees involved in our drug discovery and development activities;

•

consulting costs related to our clinical and preclinical programs;

•

external research and development expense incurred under agreements with third-party contract research organizations (CROs) and investigative sites;

•

50% shared costs incurred under the Collaboration Agreement with Alligator Bioscience;

•

manufacturing services and material expense for third-party manufacturing; and

•

overhead costs such as rent, utilities and depreciation.

We expect our research and development spending will be dependent upon such factors as the results from our clinical trials, the availability of reimbursement of research and development spending, the number of product candidates under development, the size, structure and duration of any clinical programs that we may initiate, and the costs associated with manufacturing our product candidates on a large-scale basis for later stage clinical trials. We may experience interruption of key clinical trial activities, such as site initiation, patient enrollment and clinical trial site monitoring, and key non-clinical activities due to a variety of risk factors, including macroeconomic conditions. While a number of our programs are still in the preclinical trial phase, we do not provide a breakdown of the initial associated expenses as we are often evaluating multiple product candidates simultaneously. Costs are reported in preclinical research and discovery until the program enters the clinic.

Our research and development expenses by program for the years ended December 31, 2025 and 2024 are shown in the following table:

For the Year Ended December 31,

Clinical programs:

Preclinical program, general research and discovery $ 7,484 $ 7,931

Research and development expenses was $14.5 million and $14.4 million for the years ended December 31, 2025 and 2024, respectively. The increase was primarily due to increased mipletamig and employee costs and was offset by lower costs on ALG.APV- 527 as we concluded the dose escalation trial.

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, information technology, legal and human resource functions. Other costs include facility costs not otherwise included in research and development expenses.

For the year ended December 31, 2025, general and administrative expenses increased by $1.6 million, to $11.8 million from $10.2 million for the year ended December 31, 2024. The increase was primarily due to higher employee, consulting, and legal costs.

Other Income, Net

Other income, net was $0.3 million for the year ended December 31, 2025 and other income, net was $0.5 million for the year ended December 31, 2024. The change in other income, net was primarily due to lower interest and rental income.

Liquidity and Capital Resources

Cash Flows

The following table provides information regarding our cash flows for years ended December 31, 2025 and 2024:

For the Year Ended December 31,

Net cash provided by (used in):

Investing activities — —

Net increase (decrease) in cash and cash equivalents $ 12,905 $ (8,190 )

Net cash used in operating activities for the year ended December 31, 2025, was primarily due to our net operating loss of $26.0 million and changes in our working capital accounts. Net cash used in operating activities for the year ended December 31, 2024, was primarily due to our net operating loss of $24.1 million and changes in our working capital accounts.

Net cash provided by financing activities for the year ended December 31, 2025 was primarily due to the $37.9 million net proceeds received from the issuance of common stock and $0.6 million net proceeds from the exercise of common warrants. Net cash provided by financing activities for the year ended December 31, 2024 was primarily due to the $8.9 million net proceeds received from the issuance of common stock and $6.7 million net proceeds received from the exercise of common warrants.

Sources of Liquidity

Standby Equity Purchase Agreement

On June 16, 2025, we entered into the First SEPA 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 (the First Commitment Amount) of the Company’s common stock during the 36 months following the execution of the First SEPA, subject to the 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. Pursuant to the First 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. For the year ended December 31, 2025, the Company issued 0.5 million shares of common stock to Yorkville under the First SEPA for aggregate gross proceeds of $16.3 million. As of December 31, 2025, the remaining availability under the First SEPA is $8.7 million. We filed Form S-1 for 6.9 million shares under the SEPA on October 1, 2025. A subsequent Form S-1 may be needed to access additional shares under First SEPA.

On January 8, 2026, we entered into the Second SEPA with Yorkville, pursuant to which the Company has the right, but not the obligation, to issue and sell to Yorkville from time to time up to $60.0 million (the Second Commitment Amount) 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. The Company has the option to pay the fourth and fifth installments in either cash or shares of common stock. 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. We filed Form S-1 for 7.1 million shares under the Second SEPA agreement on January 28, 2026, which represents approximately $32.6 million based on the closing price as of March 23, 2026.

At The Market Offering Agreement

On April 28, 2025, we entered the ATM Agreement with Roth , pursuant to which the Company may offer and sell up to $50 million of its 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). For the year ended December 31, 2025, we issued 0.3 million shares of our common stock at an average price of $38.92 per share under the ATM Agreement. We received $11.8 million, less issuance costs of $0.35 million, in proceeds from the issuance of these shares. There is currently no remaining availability under the ATM Agreement due to the limitations of General Instruction I.B.6.

Registration Statement

On February 14, 2025, we filed a Registration Statement on Form S-3 covering the offering, issuance, and sale up to $100 million in common stock, preferred stock, and various series of debt securities and/or warrants to purchase any of such securities, which included the unsold securities from the prior registration statement. On June 20, 2025, we filed the latest amendment to the prospectus supplement to the 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 $8.0 million. So long as the aggregate market value of our common stock held by non-affiliates is less than $75 million, we will not sell shares under the ATM Agreement with a value of more than one-third of the aggregate market value of our common stock held by non-affiliates in any 12-month period due to the limitations of General Instruction I.B.6 of Form S-3 and the current public float of our common stock. If our public float increases such that we may sell additional amounts under the ATM Agreement and the prospectus, we will file another amendment to the prospectus supplement prior to making additional sales. The limitations of General Instruction I.B.6 do not apply to sales of our shares under the First SEPA and the Second SEPA as the sales of such shares were registered under separate registration statements on Form S-1.

Common Warrants

We have an aggregate of 676,968 common warrants outstanding for which we may receive up to an additional $19.8 million in gross proceeds if exercised. The following is a summary of outstanding common warrants as of December 31, 2025:

Warrants Outstanding Exercise Price Proceeds if Exercised(in thousands)

IXINITY Milestone Payments

On February 28, 2020, Aptevo entered into the LLC Purchase Agreement with Medexus, pursuant to which we sold all of the issued and outstanding limited liability company interests of Aptevo BioTherapeutics LLC, a wholly owned subsidiary of Aptevo. On March 29, 2023, we entered into and closed a Purchase Agreement with XOMA pursuant to which we sold to XOMA our right, title, and interest to all future deferred payments from Medexus and a portion of potential milestones. As consideration, we received $9.6 million at closing from XOMA and an additional $0.05 million post-closing payment. Aptevo continues to be eligible to receive up to $5.8 million in milestone payments from Medexus upon achievement of certain regulatory and IXINITY net sales threshold.

Liquidity

We have financed our operations to date primarily through royalty and purchase agreements with various partners, sale of business products and segments, public offerings of our common stock, loan proceeds, milestone payments, research and development funding from strategic partners, revenue generated from our previously owned commercial products, and funds received at the date of our spin-off from Emergent. We had cash and cash equivalents of $21.6 million and 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. For the year ended December 31, 2025, we received $38.5 million in proceeds through various equity offerings.

Our future success is dependent on our ability to develop our product candidates and our ability to raise capital on acceptable terms. We anticipate that we will continue to incur significant operating losses for the next several years as we incur expenses to continue to execute on our development strategy to advance our preclinical and clinical stage assets. We will not generate revenues from our development stage product candidates unless and/or until we or our collaborators successfully complete development and obtain regulatory approval for such product candidates, which we expect will take a number of years and is subject to significant uncertainty. If we obtain regulatory approval for one of our development stage product candidates, we expect to incur significant commercialization expenses related to sales, marketing, manufacturing and distribution, to the extent that such costs are not paid by collaborators. We may not have sufficient cash to complete the clinical development of any of our development stage product candidates and may require additional funding in order to complete the development activities required for regulatory approval of such product candidates. We may require substantial additional funds to continue our development programs and to fulfill our planned operating goals.

We may experience delays in opportunities to partner our product candidates, due to financial and other impacts on potential partners. Additionally, we may experience potential impacts on our future milestones from Medexus due to effects of macroeconomic impacts, including, but not limited to, bank failure, and the rising and fluctuating inflation, which may impact Medexus’ ability to continue to successfully commercialize the IXINITY businesses.

There are numerous risks and uncertainties associated with research, development, and commercialization of pharmaceutical products. Accordingly, our future funding requirements may vary from our current expectations and will depend on many factors, including, but not limited to:

•

our ability to raise additional capital when needed or on acceptable terms;

•

future profitability given our historical losses;

•

our ability to maintain compliance with Nasdaq’s continued listing requirements;

•

our ability to attract, motivate and retain key personnel;

•

the timing of, and the costs involved in, completing our clinical trials, and obtaining regulatory approvals for our product candidates;

•

our ability to obtain regulatory clearance to commence clinical trials for product candidates;

•

our ability to establish and maintain strategic partnerships, licensing or other arrangements and the financial terms of such agreements;

•

the effects of macroeconomic conditions, including rising and fluctuating inflation and supply chain constraints as well as political events such as a U.S. federal government shutdown, evolving healthcare policies, and military actions;

•

our ability to successfully develop our ADAPTIR or ADAPTIR-FLEX platforms;

•

the results of our current and planned preclinical studies and clinical trials;

•

the scope, progress, results, and costs of researching and developing our product candidates, and of conducting preclinical and clinical trials, including whether clinical trial results will be consistent with the past data;

•

our reliance on third parties to effectively conduct our clinical and non-clinical trials, and to effectively carry out their contractual duties, comply with regulatory requirements or meet expected deadlines;

•

the costs involved in preparing, filing, prosecuting, maintaining, defending and enforcing patent claims, including litigation costs and the outcome of such litigation;

•

the cost of commercialization activities if any of our product candidates are approved for sale, including marketing, sales, and distribution costs; and

•

the timing, receipt and amount of any milestone payments from Medexus with respect to IXINITY; and

•

our ability to continue as a going concern.

If we are unable to raise substantial additional capital in the next year, whether on terms that are acceptable to us or at all, then we may be required to:

•

delay, limit, reduce or terminate our clinical trials or other development activities for one or more of our product candidates; and/or,

•

delay, limit, reduce or terminate our establishment of other activities that may be necessary to commercialize our product candidates, if approved.

The sale of additional equity or convertible debt securities may result in additional dilution to our stockholders. If we raise additional funds through the issuance of debt securities or preferred stock or through credit facilities, these securities and/or the loans under credit facilities could provide for rights senior to those of our common stock and could contain covenants that would restrict our operations. Our results of operations will be highly dependent on our research and development spending. 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. Additional funds may not be available when we need them, on terms that are acceptable to us, or at all. We also expect to seek additional funds through arrangements with collaborators, licensees or other third parties. These arrangements would generally require us to relinquish or encumber rights to some of our technologies or drug candidates, and we may not be able to enter into such arrangements on acceptable terms, if at all. Due to the macroeconomic factors, we may experience delays in clinical trials and non-clinical work, and opportunities to partner our product candidates, due to financial and other impacts on potential partners.

Contractual Obligations

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 of the amended lease through April 2030 and provided two options to extend the lease term, each by five years, as well as a one-time option to terminate the lease in April 2023, with nine months’ notice, or by July 2022. On May 26, 2022, we further amended our office and laboratory lease to remove the

one-time termination option in April 2023. In exchange for removing the termination option, we received six months of free rent. As a result, we recorded an additional $4.4 million of lease liability and right-of-use asset on the consolidated balance sheet in May 2022.

We have a non-exclusive Commercial Platform License Agreement with OMT (OMT License Agreement) for certain transgenic rodents of OMT's OmniAb platform. Our OMT License Agreement obligates us to make milestone and royalty payments upon achievement of certain regulatory approvals and commercialization of our product candidates. mipletamig and APVO603 are the product candidates currently subject to this agreement. Pursuant to our agreement, we are required to make a $2.0 million milestone payment upon dosing the first patient in our Phase 2 clinical trial of mipletamig.

Our principal commitments include obligations under vendor contracts to purchase research services and other purchase commitments with our vendors. In the normal course of business, we enter into services agreements with contract research organizations, contract manufacturing organizations and other third parties. Generally, these agreements provide for termination upon notice, with specified amounts due upon termination based on the timing of termination and the terms of the agreement. The actual amounts and timing of payments under these agreements are uncertain and contingent upon the initiation and completion of the services to be provided.

Critical Accounting Policies, and Significant Judgments, and Estimates

The preparation of our consolidated financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. We base our estimates on historical experience and on various other factors. Although we believe that our judgments and estimates are appropriate, actual results may differ materially from our estimates and changes in these estimates are recorded when known. An accounting policy is considered critical if it is important to a company’s financial condition and results of operations and if it requires the exercise of significant judgment and the use of estimates on the part of management in its application.

While our significant accounting policies are more fully described in Note 1 to our audited consolidated financial statements appearing elsewhere in this report, we believe the following accounting policies are the most critical to the judgments and estimates we use in the preparation of our consolidated financial statements.

Research and Development Expenses

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 our preclinical studies and all of our clinical studies have been performed by third-party contract research organizations (CRO). We review 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 enrolled patients visit at each site to date. Our estimates are highly dependent upon the timeliness and accuracy of the data provided by our CROs and data updated by our clinical sites in the electronic data center regarding the status of each program and total program spending and adjustments are made when deemed necessary.

Stock-Based Compensation

Under ASC 718, Compensation—Stock-based Compensation, we measure and recognize compensation expense for restricted stock units (RSUs), and stock options granted to our employees and directors based as of the fair value of the awards on 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:

•

the expected term of the stock option award, which we calculate using the simplified method, as permitted by the SEC Staff Accounting Bulletin No. 110, Share-Based Payment, as we have insufficient historical information regarding our stock options to provide a basis for an estimate;

•

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

•

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;

•

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

•

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

Stock-based compensation expense for RSUs, and stock options is recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the respective award. We are required to estimate a forfeiture rate to calculate the stock-based compensation expense for our awards. Our forfeiture rate is based on an analysis of our actual forfeitures since the adoption of our equity award plan. 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.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We are a smaller reporting company as defined by Rule 12b-2 of the Exchange Act, and are not required to provide the information required under this item.

Table of Contents

Index to Consolidated Financial Statements

Item 8. Financial Statements and Supplementary Data

APTEVO THERAPEUTICS INC.

Financial Statements

Consolidated Balance Sheets 76

Consolidated Statements of Operations 77

Consolidated Statements of Cash Flows 78

Consolidated Statements of Changes in Stockholders’ Equity 79

Notes to Consolidated Financial Statements 80

Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of

Aptevo Therapeutics Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Aptevo Therapeutics Inc. (the “Company”) as of December 31, 2025 and 2024, the related consolidated statements of operations, cash flows, and changes in stockholders’ equity for the years then ended, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the consolidated financial position of the Company as of December 31, 2025 and 2024, and the consolidated results of its operations and its cash flows for the years then ended, in conformity with accounting principles generally accepted in the United States of America.

Going Concern Uncertainty

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As discussed in Note 1 to the consolidated financial statements, the Company has suffered recurring losses from operations and has a net capital deficiency that raise substantial doubt about its ability to continue as a going concern. Management’s plans in regard to these matters are also described in Note 1. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures to respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matters

Critical audit matters are matters arising from the current period audit of the consolidated financial statements that were communicated or required to be communicated to the audit committee and that: (1) relate to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. We determined that there are no critical audit matters.

/s/ Baker Tilly US, LLP

Seattle, Washington

March 26, 2026

We have served as the Company’s auditor since 2020.

Aptevo Therapeutics Inc.

CONSOLIDATED BALANCE SHEETS

(in thousands, except share and per share amounts)

ASSETS

Current assets:

Prepaid expenses and other current assets 1,462 1,945

Property and equipment, net 303 543

Operating lease right-of-use asset 3,810 4,389

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:

Accrued expenses and other current liabilities 4,307 4,197

Operating lease liability, current portion 866 768

Operating lease liability, net of current portion 3,763 4,629

Stockholders' equity:

Total liabilities and stockholders' equity $ 27,194 $ 15,591

The accompanying notes are an integral part of these consolidated financial statements.

Aptevo Therapeutics Inc.

CONSOLIDATED STATEMENTS OF OPERATIONS

(in thousands, except share and per share amounts)

For the Year Ended December 31,

Operating expenses:

Other income:

Dividend attributable to down round feature of warrants (1,571 ) —

Net loss attributable to common stockholders $ (27,538 ) $ (24,130 )

Basic and diluted net loss per share: $ (87.27 ) $ (31,460.23 )

The accompanying notes are an integral part of these consolidated financial statements.

Aptevo Therapeutics Inc.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(in thousands)

For the Year Ended December 31,

Operating Activities

Adjustments to reconcile net loss to net cash used in operating activities:

Stock-based compensation 96 1,069

Depreciation and amortization 240 352

Changes in operating assets and liabilities:

Prepaid expenses and other current assets 483 217

Operating lease liability (1,376 ) (1,376 )

Net cash used in operating activities (25,592 ) (23,785 )

Investing Activities

Net cash from investing activities — —

Financing Activities

Value of equity awards withheld for tax liability — (1 )

Proceeds from exercise of common warrants, net of issuance costs 557 5,563

Payments in lieu of fractional shares — (3 )

Net cash provided by financing activities 38,497 15,595

Increase (decrease) in cash and cash equivalents 12,905 (8,190 )

Cash and cash equivalents at beginning of period 8,714 16,904

Cash and cash equivalents at end of period $ 21,619 $ 8,714

Supplemental Cash Flow Information

Warrant modification - incremental value $ 586 $ 472

Dividend attributable to down round feature of warrants 1,571 —

Fair value of December 2024 inducement transaction common warrants $ — $ 7,331

The accompanying notes are an integral part of these consolidated financial statements.

Aptevo Therapeutics Inc.

CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS’ EQUITY

(in thousands, except share amounts)

Additional Total

Common Stock Paid-In Accumulated Stockholders'

Shares Amount Capital Deficit Equity

Payment in lieu of fractional shares (1) — — (3 ) — (3 )

Warrant inducement, net of issuance cost 1 5,562 5,563

Warrant modification - incremental fair value 2,287 — 472 — 472

Stock-based compensation — — 1,069 — 1,069

Payment in lieu of fractional shares (1) (39 ) — — — —

Stock-based compensation — — 96 — 96

Dividend attributable to down round feature of warrants — — 1,571 (1,571 ) —

(1) Payments were made in lieu of fractional shares in connection with the reverse stock splits occurred in 2024 and 2025.

(2) Includes gross proceeds of $11.5 million less issuance costs of $1.9 million, which includes $0.5 million warrant modification incremental fair value.

(3) Includes gross proceeds of $39.4 million less issuance costs of $0.9 million.

The accompanying notes are an integral part of these consolidated financial statements.

Aptevo Therapeutics Inc.

Notes to Consolidated Financial Statements

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 developed two 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:

Furniture and equipment 7-10 years

Software and hardware 3-5 years or product life

Leasehold improvements Lesser of the asset life or the remaining lease term

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

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 be zero 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

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 incertain 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 Development in 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 did not 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:

December 31, December 31,

Total cash and cash equivalents $ 21,619 $ 8,714

Note 5. Property and equipment, net

Property and equipment consist of the following:

December 31,

Total property and equipment, net $ 303 $ 543

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 provide two options to extend the lease term, each by five 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 that we 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 did not 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:

As of December 31, As of December 31,

Seattle office lease, including amendment $ 3,810 $ 4,389

Lease payments:

For the Year Ended December 31,

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

(in thousands)

Total Future minimum lease payments 5,963

Less: imputed interest (1,334 )

As of December 31, 2025, the long-term and current portion of the lease liabilities were $3.8 million and $0.9 million, respectively. As of December 31, 2024, the long-term and current 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.

December 31,

Prepaid clinical expenses $ 609 $ 925

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

December 31,

Accrued clinical, research and development costs $ 1,154 $ 1,461

Accrued compensation and benefits 2,421 1,856

Accrued professional service costs 480 517

Note 8. Reverse Stock Split

On May 14 and July 24, 2025, we held 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.

The specific 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):

For the Year Ended December 31,

Dividend attributable to down round feature of warrants (1,571 ) —

Net loss attributable to common stockholders $ (27,538 ) $ (24,130 )

Basic and diluted net loss per share $ (87.27 ) $ (31,460.23 )

The following table represents all potentially dilutive shares:

As of December 31,

Unvested RSUs 6,542 —

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:

Number ofShares Weighted-Average Exercise Price Weighted-AverageRemaining Term

Expired — — —

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, the valuation assumptions for warrants issued were estimated on the measurement date using the Black-Scholes option-pricing model with the following weighted-average assumptions:

For the Year Ended December 31,

Expected dividend yield 0.00% 0.00%

Risk-free interest rate 3.97% 4.98%

Expected average life 5 years 5 years

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:

Risk-free interest rate 3.62% 3.51%

Expected average life 4.83 4.58

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 currently no 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 of one 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 a one-year or three-year period. Stock options terminate ten 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 a one-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:

For the Year Ended December 31,

Research and development $ 23 $ 302

General and administrative 73 767

Total stock-based compensation expense $ 96 $ 1,069

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 did not issue options and had no 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:

Number ofUnits WeightedAverage FairValue per Unit

Vested — —

Forfeited — —

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 did not 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):

Year ended December 31,

International — —

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

For the Year Ended December 31,

Capitalized research expenditures 4,976 7,025

Stock-based compensation 12 839

Other deferred tax assets 486 304

Other tax credits 797 —

Deferred tax assets, net of valuation 800 922

Deferred tax liability (800 ) (922 )

Net deferred tax assets $ — $ —

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:

(in thousands) Amount Percentage

Federal tax at statutory rates $ (5,453 ) 21.0 %

State and local income taxes, net of federal income tax effect — 0.0 %

Foreign tax effects — 0.0 %

Effect of changes in tax lax laws or rates enacted in the current period — 0.0 %

Effects of cross-border tax laws — 0.0 %

Tax credits

Orphan Drug tax credits (1,248 ) 4.8 %

Changes in valuation allowances 5,126 -19.7 %

Nontaxable or nondeductible items

Share-based compensation 848 -3.3 %

Other adjustments 652 -2.5 %

Changes in unrecognized tax benefits — 0.0 %

Total income tax benefit $ — 0.0 %

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:

Year Ended December 31,

Federal tax at statutory rates 21.0 %

State taxes, net of federal benefit -0.1 %

Change in valuation allowance 16.8 %

Tax credits 3.0 %

Permanent differences -0.1 %

Stock based compensation -0.8 %

Change in tax attributes -40.0 %

Other 0.2 %

Total income tax benefit 0.0 %

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 as one 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.

For the Year Ended December 31,

Operating expenses

Other segment items (a) 345 472

(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.

December 31,

Assets

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 warrants to $11.70, which represents the floor price of the June 2025 warrants.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

None.

Item 9A. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

As of December 31, 2025, management, with the participation of our Chief Executive Officer and Chief Financial Officer, performed an evaluation of the effectiveness of our disclosure controls and procedures as defined in Rules 13a- 15(e) and 15d-15(e) of the Exchange Act. Based on this evaluation, our Chief Executive Officer and Chief Financial Officer concluded that, as of December 31, 2025, the design and operation of our disclosure controls and procedures were effective to provide reasonable assurance that information we are required to disclose in reports that we file or submit under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in the SEC’s rules and forms and to provide reasonable assurance that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

Management’s Report on Internal Control over Financial Reporting

Management is responsible for establishing and maintaining adequate internal control over financial reporting, as defined in Rule 13a-15(f) of the 1934 Act. Management has assessed the effectiveness of our internal control over financial reporting as of December 31, 2025 based on criteria established in Internal Control—Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission. As a result of this assessment, management concluded that, as of December 31, 2025, our internal control over financial reporting was effective in providing reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles.

Changes in Internal Control over Financial Reporting

There have been no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the quarter ended December 31, 2025, that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Limitations on Controls

Because of inherent limitations, disclosure controls and internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Item 9B. Other Information.

In the quarter ended December 31, 2025, none of our directors or executive officers adopted, terminated or materially modified a plan for the purchase or sale of our securities intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or a non-Rule 10b5-1 trading arrangement for the purchase or sale of our securities, within the meaning of Item 408 of Regulation S-K.

Item 9C. Disclosure Regarding Foreign Jurisdictions That Prevent Inspections.

Not Applicable.

PART III

Item 10. Directors, Executives Officers and Corporate Governance.

Names of Directors and Other Information

Aptevo’s Board is divided into three classes. Each class consists, as nearly as possible, of one-third of the total number of directors, and each class has a three-year term.

The Board presently has six members. Effective April 1,2026, Jeffrey G. Lamothe will join the Board, increasing the total number of Board members to seven. The following are brief biographies of each person serving as a member of our Board.

Name Age Principal Occupation

Marvin L. White 64 President and Chief Executive Officer of Aptevo

Grady Grant, III 70 EVP/Partner of Vanigent BioPharm

Barbara Lopez Kunz 68 Chief Executive Officer of Caidya

Marvin L. White has served as our President, Chief Executive Officer (CEO) and as a member of our Board since August 2016. Effective April 1, 2026, Mr. White will retire from his position as President and CEO and transition to Executive Chair and will remain a member of our Board. From 2010 to 2016, Mr. White served as a director of Emergent, and in 2020, he rejoined the Emergent Board of Directors. From 2008 to 2014, Mr. White served as the Chief Financial Officer of St. Vincent Health, and was responsible for finance, materials management, accounting, patient financial services and managed care for all 19 hospitals and 36 joint ventures. Prior to joining St. Vincent Health in 2008, Mr. White was the Chief Financial Officer of Lilly USA, LLC, a subsidiary of Eli Lilly and Company, where he also held leadership positions in treasury and corporate finance and investment banking in the Corporate Strategy Group. He serves on the Board of Directors of OneAmerica Financial Insurance Partners, Inc., a mutual insurance and financial services company based in Indianapolis, Indiana and Delta Dental of Washington, a non-profit company. Prior to taking the role of President and Chief Executive Officer of Aptevo, Mr. White served on the Board of Directors of Washington Prime Group, a New York Stock Exchange-listed real estate investment trust (REIT) that invests in shopping centers, and CoLucid Pharmaceuticals, Inc., a pharmaceutical company that was publicly-traded until its acquisition by Eli Lilly in 2017. Mr. White earned a bachelor of science degree from Wilberforce University in Accounting and his MBA degree in Finance from Indiana University. Mr. White’s tenure as Chief Executive Officer of Aptevo and his director experience at Emergent provides valuable management and leadership experience. In addition, Mr. White provides crucial insight to the Board on company strategic planning and operations. For these reasons, the Board believes Mr. White is qualified to serve on Aptevo’s Board.

Daniel J. Abdun-Nabi has served as a member of our Board since August 2016. Mr. Abdun-Nabi served as the President and Chief Executive Officer of Emergent from 2012 to 2019 and as a director of Emergent from 2009 to 2019. Prior to that, Mr. Abdun-Nabi served in other various leadership positions at Emergent, including President and Chief Operating Officer from 2007 to 2012, Corporate Secretary from 2004 to 2008, Senior Vice President, Corporate Affairs and General Counsel from 2004 to 2007, and Vice President and General Counsel from May 2004 to December 2004. Before joining Emergent, Mr. Abdun-Nabi was General Counsel for IGEN International, Inc., a biotechnology company, and its successor BioVeris Corporation, from 1999 to 2004, and Senior Vice President, Legal Affairs, General Counsel and Secretary of North American Vaccine, Inc., a publicly traded vaccine company acquired by Baxter International Inc. In 2000. Mr. Abdun-Nabi earned a bachelor degree in political science from the University of Massachusetts Amherst, a J.D. from the University of San Diego School of Law and an LLM from Georgetown

University Law Center. The Board believes that Mr. Abdun-Nabi is qualified to serve on Aptevo's Board because of his extensive experience and knowledge of the biotechnology industry and Aptevo products.

Grady Grant, III has served as a member of our Board since August 2016. Mr. Grant is currently serving as EVP/Partner of Vanigent BioPharm, and until April 2022, was Senior Vice President of Evolve Biosystems, a biotechnology company that specializes in providing microbiome-based products to maintain a healthy newborn gut microbiome. Previously, from 2020 to 2021, he was Interim Chief Commercial Officer for New Vision Pharmaceuticals LLC, a contract pharmaceutical development and manufacturing company specializing in blow-fill-seal packaging, from 2018 to 2020, he was the Vice President of Sales for Tissue Tech Limited, a regenerative medicine company, and from 2011 to 2018, he worked as Vice President of Medical Sales for Mead Johnson Nutrition Company, a public company focused on pediatric nutrition. Prior to that, he served for 30 years at Eli Lilly and Company in various capacities, including service as Vice President of Sales Neuroscience from 2006 to 2011. Mr. Grant earned a bachelor degree in pharmaceutical science from Temple University. Mr. Grant is also certified as a Board Director by the National Association of Corporate Directors. The Board believes that Mr. Grant is qualified to serve on Aptevo's Board because of his knowledge of the pharmaceutical industry and marketed products.

Zsolt Harsanyi, Ph.D. Has served as a member of our Board since August 2016. Dr. Harsanyi has served on the Board of Directors of Emergent since 2004 and as its Chairman since April 1, 2022 and as Chairman of the Board of Directors of N-Gene Research Laboratories, Inc., a privately-held biotechnology company, since 2011. Prior to that, Dr. Harsanyi served as Chief Executive Officer and Chairman of the Board of Directors of Exponential Biotherapies Inc., a private biotechnology company, from 2004 to 2011. Prior to that, Dr. Harsanyi served as President of Porton International Inc., a pharmaceutical and vaccine company, from January 1983 to December 2004. In 1996, Dr. Harsanyi founded Dynport Vaccine Company LLC. Prior to that, he was Vice President of Corporate Finance at E.F. Hutton, Inc. Dr. Harsanyi directed the first assessment of biotechnology for the U.S. Congress’ Office of Technology Assessment, served as a consultant to the President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research and was on the faculties of Microbiology and Genetics at Cornell Medical College. Dr. Harsanyi received his bachelor degree from Amherst College and his Ph.D. in genetics from Albert Einstein College of Medicine. The Board believes Dr. Harsanyi is qualified to serve on Aptevo’s Board because of his industry experience, his senior executive and financial positions, and his public company audit committee chair experience.

Barbara Lopez Kunz has served as a member of our Board since August 2016. Ms. Kunz is currently serving as Chief Executive Officer at Caidya, a clinical research organization. Ms. Kunz retired as President and Global Chief Executive Officer of the Drug Information Association, a non-profit health care company, at the end of March 2023. Ms. Kunz serves as a director on the board of Werfen, a leader in specialized diagnostics, as Vice-Chair of the Board of Directors of Children’s National Health System Research Institute, and has served on the Board of Directors of Caidya since 2022. From 2007 to 2013, she worked as President of Health and Life Sciences Global Business at Battelle Memorial Institute, a private nonprofit applied science and technology development company. Prior to that, she worked as Executive VP/GM for Thermo Fisher Scientific Inc.’s Fisher Biosciences from 2003 to 2007 and led the Latin America regional business from 2000 to 2003 at Uniqema, a company acquired by Croda International plc in 2006. Ms. Kunz also worked as Head of Strategy/M&A of Dupont from 1997 to 1998 and was the Global VP for the Enterprise Business Group of Imperial Chemical Industries (now AstraZeneca/Croda) from 1993 to 1997. Ms. Kunz earned bachelor degrees in both biology and chemistry from Thiel College, MBA coursework at Cleveland State University, an MS in polymer science from the University of Akron and is certified in INSEAD’s international executive program. She is also certified as a Board Director by the National Association of Corporate Directors. The Board believes that Ms. Kunz is qualified to serve on Aptevo’s Board because of her leadership experience, her business acumen and knowledge of the healthcare industry.

John E. Niederhuber, M.D. has served on our Board and as our Chairman (previously Vice Chairman and Lead Independent Director) since August 2016. Effective April 1, 2026, Dr. Niederhuber will transition from his current position as Chairman of the Board to Lead Independent Director. Dr. Niederhuber is currently an adjunct professor of surgery and oncology at The Johns Hopkins University School of Medicine. Dr. Niederhuber is the former Executive Vice President of the Inova Health System, Founder of the Inova Translational Medicine Institute (Inova), and founding President and Chief Executive Officer of the Genomics and Bioinformatics Research Institute, a joint venture between Inova and the University of Virginia. Dr. Niederhuber joined the Inova Health System in 2010 as Executive Vice President of the Health System and Chief Executive Officer of Inova. He officially retired from his

100

position at Inova in 2019. Prior to Inova, he served as the Director of the National Cancer Institute, the National Institutes of Health from 2006 to 2010 and as the Director of the University of Wisconsin Comprehensive Cancer Center and professor of surgery and oncology (member of the McArdle Laboratory) at the University of Wisconsin School of Medicine from 1997 to 2005. He chaired the Department of Surgery at Stanford University School of Medicine from 1991 to 1997 and held professorships at The Johns Hopkins University School of Medicine from 1987 to 1991 and at the University of Michigan from 1973 to 1987. Dr. Niederhuber also previously served on the Board of Directors of Emergent from 2010 to 2016. Dr. Niederhuber earned a bachelor of science from Bethany College and his M.D. from The Ohio State University School of Medicine. He is a member of the National Academy of Medicine. The Board believes that Dr. Niederhuber is qualified to serve on Aptevo's Board because he provides valuable insights to the Board through his experience in the field of oncology, immunology, genomics and in the business of healthcare.

Effective April 1, 2026 (the Transition Date), Marvin White, the Company’s current President and Chief Executive Officer will retire and transition to the position of Executive Chair, and Jeffrey Lamothe, the Company’s current Chief Operating Officer, will transition to the position of President and Chief Executive Officer, In addition, Mr. Lamothe will serve as a Class III director of the Company as of the Transition Date to hold office until the 2028 annual meeting of stockholders of the Company. Accordingly, the size of the Board will be increased from six directors to seven directors effective as of the Transition Date. John E. Niederhuber, M.D., will transition from Chairman of the Board to Lead Independent Director.

Names of Officers and Biographical Information

Set forth below is information regarding the positions, ages and business experience of each of our executive officers as of the date hereof. Biographical information with regard to Mr. White is presented under “Names of Directors and Other Information” in this report.

Name Age Position(s)

Marvin L. White 64 President and Chief Executive Officer

Jeffrey G. Lamothe 60 Executive Vice President and Chief Operating Officer

Daphne Taylor 59 Senior Vice President, Chief Financial Officer

Jeffrey G. Lamothe has served as our Executive Vice President and Chief Operating Officer since March 2023. Effective April 1, 2026, Mr. Lamothe will transition from his current position to President and Chief Executive Officer and will join our Board. Mr. Lamothe leads the Clinical, Research & Development, Quality, Manufacturing and Operations organizations. He previously served as our Executive Vice President and Chief Financial Officer, leading Finance, Business Development, Investor Relations and IT. Prior to Aptevo, he was Vice President Finance, Biosciences Division at Emergent BioSolutions. Mr. Lamothe assumed this role in 2014 when Emergent concluded the acquisition of Cangene Corporation (Cangene), where he was Chief Financial Officer. Mr. Lamothe’s business experience is built on a 25+ career, spanning several industries in CEO, COO and CFO roles. Prior to Cangene Corporation, Mr. Lamothe was the Chief Financial Officer of Smith Carter Architects and Engineers Incorporated. He also previously served as President and Chief Executive Officer of Kitchen Craft Cabinetry after occupying the position of VP Finance and Chief Financial Officer with the organization. Mr. Lamothe’s other past experience includes serving as Chief Financial Officer of Motor Coach Industries and he has held various roles at James Richardson & Sons, Limited and Ernst & Young LLP.

Daphne Taylor has served as our Senior Vice President, Chief Financial Officer since March 2023 and previously served as Aptevo’s Senior Vice President of Finance where she held responsibility for all strategic planning and budgeting, treasury activities, internal and external reporting, and financial compliance. Prior to Aptevo, Daphne’s career includes 25 years of financial experience in the life sciences and technology industries. Prior to joining Aptevo, Ms. Taylor served as Chief Financial Officer at BioLife Solutions. She also served as VP, Chief Accounting Officer, and Controller at Cardiac Science Corporation and in multiple other roles, including Controller at LookSmart, SpeedTrak, CoreMark International and Pacific Telesis. Ms. Taylor began her career at Coopers & Lybrand in San

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Francisco. She is active in her community. Ms. Taylor holds a B.A. from Sonoma State University and is a Licensed CPA in Washington and California.

SoYoung Kwon has served as our Senior Vice President, General Counsel, Business Development and Corporate Affairs since March 2023, and Senior Vice President, General Counsel, Corporate Affairs and Human Resources since May 2021. Ms. Kwon serves as a Trustee of the Seattle Art Museum and President of the Washington Scholarship Foundation. She previously served as the Global Senior Vice President, General Counsel and Corporate Secretary at AGC Biologics, a contract development and manufacturing organization with facilities in the US, Europe and Asia. Ms. Kwon assumed this role after CMC Biologics, where she was Vice President, General Counsel and Corporate Secretary since September 2015, was acquired by AGC Inc. In December 2016. Prior to that, Ms. Kwon was the Vice President, General Counsel and Corporate Secretary at Onvia, Inc. From 2008 to 2015. Ms. Kwon’s other past experience includes serving as Senior Counsel at Safeco Corporation and a Corporate Associate at Graham & Dunn PC. Ms. Kwon earned her Bachelor of Arts from the University of Washington and her Juris Doctorate from Willamette University College of Law.

Corporate Governance Guidelines

The Board adopted Corporate Governance Guidelines to assist with its exercise of its duties and responsibilities and to serve the best interests of the Company and its stockholders. The Board, with the assistance of the Nominating and Corporate Governance Committee, continuously evaluates the Company’s Corporate Governance Guidelines to ensure such guidelines are effectively serving the interests of the Company’s stockholders and are up-to-date with respect to current corporate governance best practices. Accordingly, in February 2026, the Board amended its Corporate Governance Guidelines to, among other things, specify that the Chair of the Board may be an executive chair or a non-executive chair and to change the frequency of Board and committee evaluations from annual to biennial.

Board Skills and Background

Our directors bring to our Board a wide variety of skills, qualifications, and viewpoints that strengthen the Board’s ability to carry out its oversight role on behalf of our stockholders. The table below is a summary of the range of skills and experiences that each director brings to the Board, each of which we find to be relevant to our business. Because it is a summary, it does not include all of the skills, experiences, and qualifications that each director offers, and the fact that a particular experience, skill, or qualification is not listed does not mean that a director does not possess it. All of our directors exhibit high integrity, an appreciation for mix of background and thought, innovative thinking, a proven record of success, and deep knowledge of corporate governance requirements and best practices.

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Leadership Experience X X X X X X

Strategic Planning and Operations X X X X X X

Corporate Governance Experience X X X X X X

Relevant Industry Experience X X X X X X

ESG and/or Human Capital Management Experience X X X X X X

Risk Management Expertise X X X X X X

Finance Experience X X X X X X

Sales / Marketing Experience X X

Legal Expertise X

Public Company Board Experience X X X X X X

Aptevo Institutional Knowledge X X X X X X

Board Leadership Structure

Our Corporate Governance Guidelines provide the Board flexibility in determining its leadership structure.

Our Corporate Governance Guidelines provide that in the event that the Chairman of the Board is not an independent director, the Nominating and Corporate Governance Committee may nominate an independent director to serve as lead director, who shall be approved by a majority of the independent directors. The lead director, among other things, would serve as the presiding director at all executive sessions, determine the need for special meetings of the Board, and consult with directors on matters relating to corporate governance and Board performance. Because the Chairman of the Board is currently an independent director, the Board does not have a lead director at this time.

Our Corporate Governance Guidelines also provide that in the event that the Chairman of the Board is not an independent director, the Nominating and Corporate Governance Committee may nominate an independent director to serve as Lead Independent Director, who shall be approved by a majority of the independent directors. The Lead Independent Director, among other things, would serve as the presiding director at all executive sessions, determine the need for special meetings of the Board, and consult with directors on matters relating to corporate governance and

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Board performance. Because Mr. White who will become our Executive Chair effective as of the Transition Date will not be an independent director, Dr. Niederhuber will serve as our Lead Independent Director as of the Transition Date.

Role of the Board in Risk Oversight

Our Board is actively engaged in the oversight of risks we face and consideration of the appropriate responses to those risks. The Board is responsible for oversight of our risk management programs and, in performing this function, reviews the long- and short-term internal and external risks facing the Company through its participation in an annual risk assessment survey. On an annual basis, key risks, mitigation activities and potential new or emerging risks are discussed with management and further addressed with our Audit Committee as necessary. The Audit Committee at least annually discusses with senior management the Company’s cybersecurity risk profile, environmental and social risk and risk management, product risk and risk management, including guidelines and policies to govern the process by which our exposure to risk is handled. The Audit Committee also reviews and comments on an annual risk assessment performed by management. After the Audit Committee performs its review and comment function, it reports any significant findings to the Board. The Compensation Committee strives to create incentives that encourage a reasonable and appropriate level of risk-taking consistent with our business strategy. Our Compensation Committee assesses risks relating to our executive compensation plans and arrangements, and whether our compensation policies and programs have the potential to encourage excessive risk taking. The Nominating and Corporate Governance Committee is responsible for reviewing our corporate governance and developing and maintaining corporate governance policies and procedures that are appropriate in light of the risks we face.

Meetings of the Board

Our Corporate Governance Guidelines provide that the directors are responsible for attending Board meetings and meetings of committees on which they serve. The Board met 6 times during 2025. Each Board member attended 75% or more of the aggregate number of meetings of the Board and of the committees on which she or he served, held during 2025 for which she or he was a director or committee member.

Information Regarding Committees of the Board

The Board has four standing committees: an Audit Committee, a Compensation Committee, a Nominating and Corporate Governance Committee and an Executive Committee. The duties and responsibilities of each committee is set forth in such committee’s written charter. The charters of the Audit, Compensation, and Nominating and Corporate Governance Committees are available to stockholders on the Company’s website at https://aptevotherapeutics.gcs-web.com/corporate-governance/overview/. The following table provides membership for each of the Board committees:

Name Audit Compensation NominatingandCorporateGovernance Executive

APVO US Equity

APVO · 10-K · period ended 2025-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

Item 9A. Controls and Procedures.

Item 9B. Other Information.

Item 9C. Disclosure Regarding Foreign Jurisdictions That Prevent Inspections.

Item 10. Directors, Executives Officers and Corporate Governance.

APVO US Equity☆

APVO · 10-K · period ended 2025-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

Item 9A. Controls and Procedures.

Item 9B. Other Information.

Item 9C. Disclosure Regarding Foreign Jurisdictions That Prevent Inspections.

Item 10. Directors, Executives Officers and Corporate Governance.

APVO US Equity