SEC Form 424B3 filed by Aptevo Therapeutics Inc.

Filed Pursuant to Rule 424(b)(3)
Registration No. 333-287244

PROSPECTUS

Up to 3,529,420 Shares of Common Stock Issuable Upon the Exercise of Common Warrants

This prospectus relates to the resale from time to time by certain selling stockholders named herein (the “Holders”) of up to 3,529,420 shares of Common Stock, par value $0.001 per share (“Common Stock”), of Aptevo Therapeutics Inc. (“Company,” “us” or “we”), issuable upon exercise of certain common stock purchase warrants (the “Common Warrants”). The Common Warrants were issued in a private placement concurrently with the sale by the Company of 1,764,710 shares (the “Shares”) of its Common Stock in a registered direct offering pursuant to that certain securities purchase agreement (the “Purchase Agreement” and collectively, the “April 2025 Offering”). The combined purchase price of one share of Common Stock and accompanying Common Warrants was $1.19. Such shares of Common Stock underlying the Common Warrants are collectively referred to herein as the “Resale Shares.” We are registering the Resale Shares on behalf of the Holders, to be offered and sold from time to time, to satisfy certain registration rights that we have granted to the Holders pursuant to the Purchase Agreement.

The Holders may resell or dispose of the Resale Shares to or through underwriters, broker-dealers, agents, or through any other means described in the section of this prospectus entitled “Plan of Distribution.” The Holders will bear the costs of commissions and discounts, if any, attributable to the sale or disposition of the Resale Shares. We will bear all costs, expenses and fees in connection with the registration of the Resale Shares. We will not receive any of the proceeds from the sale of the Resale Shares by the Holders.

Our Common Stock is listed on the Nasdaq Capital Market under the symbol “APVO.” On May 23, 2025, the last reported sale price of our Common Stock on the Nasdaq Capital Market was $0.28 per share. Numbers in this prospectus do not reflect the reverse stock split of our common stock at the reverse split ratio of 1-for-20 that was effected on May 23, 2025.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” on page 15 of this prospectus and under similar headings in the applicable prospectus supplement, any free writing prospectuses we have authorized for use in connection with a specific offering and in the documents incorporated by reference herein and therein.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is May 28, 2025.

TABLE OF CONTENTS

About this Prospectus

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission (the "SEC") using a "shelf" registration process pursuant to Rule 415 under the
Securities Act of 1933, as amended (the “Securities Act”). Under this shelf registration process, the Holders may,
from time to time, sell or otherwise dispose the securities described in this prospectus in one or more offerings. We
will not receive any proceeds from the sale by such Holders of the securities offered by them described in this
prospectus.

If information in this prospectus is inconsistent with any document incorporated by reference that was filed with the SEC before the date of this prospectus, you should rely on this prospectus. This prospectus and the documents incorporated by reference include important information about us, the securities being offered and other information you should know before investing in our securities. You should also read and consider information in the documents we have referred you to in the sections of this prospectus entitled “Where You Can Find Additional Information” and “Incorporation of Certain Information by Reference.”

You should rely only on the information contained in, or incorporated by reference into, this prospectus (as supplemented and amended), along with the information contained in any free writing prospectuses. We have not authorized anyone to provide you with different information. We take no responsibility for and can provide no assurances as to the reliability of, any other information that others may give you. The information contained in this prospectus (and in any supplement or amendment to this prospectus) or any related free writing prospectus, and the documents incorporated by reference herein and therein, are accurate only as of their respective dates, regardless of the time of delivery of this prospectus, any applicable prospectus supplement or any related free writing prospectus, or any sale of a security. We urge you to read carefully this prospectus (as supplemented and amended), together with the information incorporated herein by reference as described under the heading “Incorporation of Certain Information by Reference” before deciding whether to invest in any of the Common Stock being offered.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information.”

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in this prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

Except as otherwise indicated herein or as the context otherwise requires, references in this prospectus to “Aptevo,” “the Company,” “we,” “us,” “our” and similar references refer to Aptevo Therapeutics Inc., a corporation organized under the laws of the State of Delaware, and its subsidiaries on a consolidated basis.

We are not making any representation to any purchasers of the securities regarding the legality of an investment in the securities by such purchasers. You should not consider any information in this prospectus to be legal, business or tax advice. We urge you to consult with your own advisors as to legal, tax, business, financial and related aspects of an investment in our Common Stock.

This prospectus and the information incorporated herein by reference include trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included or incorporated by reference into this prospectus and the information incorporated herein by reference are the property of their respective owners.

The Offering

Unless otherwise indicated, the number of shares of Common Stock to be outstanding after this offering is based on 7,678,395 shares of Common Stock outstanding as of May 12, 2025. The number of shares of Common Stock outstanding after this offering excludes:

Description of Capital Stock

As of the date of this prospectus, our certificate of incorporation, authorizes us to issue up to 500,000,000 shares of Common Stock, $0.001 par value per share, and 15,000,000 shares of preferred stock, $0.001 par value per share. Our Common Stock is registered under Section 12(b) of the Exchange Act and is listed on the Nasdaq under the trading symbol “APVO.” As of May 12, 2025, 7,678,395 shares of Common Stock were outstanding and no shares of preferred stock were outstanding.

The following summary describes the material terms of our capital stock. The summary is qualified in its entirety by reference to our certificate of incorporation and our bylaws.

Common Stock

Voting Rights.

Each holder of our Common Stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. Under our amended and restated certificate of incorporation and amended and restated bylaws, our stockholders do not have cumulative voting rights. Because of this, the holders of a majority of the shares of Common Stock entitled to vote in any election of directors can elect all of the directors standing for election, if they should so choose.

Dividends.

Subject to preferences that may be applicable to any then-outstanding shares of preferred stock, holders of Common Stock are entitled to receive ratably those dividends, if any, as may be declared from time to time by our board of directors out of legally available funds.

Liquidation.

In the event of our liquidation, dissolution or winding up, holders of Common Stock will be entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then-outstanding shares of preferred stock.

Rights and Preferences.

Each share of Common Stock includes an associated right pursuant to and as set forth in the Rights Agreement that we entered into with Broadridge Corporate Issuer Solutions, Inc. on November 8, 2020 (as amended, the “Rights Agreement”). Each right initially represents the right to purchase from us one one-thousandth of a share of our Series A Junior Participating Preferred Stock, par value $0.001 per share. This right is not exercisable until the occurrence of certain events specified in such Rights Agreement. The value attributable to these rights, if any, is reflected in the value of our Common Stock. The Rights Agreement and the rights granted thereunder will expire upon the earliest to occur of (i) the date on which all of such rights are redeemed, (ii) the date on which such rights are exchanged, and (iii) the close of business on October 31, 2025.

Fully Paid and Nonassessable.

All of our outstanding shares of Common Stock are fully paid and nonassessable.

Preferred Stock

Under our certificate of incorporation, our board of directors is authorized by resolution to divide the preferred stock into one or more series and, with respect to each series, to determine the designations, powers, preferences, rights, qualifications, limitations and restrictions thereof, including the dividend rights, conversion or exchange rights, voting rights, redemption rights and terms, liquidation preferences, sinking fund provisions and the number of shares constituting the series. Our board of directors can, without stockholder approval but subject to the terms of our certificate of incorporation, issue preferred stock with voting and other rights that could adversely affect the voting power of the holders of our Common Stock and which could have certain anti-takeover effects. Before we may issue any series of preferred stock, our board of directors will be required to adopt resolutions creating and designating such series of preferred stock.

The following summary of terms of our preferred stock is not complete. You should refer to the provisions of our certificate of incorporation, our bylaws and the resolutions containing the terms of each series of preferred stock, which have been or will be filed with the SEC at or prior to the time of issuance of such series and described in the applicable prospectus supplement. The applicable prospectus supplement may also state that any of the terms set forth herein are inapplicable to such series of preferred stock, provided that the information set forth in such prospectus supplement does not constitute a material change to the information herein such that it alters the nature of the offering or the securities being offered.

We will fix the designations, voting powers, preferences and rights of each series of preferred stock that we issue under this prospectus, as well as the qualifications, limitations or restrictions thereof, in the certificate of designation relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference herein from reports that we file with the SEC, the form of any certificate of designation that describes the terms of the series of preferred stock we are offering. We will describe in the applicable prospectus supplement the terms of the series of preferred stock being offered, including, to the extent applicable:

If we issue shares of preferred stock under this prospectus, the shares will be fully paid and non-assessable.

The issuance of preferred stock could adversely affect the voting power of holders of Common Stock and reduce the likelihood that common stockholders will receive dividend payments and payments upon liquidation. The

issuance could have the effect of decreasing the market price of the Common Stock. The issuance of preferred stock also could have the effect of delaying, deterring or preventing a change in control of us.

Outstanding Options, Restricted Stock Units, and Warrants

Unless otherwise indicated, the number of shares of Common Stock to be outstanding after this offering is based on 7,678,395 shares of Common Stock outstanding as of May 12, 2025. The number of shares of Common Stock outstanding after this offering excludes:

Warrants

2023 Common Warrants

On August 4, 2023, and November 9, 2023, we completed a public offering and entered into a warrant inducement agreement, respectively, resulting in the issuance of common warrants (the "2023 Common Warrants") to purchase up to an aggregate of 27,368 shares of Common Stock. We received aggregate net proceeds of $5.3 million, which includes non-cash warrant modification costs of $2.1 million. As of May 12, 2025, there were 750 aggregate 2023 Common Warrants outstanding with an exercise price between $379.32 per share and $1,009.36 per share and expiration dates between November 2025 and November 2028.

2024 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 91,896 shares of Common Stock (or pre-funded warrants in lieu thereof, all of which have been exercised as of May 12, 2025) and accompanying common warrants to purchase up to 183,792 shares of Common Stock at an exercise price of $49.95 per share for a combined offering price of $49.95 per share and accompanying common warrants. As of May 12, 2025, we have 3,608 common warrants outstanding with an exercise price of $49.95 per share and 8,008 common warrants with an amended exercise price of $8.60 per share that were issued in connection with the April 2024 public offering (the "April 2024 Warrants").

On July 1, 2024, we completed the a registered direct offering (the "July 2024 Registered Direct Offering") in which we issued 144,318 shares of Common Stock (or pre-funded warrants in lieu thereof, all of which have been exercised as of May 12, 2025) and accompanying common warrants to purchase up to 288,643 shares of Common Stock at an exercise price of $19.06 per share for a combined offering price of $19.06 per share and accompanying common warrants. We received $2.7 million in gross proceeds less total issuance costs of $0.8 million. Issuance costs include banker and legal fees of $0.4 million and non-cash warrant modification costs of $0.4 million. The Company recognized the $0.4 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 May 12, 2025, we have 11,687 common warrants outstanding at an amended exercise price of $8.60 per share that were issued in connection with the July 2024 Registered Direct Offering (the "July 2024 Warrants").

On September 18, 2024, we completed a registered direct offering (the "September 2024 Registered Direct Offering") in which we issued 245,702 shares of Common Stock (or pre-funded warrants in lieu thereof, all of which have been exercised as of May 12, 2025) and accompanying common warrants to purchase up to 491,403 shares of Common Stock at an exercise price of $8.60 per share for a combined offering price of $8.60 per share and accompanying common warrants. We received $3.0 million in gross proceeds less total issuance costs of $0.5 million. Issuance costs include banker and legal fees of $0.4 million and non-cash warrant modification costs of $0.1 million. The Company recognized the $0.1 million modification date incremental value of the modified warrants as compared to the original warrants as a non-cash issuance cost of the September 2024 Registered Direct Offering. As of May 12, 2025, all common warrants issued in connection with the September 2024 Registered Direct Offering (the "September 2024 Warrants") have been exercised.

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 September 2024 Warrants (together, the "Existing Warrants") to exercise for cash 823,544 Existing Warrants at a reduced exercise price of $7.50 per share. Additionally, pursuant to the December 2024 Inducement Agreement, we issued 1,647,088 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 $9.53 per share. We received $6.2 million in gross proceeds from the exercise of these warrants less total issuance costs of $0.6 million, which includes banker and legal fees. The common warrants in connection with the December 2024 Warrant Inducement were equity classified. The fair value of existing common warrants immediately before and after were $3.5 million and $3.6 million, respectively. The fair value of the newly issued warrants was $7.3 million. Given the common warrants were equity classified, the modified fair value of existing common warrants and the newly issued 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 by inducing the exercise of warrants. As of May 12, 2025, there were 1,647,088 December 2024 Warrants outstanding with an exercise price of $9.53 per share. The exercise price of the December 2024 Warrants will be amended to $1.19 per share upon approval by stockholders at a special meeting of stockholders to be held on May 14, 2025. In the event that we are unable to obtain such stockholder approval, the exercise price of the December 2024 Warrants will remain $9.53 per share.

Common Warrants - April 2025 - On May 12, 2025, we have issued and outstanding Common Warrants to purchase up to 3,529,420 shares of our Common Stock at an exercise price of $1.19 per share issued as part of our April 2025 Offering. The Common Warrants will become exercisable upon approval by stockholders and will expire 5 years from such stockholder approval (the “Stockholder Approval”). We intend to hold a special meeting of stockholders on May 14, 2025 to approve, among other things, the issuance of the Common Warrants. If we do not obtain Stockholder Approval with respect to the terms of the Common Warrants at the first special meeting of the stockholders to be held on May 14, 2025, we have agreed to use reasonable best efforts to call a meeting every sixty (60) days thereafter to seek such Stockholder Approval until the date on which Stockholder Approval is obtained or the Common Warrants are no longer outstanding. In the event that we are unable to obtain such Stockholder Approval, the Common Warrants will not be exercisable and therefore have no value. If, at any time the Common Warrants are outstanding and a fundamental transaction, as described in the Common Warrant, and generally including any reorganization, recapitalization or reclassification of our common stock, the sale, transfer or other disposition of all or substantially all of our properties or assets, our consolidation or merger with or into another person, the acquisition of more than 50% of our outstanding Common Stock, or any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding Common Stock, occurs the holders of the Common Warrants will be entitled to receive upon exercise of the Common Warrants the kind and amount of securities, cash or other property

that the holders would have received had they exercised the Common Warrants immediately prior to such fundamental transaction, other than one in which a successor entity that is a publicly traded corporation (whose stock is quoted or listed for trading on a national securities exchange, including, but not limited to, the New York Stock Exchange, the NYSE American, the Nasdaq Global Select Market, the Nasdaq Global Market or the Nasdaq Capital Market) assumes the common warrant such that the warrant shall be exercisable for the publicly traded common stock of such successor entity. Additionally, as more fully described in the Common Warrants, at the option of the holders of the common warrants the holder can receive consideration in the same type and form of an amount equal to the Black Scholes value (as defined in the common warrant) of such unexercised common warrants on the date of consummation of such transaction. Except as otherwise provided in the Common Warrants or by virtue of the holder’s ownership of shares of our Common Stock, such holder of Common Warrants does not have the rights or privileges of a holder of our Common Stock, including any voting rights, until such holder exercises such holder’s Common Warrants. The Common Warrants provide that the holders of the Common Warrants have the right to participate in distributions or dividends paid on our shares of Common Stock.

Registration Rights of holders of the Common Warrants

As set forth in the April 2025 Offering, we agreed to file a registration statement on Form S-3 (or other appropriate form, including on Form S-1, if we are not then S-3 eligible) to register the resale of the Resale Shares upon exercise of the Common Warrants (the “Resale Registration Statement”) as soon as reasonably practicable (and in any event by May 3, 2025), and to use commercially reasonable efforts to cause such Resale Registration Statement to become effective by June 2, 2025 (or by July 2, 2025 in case of “full review” of such registration statement by the SEC) and to keep the Resale Registration Statement effective at all times until no holder of the Common Warrants owns any Common Warrants or Resale Shares.

Certain Anti-Takeover Provisions of Our Certificate of Incorporation, Our Bylaws, the DGCL and our Rights Plan

Delaware Law

We are subject to Section 203 of the DGCL, which prohibits a Delaware corporation from engaging in any business combination with any interested stockholder for a period of three years after the date that such stockholder became an interested stockholder, with the following exceptions:

In general, Section 203 defines a “business combination” to include the following:

In general, Section 203 defines an “interested stockholder” as an entity or person who, together with the person’s affiliates and associates, beneficially owns, or within three years prior to the time of determination of interested stockholder status did own, 15% or more of the outstanding voting stock of the corporation.

Staggered Board; Removal of Directors. Our amended and restated certificate of incorporation provides for our board of directors to be divided into three classes with staggered three-year terms. Only one class of directors is elected at each annual meeting of our stockholders, with the other classes continuing for the remainder of their respective three-year terms. Because our stockholders do not have cumulative voting rights, stockholders holding a majority of the shares of Common Stock outstanding are able to elect all of our directors. Our certificate of incorporation and our bylaws also provide that directors may be removed by the stockholders only for cause upon the vote of 75% of our outstanding Common Stock. Furthermore, the authorized number of directors may be changed only by resolution of the board of directors, and vacancies and newly created directorships on the board of directors may, except as otherwise required by law or determined by the board, only be filled by a majority vote of the directors then serving on the board, even though less than a quorum.

Stockholder Action by Written Consent. Our amended and restated certificate of incorporation and amended and restated bylaws also provide that all stockholder actions must be effected at a duly called meeting of stockholders and eliminates the right of stockholders to act by written consent without a meeting. Our amended and restated bylaws also provide that only our chairman of the board, chief executive officer or the board of directors pursuant to a resolution adopted by a majority of the total number of authorized directors may call a special meeting of stockholders.

Requirements for Advance Notification of Stockholder Nominations, Proposals and Amendments. Our amended and restated bylaws also provide that stockholders seeking to present proposals before a meeting of stockholders to nominate candidates for election as directors at a meeting of stockholders must provide timely advance notice in writing, and specify requirements as to the form and content of a stockholder’s notice. Our certificate of incorporation and bylaws provide that the stockholders cannot amend many of the provisions described above except by a vote of 75% or more of our outstanding Common Stock.

Shareholder Rights Plan. On November 8, 2020, our board of directors adopted a rights plan pursuant to our Rights Agreement. The rights plan works by causing substantial dilution to any person or group that acquires beneficial ownership of ten percent (10%) or more of our Common Stock without the approval of our board of directors. As a result, the overall effect of the rights plan and the issuance of the rights pursuant to the rights plan may be to render more difficult or discourage a merger, tender or exchange offer or other business combination involving the Company that is not approved by our board of directors. The rights plan is not intended to interfere with any merger, tender or exchange offer or other business combination approved by our board of directors. The rights plan also does not prevent our board of directors from considering any offer that it considers to be in the best interest of our stockholders.

These provisions are intended to enhance the likelihood of continued stability in the composition of our board of directors and its policies and to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to reduce our vulnerability to hostile takeovers and to discourage certain tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging others from making tender offers for our shares and may have the effect of delaying changes in our control or management. As a consequence, these provisions may also inhibit fluctuations in the market price of our stock that could result from actual or rumored takeover attempts. We believe that the benefits of these provisions, including increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure our company, outweigh the disadvantages of discouraging takeover proposals, because negotiation of takeover proposals could result in an improvement of their terms.

On November 1, 2024, we entered into Amendment No. 4 to the Rights Agreement (the "Amendment"), dated as of November 8, 2020, between the Company and Broadridge Corporate Issuer Solutions, Inc., as Rights Agent, as amended. The Amendment extends the definition of “Final Expiration Date” (as defined in the Rights Agreement) and certain related language in the Rights Agreement to October 31, 2025. The Amendment also changes the definition of “Purchase Price” (as defined in the Rights Agreement) and certain related language in the Rights Agreement to $70 per one one-thousandth of a Preferred Share.

Transfer Agent and Registrar

The transfer agent and registrar for our Common Stock is Broadridge, which can be contacted at 51 Mercedes Way, Edgewood, NY 11717, [email protected], or +1 (720) 378-5591.

Listing on the Nasdaq Capital Market

Our Common Stock is listed on the Nasdaq Capital Market under the symbol “APVO.”

Risk Factors

An investment in our Common Stock involves a high degree of risk. Before deciding whether to invest in our Common Stock, you should consider carefully the risks and uncertainties described below and under the section captioned “Risk Factors” contained in our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2024, any subsequent Quarterly Report on Form 10-Q and other filings we make with the SEC from time to time, which are incorporated by reference herein in their entirety, together with other information in this prospectus, and in any prospectus supplement or free writing prospectus that we authorize for use in connection with this offering. If any of these risks actually occurs, our business, financial condition and results of operations could be materially and adversely affected and we may not be able to achieve our goals, the trading price of our Common Stock could decline and you might lose all or part of your investment. Additional risks not presently known to us or that we currently believe are immaterial may also significantly impair our business operations. If any of these risks occur, our business, results of operations or financial condition and prospects could be harmed. In that event, the market price of our Common Stock could decline, and you could lose all or part of your investment.

The risks included in this prospectus and the documents we have incorporated by reference into this prospectus are not the only risks we face. We may experience additional risks and uncertainties not currently known to us, or as a result of developments occurring in the future. Conditions that we currently deem to be immaterial may also materially and adversely affect our business, financial condition, cash flows and results of operations, and our ability to pay distributions to stockholders. Please also read carefully the section above entitled “Forward-Looking Statements.”

Additional Risks Related to This Offering

The number of shares being registered for resale is significant in relation to the number of our outstanding shares of Common Stock.

We have filed a registration statement of which this prospectus is a part to register the shares offered hereunder for sale into the public market by the selling stockholder. These shares represent a large number of shares of our Common Stock, and if sold in the market all at once or at about the same time, could depress the market price of our Common Stock during the period the registration statement remains effective and could also affect our ability to raise equity capital.

You may also experience future dilution as a result of future equity offerings.

In order to raise additional capital, we may in the future offer additional common shares or other securities convertible into or exchangeable for our common shares that could result in further dilution to the investors purchasing our common shares in this offering or result in downward pressure on the price of our common shares. We may sell our common shares or other securities in any other offering at prices that are higher or lower than the prices paid by the investors in this offering, and the investors purchasing shares or other securities in the future could have rights superior to existing shareholders. Moreover, to the extent that we issue subscription rights, options or warrants to purchase, or securities convertible into or exchangeable for, our common shares in the future and those subscription rights, options, warrants or other securities are exercised, converted or exchanged, stockholders may experience further dilution.

For example, on April 28, 2025, we entered into an At The Market Offering Agreement (the "Sales
Agreement") with Roth Capital Partners ("Roth"). The Sales Agreement provides that, upon the terms and subject to
the conditions set forth therein, we may issue and sell through Roth, acting as sales agent, shares of our common
stock having an aggregate offering price of up to $50 million. Any future sale of our common stock by Roth will be
effected pursuant to a registration statement (the "Registration Statement") on Form S-3 which we filed on February
14, 2025, and subsequently amended and supplemented on April 28 and April 29, 2025. As of May 12, 2025, we
have sold 2,347,114 shares of our common stock at an aggregate gross offering price of $0.4568 pursuant to the
Sales Agreement and the Registration Statement and accompanying prospectus for aggregate gross sale proceeds of
approximately $1.1 million and while we have no obligation to sell any additional shares of our common stock
under the Sales Agreement, in the future, we may sell additional shares of our common stock under the Sales
Agreement which may result in further dilution to investors purchasing our common shares in this offering.

Our Common Stock may be at risk for delisting from the Nasdaq Capital Market in the future if we do not maintain compliance with Nasdaq’s continued listing requirements. Delisting could adversely affect the liquidity of our Common Stock, and the market price of our Common Stock could decrease.

Our Common Stock is currently listed on the Nasdaq Capital Market LLC (Nasdaq), and on May 23, 2025, the last reported sale price of our Common Stock on Nasdaq was $0.28 per share. Nasdaq has minimum requirements that a company must meet to remain listed on Nasdaq, including corporate governance standards and a requirement that we maintain a minimum closing bid price of $1.00 per share, among other requirements. If the sale price of our Common Stock remains below $1.00 per share, for 30 consecutive business days, we will fail to meet the minimum closing bid price requirement by the continued listing requirements of Nasdaq Listing Rule 5550(a)(2) (the “Bid Price Requirement”). If we fail to meet the Bid Price Requirement, we are not eligible for a 180-day cure period from Nasdaq to regain compliance with such requirement because we have conducted a reverse stock split in the past year, and thus we would be immediately delisted.

To maintain our ability to comply with the Bid Price Requirement, we are holding a special meeting of our stockholders on May 14, 2025 in order to, among other things, effect a reverse stock split. If this reverse stock split is approved, we would, if necessary, seek to effectuate a reverse stock split prior to failing to meet the Bid Price Requirement.

In the future, if we fail to maintain the minimum listing requirements of Nasdaq and a final determination is made by Nasdaq that our Common Stock must be delisted, the liquidity of our Common Stock would be adversely affected, and the market price of our Common Stock could decrease. In addition, if delisted, we would no longer be subject to Nasdaq rules, including rules requiring us to have a certain number of independent directors and to meet other corporate governance standards. Our failure to be listed on Nasdaq or another established securities market would have a material adverse effect on the value of your investment in us.

If our Common Stock is not listed on Nasdaq or another national exchange, the trading price of our Common Stock is below $5.00 per share and we have net tangible assets of $6,000,000 or less, the open-market trading of our Common Stock will be subject to the "penny stock" rules promulgated under the Securities Exchange Act of 1934, as amended. If our shares become subject to the "penny stock" rules, broker-dealers may find it difficult to effectuate customer transactions, and trading activity in our securities may be adversely affected.

Use of Proceeds

We will not receive any of the proceeds from the sale or other disposition of the Resale Shares held by the Holders pursuant to this prospectus.

SELLING STOCKHOLDERS

We have prepared this prospectus to allow the Holders to sell or otherwise dispose of, from time to time, up to 3,529,420 Resale Shares.

On April 3, 2025, we entered into the Purchase Agreement with the Holders. Pursuant to the Purchase Agreement, the selling stockholders were issued common warrants to purchase up to 3,529,420 shares of our Common Stock at an exercise price of $1.19 per share in the April 2025 Offering.

We agreed in the Purchase Agreement to register for resale by the Holders the Resale Shares underlying the Common Warrants and have filed with the SEC a registration statement on Form S-1, of which this prospectus forms a part, with respect to the resale or other disposition of the securities offered from time to time by the Holders under this prospectus. We will not receive any of the proceeds of sales by the holder of any of the Resale Shares covered by this prospectus.

Beneficial ownership is determined in accordance with the rules of the SEC and includes voting or investment power with respect to shares of our Common Stock. Unless otherwise indicated below, to our knowledge, the Holders named in the table below have sole voting and investment power with respect to the shares of Common Stock beneficially owned by them. The number of shares of Common Stock beneficially owned prior to the offering for each Holder includes (i) all shares of our Common Stock held by such Holder as of May 12, 2025, and (ii) all shares of our Common Stock issuable to such Holder upon the exercise of Common Warrants. The inclusion of any shares in this table does not constitute an admission of beneficial ownership by the person named below.

The beneficial ownership information presented in the table below is as of May 12, 2025. The Holders may have sold or transferred, in transactions exempt from the registration requirements of the Securities Act, some or all of their shares of Common Stock since the date on which the information in the table below is presented. Information about the Holders may change over time.

(1) The beneficial ownership prior to this offering for each investor, based on the Company's best knowledge, includes the following:

a. Armistice Capital Master Fund Ltd: 400,000 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

b. Alto Opportunity Master Fund, SPC - Segregated Master Portfolio B: 400,000 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

c. Bigger Capital Fund, LP: 400,000 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

d. Empery Asset Master, LTD: 205,144 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

e. Empery Tax Efficient, LP: 73,044 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

f. Empery Tax Efficient III, LP: 121,812 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

g. CVI Investments, Inc: 400,000 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

h. Hudson Bay Master Fund Ltd: Includes 400,000 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025. Excludes 499,818 shares of Common Stock underlying the warrants issued on December 12, 2024 pursuant to the December 2024 Inducement Agreement (the “Inducement Warrants”) which warrants are not exercisable within 60 days of May 12, 2025 by virtue of the beneficial ownership limitations described below. Hudson Bay Capital Management LP, the investment manager of Hudson Bay Master Fund Ltd., has voting and investment power over the Common Stock, Common Warrants and Inducement Warrants. Sander Gerber is the managing member of Hudson Bay Capital GP LLC, which is the general partner of Hudson Bay Capital Management LP. Each of Hudson Bay Master Fund Ltd. and Sander Gerber disclaims beneficial ownership over the Common Stock, Common Warrants and Inducement Warrants.

i. Intracoastal Capital LLC: 310,000 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025. Mitchell P. Kopin (“Mr. Kopin”) and Daniel B. Asher (“Mr. Asher”), each of whom are managers of Intracoastal
Capital LLC (“Intracoastal”), have shared voting control and investment discretion over the securities reported herein that are held
by Intracoastal. As a result, each of Mr. Kopin and Mr. Asher may be deemed to have beneficial ownership (as determined under
Section 13(d) of the Exchange Act) of the securities reported herein that are held by Intracoastal.

j. L1 Capital Global Opportunities Master Fund: 400,000 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

k. Sabby Volatility Warrant Master Fund, Ltd.: 419,420 shares of Common Stock underlying the Common Warrants held by the Holder as of May 12, 2025.

(2) The warrants, including the Resale Shares, are subject to a beneficial ownership limitation of 4.99% or 9.99%, as applicable, which such limitation restricts the Holders from exercising that portion of the warrants that would result in the Holders and its affiliates owning, after exercise, a number of shares of common stock in excess of the beneficial ownership limitation.

(3) Because the Selling Stockholders may sell, transfer or otherwise dispose of all, some or none of the Resale Shares covered by this prospectus, we cannot determine the number of such common shares that will be sold, transferred or otherwise disposed of by the Selling Stockholders, or the amount or percentage of our common shares that will be held by the Selling Stockholders upon completion of this offering. The Common Warrants are not exercisable until the Stockholder Approval. For purposes of this table, we have assumed that the Selling Stockholders will sell all their common shares covered by this prospectus.

Certain Relationships and Related Party Transactions

On April 3, 2025, we entered into the Purchase Agreement with certain institutional investors. Pursuant to the Purchase Agreement, the Holders agreed to purchase 1,764,710 shares of our Common Stock and, in a concurrent private placement, Common Warrants to purchase up to 3,529,420 shares of Common Stock at a combined offering price of $1.19 per share.

We received aggregate net proceeds of $1.9 million from the April 2025 Offering after deducting financial advisory fees and other expenses payable by us. We would expect to receive aggregate gross proceeds of up to approximately $4.2 million if the Common Warrants are exercised.

Pursuant to the Purchase Agreement, we agreed to file a registration statement on Form S-3 (or other appropriate form if the we are not eligible to use Form S-3) to register the resale of the Resale Shares issuable upon the exercise of the Common Warrants (the "Resale Registration Statement") as soon as reasonably practicable (and in any event by May 3, 2025), and to use commercially reasonable efforts to cause such Resale Registration Statement to become effective by June 2, 2025 (or by July 2, 2025 in case of "full review" of such registration statement by the

SEC) and to keep the Resale Registration Statement effective at all times until no Holder of the Common Warrants owns any Common Warrants or Resale Shares. In the event that we fail to timely deliver to the Holders the Resale Shares without restrictive legends, we have agreed to pay certain liquidated damages to the Holders. We are registering the shares to be sold by the Holders under the registration statement of which this prospectus is a part to satisfy our obligation under the Purchase Agreement.

Plan Of Distribution

The Holders, and its pledgees, donees, transferees or other successors in interest, may from time to time offer and sell, separately or together, some or all of the Resale Shares covered by this prospectus. Registration of the Resale Shares covered by this prospectus does not mean, however, that those Resale Shares necessarily will be offered or sold.

The Resale Shares covered by this prospectus may be sold from time to time, at market prices prevailing at the time of sale, at prices related to market prices, at a fixed price or prices subject to change or at negotiated prices, by a variety of methods including the following:

In effecting sales, brokers or dealers engaged by the Holders may arrange for other brokers or dealers to participate. Broker-dealer transactions may include:

To our knowledge, the Holders have not entered into any agreements, understandings or arrangements with any underwriters or broker-dealers regarding the sale of the Resale Shares covered by this prospectus. At any time a particular offer of the securities covered by this prospectus is made, a revised prospectus or prospectus supplement, if required, will be distributed which will set forth the aggregate amount of Resale Shares covered by this prospectus being offered and the terms of the offering, including the name or names of any underwriters, dealers, brokers or agents. In addition, to the extent required, any discounts, commissions, concessions and other items constituting underwriters’ or agents’ compensation, as well as any discounts, commissions or concessions allowed or reallowed or paid to dealers, will be set forth in such revised prospectus supplement. Any such required prospectus supplement, and, if necessary, a post-effective amendment to the registration statement of which this prospectus is a part, will be filed with the SEC to reflect the disclosure of additional information with respect to the distribution of the securities covered by this prospectus.

Legal Matters

The validity of the securities being offered by this prospectus will be passed upon by Paul Hastings LLP, Washington, DC.

Experts

Our consolidated financial statements as of December 31, 2024 and 2023, and for the years then ended, incorporated in this prospectus by reference and included in our Annual Report on Form 10-K for the year ended December 31, 2024, have been audited by Moss Adams LLP, an independent registered public accounting firm, as stated in their report (which report expresses an unqualified opinion and includes an explanatory paragraph related to a going concern uncertainty), which is incorporated herein by reference. Such consolidated financial statements are incorporated by reference in reliance upon the report of such firm given their authority as experts in accounting and auditing.

Where You Can Find More Information

This prospectus is part of a registration statement on Form S-1 we filed with the SEC under the Securities Act. This prospectus does not contain all of the information set forth in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference therein. For further information with respect to us and the securities we are offering under this prospectus, we refer you to the registration statement and the exhibits and schedules filed as a part of the registration statement. Neither we nor any agent, underwriter or dealer has authorized any person to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus is accurate as of any date other than the date on the front page of this prospectus, regardless of the time of delivery of this prospectus or any sale of the securities offered by this prospectus.

We are subject to the informational requirements of the Securities Exchange Act and are required to file annual, quarterly and current reports, proxy statements and other information with the SEC. Any information we file with the SEC, including the documents incorporated by reference into this prospectus, is also available on the SEC’s website at www.sec.gov. We also make these documents publicly available, free of charge, on our website at www.aptevotherapeutics.com as soon as reasonably practicable after filing such documents with the SEC. The information contained in, or that can be accessed through, our website is not part of this prospectus.

Incorporation of Certain Information by Reference

The SEC allows us to “incorporate by reference” the information we file with it, which means that we can disclose important information to you by referring you to those documents instead of having to repeat the information in this prospectus. The information incorporated by reference is considered to be part of this prospectus, and because we are a smaller reporting company, later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings (including those made after the initial filing of the registration statement of which this prospectus is a part and prior to the effectiveness of such registration statement) we will make with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act until the termination of the offering of the shares covered by this prospectus (other than information furnished under Item 2.02 or Item 7.01 of Form 8-K):

As a smaller reporting company, we also are incorporating by reference any future information filed (rather than furnished) by us with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, after the date of the initial filing of the registration statement of which this prospectus is a part and before the effective date of the registration statement and after the date of this prospectus until the termination of the offering. Any statements contained in a previously filed document incorporated by reference into this prospectus is deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus, or in a subsequently filed document also incorporated by reference herein, modifies or supersedes that statement.

We will provide to each person, including any beneficial owner, to whom a prospectus is delivered, at no cost, upon written or oral request, a copy of any or all of the reports or documents that have been incorporated by reference in the prospectus contained in the registration statement but not delivered with the prospectus. You should direct requests for documents to:

Aptevo Therapeutics Inc.

2401 4th Avenue, Suite 1050

Seattle, WA 98121

Attn: General Counsel

(206) 838-0500

This prospectus is part of a registration statement we filed with the SEC. That registration statement and the exhibits filed along with the registration statement contain more information about us and the shares in this offering. Because information about documents referred to in this prospectus is not always complete, you should read the full documents which are filed as exhibits to the registration statement. You may read and copy the full registration statement and its exhibits at the SEC’s website.

Up to 3,529,420 Shares of Common Stock Issuable Upon the Exercise of Common Warrants

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Prospectus

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May 28, 2025