UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

APTEVO THERAPEUTICS INC.

(Exact name of Registrant as Specified in Its Charter)

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.07 Submission of Matters to a Vote of Security Holders.

On August 21, 2026, Aptevo Therapeutics Inc. (the “Company”) held its Annual Meeting of Stockholders (the “Annual Meeting”), at which a quorum was present. Stockholders considered four proposals outlined below, each of which is described in more detail in the Company’s definitive proxy statement for the Annual Meeting filed with the Securities and Exchange Commission on July 31, 2026 (the “Proxy Statement”). The final voting results with respect to each of the proposals acted upon at the 2026 Annual Meeting are set forth below.

Proposal 1: Election of Directors

The following two nominees, each of whom were named in the Proxy Statement, were elected to serve on the Board of Directors to hold office until the 2029 Annual Meeting of Stockholders and until their respective successors are duly elected and qualified, based on the following votes:

Proposal 2: Ratification of Appointment of Independent Registered Public Accounting Firm for 2026

The appointment of Baker Tilly US, LLP to serve as the Company’s independent registered public accounting firm for the year ending December 31, 2026 was approved based on the following votes:

Proposal 3: Advisory Vote on Company's 2025 Executive Compensation

The non-binding advisory vote on the compensation paid to our named executive officers was approved based on the following votes:

Proposal 4: Approval of the Company's Fourth Amended and Restated 2018 Stock Incentive Plan

The Aptevo Therapeutics Inc. Fourth Amended and Restated 2018 Stock Incentive Plan was approved based on the following votes:

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.