Aptevo Therapeutics Inc.

Item 8.01 Other Events. On July 27, 2026, Aptevo Therapeutics Inc. (the "Company") announced a new solid tumor strategy and the filing of a patent application covering a proprietary Nectin-4 x PD-L1 dual-targeting backbone. The Company believes the technology is designed to strengthen its oncology pipeline, support multiple therapeutic approaches from a single platform-derived innovation, and expand potential partnering opportunities. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated by reference herein. Item 9.01. Financial Statements and Exhibits. (d) Exhibits.

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