Aptevo Therapeutics(APVO) - Prospectus

As filed with the Securities and Exchange Commission on January 28, 2026 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 APTEVO THERAPEUTICS INC. (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of Incorporation or Organization) (Primary Standard Industrial Classification Code Number) Delaware 2834 81-1567056 (I.R.S. Employer Identification Number) 2401 4th Avenue ...