As filed with the Securities and Exchange Commission on August 1, 2023 Registration No. 333- 273067 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Amendment No. 2 to FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 APTEVO THERAPEUTICS INC. (Exact Name of Registrant as Specified in Its Charter) Delaware 2834 81-1567056 (State or Other Jurisdiction of Incorporation or Organization) (Primary Standard Industrial Classification Code Number) (I.R.S. Employer Identification ...

As filed with the Securities and Exchange Commission on June 30, 2023. Registration No. 333- 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, Suite 1050 Seattle, Washington, 98121 (206) 838-0500 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WA ...