As filed with the Securities and Exchange Commission on October 1, 2025 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) Delaware 2834 81-1567056 (State or Other Jurisdiction of Incorporation or Organization) (Primary Standard Industrial Classification Code Number) (I.R.S. Employer Identification Number) 2401 4th Avenue, ...

As filed with the Securities and Exchange Commission on June 14, 2024. THE SECURITIES ACT OF 1933 APTEVO THERAPEUTICS INC. (Exact Name of Registrant as Specified in Its Charter) Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER (State or Other Jurisdiction of Incorporation or Organization) (Primary Standard Industrial (Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent For Service) Copies to ...

As filed with the Securities and Exchange Commission on April 9, 2024. Registration No. 333-278103 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) (State or Other Jurisdiction of Incorporation or Organization) (Primary Standard Industrial Classification Code Number) Delaware 2834 81-1567056 (I.R.S. Employer Identification N ...

As filed with the Securities and Exchange Commission on March 20, 2024. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER (Primary Standard Industrial Delaware 2834 81-1567056 (I.R.S. Employer Identification Number) 2401 4th Avenue, Suite 1050 Seattle, Washington, 98121 (206) 838-0500 (Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant's Principal Executive Offices) Marvin L. White THE SECURI ...