GT Biopharma(GTBP) - Prospectus

As filed with the Securities and Exchange Commission on January 21, 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 GT BIOPHARMA, INC. (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of Incorporation or Organization) Delaware 2834 94-1620407 (Primary Standard Industrial Classification Code Number) (I.R.S. Employer Identification Number) N/A (415) 919-4040 ( ...