GT Biopharma, Inc.

We are a clinical stage biopharmaceutical company focused on the development and commercialization of novel immuno-oncology products based on our proprietary Tri-specific Killer Engager (“TriKE®”), and Tetra-specific Killer Engager (“Dual Targeting TriKE®”) fusion protein immune cell engager technology platforms. Our TriKE® and Dual Targeting TriKE® platforms generate proprietary therapeutics designed to harness and enhance the cancer killing abilities of a patient’s own natural killer cells (“NK cells”). Once bound to an NK cell, our moieties are designed to activate the NK cell to direct it to one or more specifically targeted proteins expressed on a specific type of cancer cell or virus infected cell, resulting in the targeted cell’s death. TriKE® can be designed to target any number of tumor antigens, including B7-H3, HER2, CD33 and PDL1, on hematologic malignancies or solid tumors and do not require patient-specific customization. We believe our TriKE® and Dual Targeting TriKE® platforms that activate endogenous NK cells are potentially safer than T-cell immunotherapy because there is less cytokine release syndrome and fewer neurological complications. Our preclinical data suggests that this is explained by the TriKE® dependent, CD16 directed, IL-15 proliferation of NK cells, with little effect on endogenous T cells.

Current securities

1. Submission of Matters to a Vote of Security HoldersNov 12, 2026
2. 424B3 filingOct 20, 2026
3. DEF 14A filingOct 13, 2026
4. S-1 filingOct 9, 2026
5. PRE 14A filingOct 2, 2026