GT Biopharma, Inc. (GTBP)

The company is a clinical stage biopharmaceutical business focused on developing and commercializing immuno-oncology products based on its proprietary Tri-specific Killer Engager (TriKE) and Tetra-specific Killer Engager (Dual Targeting TriKE) fusion protein platforms. These are designed to harness a patient's own natural killer (NK) cells: once bound to an NK cell, the molecule activates it and directs it to specific proteins on a cancer cell or virus-infected cell, leading to that cell's death. The company says TriKEs can be designed against many tumor antigens without patient-specific customization, and believes they may carry less cytokine release syndrome and fewer neurological complications than T-cell immunotherapy. It holds exclusive rights to the platform through licenses from the University of Minnesota and has two US patents issued in August 2021.

The pipeline is built around second-generation TriKEs that use camelid nanobody technology. GTB-3650 targets CD33 in relapsed/refractory acute myeloid leukemia and high-risk myelodysplastic syndromes. Its IND was cleared by the FDA in June 2024, and enrollment began in January 2025 in a University of Minnesota-sponsored phase 1 study. GTB-5550 targets B7-H3 on solid tumors and is the first dual camelid TriKE. Its IND was cleared in January 2026, and the company expects to start a basket trial in mid-2026. GTB-7550 targets CD19 for lupus and other autoimmune disorders and is still in development, with potential manufacturers being assessed. The first candidate, GTB-3550 (CD33), was suspended in favor of the more potent camelid-based GTB-3650.

The target markets are hematologic malignancies, including AML, the most common adult leukemia in the U.S., and MDS, along with B7-H3-positive solid tumors such as bladder, breast, colorectal, lung, prostate, head and neck cancers and others, and potentially autoimmune disease. The company expects TriKEs could be used as monotherapy or combined with standard-of-care treatments, and plans to advance candidates on its own or with partners. It has no commercial products yet.

The company owns no manufacturing facilities and relies on third-party contract manufacturers, including Cytovance Biologics, which was a related party in 2024 but not in 2025, to produce material under cGMP. It outsources much of its work to consultants and has one full-time employee. Its research is tied to the University of Minnesota through a sponsored research agreement, license agreements and a clinical trial agreement. It faces intense competition from pharmaceutical, biotechnology and cell therapy companies, as well as academic institutions, many with greater resources. Its common stock trades on the Nasdaq Capital Market under "GTBP," and it has a committed equity facility of up to $20 million.