Product Pipeline
We have a diversified TriKE™ therapeutic pipeline targeting several oncology indications.
Overview
GT Biopharma has developed a platform technology that engages the CD16 Fc receptor on NK cells, mediating tumor specific antigen targeting and an IL-15 moiety between them to induce NK cell proliferation and activation. Lead clinical programs are highlighted below. This platform technology can be applied to any known or proprietary tumor (or other target [e.g. HIV reservoirs]). Several are in research development or planned. The platform is based on the finding that the 2nd generation TriKE® are 10-40 times more potent than 1st generation TriKE and all TriKE development is now focused on this platform.
TriKE® Clinical Pipeline
GTB-3650 TriKE®
GTB-3650 is the companies first 2nd generation camelid nanobody TriKE® being tested clinically for the treatment of CD33 positive leukemias, including AML and MDS. GTB-3650 TriKE is the first TriKE clinical product that utilizes camelid nanobody technology. GTB-3650 TriKE is a Tri-specific Killer Engager molecule composed of a camelid nanobody that binds the CD16 receptor on NK cells, a single chain variable fragment (scFv) that recognizes CD33 on tumor cells, and human wild type IL-15. The IND application was cleared and enrollment started January 21, 2025. As of July 2025, we anticipate enrolling onto cohort 3, after passing formal safety review in cohort 2. Based on multiple assays of various blood biomarkers, both patients in Cohort 1 and 2 have shown evidence of increased immunologic activity, supporting GTB-3650’s ability to activate endogenous NK cells and induce NK cell expansion in cancer patients. The company plans on releasing more detailed results later in 2025 following enrollment and completion of additional dose cohorts. The trial plans to evaluate GTB-3650 in up to seven cohorts and GTB-3650 will be dosed in 72-hour continuous infusions in two-week blocks, two weeks on and two weeks off, for up to four months based on clinical benefit. The trial will assess safety, pharmacokinetics, pharmacodynamics, in vivo expansion of endogenous patient NK cells and clinical activity. More details can be found on clinicaltrials.gov with the identifier: NCT06594445.
GTB-5550 TriKE®
The GTB-5550 TriKE product candidate is in development for the treatment of B7H3 positive solid tumor cancers. GTB-5550 TriKE is a tri-specific molecule composed of a camelid nanobody that binds the CD16 receptor on NK cells, a proprietary camelid nanobody of an anti-B7H3 antibody, and human wild type IL-15. It is the first dual camelid engager in the field. Preclinical data supports activity against a number of solid tumors. GTB-5550 clinical material has been manufactured, is scheduled to be vialed this summer and FDA submission is planned for Q4 2025. Based on supportive preclinical data, this will be the first TriKE® tested with more patient friendly subcutaneous dosing. The clinical trial is planned to include several solid tumors including breast cancer, lung cancer, ovarian cancer, head and neck cancer, pancreatic cancer, bladder cancer and prostate cancer. Preclinical studies are ongoing to evaluate activity in multiple myeloma and brain tumors planning for separate trials in these settings.
GTB-7550 TriKE®
The GTB-7550 TriKE product candidate is in development for the treatment of CD19 positive lymphoid malignancies and autoimmune disease. GTB-7550 TriKE is a tri-specific molecule composed of a camelid nanobody that binds the CD16 receptor on NK cells, the single chain variable fragment (scFv) of an anti-CD19 antibody, and human wild type IL-15. GTB-7550 TriKE has been tested and published pre-clinically using models of lymphoma and chronic lymphocytic leukemia. Based on its early preclinical activity targeting normal B-cells, studies are ongoing to develop GTB-7550 in autoimmune disease. We are evaluating manufacturing bids for production of clinical material in 2026 with plans for FDA submission thereafter.
GTB-3550 TriKE® (discontinued)
GTB-3550 was the company's 1st clinical trial using a 1st generation TriKE product candidate that was initially evaluated in a Phase 1 clinical trial for the treatment of relapsed/refractory acute myeloid leukemia (AML) and high-risk myelodysplastic syndromes (MDS). GTB-3550 is a single-chain, tri-specific scFv recombinant fusion protein conjugate composed of the variable regions of the heavy and light chains of anti-CD16 and anti-CD33 antibodies and human mutant IL-15. In the completed Phase 1 clinical study, GTB-3550 was shown to be safe and well-tolerated. The study of GTB-3550 demonstrated clinical proof of concept of in vivo activity. GTB-3550 and the 1st generation platform was discontinued after strong data suggested that the 2nd generation TriKE was more potent and exhibited better preclinical anti-tumor activity with camelid nanobody technology and wild type IL-15.