공시 • Jun 09
Gt Biopharma Advances Three Trike Drug Candidates into Human Trials and Doses First Patient in Phase 1 Trial of Gtb-5550
GT Biopharma has moved three drug candidates into human testing over time and most recently expanded into solid tumors. GT Biopharma has now advanced three TriKE candidates into the clinic over time --- GTB-3550, GTB-3650 and GTB-5550 --- though its current active clinical programs are GTB-3650 and GTB-5550, with GTB-3650 having replaced the earlier GTB-3550 program. On May 14, 2026, GT Biopharma announced that the first patient had been dosed in a Phase 1 trial of GTB-5550, a B7-H3-targeted natural killer cell engager for solid tumors. It is the third drug from the company's TriKE platform to reach the clinic --- and its first real push beyond blood cancers into the much larger solid-tumor opportunity. GT Biopharma is a clinical-stage immuno-oncology company developing therapeutics based on its proprietary TriKE --- tri-specific killer engager --- natural killer cell engager platform, licensed from the University of Minnesota. Natural killer cells are part of the innate immune system and help identify and eliminate abnormal cells, while a TriKE molecule is designed to connect those NK cells to a specific cancer target and deliver a built-in interleukin-15 signal intended to support NK-cell expansion and persistence. The platform is designed to help direct the body's own first-line immune defenders toward tumor cells. GT Biopharma's pipeline reflects that broader logic, spanning hematologic malignancies, solid tumors and, in earlier-stage work, autoimmune disease. The lead active clinical program is GTB-3650, a second-generation, camelid-nanobody TriKE in a Phase 1 dose-escalation trial for relapsed or refractory CD33-expressing hematologic malignancies, specifically acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS). That trial is designed to evaluate the candidate in approximately 14 patients across seven dose cohorts, ranging from 1.25 µg/kg/day up to 100 µg/kg/day, with dosing delivered in two-week-on, two-week-off blocks. The company has reported advancing through successive cohorts and approaching the dose range its preclinical leukemia models predicted could be where efficacy emerges. The newest clinical entrant, GTB-5550, targets B7-H3, a marker expressed on the surface of a range of advanced solid tumors, in a Phase 1 dose-escalation basket trial. Its first-patient dosing in May marks GT Biopharma's expansion from the blood-cancer setting, where NK-cell approaches have shown some early promise, into the much larger solid-tumor opportunity. Behind those current active clinical programs is GTB-3550, an earlier clinical TriKE candidate that was replaced by the second-generation GTB-3650, while GTB-7550 remains an earlier-stage candidate the company is developing for CD19-positive lymphoid malignancies and autoimmune disease. The move into solid tumors with GTB-5550 is strategically significant because solid tumors represent the overwhelming majority of cancer cases --- and the part of the market where cell-based immunotherapies have historically struggled most. A target like B7-H3 is attractive because it is broadly expressed across a range of solid tumors while having more limited expression in healthy tissue. By designing GTB-5550 as a basket trial --- a study that enrolls patients with multiple tumor types under one protocol --- GT Biopharma is positioning to learn more quickly which cancers, if any, may respond. Part of what gives the TriKE story credibility is that it has evolved through successive technical generations rather than resting on a single construct. The company's first clinical molecule, GTB-3550, served as an earlier proof-of-concept program in AML and MDS before being replaced by GTB-3650. The current lead, GTB-3650, is a second-generation molecule that incorporates camelid-nanobody technology --- small, stable antibody fragments derived from camelids --- to bind the CD16 receptor on NK cells more effectively, while GTB-5550 extends that same second-generation engineering toward the B7-H3 target in solid tumors. Each generation has aimed to improve NK-cell engagement, persistence, and tumor targeting. GT Biopharma's multi-generation, multi-target pipeline is the company's answer to that question, even though clinical outcomes remain unproven. At present, however, its active clinical programs are GTB-3650 and GTB-5550, with GTB-3550 having been replaced by the second-generation GTB-3650. The May dosing of GTB-5550 is a meaningful milestone, but it is still only one step in a long, capital-intensive development process where most clinical-stage candidates ultimately fail.